Cooling and Vesiculation of 

Alae Lava Lake, Hawaii 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 935-B 

Cooling and Vesiculation of 

Alae Lava Lake, Hawaii 

By D. L. PECK 

SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 935-B 

Repeated measurements of temperatures in drill holes 

and the altitude of the surface document the cooling 

of a thin ponded basalt flow 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON:l978 
UNITED STATES DEPARTMENT OF THE INTERIOR 

CECIL D. ANDRUS, Secretary 

GEOLOGICAL SURVEY 

W.A. Radlinski, Acting Director 

Library of Congress Cataloging in Publication Data 

Peck, Dallas Lynn, 1929-

Cooling and vesiculation of Alae Lava Lake, Hawaii. 

(Solidification of Alae Lava Lake, Hawaii) 

(Geological Survey Professional Paper 935-B) 

Bibliography: p. 49-50. 

Supt. of Docs. No.: 119.16:935-B 

1. Basalt--Hawaii--Alae Lava Lake. I. Title. II. Series. III. Series: United States Geological Survey 

Professional Paper 935-B. 

QE462.B3P4 552'.2 77-608302 

For ~ale by the Superintendent of Documents, U.S. Go\·ernment Printing Office 

\Vashington, D.C. 20402 

Stock Number 024-001-03053-5 
CONTENTS 

Page 

Abstract -------------------------------------------------- 1 Density of Alae lava and variation with time-Continued 

Page 

Introduction _ _ _ _ _ _ __ ___ _ _ _ __ ____ _ _ _ _ _ _ __ __ __ __ _ _ _ _ __ __ __ __ 2 Density and vesicularity ________________________________ 19 

Acknowledgments______________________________________ 3 

Methods of study -------------------------------------- 3 

Altitude ofthe lake surface ---------------------------- 23 

Changes in altitude during solidification ____________ 24 

Drilling ____ __ _ _ _ _ __ ____ __ _ _ _ _____ __ __ __ _ _ __ __ __ __ 3 Changes in horizontal distance during solidification __ 30 

Temperature measurements ________________________ 5 Changes in altitude during further cooling __________ 31 

Measurements of the altitude of the lake surface ____ 6 Interpretation of changes in altitude ____________________ 32 

Precipitation and air temperatures__________________________ 7 Subsidence of the lake surface and calculation of the 

Temperatures coefficient of thermal expansion _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 32 in the lava lake------------------------------ 7 

Definition of crust and fluid lava________________________ 7 Changes in altitude of the surface during solidification 

Effect of coolant water on temperatures __________________ 11 of the lake _ ___ __ _ _ _ _ __ __ ____ _ _ __ ____ __ __ _ _ _ _ _ _ __ 33 

Temperatures in fluid lava below the crust ______________ 12 Calculation of the density of fluid lava in the lake________ 35 

Thermal history of the lake ________ ____________________ 13 The pattern of cooling in three dimensions __________________ 37 

Maximum temperatures and temperatures at the basal Thermal properties of Alae basalt __________________________ 40 

contact ______________________________________________ 17 Thermal modeling ____ _ _ _ _ _ _____ __ _ _ _ _ ______ _ _ _ _ _ _ _ _ __ ___ _ 45 

Density of Alae lava and variation with time of the altitude of 

the lake surface__________________________________________ 19 

Conclusions ________________________________________________ 48 

References cited____________________________________________ 49 

FIGURE 1. 

2. 

3-17. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

21. 

22. 

23. 

ILLUSTRATIONS 

Page 

Map of Alae lava lake showing contours at the base and margin and the location and identification number of 

surveying stations and drill holes------------------------------------------------------------------------ 4 

Photograph showing drilling in Alae lava lake __ _ _ _ _________ _ _ __ ____ _ _ _ _ ____ __ __ _ _ _ _ __ __ __ _ _ _ _ _ _ __ _ _ ____ __ __ _ _ 5 

Graphs showing: 

Representative temperature profiles __ ______ ____ __ _ _ ____ _ _ _ _ __ _____ _ ___ _ ____ ___ _ _ _ __ _ _ ____ __ _ _ _ _ _ _ _ _ __________ 9 

Temperature and depth of the tip of a hollow mullite probe as a function of time during its insertion into fluid lava ---- 10 

Thickness of the upper crust near the main drilling site as a function oftime ---------------------------------- 10 

Temperature profile across the zone of crystallization at the base of the crust on December 30, 1963 ______________ 11 

Temperatures near the bottom of drill hole 3 after drilling through the base of the crust ________________________ 12 

Depth of isotherms in drill hole 4 before and after drilling on November 27, 1963 ------------------------------ 12 

Temperature profile across partly molten crust and into underlying fluid lava on November 8, 1963 ______________ 13 

Depth of isotherms and rainfall from August 1963 to August 1967---------------------------------------------- 14 

Depth of isotherms from August 22 to September 17, 1963 ---------------------------------------------------- 15 

Temperature profiles in the upper part of drill hole 5 showing the effects of abundant rainfall____________________ 16 

Temperature profiles in five drill holes on January 21, 1965, and a computed profile ---------------------------- 17 

Maximum temperatures at three sites as a function of time---------------------------------------------------- 19 

Proportionate depth of the maximum temperature ------------------------------------------------------------ 20 

Average core density and porosity (vesicularity) as a function of depth__________________________________________ 20 

Maximum size of vesicles as a function of depth -------------------------------------------------------------- 21 

Photomicrograph of vesicular basalt------------------------------____________________________________________ 22 

Graph showing vesicularity as a function of time______________________________________________________________ 23 

Graph showing estimated rate of vesiculation and cumulative abundance of vesicles as a function of temperature__ 23 

Map showing rate of change in altitude of the lake surface during solidification of the lake from August 30 to 

September 24 to 26, 1963-------------------------------------------------------------------------------- 24 

Map showing rate of change in altitude of the lake surface during solidification of the lake from September 24 to 26, 

1963, to September 24, 1964 ---------------------------------------------------------------------------- 29 

Graph showing cumulative changes in altitude of five stations ------------------------------------------------ 30 

III 
IV 

FIGURES 24--27. 

24. 

25. 

26. 

27. 

28-30. 

28. 

29. 

30. 

31. 

32. 

33. 

34. 

35-39. 

35. 

36. 

37. 

38. 

39. 

40. 

TABLE 1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

CONTENTS 

Page 

Maps showing: 

Total uplift of the lake surface --------------------------------------------------------------------- _________ 30 

Changes in horizontal distance between stations during solidification ofthe lake-------------------------------- 30 

Rate of subsidence of the lake surface after complete solidification in late September 1964 ---------------------- 31 

Estimated daily average decrease in temperature in the lake from January to August 1965, as determined from 

measured rates of subsidence---------------------------------------------------------------------------- 33 

Graphs showing: 

Rates of uplift and subsidence of stations on the lake compared with maximum temperatures in the lake ________ 34 

Observed and calculated rates of uplift and subsidence at the main drilling site -------------------------------- 34 

Temperature profiles on September 25, 1963, and August 19, 1965, and a section through the lake on September 25, 

1963 -------------------------------------------------------------------------------------------------- 36 

Map showing approximate position of the outer margins of the 1,080°C isothermal surface in the lake as a function of 

time -------------------------------------------------------------------------------------------------- 38 

Map showing outer margins of the 1,000°C isothermal surface (approximately the solidus) as a function of time -- 39 

Longitudinal cross section showing the positions of the 1,0oooc isothermal surface as a function of time ---------- 40 

Longitudinal cross section showing the positions of the 700°C isothermal surface as a function of time ____________ 41 

Graphs showing: 

Thermal conductivity at 35°C of air-saturated Alae basalt ---------------------------------------------------- 42 

The ratio of conductivity at high temperature to conductivity at room temperature of four samples of basalt from Alae 

crater -------------------------------------------------------------------------------------------------- 43 

Calculated heat capacity of Alae basalt as a function of temperature____________________________________________ 44 

Calculated diffusivity of solidified Alae basalt as a function of depth and time ---------------------------------- 45 

Computed and observed temperature profiles in Alae lava lake ------------------------------------------------ 46 

Generalized radial section showing computed position of the 1,000°C isotherm after 120, 240, and 360 days ______ 48 

TABLES 

Page 

Record of drill holes in Alae lava lake ____ ____ _ _ _ _ __ __ __ _ _ _ _ _ _ _ _ __ __ _ _ _ _ _ _ _ _ __ __ __ __ _ _ _ _ _ _ __ ____ _ _ _ _ _ _ __ ____ _ _ 5 

Rainfall at the south rim of Alae crater ---------------------------------------------------------------------- 8 

Temperatures in Alae lava lake______________________________________________________________________________ 52 

Depths and values of maximum temperatures and ofbasal contact temperatures in Alae lava lake ______________ 18 

Bulk density and porosity of drill core _ _ _ _ _ _ __ __ __ _ _ _ _ ______ __ _ _ _ _ _ _ __ ______ _ _ __ ____ _ _ _ _ _ _ __ _ _ _ _ __ _ _ _ _ __ __ ____ 20 

Altitude of stations on the lake surface _____ _ _ _ _ _ __ _ _ __ _ _ _ _ _ _ __ __ __ _ _ _ _ _ _ _ _ __ __ __ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ __ __ __ _ _ _ _ _ _ 25 

Thermal conductivity of four samples of basalt from Alae crater as a function of temperature ____________________ 42 

Specific heats of minerals and calculated heat capacity of Alae basalt ------------------------------------------ 44 
SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 

By D. L. PECK 

ABSTRACT 

The August 1963 eruption of Kilauea Volcano, Hawaii, left a stagnant lake of molten lava as much as 15m deep in Alae pit crater. 

Temperatures in the lava lake, which initially were as much as 

1,140°C, were monitored by means of thermocouples in drill holes in 

the crust of the lake starting 7 days after the eruption and continuing until the entire lake had cooled to less than 100°C 4 years later. 

Solidification of the lake proceeded by the slow increase in thickness of crusts at the top and bottom of the lake. Crystalline basalt in 

the upper crust at any given time graded downward into fluid lava 

through a zone of partly molten crust in which temperatures and 

melt content increased smoothly downward. The base of the crust, 

defined as the horizon where yield strength abruptly decreased, was 

at a temperature of 1,065°C±5°C; at this temperature crystals and 

melt were in approximately equal abundance. The lava was completely crystallized except for a sparse silicic residuum at 980± 10°C. 

The thickness of upper crust and the depth of isotherms in the crust 

and melt increased linearly with the square root of time during the 

first three months. Throughout this period, the thickness of upper 

crust in meters was 0.00132 vt-0.18, where t equals time in seconds 

after the eruption. The lake solidified (that is, cooled to less than 

1,065°C) 10% months after it had formed, and it cooled below the 

solidus temperature of 980°C 2% months later. Two years after the 

eruption the maximum temperature in the lake was 672°C. Two 

years later, it had fallen to 86°C. As the lake cooled, the maximum 

temperature was found at steadily increasing depths; the proportionate depth was 0.6 at solidification, 0.8, 2 years after the eruption, 

and greater than 1.0 (that is, below the lake) 2 years later. Rainfall, 

which ranged from 2.0 to 3.35 m/year, apparently did not greatly 

decrease the time of solidification, but it did strongly affect temperatures in the upper crust during solidification and greatly increased 

the rate of postsolidification cooling. Temperatures at the basal contact of the lake were measured repeatedly in drill holes that completely pierced the lake after it solidified. Uncertainties as to the 

precise location of the contact in each hole limit the accuracy of the 

determined values, but the data indicate a maximum contact temperature of 700± 15°C, 60 percent of the initial temperature of the 

lake. 

The molten lava in Alae vesiculated because of the exsolution of 

gases as it cooled and solidified. The abundance of vesicles, as determined by point counts and density measurements on drill core, decreased from 40 percent near the surface to a nearly constant 11 

percent below 3 m. Large spheroidal vesicles, which were abundant 

near the surface but decreased sharply in size and abundance with 

depth, apparently recorded degassing of the super-saturated lava 

during the first 100 days after the eruption. Below 6 m the vesicles 

are almost entirely minute, angular pores formed at lower temperatures from gas exsolved from the lava during crystallization. Because 

of vesiculation, the molten lava in the lake expanded as it solidified, 

causing the surface of the lake to extend horizontally and to rise 

vertically. The solidified margin, in contrast, subsided because of 

thermal contraction. During the year of solidification, the surface 

above the thick central part of the lake rose as much as 0.25 m 

whereas the margin subsided as much as 0.06 m. Repeated surveys of 

the altitude of stations on the lake surface, accordingly, outlined the 

lens of fluid lava and partly molten crust at temperatures of more 

than 1 ,oooac and recorded its shrinkage with time. They show the 

location of the last lava to solidify and demonstrate that the lake 

solidified more rapidly where it thinned over a buried 1840 spatter 

cone. The maximum uplift during any given time interval was above 

the lateral edge of the 1,080°C isothermal surface, that is, near the 

crust-fluid lava interface in the lake. After the last interstitial melt 

in the lake had solidified in late September, 1964, the entire lake 

surface subsided at a rate that decreased from 0.006 em/day in late 

1964 to 0.003 em/day between May, 1966, and September, 1967. In 

the first year after solidification, subsidence was greatest between 

the center and edge of the lake in a belt that migrated inward with 

time and presumedly defined the part of the lake undergoing the 

most rapid cooling-possibly because of the cooling effect of circulating rain water in the cooler margin of the lake. 

Comparison of subsidence rates with changes in temperature in 

the lake indicates that the effective bulk coefficient of linear thermal 

expansion was 3± 1 x 10-6 ;o C. This value is approximately one-half 

that of the values reported from measurements on similar rocks in 

the laboratory. The differences probably can be attributed to the 

formation of micro fractures during cooling of the basalt as the result 

of differential thermal contraction of the constituent mineral grains 

and glass. Where one uses this value for the coefficient of thermal 

expansion and relevant temperature data, the density of molten lava 

in Alae in September 1963 can be calculated from the average density of drill core and the change in volume during solidification and 

further cooling indicated by the level surveys. The calculated value 

of2.79±0.03 g/cm3 is the bulk density at 1,130°C offiuid basaltic lava 

containing an estimated 15 percent crystals. The calculated density 

of the melt fraction itself, assuming that exsolved gases are negligible, is 2.74 g/cm3 • 

Several thermal properties of Alae basalt were measured in the 

laboratory or were calculated from laboratory data on the constituent minerals. The conductivity at room temperature of basalt 

from Alae lava lake and of similar Hawaiian basalts decreases with 

increasing porosity and increases with increasing olivine content 

(Robertson and Peck, 1974). Conductivity at room temperature, KRT, 

for the relatively olivine-poor Alae basalt with air in the pores is 
2 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

related to porosity, ¢, by the expression KRT = (1.929-1.554¢)2 . 

Previously unpublished experimental measurements on basalt from 

Alae crater by Kaoru Kawada (1966) and by H. R. Shaw (1966) 

indicate that the conductivity of vesicular basalt increases linearly 

with temperature at a rate of 0.03-0.09 percentfCC, presumedly because of radiative heat transfer across the vesicles, convective heat 

transfer by air in the vesicles, or progressive closing of microfractures as the result of thermal expansion of the sample during heating. The heat capacity (e) was calculated by R. A. Robie from modal 

and laboratory data and was fitted to the following function of temperature (T, in Kelvins): 

c = 0.2356 + 4.3635 X 10-5T- 6.3440 X 103 /T2. 

Thermal diffusivity varied in the cooling lava lake with time and 

depth. Calculated values typically increased from about 0.005 cm2 / 

sec near the surface to 0.006 cm2/sec at depths below 2--5 m. The 

latent heat of completely crystalline Alae basalt, as calculated from 

experimentally determined heats of fusion of the constituent minerals (and the normative minerals in the glass) is 94 to 85 cal/g. The 

calculated latent heat that was released during crystallization in the 

lake, however, would have been almost 20 percent less than that 

value, 77-67 cal/g, as the result of the crystallization prior to eruption of 13 percent olivine, pyroxene, and plagioclase and the retention of nearly 7 percent silicic residuum at the end of crystallization. 

The cooling history of the lake was analyzed by comparing measured temperature profiles with profiles computed on the basis of 

numerical analysis of one- and two-dimensional lava lake cooling 

models. Measured temperature profiles in the central part of the lake 

can be approximated with one-dimensional models that use a constant density for the basalt, a constant diffusivity of 0.006 cm2/sec, 

and the calculated heat loss of 620 cal/cc from heating and vaporization of the measured rainfall. A better correspon~ence is obtained 

using more complex models incorporating variable thermal and 

physical properties for the basalt. In the computations, diffusivity 

was allowed to vary with the calculated increase of heat capacity 

with temperature, with the measured increase in density with increasing depth in the lake, and with variations of conductivity with 

temperature and basalt vesicularity. Heat loss by heating and vaporization of rain water was computed using the measured density 

structure of the lake. Low values for density and conductivity were 

given to a shallow cell in the lake to simulate the highly vesicular 

and cavernous zone found at depths between 0.3-1.2 m. The closest 

match of computed and observed temperatures was obtained using a 

latent heat of 80± 10 cal/g (from 80 percent crystallization) and conductivity (KT) that was related to temperature, T°C, and conductivity at room temperature, KRT, by the expression KT = KRT(1+{3T), 

where B equals 0.0006±0.0001. In the computations, 10 representative profiles measured during the first year of cooling were matched 

at 1-foot (0.3 m) intervals with an average deviation of 2°C. 

Computations using two-dimensional models confirmed the lateral 

variations with time of temperatures in the lake inferred from temperature measurements in drill holes and precise level studies, and 

indicate that temperatures in the lake were decreased more than 1 oc 

by marginal cooling during the first year only in the outer 15m of 

the lake, and in the fourth year only in the outer 45 m. Computations 

using "rain" and "no rain" models indicate that the lake had cooled to 

100°C by mid-April 1967, 4Y2 months before the final temperature 

measurements. Without rain the lake would have taken 19.5 years 

to cool to 100°C. 

INTRODUCTION 

Six days after the August 1963 eruption of Kilauea 

Volcano, Hawaii, had formed a shallow lake ofbasaltic 

lava in Alae crater, a hole was drilled 0.86 m into the 

crust of the lake to within 0.01 m of the molten lava. 

Temperatures were measured in the drill hole the following day, and a grid of stations was established over 

the surface of the lake. During the ensuing year of 

solidification of the lava lake and the following 3 years 

of cooling to less than 100°C, several additional holes 

were drilled in the lake, temperatures were measured 

repeatedly, and the relative altitudes of the stations 

were periodically redetermined. These measurements 

provide a unique body of data on the rate and pattern of 

cooling of a ponded basaltic lava flow. Data from additional measurements on drill core from the lake, including density, vesicularity, and thermal conductivity, together with thermal coefficients calculated from 

the modal mineral composition of the core, were used 

in detailed comparison of the observed cooling history 

with numerical cooling models. 

This report is the second of three chapters describing 

the recorded history of Alae lava lake. Chapter A describes the eruption of August 1963, and the surface 

features of the lava lake including joint cracks. Chapter C (Wright and Peck, 1978) presents the results of 

chemical and petrographic studies of pumice from the 

eruption and drill core from the lake. Aspects of the 

cooling history of the Alae lava lake have been described in the following preliminary reports: Peck, 

Moore and Kojima (1964) reported temperature measurements in the lake through February, 1964; Peck, 

Wright, and Moore (1966) described the crystallization 

of basalt in the lake; Decker and Peck (1967) analyzed 

infrared temperatures at the lake surface. Shaw, 

Hamilton, and Peck (1977) formulated numerical models for the cooling history of lava lakes, which were 

applied to Alae lava lake by Peck, Hamilton, and Shaw 

(1977). Temperature measurements in other recent 

Kilauean lava lakes are reported by Ault, Eaton, and 

Richter (1961), Ault, Richter, and Stewart (1962), 

Rawson (1960), Richter and Moore (1966), Wright, 

Kinoshita, and Peck (1968), and Wright and Okamura 

(1977). Wright, Peck, and Shaw (1976) summarize 

studies made on all three Kilauean lava lakes. 

Alae crater was one of several pit craters on the 

upper east rift zone of Kilauea Volcano, Island of 

Hawaii. I refer to the crater and the August 1963 lava 

lake in the past tense because the lava lake was buried 

by eruptions starting in February 1969 (Swanson and 

others, 1971) and the crater was later completely filled 

with lava and the site covered by a broad, 100-m-high 

basaltic dome satellitic to the new shield Mauna Ulu 

(Swanson and others, 1973; Swanson and Peterson, 

1972). The crater was about 8 km southeast of the 

summit caldera, and in 1963 was adjacent to the hardsurface Chain-of-Craters Road (Peck and Kinoshita, 

1976, fig. 2). The surface of the lava lake was 150 m 

below the rim of the crater and could be reached by a 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 3 

rude trail assisted by ropes over the steeper parts. Because of the steepness of the trail, an aerial tram into 

the crater was constructed for lowering equipment and 

water soon after the August 1963 eruption, before a 

program of drilling and other studies was started. 

The eruption that formed the August 1963 lava lake 

lasted from 18h10m1 August 21 to 08h10m August 23. 

The bulk of the lava in the lake was erupted during the 

first few hours, when fountains on the floor and north 

wall of the crater fed lava into the lake at rates as great 

as 2.3 x 105m3 per hour and maximum temperatures of 

about 1,160°C. During the last 12 hours of the eruption, the rate of extrusion dropped to near zero and 

maximum temperatures fell to 1,140°C. Near the end 

of the eruption, 1.8 x 105m3 of lava drained back into 

the vents, leaving a stagnant lake containing 6.6 x 

105m3 of homogeneous tholeiitic basalt. The lake was 

an elliptical lens 305m long, 245m wide, and as much 

as 15m deep. The outline of the lake, contours at the 

base and margin, and the location of surveying stations 

and drill holes are shown in figure 1, together with 

cross sections along the major and minor axes. 

All but the northwest end of the lake was bordered 

by a levee of strongly jointed, discontinuous pressure 

ridges, and the levee was bounded for most of its length 

by a moat 8--15 m wide and about 2m deep. The lake 

within the levee had a hummocky surface that sloped 

almost imperceptibly toward the vent at the north end 

of the lake. The surface was nearly fiat having an average relief of less than 0.3 m, but it was crossed by 

sharp pressure ridges and linear ooze ups that stood as 

high as 1 m above the lake surface. The lake deepened 

sharply inward from the edge to an average maximum 

depth of 14.0 m. The base of most of the lake was also 

nearly fiat, but it sloped at a small angle to a low area 

beneath the north-central part of the lake, and the lake 

thinned to 11.3 m over a buried spatter ridge formed 

during the eruption of 1840. The lake surface was broken by a network of joint cracks, some of which were 

opened during the later part of the eruption to form 

gaping crevasses as much as 30 em wide and 2 m deep 

(Peck and Kinoshita, 1976, fig. 31). Other joint cracks 

formed as the result of thermal contraction during 

later cooling of the lake (Peck and Minakami, 1968). 

Solidified lava from depths below 1.5 m in the lake is 

homogeneous gray basalt containing sparse olivine 

phenocrysts in a fine-grained intergranular 

groundmass. The average modal composition in weight 

percent (Wright and Peck, 1978) is olivine, 3.5; 

clinopyroxene, 42.1; plagioclase, 41.6; ilmenite, 4.4; 

magnetite, 1.0; apatite, 0.65; and clear residual glass, 

6. 75. The Alae basalt is a tholeiite having a very uni1 AI! times given are in hours and minutes, Hawaii Standard Time. 

form bulk chemical composition as follows (in weight 

percent): Si02, 50.4 7; Ah03, 13.67; Fe203, 1.30; FeO, 

9.80; MgO, 7.55; CaO, 11.11; N~O, 2.38; K20, 0.54; 

Ti02, 2.74; P205, 0.27; MnO, 0.17. 

ACKNOWLEDGMENTS 

The study of Alae lava lake was a team effort by the 

staff of the Geological Survey's Hawaiian Volcano Observatory. It was started under the direction of 

Scientist-in-Charge, James G. Moore, and was completed under his successor, Howard A. Powers. Thomas 

L. Wright helped in all aspects of the field studies. In 

the gathering of the temperature data, I am particularly indebted to the following staff members: George 

Kojima, who constructed the thermocouples; William 

Francis, Reginald Okamura, Eliot Endo, and Willie 

Kinoshita, who helped in the drilling and in the temperature measurements; Burton Loucks, who made 

much of the special equipment used in the study; and 

John Forbes, who made the rainfall measurements. 

The continuous recording of temperatures in drill holes 

in the lake was a joint effort with a visiting group of 

scientists and technicians from Japan that included 

Profs. T. Minakami, D. Shimozuru, S. Aramaki, and K. 

Kamo, and Messrs. T. Miyasaki and S. Hiraga. Dr. 

Aramaki also helped in the drilling. Reginald Okamura and Eliot Endo helped with the level surveys and 

made most of the measurements ofbulk and grain density. Analysis of the temperature data was made possible by the laboratory measurements of thermal properties by E. C. Robertson, Prof. Kaoru Kawada, and Joel 

H. Swartz and by the numerical analysis by Prof. J. C. 

Jaeger, H. R. Shaw, and M.S. Hamilton. R. A. Robie, 

D. R. Wones, and H. S. Yoder supplied essential data 

on other thermal properties. 

METHODS OF STUDY 

DRILLING 

Holes were drilled in the solidified crust of the lava 

using tungsten carbide bits in a portable core drill 

powered by a 9-horsepower gasoline engine (fig. 2). 

Most of the holes were 2.86 em in diameter, yielding 

1.43 em diameter core, but the upper part of one hole 

(drill hole 9) was drilled to 3.8 em diameter with EX 

bits. Twelve holes were drilled during the 15 months 

following the eruption; the holes had a total depth of 

100m. Dates and depths of drilling are given in table 1, 

and the location of the holes are plotted in figure 1. A 

total of about 18 kg of core was recovered from the lake 

during the drilling. All except the first two holes were 

drilled by mounting the drill on a portable mast anchored in the crust and cooling the bits by means of 

water pumped through the drill pipe by a portable 31.4 

horsepower gasoline engine. The water was fed 
4 

A 

EXPLANATION 

Surveying station on lake surface 

Drill hole 

-- Edge of lake 

SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

·26 

2&12. f]() 

1• •3 & 4 

·6 • ·7 ·8 

7&8 

0 

·16 ·24 

·30 ·17 

B 

0 50 100 METERS 

Contours in feet above sea level 

A A' 

2600~-r-r-id_g_e ___________________________________________________ __ 

2500~----------------------------------------------------------------------------------~ 

I ~ ~--------------------------------~ FEET ABOVE 

SEA LEVEL 

0 25 METERS 

2600t~--------~· 2500----------~------------------------------------------------------------------------L 

FEET ABOVE 

SEA LEVEL 

A' 

FIGURE 1.- Map of Alae lava lake showing contours at the base and margin and the location and identification 

number of surveying stations and drill holes. Cross sections along the major axis (A-A') and the minor axis (B-B') 

of the lake have the same horizontal and vertical scale. The structure beneath the northern part of the lake is a 

buried spatter ridge formed in the 1840 eruption. Topography prepared by photogrammetric methods from aerial 

photographs taken February 15, 1963, by the U.S. Geological Survey. 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HAWAII 5 

FIGURE 2.-Drilling in Alae lava lake, November HJ63. The 

mast-mounted, portable drill is forced downward by applying pressure to a lever arm. Coolant water pumped through 

the drill stern turns to steam in the hot crust of the lake and 

rises along joint cracks in the drilling area. 

through hoses from the rim of the crater and stored in a 

50-gallon (190 liter) steel drum near the drilling site. 

About 100 liters of water were used for each linear 

meter of drilling. The first two holes were drilled by 

holding the drill and pouring water into the hole by 

hand. 

Seven of the holes were drilled through the crust and 

into the underlying molten lava. In each hole, the drill 

fell under its own weight when the drill bit reached the 

base of the upper crust. When the drill stem was withdrawn, in most instances, superheated steam blasted 

up through the drill hole, sounding like a jet engine 

and continuing for as long as 12 minutes. In one hole, 

temperatures of 675°C were measured in the water 

vapor, and the collar of the drill hole was heated to 

glowing red. Four holes were drilled through the center 

of the lake and into the lower crust to near the basal 

contact, and core of the underlying 1840 lava was recovered from one of these (DH 9). 

Drilling rates averaged 1m an hour when all equipment was working properly. Most of the drilling, however, was slowed by mechanical failure of the water 

pump or drill. All equipment used on the lake corroded 

at an accelerated rate because of the high temperatures and rainfall and the abundance of sulfur in gases 

from the lake. 

TEMPERATURE MEASUREMENTS 

Temperatures in drill holes were measured repeatedly during the 4-year study of the cooling lake. 

TABLE 1.-Record of drill holes in Alae lava lake 

Date 

1963: 

Aug. 29 ________ 

Sept. 3 --------

Sept. 6 --------

Sept. 17 ________ 

Oct. 1 and Oct. 2 

Oct. 24 --------

Nov. 7 -------- Nov. 20 ________ Nov. 27 ________ Dec. 16 ________ 

1964: 

Jan. 29 

Apr. 1 and Apr. 2 

Apr. 15 ________ 

Apr. 22 ________ 

Apr. 22 ________ 

Apr. 29 ____ __ __ 

June 4 -------- June 10 ________ June 17 ________ 

June 18 ________ 

July 28 ________ July 29 ________ 

Sept. ll ________ 

Oct. 20 --------

Oct. 22 --------

Nov. 17 _____ ___ 

Nov. 19 ________ 

Drill hole 

No. 

1 

1 

1 

2 

1 

3 

3 

3 

4 

4 

5 

5 

6 

6 

6 

7 

7 

7 

7 

8 

8 

9 

9 

9 

9 

10 

11 

11 

12 

12 

NOTE.- Location of drill holes: 

Depths of interval drilled (meters) 

0-0.863 

0.814-1.14 

1.10-1.40 

0-.655 

1.28--1.70 

0-2.84 

2.38--3.4 75 

3.02r-4.08 

0-4.66 

3.44-4.66 

0-8.90 

5.33-6.40 

0-9.83 

5.41-13.05 

5.91-10.7 

0-0.25 

0-6.1 

6.00-6.64 

6.51-7.13 

0-6.325 

6.325-8.73 

0-3.57 

3.57-3.87 

3.87-6.92 

10.52r-16.12 

0-4.9 

0-2.7 

2.7- 4.9 

0-4.79 

4.79-14.3 

Comments 

To base of crust. 

To base of crust. 

Do. 

Do. 

Do. 

Do. 

Through 0.7 rn of 

melt; base of lake 

estimated to be at 

9:!:1 m. 

Plug of ooze. Through 2 rn of melt 

into lower crust. 

Through plug of ooze and lower 

crust to near base 

of lake. 

Through plug of 

ooze. 

Mast hole. 

Through 0.3 m of 

melt into lower 

crust. 

Through partly 

molten center of 

lake into lower 

crust. 

Through base of 

lake at approximately 14.5 rn and 

into 1840 lava 

(cored between 

14.6 and 15.2 m). 

Through base of 

lake at approximately 13.7 rn (inferred from 

presence of cavernous layer between 

13.1 and 14.3 m). 

~-----

1. Ncar the major axis of the lava lake on the opposite side from the vents, 50.3 m S 44 E of 

the center of the lake (fig.U; altitude of collar 2,567.2 feet t782.48ml on Feb. 10, 

1964. 

2. 4.88 m N 75' E of drill hole I; altitude of collar 2,567.3 feet 1782.51 m l on Feb. 10, 1964. 

3. 6.1 m S 15' E of drill hole 1: altitude of collar 2,567.3 feet 1782.51 m > on Feb. 10, 1964. 

4. 0.3 m N 75' E of drill hole 3; altitude of collar 2,567.3 feet 1782.51 ml on Feb. 10, 1964. 

5. 93.0 m S 49' E of drill hole 1: altitude of collar 2,565.8 feet 1782.06 m l on Feb. 10, 1964. 

6. 73.2 m S 17' E of drill hole 1: altitude of collar 2,567 .4 feet 1782.54 ml on Sept. 24 , 1964. 

7. 11.0 m S 85' \V of drill hole 1: a ltitude of collar 2,566.9 feet 1782.39 m> on May 12 , 1964. 

8. 0.3 m SW of drill hole 7: altitude of collar 2,566.9 feetl782.39 m l on May 12, 1964. 

9. 79.2 m N 42' \V of drill hole 1: altitude of collar 2,567.5 feet 1782.57 m> on July 31, 1964. 

10. 94.5 m N 16'E of drill hole 1: altitude of collar 2,568.0 feetl782.73 m > on Nov. 3, 1964. 

11. 100.6 m S 87°W of dri ll hole I: altitude of collar 2,566.9 feet 1782.39 rn1 on No\'. 3, 1964. 

12. 0.7 m due east of drill hole 2: altitude of collar 2,567.5 feet f/82.57 m l on Jan. 21, 1965. 
6 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

Most of the measurements were made with stainlesssteel-sheathed thermocouples of heavy-gage chromelalumel, using a portable millivolt potentiometer and a 

ooc reference junction in an ice-filled vacuum bottle, 

Temperatures of the lake surface were measured by 

means of a mercury thermometer. During the first few 

months, repeated a ttempts were made to measure 

temperatures in the holes with platinum-platinum 

plus 10 percent rhodium thermocouples made with 

fine-gage wire. Most of these attempts were unsuccessful because the wires broke near the junction immediately after inserting the thermocouple, presumedly as a result of the stress caused by thermal 

expansion of the steel sheathing. 

The thermocouples were constructed in the Hawaiian Volcano Observatory by stringing l-inch (2.54 

cm)-long ceramic beads onto thermocouple wire, and 

inserting the wire and beads in %-inch (0.95 em) O.D. 

stainless-steel tubing welded shut at one end. 

Hastalloy-C tubing proved to be most resistant to corrosion. Most of the thermocouples had five junctions, 

spaced 1 or 3 feet (0.305 or 0.914 m) apart. Many of the 

thermocouples were more than 15m long and required 

considerable care in handling. The potentiometer used 

in the measurements has a reproducible reading accuracy of 0.01 mv. Temperature readings of several but 

not all of the thermocouples were compared with those 

of a National Bureau of Standards platinum-platinum 

plus 10 percent rhodium thermocouple at the Observatory. Most of the temperature measurements probably have an accuracy of±0.5 percent at 500°C and ±1 

percent at 1,000°C, but uncertainties in the depth of 

measurement decrease the accuracy of the recorded 

temperatures. The depth of the thermocouple junctions 

in the drill holes was determined by marking each 

thermocouple sheathing, using a steel tape, and were 

recorded to an accuracy of ±0.05 feet (1.5) em). Thermal 

expansion of the sheathing of thermocouples made accurate depth measurements in the deeper holes difficult; thermocouples inserted rapidly to the bottom of 

the 15m holes expanded as much as 6 em within a few 

minutes. 

Each thermocouple could be used only a few times 

because of corrosion of the sheathing which allowed 

sulfur- and water-rich gases given off by the cooling 

basalt to come in contact with the thermo-couple wires. 

These gases reacted rapidly with the chromel wire, destroying continuity in the thermocouple . During times 

of heavy rains, water collected within the sheathing of 

the thermocouples left on the lava lake. When these 

were subsequently used in the drill holes, steam caused 

shorting between the wires. Consistent readings could 

not be obtained until the entire length of the thermocouple was baked dry in a deep drill hole in the hot lake. 

In several drill holes, temperatures were measured 

both in the crust and in the underlying melt. Measurements in the melt were achieved by attaching a 

ceramic probe to the drill string and pushing it into the 

melt through the bottom of a drill hole after drilling 

through the base of the crust. Temperatures were then 

measured with a thermocouple inserted into the drill 

string and probe. Probes as long as 3.0 m were constructed from 0.75 m lengths of 2.5-cm O.D. mullite 

tubes (the lower one closed at one end), were joined 

with 10-cm sleeves cemented with silica cement, and 

were attached to the drill steel with a machined fitting. 

The whole unit was placed in the drill hole after drilling was completed, and the temperature in the bottom 

of the drill hole was measured by means of a thermocouple inserted in the probe. After the temperature 

had reached 1,065°C-l,070°C, the unit could be pushed 

slowly into the melt. Sometimes, but not always, it 

could also be pulled out. Use of excessive pressure 

caused cracking of the probes, allowing melt to enter. 

An unbroken probe was not emplaced into the melt 

successfully until December 2, 1963, after six unsuccessful attempts over the preceding 3 months. Later 

work in the 1965 lava lake in Makaopuhi crater has 

shown that stainless-steel probes can be used successfully for long periods in the melt, and they can be 

emplaced with far less hazard of breakage. 

MEASCRE~ENTSOFTHEALTITCDEOFTHELAKESURFACE 

On August 30, 1963, 17 stations were laid out at 

100-foot (30.48 m) intervals along the major and minor 

axes of the lake by means of a transit and steel tape 

(fig. 1), and 2 additional stations (12 and 19) were 

marked by chiseling squares on the highest parts of 2 

talus blocks at the ends ofthe minor axis. This grid was 

augmented in mid-September with 12 stations along 

two cross lines parallel to and 200 feet (60.96 m) from 

the minor axis. A few additional stations were added 

during the following year. The stations were marked 

by driving 5 em concrete nails into the crust through 

stamped copper and aluminum tags. Distances between stations were measured on August 30 to ± 1.5 

em; during the following year they were remeasured 

several times with more care to ±0.3 em. Relative altitudes of the stations with respect to station 19 on the 

talus were determined with a fiberglass stadia rod and 

a surveyor's transit (using the transit as a level by 

means of the striding bubble); later, a self-leveling 

surveyor's level was used. Relative altitudes of the stations were measured 21 times during the 4 years of 

study- at 2-week intervals during the first month, 

1-month intervals during the following year, approximately 3-month intervals during the second year, and 

finally , on days near the end of the third and fourth 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HA WAil 7 

years. With few exceptions, all level lines were closed 

and the errors distributed. 

The measurements of altitudes on August 30, 1963, 

were taken with a damaged transit and may be in error 

by as much as 1.5 em. Later altitudes relative to the 

stations on the talus are accurate to ±0.2 em, and the 

use of the surveyor's level after September, 1964, reduced the error to about±0.1 em. The relative altitudes 

of stations on the surface of the lake were measured 

relative to the rim of the crater to ±0.3 m by resection 

and vertical angle with a transit from two stations on 

the rim joined by a taped base line. 

PRECIPITATION AND AIR TEMPERATURES 

Alae crater is within the rain forest that blankets 

the northeast slope of Kilauea Volcano. Some rain falls 

during all but a few weeks each year, but most of the 

precipitation comes during ~~Kona" (southerly) storms 

in the fall and winter. Precipitation was monitored by 

means of a continuously recording rain gage at the 

south rim of the crater from September 12, 1963, to 

March 18, 1965, and also by means of a standard gage 

at the same location from November 16, 1964, through 

September 1967. 

Rainfall during the 4 years covered by this report 

varied from 200 em to 335 em per year and totaled 

1,012 em. The recorded precipitation for weekly intervals is given in table 2. 

Air temperatures were recorded at Alae crater only 

during September, 1963. From September 12 to October 1, 1963, the temperature at the south rim ranged 

fro 17.1 o to 25.5°C and averaged 19.8°C. 

An average air temperature during the years that 

the Alae lava lake cooled can be estimated from recordings at Hawaii Volcanoes National Park Headquarters. From October 1963 through September 1966, 

temperatures there ranged from 5°C to 26°C and averaged 15.6°C. As the mean temperature on the island of 

Hawaii falls at the rate of about 1 ac per 150m rise in 

altitude (Stearns and Macdonald, 1946, p. 209), the 

mean air temperature during that period at the rim of 

Alae, which is 300m lower than Park Headquarters, 

was probably about 18°C. 

TEMPERATURES IN THE LAVA LAKE 

Temperatures in Alae lava lake were monitored by 

means of thermocouples in drill holes on 4 7 separate 

days over a 4 year period beginning 7 days after the 

eruption. Measured temperatures ranged from 16°C at 

the surface of the lake margin during the early morning of December 18, 1964, to 1,135°C in molten lava 

2.3 m below the crust of the lake on November 8, 1963. 

The lake solidified (cooled to less than 1,065°C) by midJuly 1964, 10% months after the eruption, and the last 

interstitial melt solidified by late September 1964, 2% 

months later. The entire lake cooled to less than 100°C 

in less than 4 years, as shown by the last measured 

temperature profile on August 31, 1967. Five representative temperature profiles, including the first and 

last ones, measured, are shown in figure 3, and selected 

temperature data are given in table 3. These are 

mostly from temperature profiles least affected by 

coolant water used during drilling and not affected by 

failing thermocouples, but include some data showing 

the chilling effect of coolant water and later thermal 

recovery of the crust. 

DEFINITION OF CRUST AND FLUID LAVA 

While it solidified, Alae lava lake, like other recent 

Kilauean lava lakes, consisted of a fluid interior and 

upper and lower crusts. Above the base of the upper 

crust (and below the top of the lower) was a broad zone 

of partly molten crust in which temperatures and 

abundance of the melt fraction increased smoothly 

downward from completely solidified crust to fluid lava 

containing subordinate crystals (Richter and Moore, 

1966; Wright and others, 1968). The zone extended 

from a temperature of 980°C downward to the base of 

the crust at 1,065°C, at which temperature the yield 

strength of the lava abruptly decreased. At progressively greater depths below the upper crust, the abundance of crystals in the fluid lava steadily decreased to 

the depth of the maximum temperature in the lake. 

When the base of the crust was penetrated in drilling, the lava no longer offered strong resistance to the 

drill, and the drill fell under its own weight. In the six 

complete penetrations of the base of the crust in Alae, 

the horizon at which failure took place was between 0.1 

and 1m below the depth of the 1,065°C isotherm and at 

a temperature (before drilling) ofbetween 1,070°C and 

1,100°C. During drilling, the environment at the base 

of the crust was complex. As the drill penetrated the 

zone of crystallization, coolant water pumped through 

the drill stem quenched the melt fraction of the enclosing lava to glass until a level was reached where lava 

temperatures were so great that little or no selvage of 

glass was formed. The exact temperature of this horizon as reconstructed from temperature profiles measured before and after drilling varied from one drilling 

operation to another, depending on the rate of drilling 

and amount of coolant water used. 

After the base of the crust was penetrated by drilling 

in this way, a hollow probe could be pushed through 

the drill hole and into the underlying fluid lava. After 

each penetration we had to wait some time until the 

quenched lava at the base of the hole had become sufficiently warmed, a period ranging from a few hours 
8 SOLIDIFICATION OF ALAE LA VA LAKE, HA WAil 

TABLE 2.-Rainfall at the south rim of Alae crater 

Date 

August 22, 1963 _______________ _ 29 _____________________ _ 

September 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

October 3 _____________________ _ 10 _____________________ _ 17 _____________________ _ 24 _____________________ _ 

31 _____________________ _ 

November 7 _____________________ _ 14 _____________________ _ 21 _____________________ _ 

28 _____________________ _ 

December 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

January 2, 1964 _______________ _ 9 _____________________ _ 

16 _____________________ _ 23 _____________________ _ 30 _____________________ _ 

February 6 _____________________ _ 13 _____________________ _ 20 _____________________ _ 

27 _____________________ _ 

~arch 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

April 2 _____________________ _ 9 _____________________ _ 16 _____________________ _ 23 _____________________ _ 

30 _____________________ _ 

~ay 7 _____________________ _ 14 _____________________ _ 21 _____________________ _ 28 _____________________ _ 

June 4 _____________________ _ 11 _____________________ _ 18 _____________________ _ 25 _____________________ _ 

July 2 _____________________ _ 9 _____________________ _ 16 _____________________ _ 

23 _____________________ _ 30 _____________________ _ 

August 6 _____________________ _ 13 _____________________ _ 20 _____________________ _ 27 _____________________ _ 

September 3 _____________________ _ 10 _____________________ _ 17 _____________________ _ 24 _____________________ _ 

October 1 _____________________ _ 

8 _____________________ _ 15 _____________________ _ 22 _____________________ _ 29 _____________________ _ 

November 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

December 3 _____________________ _ 10 _____________________ _ 

17 ___ ~------------------ 24 _____________________ _ 31 _____________________ _ 

January 7, 1965 _______________ _ 14 _____________________ _ 

Rainfall (em) 

Between dates 

15 

10 

10 

6.6 

.5 

2.5 

2.8 

0 

.3 

1.5 

.3 

.3 

3.0 

1.3 

.8 

.8 

1.0 

0 

.3 

32.3 

0 

7.9 

2.5 

.5 

4.3 

16.3 

7.1 

5.6 

15.0 

1.8 

27.7 

1.0 

3.8 

1.3 

4.3 

5.6 

5.1 

5.6 

2.0 

18.8 

0 

0.5 

0 

.5 

2.5 

0 

.8 

0 

.5 

.8 

.3 

0 

0 

0 

1.5 

2.8 

1.3 

.5 

1.0 

.3 

0 

.5 

1.3 

16.3 

2.0 

1.8 

0 

7.6 

8.9 

12.2 

1.0 

7.1 

5.8 

Total 

5 

5 

5 

11.6 

12.1 

14.6 

17.4 

17.4 

17.7 

19.2 

19.5 

19.8 

22.8 

24.1 

24.9 

25.7 

26.7 

26.7 

27.0 

59.3 

59.3 

67.2 

69.7 

70.2 

74.5 

90.8 

97.9 

103.5 

118.5 

120.3 

148.0 

149.0 

152.8 

154.1 

158.4 

164.0 

169.1 

174.7 

176.7 

195.5 

195.5 

196.0 

196.0 

196.5 

199.0 

199.0 

199.8 

199.8 

200.3 

201.1 

201.4 

201.4 

201.4 

201.4 

202.9 

205.7 

207.0 

207.5 

208.5 

208.8 

208.8 

209.3 

210.6 

226.9 

228.9 

230.7 

230.7 

238.3 

247.2 

259.4 

260.4 

267.5 

273.3 

TABLE 2.-Rainfall at the south rim of Alae crater-Continued 

Date 

January 2L ____________________ _ 28 _____________________ _ 

February 4 _____________________ _ 11 _____________________ _ 18 _____________________ _ 25 _____________________ _ 

~arch 4 _____________________ _ 11 _____________________ _ 16 _____________________ _ 22 _____________________ _ 29 _____________________ _ 

April 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 

26 _____________________ _ 

~ay 3 _____________________ _ 10 _____________________ _ 

17 _____________________ _ 24 _____________________ _ 31 _____________________ _ 

June 7 _____________________ _ 14 _____________________ _ 21 _____________________ _ 28 _____________________ _ 

July 6 _____________________ _ 13 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

August 4 _____________________ _ 9 _____________________ _ 16 _____________________ _ 23 _____________________ _ 30 _____________________ _ 

September 7 _____________________ _ 13 _____________________ _ 20 _____________________ _ 

27 _____________________ _ 

October 4 _____________________ _ 11 _____________________ _ 18 _____________________ _ 25 _____________________ _ 

November 1 _____________________ _ 8 _____________________ _ 

15 _____________________ _ 22 _____________________ _ 29 _____________________ _ 

December 6 _____________________ _ 20 _____________________ _ 

January 5, 1966 _______________ _ 10 _____________________ _ 17 _____________________ _ 24 _____________________ _ 31 _____________________ _ 

February 7 _____________________ _ 15 _____________________ _ 21 _____________________ _ 28 _____________________ _ 

~arch 7 _____________________ _ 14 _____________________ _ 21 _____________________ _ 28 _____________________ _ 

31 _____________________ _ 

April 1 L ____________________ _ 18 _____________________ _ 25 _____________________ _ ~ay 2 _____________________ _ 9 _____________________ _ 16 _____________________ _ 23 _____________________ _ 31 _____________________ _ 

June 6 _____________________ _ 13 _____________________ _ 20 _____________________ _ 27 _____________________ _ 

Rainfall (em) 

Between dates 

2.8 

7.1 

0 

2.0 

.8 

.3 

.3 

4.1 

0 

6.4 

3.8 

19.1 

14.2 

31.8 

1.8 

10.9 

43.2 

4.1 

3.6 

3.3 

3.0 

1.5 

1.3 

1.5 

.8 

1.5 

2.8 

2.3 

1.5 

1.0 

1.0 

1.8 

.3 

.5 

9.9 

1.3 

.5 

.8 

3.0 

5.3 

9.4 

.3 

9.4 

46.5 

4.8 

3.6 

1.5 

15.7 

4.3 

1.3 

1.0 

3.8 

3.6 

9.4 

9.4 

3.6 

0.5 

.8 

.3 

8.4 

1.5 

.5 

4.3 

2.3 

2.0 

4.3 

.8 

9.4 

1.3 

2.8 

1.8 

1.3 

1.5 

4.1 

Total 

276.1 

283.2 

283.2 

285.2 

286.0 

286.3 

286.6 

290.7 

290.7 

297.1 

300.9 

320.0 

334.2 

366.0 

367.8 

378.7 

421.9 

426.0 

429.6 

432.9 

435.9 

437.4 

438.7 

440.2 

441.0 

442.5 

445.3 

447.6 

449.1 

450.1 

451.1 

452.9 

453.2 

453.7 

463.6 

464.9 

465.4 

466.2 

469.2 

474.5 

483.9 

484.2 

493.6 

540.1 

544.9 

548.5 

550.0 

565.7 

570.0 

571.3 

572.3 

576.1 

579.7 

589.1 

598.5 

602.1 

602.6 

603.4 

603.7 

612.i 

613.6 

614.1 

618.4 

620.'1 

622.7 

627.0 

627.8 

637.2 

638.5 

641.3 

643.1 

644.4. 

645.9 

650.0 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 9 

Date 

July 5 _____________________ _ 11 _____________________ _ 18 _____________________ _ 

25 _____________________ _ 

1\ugust 1 _____________________ _ 8 _____________________ _ 

15 _____________________ _ 22 _____________________ _ 29 _____________________ _ 

September 6 _____________________ _ 12 _____________________ _ 

19 _____________________ _ 26 _____________________ _ 

October 3 _____________________ _ 10 _____________________ _ 17 _____________________ _ 24 _____________________ _ 31 _____________________ _ 

November 7 _____________________ _ 15 _____________________ _ 21 _____________________ _ 28 _____________________ _ 

December 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 

27 _____________________ _ 

January 3, 1967 _______________ _ 9 _____________________ _ 16 _____________________ _ 23 _____________________ _ 31 _____________________ _ 

February 3 _____________________ _ 14 _____________________ _ 20 _____________________ _ 27 _____________________ _ 

~arch 6 _____________________ _ 13 _____________________ _ 20 _____________________ _ 27 _____________________ _ 

April 3 _____________________ _ 11 _____________________ _ 

17 _____________________ _ 24 _____________________ _ 

~ay 1 _____________________ _ 8 _____________________ _ 

15 _____________________ _ 22 _____________________ _ 

29 _____________________ _ 29 _____________________ _ 

June 5 _____________________ _ 12 _____________________ _ 19 _____________________ _ 26 _____________________ _ 

July 5 _____________________ _ 10 _____________________ _ 17 _____________________ _ 

24 _____________________ _ 31 _____________________ _ 

August 8 _____________________ _ 14 _____________________ _ 21 _____________________ _ 

28 _____________________ _ 

1Estimated rainfall. 

Rainfall (em) 

Between dates 

5.1 

.8 

5.6 

7.6 

1.5 

1.0 

.5 

4.6 

3.3 

2.0 

3.0 

4.6 

9.7 

5.3 

1.0 

15.0 

3.8 

.8 

35.6 

2.0 

5.8 

18.0 

1.5 

5.1 

2.5 

4.3 

22.1 

1.5 

4.6 

1.3 

1.0 

1.0 

14.0 

3.0 

.5 

4.6 

6.4 

13.7 

10.2 

8.1 

7.4 

7.6 

7.6 

4.3 

3.8 

20.3 

1.0 

2.0 

2.0 

1.8 

1.8 

1.5 

2.8 

5.1 

4.8 

5.6 

5.6 

2.5 

8.1 

25.7 

.5 

.3 

Total 

655.1 

655.9 

661.5 

669.1 

670.6 

671.6 

672.1 

676.7 

680.0 

682.0 

685.0 

689.6 

699.3 

704.6 

705.6 

720.6 

724.4 

725.2 

760.8 

762.8 

768.6 

786.6 

788.1 

793.2 

795.7 

800.0 

822.1 

824.6 

829.2 

830.5 

831.5 

832.5 

846.5 

849.5 

850.0 

854.6 

861.0 

874.7 

884.9 

893.0 

900.4 

908.0 

915.6 

919.9 

923.7 

944.0 

945.0 

945.0 

947.0 

948.8 

950.6 

952.1 

954.9 

960.0 

964.0 

970.4 

976.0 

978.5 

986.6 

1,012.3 

1,012.8 

1,013.1 

when the crust was thin and little coolant water was 

used to several days when much coolant water was 

used in repeated drilling at one site through the 

thicker crust. Each probe, which consisted of a pointed 

mullite tube l-inch (2.54 em) in diameter with walls 

0.25 em thick, was pushed slowly under a load of about 

en 

a: 5 LU 

r 

LU 

~ 

~ 

I~ 

r 

a. 

~ 10 

0 200 400 600 800 1000 1200 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 3-Representative temperature profiles in Alae lava lake. 

200 pounds. The temperature and depth of the tip of 

the probe during its insertion on October 2, 1963 is 

shown as a function of time in figure 4. On this date, as 

in each of the six attempts to emplace a probe in the 

melt, rapid penetration took place when the temperature at the tip of the probe was between 1,065°C and 

1,070°C. The best value for the temperature of insertion was 1,067°±2°C, as reported earlier (Peck and 

others, 1964), but this value was later rounded to 

1,065°C (Peck and others, 1966). The value, which represents the softening temperature of basaltic glass and 

crystals under the conditions of the experiment, is 

somewhat arbitrarily assigned as the temperature of 

the base of the crust. It is identical with the value 

determined in Kilauea Iki lava lake (Ault and others, 

1962; Richter and Moore, 1966) and within the limits of 

error of the value of 1,070°C determined in Makaopuhi 

lava lake (Wright and others, 1968). 

The rate at which the upper crust of Alae lava lake 

grew in thickness decreased rapidly from the beginning of solidification at the end of the eruption until a 

short time before complete solidification of the lake. 

The thickness of crust increased at the rate of about 

0.14 m per day at the end of 1 day, 0.07 m per day at 10 

days, 0.02 m per day at 100 days, and 0.015 m per day 

at 250 days. After 270 days the rate increased again at 

the main drilling site, reaching 0.06 m per day shortly 

before solidification was complete there at 300 days. 

The thickness of crust in the upper part of the lake at 

the main drilling site (DHl, 3, 4, 7, and 8), as determined from temperature profiles in the drill holes, is 

plotted against time in days after the eruption in figure 

5. The depths at which fluid lava was reached in drilling are also shown. As discussed above, these depths 
10 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

(/) 2.92 

a: 

w 

1-

~ 2.96 

~ 

£3.00 

1-

a.. 

w 

Cl 3.04 

3 .08 '-----'---'-____..J'-------'---'--'-------'---'--'-----'-<j----'----' 

w 

01050~~-~-~~-~-~~-~-~~-~~ 

<( 

~,~1060 

::JI-

~ ~1070 a:u 

~ ~1080 ~w 

wa: 

1- <.::11090 

w 

Cl 

z1100'-------'--~~.______._ _ _,___.______._ _ _,___.______._ _ _,____, 

- 0 10 20 30 40 50 60 70 80 90 100 110 120 

TIME, IN MINUTES, AFTER 10h 40m OCTOBER 2, 1963 

FIGURE 4.-Temperature and depth of the tip of a hollow mullite 

probe as a function of time during its insertion into fluid lava 

through the base of drill hole 3 on October 2, 1963, after drilling 

was completed at 10h40m. 

were consistently greater than the depth of the 1,065°C 

isotherm. As shown in figure 5, the thickness of the 

crust as a function of time plots as a curved line having 

progressively decreasing slope during the first few 

months after the eruption. With respect to the square 

root of time, however, the thickness of the crust and the 

depth of isotherms in the crust and melt plot as 

straight line segments during the first 3 months, as 

discussed on page 13. 

Petrographic study of drill core from the lake shows 

that lava at a temperature of 1,065°C at the base of the 

crust contained 50 percent liquid (quenched to glass in 

the core) in a meshwork of crystals. At the inferred 

solidus temperature of 980°C and at lesser temperatures, the quenched lava contains a nearly constant 7 

percent glass. At greater temperatures, the abundance 

of glass quenched from liquid increases smoothly to 

1,070°C, the highest temperature core recovered from 

the lake. At 1,140°C, the projected maximum temperature in the lake, the lava contained about 13 percent 

crystals, as shown by the crystal content of pumice air 

quenched at this temperature during the final phases 

of the eruption, August 22 and 23, 1963. Temperatures 

across the zone of partly molten crust and the underlying fluid lava down to a temperature of 1,100oC on 

December 30, 1963, are shown in figure 6, together 

with a curve showing the relative abundance of the 

melt fraction. This curve was derived by petrographic 

0 

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w 

1-

w 

~ 2 ~ 

~ j_ (/) 

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a: j_ u 

a: 4 w 

_L. 

a.. 

a.. 

::J _Lj_ 

u.. 

0 

(/) 

(/) 

w 6 z 

~ 

~ 

I 

1-

8 

0 100 

TIME, IN DAYS, AFTER AUGUST 22, 1963 

FIGURE 5.-Thickness of the upper crust of Alae lava lake near the 

main drilling site (DH 1, 3, 4, 7, and 8) as a function oftime in days 

after August 22, 1963 (dots and curve). The depths at which fluid 

lava was reached in drilling are shown by vertical and horizontal 

bars. 

study of core from several drill holes in Alae and in 

Makaopuhi lava lake (Wright and Peck, 1978; 

Wright and Okamura, 1977.) The temperature profile 

was measured in a ceramic tube emplaced in drill hole 

4 through the crust and into underlying melt to a total 

depth of 5.5 m on December 2, 1963, 5 days after the 

hole was drilled through the crust. The profile shows 

the typical pronounced decrease in temperature gradient downward across the crust-fluid lava interface; 

this downward gradient was evident in each of the profiles measured across the zone on 11 separate days. 

Computer analysis of the thermal data (p. 43; Peck and 

others, 1976, fig. 6) indicates that the decrease can be 

attributed to the release of latent heat of crystallization within the zone rather than by a pronounced 

downward increase in thermal conductivity. The departure of the temperature profile from a smooth curve 

at a depth of about 4. 7 m takes place at the horizon 

where the base of the crust was penetrated by drilling 

more than 1 month earlier; very likely this departure 

is an artifact of chilling by coolant water used in the 

drilling, as discussed in the following section. 

The rate of crystallization with respect to change in 

temperature, measured by the decrease in the abundance of the melt fraction in samples quenched from 

different temperatures, was greater between 1,080oC 

and 1,050°C than at greater and lesser temperatures. 

The maximum crystallization rate was between 

1,065°C and 1,060°C, where the abundance of melt decreased nearly 8 percent. This relationship is shown by 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 11 

TEMPERATURE, IN DEGREES CENTIGRADE 

900 1 000 11 00 

3 

Crystal I ized basalt 

(/) 

0: 

w 4 1-

w Partly molten crust 

~ 

~ ..0 

..... 0 

T. ;oo 

1- ..... 1',..0 a.. 

w '? 

0 

0_... 

" " \~ 

5 \~ 

\ 

Fluid lava \ 

\ 

I 

\ 

I 

0 20 40 60 80 

WEIGHT PERCENT 

FIGURE 6.-Temperature profile across the zone of crystallization at 

the base of the crust on December 30, 1963. Closed circles indicate 

measured temperatures. The inflection of the profile at 4. 7 m is an 

artifact of coolant water used in drilling, as discussed in the text. 

Curve showing the relative abundance of the melt fraction was 

derived from study of core from several drill holes in Alae and 

Makaopuhi lava lakes (Wright and Peck, 1978). 

study not only of drill core from Alae (Wright and Peck, 

1978), but also of samples from a greater variety of 

temperatures from the 1965 Makaopuhi lava lake 

(Wright and others, 1968, fig. 12); the relationship differs from preliminary estimates of Peck, Wright, and 

Moore (1966, p. 11) which suggested a nearly linear 

relationship between the abundance of melt and temperature. During further cooling, from 1,065°C to 

980oC within the zone of partly molten crust, the melt 

fraction continued to decrease in abundance and its 

composition became more silicic, as shown by the refractive index of glass quenched from melt; the 

analyzed composition of quenched melt that oozed into 

drill holes; and the analyzed composition of residual 

glass separated from drill core from the crust (Peck and 

others, 1966, fig. 5 and table 1; Wright and Peck, 

1978). The silica content increases from 50.3 percent at 

1,065°C to 75.8 percent at 980°C. 

Because of the marked decrease in the proportion of 

melt upward across the zone of partly molten crust, and 

to a lesser extent because of the decrease in melt ternperature and increase in silica content, the viscosity of 

the lava increases sharply upward across the zone. 

Judging from the analysis of Shaw (1969, p. 51~520 

and fig. 4), which was based on field measurements of 

viscosity in Makaopuhi lava lake (Shaw and others, 

1968) as well as on laboratory measurements of viscosity of basaltic melts and silicone fluid-glass sphere suspensions, the limiting viscosity in Alae lava lake increased upward across the zone of crystallization from 

about 107 at 1,065°C to 1018 at 980°C. 

EFFECT OF COOLANT WATER ON TEMPERATURES 

As described in the section on "Drilling," the penetration of fluid lava below the crust was followed, after 

removal of the drill stem, by ajet of superheated steam. 

After each steam blast, temperature profiles in the bottom of the hole showed a reversal; temperatures increased with depth to a maximum near the position of 

the 1,065° isotherm before drilling and then decreased 

with greater depth for %-1 m to a minimum near the 

depth of penetration into the melt during drilling. 

Shortly after the penetration and steam blast of 

November 27, 1963, for example, the temperature was 

975°C at a depth of 4.36 m but was only 700 oc at 

4.66m. Temperatures in drill hole 3, after drilling was 

completed at 12h20m on November 7, 1963, are shown 

in figure 7. The temperatures, which were measured at 

five different times during the 2-hour period of 

emplacement of a hollow probe into the melt, demonstrate the lower rate of thermal recovery with time 

near the base of the drill hole as compared with rates at 

more shallow depths. As shown in the figure, a 

minimum temperature was found at a depth of about 

4.1 m, just below the depth of penetration into fluid 

lava. The steam blasts and temperature reversals took 

place only after drilling into fluid lava. Apparently, 

both were caused by vaporized coolant water. When 

drilling within the crust, the steam escapes up the drill 

hole or laterally through joint cracks in the crust. The 

fluid lava, in contrast, traps the steam against the drill 

stem until the latter is withdrawn. 

The temperature data from the lake discussed in the 

following sections were selected to avoid, as much as 

possible, the marked depression of isotherms caused by 

coolant water used in drilling. The effects of such water 

were marked after October 1, when we began pumping 

coolant water through the drill pipe with a portable 

engine during drilling instead of pouring it into the 

hole by hand. Usually about 100 liters of water were 

used for each linear meter of drilling, but at times as 

much as 600 liters/meter were used. After repeated 

drilling at the main site in the southeast part of the 

lake during October and November 1963, temperatures were probably decreased in a considerable volume of crust beneath the site. After drilling, tempera-
12 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

2.8 

3.0 

(J) 

a: 

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fUJ 

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~ 3.6 

£ 

fa.. 

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0 3.8 

4.4L---~-----L----~----~----~--~~--~ 

500 600 700 800 900 1000 11 00 1 200 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 7.-Temperatures near the bottom of drill hole 3 after drilling through the base of the crust at 12h20m November 7, 1963. 

Depth at which fluid lava was encountered during drilling is 

marked by hachured line at 4.068 m. 

tures in the lower part of the crust recovered to near 

predrilling levels within a few days, but those in the 

upper part required many weeks; temperatures at a 

depth of 30 em were still rising 32 days after the drilling on November 27. Temperatures at a depth of0.915 

min drill hole 3 were monitored continuously after the 

hole was deepened October 24, 1963, from 2.38--3.48 m 

using about 150 liters of coolant water. The continuous 

monitoring was part of a cooperative program with a 

visiting team of scientists and technicians from Japan, 

described on page 15. The temperature at this depth, 

which was 570°C before drilling, climbed smoothly 

after drilling from 340°C at 23h October 24 to 517°C at 

03h November 4. The recovery of temperatures at different depths after drilling is shown in figure 8, on 

which are plotted the depths of isotherms in the crust 

after drilling on November 27, 1963. Because only 

about 200 liters of water were used in the drilling on 

this date, the isotherms were not as strongly depressed 

Drilling completed 

14h Nov. 27 

I' co CD 0 C'\J C'\J C'\J I!) .- M 

> u u u u 0 Q) Q) Q) Q) 

z 0 0 0 0 

(J) 

a: 

UJ 2 

fUJ 

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£ 

fa.. 

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4 

5L---~----~----~----~----~----~----~ 

0 10 20 30 

TIME, IN DAYS, AFTER oh NOVEMBER 27, 1963 

FIGURE 8.-Depth of isotherms in drill hole 4 before and after drilling on November 27, 1963. Circles represent measured temperatures. Triangles represent extrapolated temperatures. 

as they were by other drilling operations. Increases in 

temperature with time were more closely monitored, 

however, because of repeated attempts to emplace a 

probe through the drill hole into molten lava and repeated measurements of temperatures in the probe 

once it was successfully emplaced. The figure shows the 

different relative depression and recovery rates of 

isotherms at different depths in the crust. 

TEMPERATURES IN FLUID LAVA BELOW THE CRUST 

Temperature profiles extending to 1,100°C or 

more-that is, to depths well below the base of the 

crust-were measured on October 24, November 8, and 

December 2, 3, 5, 18, and 30, 1963 (table 3). The longest 

profile in fluid lava was measured in a hollow ceramic 

probe on November 8, 1963 (fig. 9), 1 day after drilling 

into fluid lava at a depth of 4.08 m. The maximum 

temperature measured was 1,135°C at a depth of 5.46 

m, an estimated 2 m above the depth of the maximum 

temperature in the lake. The very low temperature 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 13 

3.5 

en 

a: 

w 

1-

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~ 4.0 

£ 

1-

a.. 

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Cl 

4.5 

900 1000 1100 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 9.-Temperature profile across partly molten crust and into 

underlying fluid lava on November 8, 1963. Open circles indicate 

measured temperatures. The zone of partly molten crust (980oC to 

1,065°C) is shaded and the base of the crust (1,065°C) hachured. 

gradient in the melt shown by the profile, only 8.5°/m 

between 1,130° and 1,135°C, contrasts with the gradient of 240°/m measured in the crust between 710°C 

and 985°C before drilling on November 5. As in the 

profile measured December 30, 1963 (fig. 6), the 

November 8 profile shows some residual effect from 

coolant water used in drilling; the profile departs from 

a smooth curve at the approximate depth ( 4.1 m) where 

the drill broke into fluid lava on November 7. 

THERMAL HISTORY OF THE LAKE 

Temperatures in Alae lava lake during the 4 years 

when it solidified and cooled to less than 100°C are 

summarized in figure 10, in which the depths of 

isotherms in the lake, including the 1,065°C isotherm 

at the base of the crust, are plotted as a function of the 

square root of time after 06h August 22, 1963. The 

temperature profiles used in preparing the plot were 

selected to reduce to a minimum the effects of coolant 

water and are given and marked in table 3. The solid 

lines (and short-dashed extrapolations) represent the 

depths of isotherms near the center of the lake in drill 

holes 1, 3, 4, 7, 8, and 9. The long-dashed lines represent the depths of isotherms as measured in drill hole 

12, the only deep drill hole that remained open and 

accessible to measurements during the final stages of 

cooling of the solidified lake. Temperatures at shallow 

depths in drill hole 12 are not representative of the 

lake as a whole, apparently because of heating of the 

lava enclosing the drill hole by gases rising through a 

fracture intersected by the hole. Also shown in the 

figure are the depths of the base of the lake at the main 

drilling site and at drill holes 9 and 12, and the 

cumulative rainfall at the south rim of Alae crater. 

Contact temperatures at the lake surface were measured by means of mercury thermometers near the collars of drill holes on many days when temperatures 

were measured in the drill holes. The measured daytime surface temperature during the first 2 years of 

cooling of the lake over the central part of the lake 

ranged from 80°C to 30oC and averaged about 70°C 

during the first 5 months and about 40°C thereafter. 

Surface contact and radiation temperatures were measured systematically at 30-cm intervals along a 31-m 

base line near the center of the lake and at two ~~coldbase" stations at the thin margins of the lake in 

November and December 1964 when the maximum 

temperature in the lake was about 900°C. Contact 

temperatures were measured by means of thermocouple, and infrared radiation temperatures (>3 

micrometers wavelength) by means of a radiometer 

that views a conic section of 28° and was held 30 em 

above the ground. The results of the measurements 

and the calculated heat loss by radiation have been 

reported by Decker and Peck (1967). Radiation temperatures ranged from l5°C over the cooled margins of 

the lake at night to 85°C over fuming joint cracks near 

the center of the lake. The measurements show marked 

highs over fuming cracks and less marked highs over 

older cracks (Decker and Peck, 1967, fig. 3). During the 

day, radiation from most of the surface of the still hot 

center of the lava lake was not measurably different 

from the radiation from the sunlit basalt at the thin 

cooled margin of the lake. At night, however, radiation 

heat loss from internal sources over the central part of 

the lake was appreciable, constituting about 20 percent 

of the heat conducted to the surface. 

The thickness of crust and the depth of isotherms in 

the crust and melt plot as nearly straight-line seg-
14 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

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<Cz 

s ~' 8 

::;:!_,l 

:::><C 

u u. 4 z 

AUG 1966 1967 

~ 0~--------~-----===-=~==~==~--~----------L_ __________ L_ ________ ~-----------L----------~ 

2 

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0 2 3 4 5 6 7 8 9 10 11 

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0 5 10 15 20 25 30 35 40 

SQUARE ROOT OF TIME, IN DAYS, AFTER AUGUST 22, 1963 

FIGURE 10.-Depth of isotherms (in degrees centigrade) in Alae lava lake from August 1963 to August 1967 as a function 

ofthe square root of time after 06h August 22, 1963, and recorded rainfall at the south rim of Alae crater. Temperature measurements used in constructing the plot are marked in table 3. Rainfall is given in table 1, and the location of 

the drill holes plotted in figure 1. Temperature profiles (0-11) used in thermal modeling (see section on "Thermal Modeling") are marked above the zero depth line. 

ments against the square root of time during the first 3 

months. This relationship follows from heatconduction theory for the conductive cooling of a semiinfinite slab (Carslaw and Jaeger, 1959, p. 285), as discussed by Peck, Moore, and Kojima (1964, p. D4). The 

linear relationship is particularly well shown by temperature data collected during early and midSeptember, 1963 when rainfall was relatively sparse 

and little coolant water was used in the drilling. The 

depths of selected isotherms are shown in figure 11 for 

the first 25 days after the eruption as a function of the 

square root of time after 06h August 22, 1963. These 

depths lie on straight-line segments from September 3 

to September 17. The excessive depths of the isotherms 

on August 30 were caused by coolant water used the 

previous day during the first drilling in the crust of the 

lake. Because of heavy rains on September 17, the 

depths of isotherms as measured 2 days later were de-
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 15 

CJ) 

a: 

w 

1-

w 

~ 

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I, 

1-

a.. 

w 

a 

0.5 

1.0 

1.5 

SQUARE ROOT OF TIME, IN DAYS, 

AFTER 06h AUGUST 22, 1963 

FIGURE 11.-Depth of isotherms (in degrees Centigrade) in Alae lava 

lake from August 22 to September 17, 1963, as a function of the 

square root of time in days after 06h August 22. Dashed lines are 

extrapolations of isotherms to zero depth on the basis of estimated 

thicknesses of crust during the August 1963 eruption on Alae crater and measured surface temperatures during the March 1965 

eruption in Makaopuhi crater. Short-dashed lines are linear extrapolations of straight-line segments defined by the depth of measured temperatures from September 3 to 17. Vertical bars a, b, and 

care thickness of crust estimated during the eruption, as discussed 

in the text. 

pressed as much as 0.15 m. During the following month 

and a half, the plotted depths continued to lie below the 

straight-line segments because of occasional heavy 

rains and the use of more abundant drilling water, but 

during periods of no rain or drilling, the depths tended 

to approach that of the straight-line segments. 

The choice of zero time for the plot of figure 11 is 

arbitrary, because the exact time of formation of the 

crust varied from place to place on the lake. Some crust 

near the vent was not formed until drain back at the 

end of the eruption at 08h10m August 23. Crust over 

linear ooze ups farther from the vent formed mostly 

during die-back of activity during the evening of August 22. Most of the crust over the central part of the 

lake probably formed by 06h, August 22, when the rate 

of eruption dropped to nearly zero (Peck and Kinoshita, 

1976). Estimates of the thickness of crust during the 

first several hours after its formation are also shown in 

figure 11. Thickness a of 8-10 em is based on the average thickness of pahoehoe slabs in the lava levee at the 

edge of the lake; the slabs are from crust that was 

rafted across the lake in about 1% hours during the 

night of August 21-22. Thickness b of 1~25 em was 

estimated during a trip to the edge of the lava lake at 

18h30m on August 22; at that time the crust was barely 

thick enough to walk upon with caution. Thickness c of 

2~30 em is based on the thickness of slabby crust in 

tumuli on the lake that were formed during drain back 

of molten lava into the vent after 06h, August 23. The 

depths of isotherms as measured in the drill holes are 

extrapolated backward in time as dashed lines to their 

inferred intersection with the zero depth axis on the 

basis of repeated optical pyrometer and thermometer 

measurements of surface temperatures during the 

March, 1965, eruption in Makaopuhi crater. Surface 

temperatures there dropped to 0.9 of the initial value 

after H~--20 seconds, to 400°C after 30 minutes, to 

200°C after 4 hours, and to 1 oooc after 1 day. 

Linear projections backward in time of the segments 

established by the depths of isotherms in drill holes 

September 3-17 (dotted lines, fig. 11) do not intersect 

each other and the zero-depth axis unless an origin 

time of 12h August 24, well after the end of the eruption, is selected. The intersection in figure 9 is at V days 

equals 0.55, that is, 13h15m, August 22. The exact time 

corresponding to the intersection has no real meaning; 

it reflects both the thermal constants and environment 

of the newly formed crust and also the somewhat arbitrarily chosen origin time. Intersection to the right of 

the origin, however, is significant. It records slower 

cooling of the crust and upper part of the melt with 

respect to the square root during the first few days. For 

the most part this probably was the result of the higher 

surface temperatures, but it may also have reflected a 

lower thermal diffusivity of the thin, highly vesicular 

crust as well as heating of the crust by gases exsolved 

from the underlying molten lava. 

Temperatures near the base of the crust were monitored continuously at fixed positions in drill holes in 

the crust of the lake for several periods from midSeptember to mid-December 1963. Temperatures were 

recorded as part of an investigation of possible variations in temperature arising from convection of molten 

lava in the lake and were carried out as a joint effort 

with a visiting team of scientists and technicians from 

Japan headed by Prof. T. Minakami. Millivolt differences were carried over wires to a millivolt chart recorder at the southeast rim of the crater from thermocouples fixed near the bottom of drill holes and from 

a thermistor in the vacuum bottle cold junction. Re-
16 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

corded temperatures in the drill holes were checked 

periodically when temperature profiles were measured 

in the drill holes. From October 29 to November 5, 

1963, for example, temperatures were recorded from a 

depth of 2.9 m in drill hole 3, which was deepened on 

October 24 from 2.38 m to 3.48 m, and the plotted 

temperatures were averaged over 1 hour periods. The 

temperature at this depth, which was initially within 

the zone of crystallization, fell smoothly during the 

monitoring period from 1,021 ac to 958°C. No systematic fluctuations were recorded that exceeded the precision of the thermocouple. 

As shown in figure 10, the depths of isotherms deep 

in the crust and in the underlying fluid lava were 

nearly linear with respect to root time until early 

November 1963 and thereafter departed only slightly 

from linearity until the lake had solidified (cooled to 

less than 1,065°C) in early July 1964. Isotherms at 

shallow depths in the crust, however, departed markedly from linearity starting in early January 1964 

largely as the result of rainfall. During the first 5 

months of 1964, 166 em of rain were recorded at the 

south rim of the crater, in contrast to the 29 em that 

fell during the preceding 4 months. Heating and vaporization of the rain water quenched a layer of crust 

immediately below the lake surface to steam temperature (97°C at the altitude of the lake), depressing the 

100°C isotherm from 0.09 m to a depth of 1.22 mover 

the 5 months of abundant rainfall. After the rains 

ceased, the 100°C isotherm slowly decreased in depth 

as heat flowed into the surface layer from the underlying crust, but it was depressed again by abundant rainfall beginning in late February, 1965. Depression of 

the 200°C to 700°C isotherms by the early 1964 rains 

and their later partial recovery is also readily apparent 

in figure 10. As discussed in the section on ~~Thermal 

Modeling", measured temperatures can be closely 

matched by computed temperatures by withdrawing 

620 calories (540 cal/g heat of vaporization and 80 cal/g 

for heating from about 20° to 100°C) for each centimeter of measured rainfall. The effects of the heavy rains 

of January through May 1964 on the crust enclosing 

the upper part of drill hole 5 are shown in figure 12. 

The hole was first drilled to a depth of 8.9 m through 

the partly molten center of the lake near its margin on 

December 16, 1963, and the central1.07 m redrilled on 

January 29, 1964, to clear it of ooze. Thereafter no 

drilling took place in or near the hole. Figure 12 shows 

the progressive formation of a chilled layer near the 

surface and the later temperature recovery. At depths 

in the lava lake greater than about 2.5 m the cooling 

effect of rain water is less obvious. 

Temperatures at a given depth varied significantly 

from one drill hole to another, even in the holes in the 

en 

a: 

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~ 

I 

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0 

200 400 600 800 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 12.-Temperature profiles in the upper part of drill hole 5 

near the southeast margin of Alae lava lake, showing the effects of 

abundant rainfall in the first 5 months of 1964. 

central part of the lake. During the first month after 

the eruption, measured temperatures in the upper 0.6 

m of crust in drill holes 1 and 2 differed by 10-30oC 

(data for Sept. 9 and 11, 1963, table 3). During the 

second month, measured temperatures in the upper 1.6 

min drill holes 1 and 3 differed by 10-25°C (Oct. 24 and 

Nov. 5, 1963, table 3). Measured differences in temperature in different drill holes were greater during the 

second year of cooling, as illustrated in figure 13, which 

shows temperature profiles in five drill holes on 

January 21, 1965, 4 months after complete solidification of the lake. Also shown is a computed temperature 

profile for the same day, based on a numerical model 

for a lake 49 feet (14.9 m) thick (fig. 39). The coldest 

hole, drill hole 5, was only about 30m from the edge of 

the lake. Temperatures at a given depth within th~ 

upper 5 m of crust in three of the more centrally located 

holes (DH9, 10, and 11) varied within a range of 5ooe-,. 

100°C. Temperatures in the other drill hole (DH12) 

were consistently 25--100°C greater than those in any 

other drill hole at depths of 8 m and less. At greater 

depths in drill hole 12, temperatures were less than 

those in drill hole 9 because the lava lake was 1% m 

shallower beneath the drill site. The differences in 

temperature reflect lateral variation in porosity (and 

conductivity) at shallow depths in the lake and cooling 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HA WAil 17 

0 

2 

4 

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UJ i;: I 

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12 

14 

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0 1 00 200 300 400 500 600 700 800 900 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 13.-Temperature profiles in five drill holes in Alae lava lake 

on January 21, 1965, and a computed profile for the same day 

based on a numerical model for a lake 49 feet (14.9 m) thick (fig. 

39). Location of drill holes is shown in figure 1. Symbols indicate 

measured temperatures. Hachured lines beneath three of the profiles indicate the approximate depth of the base of the lake at these 

sites. 

along joint cracks, although all holes were drilled as 

far as possible from known cracks. Lateral variations 

in vesicularity (porosity) in the lake were caused by 

differential entrapment of rising gases near the end of 

the eruption when the crust was 0.3--1.2 m thick (Peck 

and Minakami, 1968, p. 1154). Thermal conductivity 

decreases markedly with increased porosity as discussed on p. 41. Near the end of the eruption, the crust 

of Alae lava lake was broken by a network of cracks 

outlining polygonal slabs of crust 3--4.5 m across (Peck 

and Kinoshita, 1976); some of these cracks were drawn 

open during drain back at the end of the eruption, 

forming gaping crevasses as much as 30 em wide which 

diverged outward from the central part of the lake. 

Seven days after the eruption, the temperature at a 

depth of 1.5 min an open crack 12m southeast of drill 

hole 1 was 885°C. On this date, the base of the crust (at 

1,065°C) below drill hole 1 was at a depth of only 1 m. 

Within a few weeks, the walls of these cracks cooled to 

less than red heat; by June 9, 1964, the temperature at 

a depth of 2 m in the crack southeast of drill hole 1 was 

only 35°C. Lava adjacent to the cracks was cooled by 

air circulating in the cracks and by rainwater flowing 

into them. As a result, isothermal surfaces in the crust 

were strongly depressed near the cracks. As the crust 

of the lake cooled, cracks split to become deeper, and 

new cracks opened. Some of these provided channelways for hot gases that streamed upward from the molten and newly solidified basalt at depth in the lake and 

heated lava adjacent to the cracks. Drill hole 12 was 

split by such a crack; during drilling, water was turned 

to steam along the crack, making the drilling operation 

difficult. Rising gases along this crack caused temperatures at shallow depths in the drill hole to be greater 

than those in other holes. 

MAXIMUM TEMPERATURES AND TEMPERATURES 

AT THE BASAL CONTACT 

Maximum temperatures in the central part of Alae 

lava lake are estimated to have been 1,140°C on 

November 8, 1963, and 1,120°C on December 30, 1963, 

on the basis of 2 m extrapolations of temperature profiles measured in the crust and underlying fluid lava on 

those dates (figs. 6, 9). These values compare with 

maximum extrusion temperatures which fell from an 

estimated 1,160°C at the beginning of the eruption on 

August 21, 1963, to 1,140°C near the end of the eruption during the evening of August 22. Maximum temperatures in the lake were first measured beneath its 

thin margin on December 18, 1963, when a value of 

1,066°C was recorded at a depth of 5.5 min drill hole 5 

(table 4). Maximum temperatures beneath the central 

part were first measured on July 2, 1964, 10% months 

after the eruption, when a value of 1,050°C was recorded at a depth of 8.2 min drill hole 8. Beneath the 

main drilling site on the central part of the lake, 

maximum temperatures in the lake fell steadily during 

the following 3 years, decreasing to 672°C on August 

19, 1965, to 4 76°C on May 27, 1966. On August 31, 

1967, the maximum temperature measured was 90°C 

at the bottom of drill hole 12, 1.1 m greater than the 

assumed depth of the base of the lake at that site. The 

measured values are very similar to values computed 

using numerical models, as discussed on p. 4 7. 

Maximum temperatures in the lake beneath the 

main drilling site, (DH3, 4, 8, and 12), in the thin margin (DH5), and in the thickest part of the lake (DH9) 

are plotted in figure 14 as a function of the square root 

of time. The values beneath sites near the center of the 

lake plot as nearly linear curves at temperatures less 

than about 1,050°C, facilitating the estimates of 

maximum temperatures on intermediate dates. Also 

indicated in figure 14 are maximum temperatures 

computed for a lake 49 feet (14.9 m) thick using the 

numerical model discussed in the section on ~~Thermal 

Modeling" and illustrated in figure 39. The computed 

temperatures agree closely with the measured values 
18 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

TABLE 4.-Depth and values of maximum temperatures and of basal 

contact temperatures in Alae lava lake 

Date 

Nov. 

Dec. 

8 

18 

30 

30 

Drill 

hole 

3 

5 

3 

5 

Jan. 29 5 

Feb. 17 5 

26 5 

March 24 5 

April 3 6 

13 5 

May 22 6 

27 5 

June 17 5 

July 2 8 

2 5 

27 5 

Aug. 14 5 

Sept. 3 5 

15 9 

21 5 

21 9 

Oct. 16 5 

16 9 

Dec. 8 5 

8 9 

8 12 

Jan. 21 5 

21 9 

21 12 

March 2 5 

2 9 

2 12 

July 6 5 

6 9 

6 12 

Aug. 19 5 

19 9 

19 12 

May 27 12 

Aug. 31 12 

Depth of maximum temperature in meters (most values ±0.15 m) 

1963 

Maximum 

temperature in oc 

estimated 7.5 

5.5 

estimated 7.5 

5.55 

estimated 1,140 

1,066 

estimated 1,120 

1,053 

1964 

5.6 

5.85 

5.9 

6.0 

7.5 

6.1 

7.5 

5.7 

5.8 

8.2 

5.5 

5.2 

4.7 

4.4 

9.3 

4.6 

9.1 

4.0 

9.3 

4.0 

9.3 

8.5 

1965 

4.3 

9.75 

8.5 

4.3 

9.9 

8.7 

4.9 

11.0 

9.75 

4.9 

11.6 

9.75 

1966 

11.9 

1967 

960 

915 

889 

812 

1,060 

750 

1,052 

636 

580 

1,050 

552 

512 

494 

476 

1,005 

455 

995 

440 

950 

392 

902 

872 

328 

865 

850 

285 

833 

817 

95 

725 

720 

95 

688 

672 

476 

Basal contact temperature in °C1 

(values in paren- theses are preferred) 

725±50 

(695) 

690±30 

(710) 

695±45 

(670) 

645±45 

(675) 

685±50 

(655) 

630±40 

(660) 

640±30 

(615) 

585±30 

(610) 

620±30 

(600) 

570±30 

(595) 

460±10 

(465) 

13.1 88±22 88±2 

(86) 

in DH9. The values for drill hole 5 plot more erratically 

than those for other drill holes, at least in part because 

of the effect of abundant rainfall on the relatively cool 

margin of the lake after the heavy rains in early 1964 

and early 1965. 

The depth of the maximum temperature beneath the 

central part of the lake (table 4) fell systematically 

with time as the temperature decreased. Ranges of 

values for the proportionate depth (the ratio of depth of 

the maximum temperature to the thickness of the lake) 

in several drill holes are plotted as a function of the 

maximum temperature in figure 15. A large range of 

values for the proportionate depth for each hole is indicated in the figure because of uncertainties in the 

depth of the basal contact. This uncertainty for drill 

holes 9 and 12 can be greatly reduced if we can assume 

that the proportionate depth of the maximum temperature was the same in each hole on any given day. On 

this basis, the lake thickness was 14.9±0.1 m at DH9 

and 13.3±0.2 at DH12. The same values are obtained 

from similar assumptions as to the values of the contact temperatures. The smooth curve in figure 15 was 

constructed using these values for lake thickness and 

shows a decrease in the proportionate depth from about 

0.6 when the maximum temperature was 1,050°-

1,0000C, to 0.75 at 680°, 0.9 at 475°, and 1.1 or more 

(below the lake) at 90°. Computed proportionate 

depths are also shown, based on the model illustrated 

in figure 39. 

Contact temperatures at the base of the central part 

of the lake were first measured on December 8, 1964 

and are given in table 4. Large ranges of values are 

indicated because of uncertainties in the exact depth of 

the basal contact in each hole, but the ranges for drill 

holes 9 and 12 can be reduced by the assumptions discussed above. On this basis, contact temperatures were 

as much as 700± 10°C (60 percent of the beginning 

temperature of the lake) when first measured on December 8, 1964, and decreased slowly to 600°± 10°C on 

August 19, 1965. Computed contact temperatures at 

the base of a lake 49 feet (14.9 m) thick with a latent 

heat of 80 cal/g fell from 668°C to 606°C for the same 

period. From May 27, 1966, to August 31, 1967, the 

measured contact temperatures fell from 465°C to 

86°C. 

Footnotes to table 4. 

'Depth of basal contact estimated to be 9± 1 m in DH5; 13± 1 m in DH6, and 14± 1 m in DH8, based on vertical angle and level surveys after formation of the lake (table 6) and preeruption topography of Alae crater determined photogrammetrically (fig. 1 ). pepth of basal contact in DH9 determined to be 14.5±0.8 m, on the basis of the recovery ofdnll core of 1840 lava between 14.6 and 15.2 m. Depth ofbasal contact in DH12 estimated to be 13.7±0.6 m on the basis of a cavernous layer penetrated in drilling between 13.1 and 14.3 m. If the assumption is valid that basal contact temperatures beneath drill holes 9 and 12 and the proportionate depths of the maximum temperature were the same on a given day, the depths of the basal contact are 14.9±0.1 m at DH9 and 13.3±0.2 m at DH12. Contact temperatures at these depths are shown in parentheses. 2The maximum temperature measured was 90°C at the bottom of the drill hole 1.2 m below the assumed depth of the base of the lake. 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HAWAII 19 

w 

~ 1000 

a: 

(.9 

1-

z 

w 

u 

~ 800 

w 

a: 

(.9 

w 

0 

~ 

(J)- 600 

w 

a: 

::J 

1-

<! 

a: 

w 

c.. 

~ 

w 

1-

~ 

::J 

~ 

400 

X 200 <! 

~ 

- ____ * ______ _ 

Drill H x O/es 3 

'4 8 X 

, , and 12 

X 

SQUARE ROOT OF TIME, IN DAYS, AFTER AUGUST 22, 1963 

FIGURE 14.-Maximum temperatures at three sites in Alae lava lake as a function of the square root of time in days. Location of drill 

holes shown in figure 1. Crosses indicate computed temperatures derived from figure 39; black circles indicate measured temperatures 

in drill hole 9; open circles indicate measured temperatures in other drill holes. 

DENSITY OF ALAE LAVA 

AND VARIATION WITH TIME 

OF THE ALTITUDE OF THE LAKE SURFACE 

Molten basalt in Alae lava lake vesiculated because 

of the exsolution of gases as the lava cooled and solidified. The rate of vesiculation with time was recorded 

in the abundance of vesicles in solidified basalt newly 

added to the crust of the lake. The variation of vesiculation with temperature can be deduced from the size 

and shape of vesicles and the petrography of quenched 

partly molten basalt in drill core from near the base of 

the crust. Because of vesiculation, fluid lava in the lake 

expanded as it solidified, causing the surface of the 

lake to extend horizontally and to rise vertically. The 

solidified margin, in contrast, subsided because of 

thermal contraction. As a result, we were able to determine the outline of the lens of fluid and partly molten lava and record its shrinkage with time by means 

of repeated surveys of the altitude of stations on the 

lake surface as well as the measurement of temperatures in drill holes. Data from the surveys and other 

measurements are used to calculate the density of fluid 

lava in the lake early in its cooling history. Repeated 

surveys of the stations after solidification of the lake 

reveal the pattern of continued cooling and provide 

data that are used to calculate the bulk coefficient of 

thermal expansion. This section presents data on the 

density and vesicularity of the lava and on the changing altitude of the lake surface; the integration of this 

data and temperature data provides an analysis of the 

altitude changes. 

DENSITY AND VESICULARITY 

The measured density of individual pieces of drill 

core of solidified basalt from the lake ranges from 1.66 

to 2.78 g/cc. In general density increased downward in 

the lake from an average value of 1.80 g/cc within 10 

em of the upper surface to a nearly constant 2.67 to 

2.68 glee at depths below 3 m. Average values of density at 0.3-m intervals from the surface to a depth of 3 

m and at 11;2 m-intervals below that are given in table 

5 and plotted in figure 16. Density was determined by 

planing flat the ends of each core 1 em or more in 

length from the 12 drill holes and measuring its volume and weight. A total length of 429 em of core was 

measured (almost all 1.43 em diam), an average of 
20 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

I 0.6 

fa.. 

UJ 

Cl 

~ 0.7 

<( 

z 

0 

i= 

~ 0.8 a.. 

0 

c: 

a.. 

0.9 

X 

1.0~-----L------~----~------~------~~--~ 

1200 1000 800 600 400 200 0 

MAXIMUM TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 15.-Proportionate depth of the maximum temperature in 

four drill holes in the central part of the lake as a function of the 

value of the maximum temperature. The smooth curve was constructed on the assumption that the proportionate depths of the 

maximum temperatures in DH9 and 12 and values of the basal 

contact temperatures were the same in each drill hole. Crosses 

indicate computed depths and temperatures based on the thermal 

model illustrated in figure 39. 

about 30 percent for each interval. Because only a few 

drill holes penetrated the lower half of the lake, only a 

small amount of core was recovered below 6 m. Core 

recovery also was poor from the more vesicular zones in 

the lake, particularly from the highly vesicular and 

cavernous layer at a depth between 0.3 and 0.6 m. The 

density values listed in table 5 and plotted in figure 16 

are probably biased towards greater density, particularly for depths less than 5 m. 

TABLE 5.-Bulk density and porosity of drill core [All values are for core collected from temperatures less than l,OOOoC) 

Depth interval (m) 

0- 0.3 

0.3- 0.6 0.~ 0.9 

0.9- 1.2 

1.2- 1.5 

L&- 1.8 

1.8- 2.1 

2.1- 2.4 

2.4- 2.7 

2.7- 3.0 

3.0- 4.5 

4.&- 6.0 

6.0- 7.5 

7.5- 9.0 

9.0-10.5 

10.&-12.0 

12.0-13.5 

Total length of core (em) 

123 

7 

17 

17 

14 

17 

25 

16 

30 

13 

51 

29 

20 

7 

14 

15 

14 

Average1 

density 

(glee) 

1.91 

2.12 

2.22 

2.36 

2.34 

2.47 

2.50 

2.43 

2.59 

2.61 

2.68 

2.67 

2.65 

2.68 

2.68 

2.67 

2.66 

1Weighted by length of each piece of core. 

Range in measured 

density 

(glee) 

1.6~2.43 

1.8~2.43 

1.7&-2.47 

1.91-2.64 

1.91-2.64 

2.13-2.56 

2.19-2.60 

2.19-2.65 

2.37-2.71 

2.52-2.71 

2.54-2.78 

2.60-2.70 

2.61-2.65 

2.61-2.70 

2.6&-2.70 

2.63-2.75 

2.63-2.72 

2Porosity calculated using the average measured grain density of 3.01 glee. 

Calculated2 

porosity 

(in percent) 

37 

30 

26 

22 

22 

18 

17 

19 

14 

13 

11 

11 

12 

11 

11 

11 

12 

CJ) 

c: 

2 

3 

4 

5 

~ 6 UJ 

~ 

z 7 

I 

f-fu 8 0 

9 

10 

11 

13 

Jill I~ .JI II 

1

1

"1.1 I : 

I I I: • I J I : 

Porosity ("=' vesicularity), in percent : I ~~~ ~ ~~ 1 111 ~ I 

ll 

I ~I' II]' 

II 

10 

40 

30 

20 

14~~---L---L--~--~--~~--~--~--~--~~ 

1.6 1.8 2.0 2.2 2.4 2.6 2.8 

CORE DENSITY, IN GRAMS PER CUBIC CENTIMETER 

FIGURE 16.-Average core density and porosity (approximately equal 

to vesicularity) as a function of depth. Vertical bars indicate density of individual pieces of core from the indicated interval. X's 

show average values for 0.3-m intervals from 0 to 3 m and 1% m 

intervals below. 

Density increased with depth in the lake because of a 

decrease in the abundance of vesicles. Because of the 

nearly constant mineralogic composition of the Alae 

basalt, the porosity, cp, in percent, can be calculated 

from the bulk density, Pb, and the average grain density, pg, using the following equation (Daly and 

others, 1966, p. 21): 

"' = 100 ( 1 - ~; ) 

The grain densities of eight samples of basalt from the 

lake range from 2.92 to 3.04 glee and average 3.01 g/cc. 

Porosity of the basalt is nearly equivalent to the vesicularity. A small proportion of the porosity of all the 

samples, however, probably is caused by microfractures that formed as the result of thermal stresses induced by cooling. The microfracture porosity is 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 21 

suggested by analysis of laboratory measurements of 

thermal conductivity of Alae and other Hawaiian 

basalt samples (Robertson and Peck, 1974) and by 

comparison of the coefficient of thermal expansion calculated from temperature and leveling data from Alae 

with values measured in the laboratory (Skinner, 

1966; Richter and Simmons, 1974). As microfracture 

porosity probably is only about 0.3 percent or less of 

each sample (p. 33), it was disregarded in converting 

calculated porosity to vesicularity. Vesicularity so calculated agrees closely with modal vesicularity measured in thin sections. In general, it decreased from 40 

percent near the surface of the lake to a nearly constant 11 percent below 3 m. 

In detail, vesicularity did not decrease smoothly with 

depth. In at least some of the drill holes, it increased 

downward from the surface to maximum values in a 

highly cavernous layer at depths between 0.3 and 1.2 

m and then decreased with greater depth. During the 

drilling of several holes at these depths, the drill fell 

abruptly as much as a tenth of a meter. Little core was 

recovered from this interval from any of the drill 

holes, particularly from a depth of 0.3-0.6 m. Caverns 

at shallow depth were detected by stamping on the surface during a detailed study of surface features and 

joint cracks (Peck and Minakami, 1968, fig. 3; Peck and 

Kinoshita, 1976, fig. 33). Fifteen cavities were detected 

in an area approximately 100 feet (30.5 m) square. The 

cavities were beneath the central parts of the broad 

hummocks that made up the surface of the lake and 

were formed near the end of the eruption by the entrapment of rising gases below a thin surface crust. 

The appearance of similar features in older flows exposed on crater walls and roadcuts suggests that the 

cavities in Alae were lensoid openings a few tenths of a 

meter high and a meter or two in diameter. Below the 

cavernous layer to depths of about 5 m, the lava consisted of vague, alternating layers of more and less 

vesicular basalt a few centimeters or fractions of a centimeter in thickness. In general, the width of the vesicular layers decreased and the spacing between the 

layers increased with depth. They were sparse below 3 

m and disappeared at a depth of about 5 m. 

The size of vesicles in the lava increased from a 

minimum at the surface to a maximum at depths of 

about 30 em, and then decreased with greater depth. 

The average size of the 10 largest vesicles in each core 

interval increased linearly from 2 mm at the surface to 

8 mm at a depth of 0.3 m, as shown in figure 17. Below 

0.3 m, the average size of the largest vesicles decreased, reaching a minimum of about 1 mm between 6 

and 12 m and increasing slightly near the base of the 

lake. The vesicles were round to spheroidal in the 

upper meter of glass-rich basalt, but the more com-

(/) 

a: 

UJ 

fUJ 

~ 

~ 

Ifa.. 

UJ 

0 

0 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

0 

oolo I .. • •'I "'""'1.•• 

1 ~~ ·~~~~ } Zone of 1 1 1 large cav1t1es 

I I II 

I I I II I 

I 1111 I Ill I 

II I Ill I I I 

I 1

1 I 

Ill Ill I 

I 1: 

I II 

I 

I 

I 

I 

II 

MAXIMUM VESICLE SIZE, 

I 

IN MILLIMETERS, 

(/) IN UPPER 30 CENTIMETERS 

a: zw 0 2 4 6 8 

-f- 0 

I I' I II 

Ill I 1111 I 

UJ 

~~ 10 

I 

a.- I UJ f- 20 oz lh I I UJ I u1 

30 

2 4 6 8 

MAXIMUM VESICLE SIZE, IN MILLIMETERS 

FIGURE 17.-Maximum size of vesicles as a function of depth. 

pletely crystallized basalt at greater depths contained 

increasingly abundant minute angular vesicles, the 

voids characteristic of diktytaxitic texture . Below 6 m 

the vesicles were almost entirely of the minute angular 

type. Both types of vesicles are shown in the photomicrograph of figure 18, which was taken of core collected 

November 17, 1964, from a depth of 1.5-2.1 m in drill 

hole 12. 

The large, round vesicles apparently formed at high 

temperatures in relatively fluid lava, most of them 

probably at temperatures of approximately 1,100°C or 

more, and their decrease in abundance with depth in 

the lake recorded the degassing and approach to 

equilibrium gas content of the Alae lava. The lava was 

supersaturated with gas on eruption because of the decrease in confining pressure from the magma conduits 

to the surface. The relative rate of degassing with time 

can be estimated by comparing the change in vesicularity with depth to the change in depth with time of 

the 1,100°C isotherm. As shown in figure 19, this comparison suggests that the rate of degassing decreased 
22 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

A 

B FIGURE lB.-Photomicrograph of vesicular basalt from a depth of 1.5-2.1 m in drill hole 

12. A, plane-polarized light. B , Crossed nicols. The smooth round vesicle (V), a millimeter in diameter, presumedly formed from gas exsolved from the supersaturated fluid 

lava at temperatures of 1,100°C or more; minute angular vesicles (A) formed at lower 

temperatures in the transient zone of crystallization from gas driven out of solution by 

crystallization. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 23 

40 

Iz 

w 

u 

a: 

w 

a.. 30 

~ 

-r' 

!:::: 

a: 

<( 

....J 20 :::> 

~ (/) 

w 

> 

10 

0 40 80 120 160 200 

TIME, IN DAYS, AFTER AUGUST 22,1963 

FIGURE 19.-Vesicularity of depth intervals in the upper part of the 

crust of Alae lava lake as a function of the time for each interval to 

cool to 1,100°C. Vertical bars indicate the vesicularity of depth 

intervals that are 0.3 m thick in the upper 4.5 m and 1.5 m thick 

below. The plot records the strong degassing of the Alae lava during the first 30 days after the eruption. 

drastically during the first 30 days, during which time 

the upper 2.5 meters of the lake cooled to less than 

1,100°C; thereafter, gas from the slightly oversaturated fluid lava slowly exsolved until the lava reached 

an equilibrium gas content approximately 100 days 

after the eruption, when the upper 4.5 m had cooled to 

less than 1,100°C. Rapid degassing of the ponded lava 

in Makaopuhi crater during the first 4 months after the 

March 1965 eruption was demonstrated by Finlayson, 

Barnes, and Naughton (1968, fig. 5); they determined 

by chemical analysis the rapid depletion of carbon and 

sulfur in gas collected from drill holes in the crust of 

the lake. 

The size and shape of the minute angular pores and 

their rather constant abundance from top to bottom in 

the solidified lake suggest that they formed at lower 

temperatures than the spheroidal vesicles and near the 

crust-fluid lava interface, where growth of vesicles was 

constrained by a meshwork of crystals and higher viscosity melt. The vesicles apparently formed from gases 

exsolved from the melt because of the crystallization of 

anhydrous minerals-that is, ~~second boiling" of the 

melt. The rather constant 11 percent vesicularity at 

depths below 3 m would represent 0.0025 percent gas 

by weight, assuming the gas were water vapor. The 

relative abundance of the angular pores at different 

temperatures within the zone of crystallization could 

not be determined from the drill core because core from 

the zone also contains vesicles formed from vaporized 

coolant water. The natural abundance of the angular 

pores with temperature and the rate of vesiculation 

within the zone, however, can be estimated from the 

rate of crystallization with temperature. The estimated 

14 

w 

u 12 

Zt-

<(z 

aw 

z u 10 ::>a: 

cnw 

<(a.. 

w w 8 

:::3 

1--....J 

<( 0 6 ....J> 

=>z ::?!_ 

B 4 

.....---

/ / ............ 

I / 

I 

I 

I 

I 

\ 

I 

I . . VRate of ves1culat1on 

I 

I 

I 

I 

I 

\ 

\ 

\ 

\ 

\ 

\ 

\ 

"' " '-. '-....._ 

2 // Cumulative abundance --- I of vesicles 

TEMPERATURE, IN DEGREES CENTIGRADE 

w 

a 

<( 

a: 

c:J 

i= 

1.2 £ iE 

OU 

i=~ 1.0 :5 a: 

:::>~ 

~a 0.8 t3 f::: 

>Z 

u.w 

0.6 0~ ww 

t-a.. 

<(w 0.4 a: ::?! 

:::> 

....J 

0.2 ~ 

~ 

FIGURE 20.-Estimated rate of vesiculation (dashed curve) and 

cumulative abundance of minute angular vesicles (solid curve) as a 

function of temperature. 

rate of vesiculation and the cumulative abundance of 

vesicles (fig. 20) are based on petrographic observations of crystal abundance and calculations from chemical analyses of samples from Alae and Makaopuhi 

lava lakes (Wright and Peck, 1978). The calculations suggest that the maximum rate of vesiculation 

(1.6 percent vesicles formed for a 1 oc drop in temperature) took place between 1,060 and 1,065°C, and that 

two-thirds of the vesicles were formed between 1,100°C 

and 1,030°C. A strong peak of vesiculation at 1,060-

1,0650C is confirmed by calculations (p. 34) that show 

good agreement between the observed uplift during 

solidification at the main drilling site and the uplift 

calculated on the assumption that vesiculation took 

place at 1,065°C. 

ALTITUDE OF THE LAKE SURF ACE 

Repeated surveys of the altitude of a grid of stations 

on the lake surface over the 4-year period of solidification and continued cooling reveal a complex, changing 

pattern of uplift and subsidence. During the year of 

solidification, the surface above the thick central part 

of the lake rose as much as 25 em and the margin 

subsided as much as 6 em. During the following 3 years 

of continued cooling, the entire lake surface subsided. 

Interpretation of the changes in altitude involves not 

only analysis of the leveling data but also integration 

of that data with temperature measurements, surveys 

of horizontal extension and contraction of the lake surface, and data on density and vesicularity of the crust 

of the lake. Accordingly, data on the altitude and hori-
24 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

A B 

10 -15 

-20 

-40 15 

-70 11 

20 -io - i oo :_so 9 4 9 11 3.7 11 -13 11 11 6 

-20 11 

-2 

4 

August 30 to September 11, 1963 September 11 to September 24 to 26, 1963 

0 50 100 METERS 

Values in em/day x 100 

FIGURE 21.-Rate of change in altitude of the surface of Alae lava lake during solidification of the lake from August 

30 to September 24-26, 1963. Values are in em/day x 102 • A, August 30 to September 11 1963· B September 11 

to September 24-26, 1963. ' ' ' 

zontal separation of stations are presented first, followed by interpretations of the recorded changes. 

CHANGES IN ALTITUDE DURING SOLIDIFICATION 

<?n August 30, 1963, 7 days after the eruption, the 

altitudes of nine stations on the lake were measured 

approximately. 2 When they were remeasured 12 days 

later on September 11, seven of them had subsided 

decreasing in altitude as much as 12.2 em, as shown i~ figure 21 A and listed in table 6. The full cross of 17 

stations was leveled on September 11 and again September 24-26. During the 2-week interval, most of the 

stations near the edge of the lake subsided, and most of 

those near the center were uplifted (fig. 21 B). The 

greatest uplift was 5.2 em at station 5, near the center 

of the lake. 

The complete grid of stations was established and 

their relative altitudes measured September 24-26, 

and at monthly intervals for the following year while 

the lake continued to solidify. Changes in altitude are 

p~otted and contoured as rates of change per day for six 

bimonthly periods in figure 22. The average rate of 

uplift of all stations was greatest during October and 

November 1963 (0.08 em/day) and fell steadily thereafter to 0.05 em/day for March and April 1964, 0.02 

em/day for June and July, and 0.003 em/day for August 

and September. The relative changes of altitude of the 

.

2As described in the section on methods of study, p. 7, the initial survey was conducted 

with a damaged transit, and the measured altitudes may be in error by as much as 1.5 em. 

different stations on the lake showed a consistent pattern during each bimonthly period of the year. The 

margin of the lake subsided and the central part rose. 

The line between areas of uplift and subsidence migrated inward, very slowly during the first 6 months 

but more rapidly during the rest of the year. Uplift was 

not constant over the central part of the lake. During 

the first 8 months it was greatest in a belt part way 

between the center and the edge of the lake. During the 

last 4 months, the greatest uplift was near the center of 

the lake. Comparison of the patterns of uplift and subsidence with the contour map of the base of the lake 

(fig. 1) suggests a relationship between changes in altitude and the depth of the lake. This relationship can 

be seen most clearly in the changes during April to 

June 1964 (fig. 22 D), when the ring of maximum uplift 

and the line between uplift and subsidence bent inward 

where the northern part of the lake thinned over a 

buried 1840 spatter ridge and where the southeast part 

thinned over a less pronounced ridge. 

Several stations were added during the year to determine whether differences in altitude changes between stations of the grid took place smoothly or abruptly with distance. Two stations (37 and 38) were 

marked in early December 1963 on the crests of small 

tumuli near station 4 at the center of the lake, and five 

stations (42 through 46) were added in early January 

1964 on the north-central part of the lake between stations 3 and 29. Repeated level measurements over the 

following 6 months showed no abrupt changes in altitude between these closely spaced stations. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 25 

TABLE 6.-Altitude of stations on the lake surface 

[Altitudes given in feet above sea level (1 foot = 0.3048 mi. Figures in parentheses show change in altitude between dates] 

Station Aug. 30, 1963 Sept. 11, 1963 Sept. 24-26, 1963 

-------~--

1 ------------ 2566.98 ( +0.04) 2567.015 ( +0.027) 

2 ------------ 66.43 (+.02) 66.453 (+.117) 

3 ------------ 65.75 (+.04) 65.793 ( +.041) 

4 ------------ 2566.22 (+0.07) 66.29 (+.06) 66.346 (+.094) 

5 ------------ 67.08 ( -.06) 67.02 (+.17) 67.190 ( +.153) 

6 ------------ 66.85 (-.40) 66.45 (+.05) 66.498 (+.134) 

7 ------------ 66.93 (-.32) 66.61 (-.06) 66.545 ( +.082) 

8 ------------ 67.93 (+.05) 67.981 (+.132) 

9 ------------ 66.70 (+.05) 66.751 (+.057) 

11 ------------ 65.07 (+.03) 65.10 ( -.07) 65.029 ( -.062) 

12 ------------ 2568.10 assumed 68.10 (-.11) 67.989 (-.009) 

13 ------------ 67.05 (-.24) 66.81 (-.09) 66.721 ( +.131) 14 ------------ 67.14 (-.16) 66.98 (+.07) 67.050 ( +.087) 15 ------------ 66.96 (-.28) 66.68 (+.05) 66.726 (+.122) 16 ------------ 66.51 (-.06) 66.45 (+.05) 66.495 ( +.097) 17 ------------ 67.04 (-.01) 67.028 ( +.030) 

18 ------------ 65.58 (+.02) 65.60 (+.032) 

19 ------------ 2568.09 assumed 2568.09 assumed 

20 ------------ 66.781 (+.100) 

21 ------------ 66.649 (+.153) 

22 ------------ 66.513 (+.177) 

23 ------------ 68.60 (0) 68.604 (-.052) 

24 ------------ 67.195 (+.116) 

25 ------------ 67.701 (+.069) 

26 ------------ 67.086 (+.082) 

27 ------------ 68.026 (+.113) 

28 ------------ 66.613 (+.016) 

29 ------------ 66.411 (+.227) 

30 ------------ 65.955 (+.073) 31 ------------ 68.176 (-.088) 

32 ------------ 67.734 (-.052) 

33 ------------ 66.868 (+.146) 

34 ------------ 67.485 ( -.113) 

35 ------------ 67.814 (-.005) 

37 ------------ 38 ------------ 41 ------------ 47 ------------ --- -- __ ,_ ---------------------~------------~---

-----~~------

Station Oct. 30, 1!:163 Dec. 4, 1963 Jan. 2, 1964 

-- --------------------- ---------~-----

1 ------------ 2567.042 ( +0.070) 2567.112 (+0.030) 2567.142 (+0.092) 2 ------------ 66.570 (+.108) 66.678 ( +.053) 65.731 (+.079) 3 ------------ 65.834 ( +.073) 65.907 ( +.025) 65.932 ( +.088) 4 ------------ 66.440 ( +.129) 66.569 (+.019) 66.588 (+.083) 5 ------------ 67.343 (+.062) 67.405 (+.002) 67.407 (+.053) 6 ------------ 66.632 (+.079) 66.711 (+.025) 66.736 ( +.064) 7 ------------ 66.627 ( +.033) 66.660 (+.032) 66.692 ( +.053) 8 ------------ 68.113 (+.140) 68.253 (+.103) 68.356 ( +.139) 9 ------------ 66.808 (+.092) 66.900 (+.076) 66.976 ( +.104) 11 ------------ 64.967 ( +.001) 64.968 (-.011) 64.957 ( +.010) 12 ------------ 67.980 (+.023) 68.003 (-.010) 67.993 (+.006) 13 ------------ 66.852 (+.132) 66.984 ( +.082) 67.066 (+.127) 14 ------------ 67.137 (+.049) 67.186 (+.037) 67.223 (+.056) 15 ------------ 66.848 (+.056) 66.904 ( +.018) 66.922 (+.057) 16 ------------ 66.592 ( +.111) 66.703 (+.038) 66.741 (+.056) 17 ------------ 67.058 ( +.099) 67.157 (+.063) 67.220 (+.071) 18 ------------ 65.632 ( +.040) 65.672 (+.033) 65.705 (+.055) 19 ------------ 2568.09 assumed 2568.09 assumed 2568.09 assumed 

20 ------------ 66.881 ( +.074) 66.955 (+.041) 66.996 (+.107) 21 ------------ 66.802 ( +.145) 66.947 (+.042) 66.989 (+.121) 22 ------------ 66.690 (+.137) 66.827 ( -.003) 66.824 ( +.095) 23 ------------ 68.552 ( -.032) 68.520 (-.022) 68.498 (-.016) 24 ------------ 67.311 (+.115) 67.426 (+.040) 67.466 ( +.078) 25 ------------ 67.770 ( +.070) 67.840 ( +.030) 67.870 ( +.095) 26 ------------ 67.168 ( +.139) 67.307 ( +.043) 67.350 ( +.088) 27 ------------ 68.139 (+.106) 68.245 (+.074) 68.319 ( +.117) 28 ------------ 66.629 ( +.104) 66.733 (+.057) 66.790 (+.150) 29 ------------ 66.638 (+.119) 66.757 ( +.012) 66.769 ( +.111) 30 ------------ 66.028 ( +.107) 66.135 ( +.051) 66.186 (+.102) 31 ------------ 66.088 (-.028) 68.060 (-.024) 68.036 (-.024) 32 ------------ 67.682 ( -.003) 67.679 ( +.002) 67.681 ( +.027) 33 ------------ 67.014 ( +.101) 67.115 (+.038) 67.153 ( +.101) 34 ------------ 67.372 (0) 67.372 (-.027) 67.345 (+.020) 35 --· --------- 67.809 (+.063) 67.872 (+.024) 67.896 (+.061) 
26 SOLIDIFICATION OF ALAE LA VA LAKE, HA WAil 

TABLE 6.-Altitude of stations on the lake swface-Continued 

Station Oct. 30, 1963 Dec. 4, 1963 Jan. 2, 1964 

37 ------------ 68.667 (+.025) 68.692 (+.077) 38 ------------ 68.335 (+.049) 68.384 ( +.096) 41 ------------ 65.934 ( -.014) 47 ------------

Station Feb. 7-10, 1964 Mar. 3, 1964 Apr. 13, 1964 

1 ------------ 2567.234 (+0.036) 2567.270 (+0.048) 2567.318 (+0.026) 2 ------------ 66.810 ( +.032) 66.842 ( +.063) 66.905 ( +.078) 3 ------------ 66.020 (+.024) 66.044 (+.054) 66.098 (+.048) 4 ------------ 66.671 (+.023) 66.694 ( +.053) 66.747 (+.057) 5 ------------ 67.460 (+.016) 67.476 (+.055) 67.531 ( +.045) 6 ------------ 66.800 (+.036) 66.836 ( +.069) 66.905 ( +.055) 7 ------------ 66.745 ( +.055) 66.800 (+.114) 66.914 ( +.042) 8 ------------ 68.495 ( +.074) 68.569 (+.153) 68.722 ( +.033) 9 ------------ 67.080 ( +.073) 67.153 ( +.093) 67.246 (-.027) 11 ------------ 64.967 ( +.004) 64.971 ( -.032) 64.939 (-.003) 12 ------------ 67.999 (+.013) 68.012 (-.019) 67.993 ( -.001) 13 ------------ 67.193 ( +.106) 67.299 ( +.092) 67.391 ( +.071) 14 ------------ 67.279 ( +.053) 67.332 ( +.043) 67.375 (+.065) 15 ------------ 66.979 (+.032) 67.011 (+.049) 67.060 (+.056) 16 ------------ 66.797 (+.032) 66.829 (+.065) 66.894 (+.070) 17 ------------ 67.291 ( +.042) 61.333 (+.082) 67.415 (+.066) 18 ------------ 65.760 (+.042) 65.802 (+.046) 65.848 ( +.003) 19 ------------ 2568.09 assumed 2568.09 assumed 2568.09 assumed 

20 ------------ 67.103 (+.006) 

21 ------------ 67.110 (+.037) 

22 ------------ 66.919 (+.052) 

23 ------------ 68.482 (+.006) 68.488 (-.024) 68.464 (-.030) 24 ------------ 67.544 (+.037) 67.581 ( +.093) 67.674 ( +.058) 25 ------------ 67.965 ( +.052) 68.017 ( +.095) 68.112 (+.004) 26 ------------ 67.438 ( +.033) 67.471 (+.094) 67.565 ( +.056) 27 ------------ 68.436 (+.056) 68.492 (+.132) 68.624 (+.059) 28 ------------ 66.940 ( +.048) 66.988 ( +.020) 67.008 (+.014) 29 ------------ 66.880 (+.027) 66.907 (+.060) 66.967 ( +.150) 30 ------------ 66.288 (+.030) 66.318 (+.060) 66.378 (+.092) 31 ------------ 68.012 (+.015) 68.027 (-.010) 68.017 (-.017) 32 ------------ 67.708 ( -.012) 67.696 ( +.007) 67.703 (-.037) 33 ------------ 67.254 (+.047) 66.301 (+.147) 67.448 ( +.040) 34 ------------ 67.365 ( -.015) 67.350 (-.014) 67.336 (+.001) 35 ------------ 67.957 ( -.003) 67.954 (-.026) 67.928 ( -.001) 37 ------------ 68.769 (+.025) 68.794 ( +.048) 68.842 (+.058) 38 ------------ 68.480 (+.033) 68.513 ( +.069) 68.582 ( +.059) 41 ------------ 65.920 ( +.010) 65.930 (-.035) 65.895 (-.031) 47 ------------ 67.447 (-.012) -------------------------- --------------------

Station May 12, 1964 June 9, 1964 July 6, 1964 

1 ------------ 2567.344 ( +0.022) 2567.366 ( +0.002) 2567.368 ( +0.009) 2 ------------ 66.983 ( +.082) 67.065 (+.035) 67.100 (+.028) 3 ------------ 66.146 ( +.048) 66.194 (+.058) 66.252 (+.070) 4 ------------ 66.804 (+.071) 66.875 ( +.062) 66.937 (+.032) 5 ------------ 67.576 (+.073) 67.649 (+.055) 67.704 ( +.052) 6 ------------ 66.960 ( +.133) 67.093 (+.032) 67.125 ( +.008) 7 ------------ 66.956 ( +.017) 66.973 ( +.007) 66.966 ( +.003) 8 ------------ 68.755 ( +.031) 68.786 ( -.008) 68.778 ( -.017) 

9 ------------ 67.219 (+.005) 67.224 (-.010) 67.214 (-.010) 

11 ------------ 64.936 (.000) 64.936 ( -.001) 64.935 (-.003) 12 ------------ 67.992 ( +.005) 67.997 ( -.005) 67.992 (-.006) 13 ------------ 67.462 ( +.007) 67.469 ( -.003) 67.466 (.000) 14 ------------ 67.440 (+.097) 67.537 ( +.109) 67.646 (+.053) 15 ------------ 67.116 (+.103) 67.219 ( +.104) 67.323 ( +.023) 16 ------------ 66.964 ( +.044) 67.008 (+.019) 67.027 ( +.008) 17 ------------ 67.481 ( +.024) 67.505 ( +.001) 67.506 (-.003) 18 ------------ 65.851 (-.021) 65.830 ( -.010) 65.820 ( -.017) 19 ------------ 2568.09 assumed 2568.09 assumed 2568.09 assumed 

20 ------------ 21 ------------ 22 ------------ 23 ------------ 68.434 ( +.002) 68.436 ( -.005) 68.431 (-.017) 

24 ------------ 67.732 ( +.114) 67.846 ( +.009) 67.855 (-.010) 

25 ------------ 68.116 ( +.002) 68.118 ( -.021) 68.097 (-.005) 26 ------------ 67.621 (+.124) 67.745 ( +.035) 67.780 ( -.015) 

27 ------------ 68.683 ( +.007) 68.690 ( +.006) 68.696 ( -.006) 28 ------------ 67.022 (-.003) 67.019 (-.010) 67.009 ( +.003) 29 ------------ 67.017 (+.085) 67.102 ( +.071) 67.173 ( +.032) 
Station 

30 ------------ 31 

32 

33 

34 

35 

37 

38 

41 

47 

Station 

1 ------------ 2 

3 

4 

5 

6 

7 

8 

9 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

37 

38 

41 

47 

Station 

1 ------------ 2 

3 

4 

5 

6 

7 

8 

9 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

COOLING AND VESICULATION OF ALAE LA VA LAKE, HAWAII 

TABLE 6.-Altitude of stations on the lake surface-Continued 

May 12, 1964 

66.470 

68.000 

67.666 

67.488 

67.337 

67.919 

68.900 

68.641 

65.864 

67.435 

July 31, 1964 

2567.377 

67.128 

66.322 

66.969 

67.756 

67.133 

66.969 

68.761 

67.204 

64.932 

67.986 

67.466 

67.699 

67.346 

67.035 

67.503 

65.803 

2568.09 assumed 

68.414 

67.845 

68.092 

67.765 

68.690 

67.012 

67.205 

66.542 

67.955 

67.661 

67.484 

67.304 

67.871 

69.106 

68.751 

65.832 

67.426 

Nov. 3, 1964 

2567.345 

67.126 

66.347 

67.014 

67.779 

67.107 

66.944 

68.752 

67.169 

64.924 

67.994 

67.453 

67.713 

67.355 

67.027 

67.475 

65.764 

2568.09 assumed 

68.397 

(+.049) 

(-.014) 

(-.008) 

(+.003) 

(-.028) 

(-.012) 

(+.071) 

(+.048) 

(-.005) 

(+.002) 

(-0.014) 

(+.008) 

(+.013) 

(+.035) 

(+.015) 

(.000) 

(-.012) 

( +.001) 

(-.015) 

( +.003) 

(+.007) 

(-.006) 

(+.020) 

(+.026) 

(+.018) 

(-.009) 

(-.022) 

(-.004) 

(-.004) 

(-.025) 

(+.005) 

(-.006) 

(-.007) 

(+.005) 

(-.018) 

(-.019) 

(-.019) 

(+.001) 

(-.023) 

(-.008) 

(+.027) 

(+.009) 

(-.015) 

(-.010) 

(-0.028) 

(-.014) 

(-.017) 

(-.014) 

(-.002) 

( -.001) 

(-.005) 

(-.015) 

(-.035) 

(-.001) 

(+.014) 

(-.015) 

( -.008) 

(-.006) 

(-.010) 

(-.019) 

(-.047) 

(-.002) 

June 9, 1964 

66.519 

67.986 

67.658 

67.491 

67.309 

67.907 

68.971 

68.689 

65.859 

67.437 

Aug. 27, 1964 

2567.363 

67.136 

66.335 

67.004 

67.771 

67.133 

66.957 

68.792 

67.189 

64.935 

67.993 

67.460 

67.719 

67.372 

67.053 

67.494 

65.781 

2568.09 assumed 

68.410 

67.841 

68.067 

67.770 

68.684 

67.005 

67.210 

66.524 

67.936 

67.642 

67.485 

67.281 

67.863 

69.133 

68.760 

65.817 

67.416 

Jan. 21, 1965 

2567.317 

67.112 

66.330 

67.000 

67.777 

67.106 

66.939 

68.737 

67.134 

64.923 

68.008 

67.438 

67.705 

67.349 

67.017 

67.456 

65.717 

2568.09 assumed 

68.395 

(+.029) 

(-.027) 

(+.004) 

(-.003) 

(-.009) 

(-.015) 

(+.073) 

( +.040) 

(-.014) 

(-.001) 

(-0.010) 

( -.003) 

(-.014) 

(+.009) 

(+.017) 

(-.005) 

(+.004) 

(-.006) 

(-.003) 

(-.008) 

(.000) 

(-.002) 

(-.002) 

(-.009) 

(-.013) 

(-.005) 

(+.002) 

(-.005) 

(-.007) 

(+.006) 

(-.004) 

( +.001) 

(-.014) 

(-.011) 

(-.001) 

(.000) 

( -.001) 

(-.015) 

(-.006) 

(-.032) 

(+.013) 

(+.007) 

(+.004) 

(+.004) 

(-0.070) 

( -.038) 

(-.036) 

( -.025) 

(-.023) 

( -.023) 

(-.016) 

( -.030) 

(-.027) 

(-.004) 

(+.004) 

(-.034) 

( -.022) 

(-.023) 

( -.031) 

( -.031) 

(-.041) 

(+.011) 

July 6, 1964 

66.54/j 

67.959 

67.662 

67.488 

67.300 

67.892 

69.044 

68.729 

65.845 

67.436 

Sept. 24, 1964 

2567.353 

67.133 

66.349 

67.013 

67.788 

67.128 

66.961 

68.756 

67.186 

64.927 

67.993 

67.458 

67.717 

67.363 

67.040 

67.489 

65.783 

2568.09 assumed 

68.405 

67.834 

68.073 

67.766 

68.685 

66.991 

67.199 

66.523 

67.936 

67.641 

67.470 

67.275 

67.831 

69.146 

68.767 

65.821 

67.420 

May 11, 1965 

2567.247 

67.074 

66.294 

66.975 

67.754 

67.083 

66.923 

68.707 

67.107 

64.919 

68.012 

67.404 

67.683 

67.326 

66.986 

67.425 

65.676 

2568.09 assumed 

68.406 

27 

( -.006) 

(-.004) 

( -.001) 

(-.004) 

(+.004) 

( -.021) 

(+.062) 

(+.022) 

(-.013) 

(-.010) 

(-0.008) 

( -.007) 

(-.002) 

( +.001) 

(-.009) 

(-.021) 

(-.017) 

( -.004) 

(-.017) 

( -.003) 

( +.001) 

(-.005) 

(-.004) 

( -.008) 

( -.013) 

( -.014) 

(-.019) 

(-.008) 

(-.012) 

( -.029) 

(-.004) 

(-.004) 

( +.001) 

(+.004) 

( -.002) 

(-.021) 

(-.012) 

(+.002) 

(-.011) 

( -.005) 

(-.007) 

(-.002) 

( -.014) 

( -0.003) 

(+.004) 

(-.002) 

(+.005) 

0 

(-.005) 

(+.002) 

0 

( +.001) 

(+.Ol5) 

(+.013) 

( +.013) 

0 

(-.003) 

(-.011) 

(+.002) 
28 

Station 

24 ------------ 25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

37 

38 

41 

47 

Station 

1 ------------ 2 

3 

4 

5 

6 

7 

8 

9 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

37 

38 

41 

47 

Nov. 3, 1964 

67.822 

68.044 

67.762 

68.681 

66.992 

67.203 

66.521 

67.915 

67.629 

67.472 

67.264 

67.826 

69.139 

68.765 

65.807 

Aug. 19, 1965 

SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

TABLE 6.-Altitudes of stations on the lake surface-Continued 

Jan. 21, 1965 

(-.015) 67.807 (-.028) 

(-.023) 68.021 ( -.022) 

(.000) 67.762 (-.014) 

( -.013) 68.668 (-.027) 

(-.030) 66.962 (-.059) 

( -.016) 67.187 (-.038) 

(-.022) 66.499 (-.028) 

( -.018) 67.897 0 

(-.030) 67.599 (-.016) 

(-.028) 67.444 (-.047) 

( -.031) 67.233 (-.031) 

(-.030) 67.796 (-.039) 

(-.016) 65.791 ( +.013) 

------------ - - - -- ---- -------------- ------------ -----

May 27, 1966 

May 11,1965 

67.779 

67.999 

67.748 

68.641 

66.903 

67.149 

66.471 

67.897 

67.583 

67.397 

67.202 

67.757 

65.804 

- - - - -~~ 

Aug. 31, 1967 

----- -·-------------------~~-------------------------------------------- -

2567.244 

67.078 

66.292 

66.980 

67.754 

67.078 

66.925 

68.707 

67.108 

67.419 

67.696 

67.339 

66.986 

67.422 

65.665 

2568.09 assumed 

68.408 

67.774 

67.994 

67.754 

68.648 

66.902 

67.151 

66.473 

67.901 

67.593 

67.402 

67.204 

67.779 

( +0.049) 

(+.011) 

(+.007) 

(+.032) 

(+.015) 

(+.019) 

( -.038) 

( -.041) 

(+.036) 

( +.029) 

(+.031) 

(+.020) 

(+.003) 

(+.021) 

(+.001) 

(-.024) 

(-.009) 

( +.022) 

(+.002) 

(+.029) 

( +.022) 

(+.031) 

( +.019) 

(+.060) 

(+.017) 

( +.077) 

2567.293 

67.089 

66.299 

67.786 

67.093 

66.943 

68.669 

67.067 

65.059 

67.849 

67.455 

67.725 

67.370 

67.006 

67.425 

65.686 

2568.09 assumed 

68.409 

67.750 

67.985 

67.777 

68.650 

66.931 

67.173 

66.514 

67.920 

67.653 

67.419 

67.279 

(-0.017) 2567.276 

(-.077) 67.002 

(-.108) 66.191 

66.918 

(-.082) 67.704 

(-.042) 67.051 

(-.037) 66.906 

(-.048) 68.621 

(-.029) 67.038 

(+.003) 65.062 

0 2567.849 assumed 

(-.013) 67.442 

(-.078) 67.647 

(-.068) 67.302 

( -.067) 66.939 

(-.043) 67.382 

( -.037) 65.649 

(-.043) 68.047 

(-.014) 68.395 

(-.043) 67.708 

(-.033) 67.952 

(-.044) 67.733 

( -.032) 68.618 

(-.034) 66.897 

(-.094) 67.079 

(-.065) 66.449 

(-.027) 67.893 

(-.009) 67.644 

(-.106) 67.313 

(-.033) 67.246 

(-.005) 

( -.005) 

(+.006) 

( +.007) 

(-.001) 

(+.002) 

( +.002) 

(+.004) 

(+.010) 

( +.005) 

(+.002) 

(+.022) 

Cumulative changes in altitude of five representative stations on the lake are shown (fig. 23) as a function 

of time in days after the eruption. The stations include 

three (18, 23, and 35) within 30 m of the edge of the 

lake, one (29) about halfway between the center and 

edge, and one (15) near the center. Uplift of the station 

closest to the edge of the lake, 23, if it ever occurred, 

must have preceded the beginning of the survey. For 

the two other stations near the edge, subsidence followed uplift 200-300 days after the eruption. The two 

remaining stations 8how a pattern of changing altitude 

with time that was typical of almost all stations over 

the thick central part of the lake. During the second 

and third weeks after the eruption, station 15 subsided 

markedly, as did most of the few central stations surveyed. Thereafter, the stations were uplifted at a rate 

that decreased over the next several months to a nearly 

constant value. Shortly before the maximum uplift was 

reached, the rate of uplift increased to a high value for 

a month before quickly dropping to zero and to negative values. 

The greatest cumulative uplift of the five stations 

was not at the stations near the center of the lake, but 

instead at station 29, part way between the center and 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HA WAil 

A B 

September 24 and 26 to December 4, 1963 December 4, 1963 to February 7 and 10, 1964 

c D 

·0 

.!-2 

February 7 and 10 to April 13,1964 April 13 to June 9, 1964 

E F 

-'-2 ·0 -'-1 

·0 _:_1 · 1 ·O 

-'-2 ·1 ·0 ...:. 1 

-'-1 ·0 ·0 ·O -'-1 ...:. 1 

·O 

0 ·0 -=-1 

-'- 1 -'-1 -=- 1 

.:._2 .:...1 

.:...2 -=-1 

June 9 to July 31 , 1964 July 31 to September 24, 1964 

0 50 100 METERS 

Contour interval 0.04 em/day 

FIGURE 2~! -Rate of change in altitude of the surface of Alae lava lake during solidification of the lake from 

September 24-26, 1963, to September 24, 1964. Values shown in centimeters per day x 102 . Shaded areas were 

uplifted during the leveling interval. A , September 24 and 26 to December 4, 1963. B, December 4, 1963, to 

February 7 and 10, 1964. C, February 7 and 10 to April13, 1964. D, April13 to June 9, 1964. E, June 9 to July 31, 

1964. F, July 31 to September 24, 1964. 

29 
30 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

._!_ 0.3 r-----.---r---.--r---.--r---.----, 

w 

~ ~ w 

0 

(j)U) 

mer: 

::JW 

U)f- 0.1 ow 

z2 

<{Z 

.:+:. 

fu. 

-' - 0.1 L_ _ __L,-_ _L_ _ __j~--L,---.L._ _ ___L __ _,_, __ 

~ 0 100 200 300 400 500 600 700 800 

TIME, IN DAYS, AFTER AUGUST 22, 1963 

FIGURE 23.-Cumulative changes in altitude of five stations on the 

lake after September 24-26, 1963, as a function of time in days 

after August 22, 1963. Location of stations plotted in figure L 

Stations 18, 23, and 35 are within 30 m of the edge of the Jake; 

station 29 is about 75 m from the edge ; and station 15 is near the 

center and deepest part of the lake. 

edge of the lake. A similar relationship for other stations on the lake is shown in figure 24, on which is 

plotted the total cumulative uplift (later subsidence 

not subtracted) for the period September 24-26, 1963, 

to September 24, 1964, of all 29 main stations on the 

grid. The figure shows two areas of maximum uplift 

part way between the center and the eastern and western margins of the lake. 

CHANGES IN HORIZONTA L DISTA NCE 

D U RI NG SOLIDIFICATION 

During the year that the lake solidified, distances 

A 

September to December 1963 

0 50 

Contour i nterva I 

0 50 100 METERS 

Contour interval 5 centimeters 

FIGURE 24.-Total uplift of the lake surface after September 

24-25, 1963. 

between stations on the surface of the lake also 

changed in a consistent manner. The first measurements of the distances were on August 30, and September 3 and 11, 1963. When the distances were remeasured on December 4 and 17, 1963, the crust of the 

central part and north edge of the lake had expanded, 

and that of most of the lake margin had contracted, as 

shown in figure 25A . The greatest change was an expansion of 32±1.8 em between stations 3 and 4. When 

the distances were remeasured on July 27, 1964, similar but much smaller changes were found (fig. 25B). An 

B 

0 · - 5 

0 0 .I 

December 1963 to July 27, 1964 

100 METERS 

10 centimeters 

FIGURE 25.-Changes in horizontal distance between stations on the surface of Alae lava Jake during solidification 

of the lake. A, Changes 1.5 em and greater between September and December 1963. B, Changes greater than 

0.6 em between December 1963 and late July 1964. Areas that underwent expansion are more heavily shaded. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 31 

Contour interval 0 .005 em/day 

September 24, 1964 to January 21, 1965 

·0 

Contour interval 0.001 em/day 

May 27, 1966 to August 31, 1967 

A 

c 

0 50 

Contour interval 0.005 em/day 

January 21 to August 19, 1965 

Axes of trough of maximum subsidence 

100 METERS 

B 

D 

FIGURE 26.-Rate of subsidence of the lake surface after complete solidification in late September 1964. Values in 

centimeters per day x 103 . A , September 24, 1964 to January 21, 1965. B, January 21 to August 19, 1965. C, May 

27, 1966 to August 31, 1967. D, Approximate positions of the axis of the belt of maximum subsidence between 

September 1964 and August 1965 and the point of maximum subsidence between May 1966 and August 1967. 

Areas that underwent subsidence of more than 0.005 em/day are shaded. 

area of expansion in the central part of the lake was 

surrounded by a ring of contraction, which in turn was 

bordered on the north by a marginal area of expansion. 

The greatest increase was 2.7±0.6 em between stations 

3 and 4, and stations 7 and 26. The greatest decrease 

was 5.2±0.6 em between stations 9 and 23. 

CHANGES IN ALTITUDE DURING FURTHER COOLING 

After the last interstitial melt in the lake solidified 

in late September 1964, the altitude of the surface continued to change. The entire surface of the lake subsided, falling an average of 0.006 em/day between September 1964 and January 1965, 0.004 em/day between 

January and August 1965, and 0.003 em/day between 

May 1966 and September 1967 (table 6). 3 The rate of 

subsidence was not constant over the lake. From September 1964 to January 1965 and from January to August 1965, subsidence was greatest in a belt part way 

between the center and the edge of the lake (fig. 26A 

and B). This belt migrated inward approximately 15m 

between the successive surveys (fig. 26D). Presumedly, 

the survey in May 1966, if it had been successful, 

would have disclosed a similar ring of maximum subsidence closer to the center ofthe lake. During the final 

leveling period (fig. 26C), the contours of equal subsid-

' The pattern and rate of subsidence between August 1965 and May 1966 is not known 

becau~e the lake ~urface and base stations were shifted during an earthquake shortly before 

the survey of May 1966. 
32 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

ence form a rude bullseye pattern having the 

maximum subsidence over the deepest part of the lake 

near station 3. 

INTERPRETATION OF CHANGES IN ALTITUDE 

SUBSIDENCE OF THE LAKE SURFACE AND CALCULATION 

OF THE COEFFICIENT OF THERMAL EXPANSION 

The processes causing subsidence of the surface after 

the lava lake had solidified will be discussed before 

taking up the more complex subject of altitude changes 

before complete solidification. Because fewer processes 

are involved-we can exclude lateral flowage of fluid 

lava and changes of bulk density upon crystallization 

and vesiculation-the interpretation is less ambiguous. 

Subsidence of the surface after solidification of the 

lake is attributed to thermal contraction of the cooling 

basalt. The thermal contraction also caused the opening of joint cracks (Peck and Minakami, 1968; Peck and 

Kinoshita, 1976). However, as prehistoric Kilauean 

flows and lava lakes exposed in section show joints that 

are mostly or entirely vertical or nearly vertical rather 

than horizontal, the altitude of the Alae lake surface 

probably was affected little, if any, by jointing. As will 

be shown later, microfracturing of the basalt very 

probably took place during cooling, resulting in a decrease of both subsidence and thermal conductivity. 

The effective bulk coefficient of thermal expansion of 

the Alae basalt can be calculated by comparing the 

changes in average temperature of the lake (measured 

in drill holes penetrating the base) with the change in 

altitude of stations near the collars of the holes. The 

mean coefficient of linear thermal expansion (aL) is 

given by the following formula (Skinner, 1966, p. 94): 

1 (6.£) 

L (AT) 

For the lava lake, L equals the thickness of the lake, AL 

equals the change in thickness (that is, the change in 

relative altitude of the surface) for a given interval of 

time, and AT equals the change in average temperature 

during the same interval of time. 

Relevant data are available for two surveying intervals at the main drilling site (DH12) and for one interval at station 4, above the deepest part of the lake. 

Drill hole 12, which was equidistant from stations 6 

and 26, pierced the base of the lake at a probable depth 

of 13.3±0.2 m (see table 4). Station 4 was 3.6 m east of 

drill hole 9, which penetrated 1,840 lava below the lake 

at a probable depth of14.9±0.1 m. Changes in altitude 

and temperature at the two sites and the calculated 

linear coefficient of expansion are listed below. 

Date, drill hole, and 

Average change Change in Coeflicient of 

in te~t(;~ature thermal expansion 

survey stations altitude (em) (X 106/"C) 

January 21 to 

August 19, 1965 

DH9 and Sta. 4 __ ____ -170 -0.61 2.4 

DH12 and Sta. 

6 and 26 ______ ____ -155 - .55 2.7 

May 27, 1966 to 

August 31, 1967 

DH12 and Sta. 6 and 26 ______ ____ -295 -1.28 3.3 

Taking into consideration the possible errors in determining changes in altitude, the effective bulk coefficient of linear thermal expansion is thus 3± 1 x 10-s; 

°C. 4 This value is approximately one-half the values 

reported from measurements on similar rocks in the 

laboratory. Skinner (1966, p. 94) gives an average 

value of5.4 x 10-s;oc for 10 laboratory determinations 

o~ the coefficient of linear thermal expansion of basalt, 

diabase, and gabbro. Richter and Simmons (1974, table 

2) give a measured value of18.8 x 10-6 ;oC and a calculated value of 19.0 x 10- 6 ;oC for the coefficient of volume thermal expansion of the chemically and 

mineralogically similar Frederick diabase; these values are equivalent to a coefficient of linear thermal 

expansion of 6.3 x 10-6 ;oC. 

The difference between the value of the coefficient of 

thermal expansion determined in situ for Alae basalt 

and those determined in the laboratory on similar but 

coarser grained, more slowly cooled rocks can probably 

be attributed to the formation of microfractures across 

grains and along grain boundaries during cooling of 

the basalt as the result of stresses induced by differential thermal contraction of the constituent mineral 

grains. This conclusion is supported by the experimental work of Richter and Simmons (1974), which showed 

that high heating rates and heating to high temperatures (>350°C) induce microfracturing that reduces 

the observed thermal expansion and results in a permanent lengthening of the samples. The two diabase 

samples studied by them lengthened 0.5 to 1.5 x 10- 3 , 

after repeated heating to temperatures of 550-660°C. 

Assuming that microfracturing reduced the effective 

bulk coefficient of linear thermal expansion in Alae 

lava lake by 50 percent, as indicated by comparison of 

the field and laboratory data, the expansion of the lake 

(actually, decreased subsidence) inferred to have taken 

place because of microfracturing during cooling from 

980oC to 20oc was 3 x 10- 3 , the same order of mag-

'Thermal modeling of temperatures within and below the lake (p. 45-47 ) suggests that 

changes in altitude caused by cooling and thermal contraction of the Jake from January to 

August 1965 may have been reduced by about 10 percent because of heating and thermal 

expansiOn of lava beneath the lake. In contrast, changes in altitude from May 1966 to 

August ~967 may have been increased by about 10 percent because of cooling and thermal 

contractiOn of th~ und~rlying lava. Taking this effect into consideration would bring the 

calcula~ed coefficients for the two periods into better agreement with the average va lue of 

3 X 10 °1°C, 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 33 

nitude as the strains measured in the laboratory. 

The presence of relatively abundant microfractures 

in Alae basalt was inferred independently from theresults of thermal conductivity measurements on samples from Alae lava lake and other Hawaiian lava 

flows. As reported by Robertson and Peck (1974) and 

discussed on p. 43 of this report, the effective conductivity of the samples studied was found to be 40 percent 

less than the measured or calculated inherent conductivity. On the basis of studies by Walsh and Decker 

(1966), the disparity was ascribed to microfractures, 

which were thought to form 0.5 percent or less of the 

solid portion of the samples. If the difference between 

the observed bulk coefficient of thermal expansion in 

Alae lava lake and the coefficient measured on similar 

rocks in the laboratory was caused entirely by microfracturing of Alae basalt, then microfracture porosity 

of the basalt was 0.3 percent. 

When the calculated value of 3 X 10-6 rc is used for 

the coefficient of linear thermal expansion, the contour 

maps of rates of subsidence can be used to estimate 

average rates of change of temperature in the lake 

below the surveying stations. The plot of figure 27 was 

prepared in this manner from figure 26B, and shows 

the estimated daily average decrease in temperature 

from January to August 1965. Excluding the cold margin of the lake, the calculated cooling rates during this 

period ranged from average values of about 0.7°C/day 

in the central part of the lake to a maximum of 2.7°C/ 

day below station 1, 30m from the north margin. Cool0 50 100 METERS 

Contour interval 0.5 degrees centigrade 

FIGURE 27.-Estimated daily average decrease in temperature 

in degrees centigrade in the lake from January to August 

1965, as determined from measured rates of subsidence during that period (fig. 26B) and the observed bulk coefficient of 

linear thermal expansion of 3 x 10-6 ;oc. The sites of drill 

holes 9 and 12 are marked. 

ing rates were highest in a ring (or annular volume) 

underlying the belt of maximum subsidence shown in 

figure 26B. This ring migrated inward as the lake 

cooled from September 1964 to August 1965, as shown 

by the relative positions of the axes of maximum subsidence in figure 26D. Temperatures in the lake decreased sharply across the ring. Midway in the 

January to August 1965 interval, for example, the 

maximum temperature in drill hole 12, 60 m inside the 

ring was 760°C, whereas the maximum in drill hole 5, 

30 m outside the ring was only 95°C. The average cooling rate of 0. 7°C/day for the central part of the lake 

inferred by the subsidence rates is approximately the 

same as the value for this period of0.9°C/day computed 

from the one-dimensional thermal model illustrated in 

figure 39. Because inferred cooling rates greatly exceeded this value in the ring of maximum subsidence 

and because the ring moved inward towards the lake in 

successive surveying periods, the ring is interpreted to 

be that part of the lake that was undergoing rapid cooling. Numerical analysis using two-dimensional models 

(p. 4 7) does not indicate the existence of such a zone 

of maximum cooling part way between the center and 

margin of the lake. Presumedly, the observed belt reflects some cooling process that was not incorporated in 

the model-possibly convective heat transfer by circulating rainwater in the cooler margin of the lake. 

CHANGES IN ALTITlJDE OF THE SURFACE Dl'RI~G 

SOLIDIFICATION OF THE LAKE 

The most striking and consistent aspect of the contour maps showing rate of change of altitude during 

solidification of the lake (fig. 22) is the presence during 

each bimonthly period from September 1963 to September 1964 of a central area that had undergone uplift bordered by a marginal ring that had subsided. 

Subsidence of the entire lake surface after complete 

solidification suggests that before complete solidification the marginal ring of subsidence overlay the solidified outer part of the lake and that some process 

going on in the central lens of molten lava caused uplift 

of the over lying surface. This hypothesis can be tested 

by comparing temperatures in drill holes with rates of 

uplift and subsidence at the collars of the holes. Figure 

28 shows rates of uplift and subsidence at stations on 

the lake compared with maximum temperatures in 

nearby drill holes. Each maximum temperature plotted is at the midpoint between the times of the corresponding level measurements. The temperatures were 

determined from plots of maximum temperature versus time (fig. 14); the plots were based on measurements in drill holes at the main drilling site and also in 

drill holes 5, 6, and 9. The plot in figure 28 shows that 

uplift took place only over that part of the lake that 
34 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

0.08 

(/) 

a: 

~>-0.06 1-UJ<( 

!:!:~o 

-li=a:oo4 a.ZUJ . ::JUJO. (.) 

~ 0.02 

600 400 

MAXIMUM TEMPERATURE, IN DEGREES CENTIGRADE 

AT MIDPOINT IN LEVELING INTERVAL 

FIGURE 28.-Rates of uplift and subsidence of stations on the 

lake compared with maximum temperatures in the lake in 

nearby drill holes. Maximum temperatures are at the midpoints between times of level measurements. Width and 

length of bars indicate the uncertainty of the data. 

had maximum temperatures of 1,000°±20°C or more, a 

value approximately the same as the solidus temperature of the basalt (980°C) determined from petrographic study of drill core from the lake. Uplift, therefore, took place not only over the fluid core of the lake 

(T> 1,065°C) but also over the relatively rigid, but 

partly molten part still undergoing crystallization 

(1,065°C>T>980°). Subsidence was limited to the completely crystallized but still cooling margin. The line 

between uplift and subsidence corresponded to the 

outer margin of the 1,000° isothermal envelope, and 

the level measurements can be used to follow in detail 

the shrinkage of the lens of fluid and partly molten 

basalt as discussed on p. 39 and shown in figure 32. 

Changes with time in the rate of uplift of stations 

above the thick central part of the lake during solidification (figs. 22 and 23) were analyzed by comparing the 

rate of change of uplift at the main drilling site with 

rates of uplift calculated on the assumption that uplift 

was caused by vesiculation of the lava during solidification. The calculations, which are discussed below, 

show that the observed uplift can largely but not entirely be duplicated on the basis of this assumption. 

The observed rates of uplift and subsidence at the 

main drilling site (DH1, 2, 3, 4, 7, 8, and 12) from 

August 30, 1963, to September 24, 1964, are shown as 

circles joined by solid line segments in figure 29. Rates 

are based on the average uplift and subsidence of stations 6 and 26, which span the site, and were plotted at 

the midpoint of each surveying interval. Points joined 

by dashed line segments show calculated rates of uplift 

for the same time intervals based on measured temperatures in the drill holes and computed temperatures 

2 ~ 

\ (/) \ a: UJ \ 

1- \ UJ \ ~>- \ -l<( \ ~0 \ ~a: ~ zUl \ -a. \ ~--~ 

L.L 

_J 

a. 

::J 

DAYS AFTER AUGUST 22, 1963 

FIGURE 29.-0bserved and calculated rates of uplift and subsidence at the main drilling site from August 30, 1963, to 

September 24, 1964. Circles joined by solid lines are observed rates, plotted at the midpoints of the surveying 

intervals. Dots joined by dashed lines are calculated rates, 

as described in the text, p. 34, 35. 

from a numerical model for a lake 4 7 feet (14.3 m) thick 

with a latent heat of 80 cal/g and a variable diffusivity, 

as discussed on p. 45. For each surveying interval, the 

uplift (ilL) caused by formation of new crust was calculated by subtracting the subsidence due to crystallization of the new crust from the uplift caused by simultaneous vesiculation. In analogy with the relationship 

between linear and volume thermal expansion (Dane, 

1941, p. 29) the net uplift was taken to be one-third the 

net expansion during solidification. In order to simplify 

the calculations, subsidence caused by thermal contraction of cooling crust and fluid lava was neglected 

(the effect is approximately an order of magnitude less 

than the observed rates of uplift), and crystallization 

and vesiculation were assumed to take place at 

1,065°C. The calculations are based on the following 

factors: the observed increase in thickness of the upper 

crust (il.Du) during each leveling period (fig. 11); the 

computed increase in thickness of the lower crust 

(il.DL); the porosity (cf>u and cf>L) of solidified lava at 

those depths (table 5), as calculated from the measured 

bulk density of drill core; the density of 2. 79 glee for 

fluid lava in the lake (pm)), as calculated from leveling 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 35 

and other data (p. 35-37); and the grain density (pg) of 

crystallized Alae basalt at 980°C, as calculated from 

the grain density at room temperature (3.01 glee) and 

the observed bulk coefficient of thermal expansion 

(p. 32). Expansion caused by vesiculation is proportional to the volume of vesicles and hence the porosity 

of newly formed crust, and equals cf>il!J. Contraction 

caused by crystallization is proportional to the difference between the density of fluid lava and the grain 

density of crystalline basalt, and equals 

( PmP.- Pg) ilD. 

g 

The formulation is as follows: 

AL = Va[il!Jucf>u+il!JLcf>L + (il!Ju+il!JL)(Pm ~Pt )] 

Figure 29 shows a good correlation between observed 

and calculated rates from October 1963 (50 days) to 

July 1964 (300 days), indicating that uplift can indeed 

be attributed to vesiculation during solidification of 

new crust. The observed and calculated rates of uplift 

fell from an initial value of 1 mm/day at 50 days to a 

rather constant 0.5 mm/day after 100 days because of a 

progressive decrease in the vesicularity of new upper 

crust formed at greater depth and a decrease in the 

rate of solidification. The rates remained relatively 

constant until about 275 days when the margin of the 

lens of fluid lava passed beneath the site causing a 

short burst of rapid uplift. The rate thereafter rapidly 

decreased to zero as the entire lake beneath the site 

cooled to below the solidus. The divergence between 

calculated and observed rates of uplift at 275 days 

probably results from the simplifying assumption that 

all crystallization and vesiculation took place at 

1,065°C. The divergence during the first month after 

the eruption shows that uplift from vesiculation at the 

site during this period was offset by another processvery probably by lateral flowage of lava. Between August 30 and September 11, subsidence was measured at 

all but two of the nine stations measured (fig. 21A), and 

the pattern of uplift and subsidence suggests continued 

drainback of lava toward the vent. The changes measured between September 11 and 26 (fig. 21B), form a 

more complex pattern and may record not only uplift 

due to solidification of vesicular crust and changes due 

to lateral flowage, but also structural warping caused 

by horizontal expansion of the crust. Because of the 

correlation in time between a late stage, high rate of 

uplift at a site and the passage of the outer margin of 

the lens of fluid lava beneath the site, the leveling data 

of the full grid of stations can be used to determine the 

approximate outline of the lens of fluid lava during 

each successive leveling period. This approach was 

used in constructing figure 31, which is presented later 

in this report. The results are not as accurate as the 

outline of the 1,000° isothermal envelope (fig. 32), because the date of zero uplift at each station can be 

determined more accurately than the date of maximum 

uplift. 

If uplift at each station of the lake was caused solely 

by expansion of fluid lava upon solidification, as 

suggested for the main drilling site after late September 1963 by the preceding analysis, then the ratio 

of lake thickness to total uplift at each station should 

be the same. Indeed, the total uplift at most stations 

after late September 1963 (fig. 24) was 1.4±0.2 percent 

of the lake thickness. Exceptions include the stations 

near the lake margin, all of which had smaller proportionate uplifts or even net subsidence. Some of these 

stations overlay parts of the lake that had largely or 

completely solidified by the date of the first complete 

survey. For other stations, uplift was diminished by 

seepage of the underlying lava toward the vent and 

central parts of the lake during the first several leveling periods. Several stations nearer the center of the 

lake (8, 13, and 29) have proportionate uplifts substantially higher than average (1. 7-1.8 percent), and station 7 had proportionately less (1.0 percent). Stations 

with greater than average uplift are in broad areas 

part way between the center of the lake and the eastern and western margins. Inspection of plots of 

cumulative uplift for each station, such as that for station 29 in figure 23, reveals that the higher or lower 

than average uplift at these stations took place between September 1963 and February 1964. The greater 

than average uplift may have been caused by the seepage of lava from the lake margins into the fluid core 

beneath the stations. However, another possible explanation for the differences in total uplift is suggested 

by the measured lateral expansion of the crust over the 

central part of the lake between September 1963 and 

July 1964 (fig. 25). The outward thrust of the central 

crust may have caused flexure of the crust between the 

expanding center of the lake and the solidified margin, 

forming anticlinal ridges and troughs. After April 

1964, the greater thickness of crust over the central 

part of the lake and the greater width of solidified margin may have formed a container of solid basalt sufficiently rigid to prevent continued outward thrusting 

and the resulting warping. 

CALCULATION OF THE DENSITY 

OF FLUID LAVA IN THE LAKE 

Assuming that the average uplift of the surface 

above the lake after late September 1963 was caused 

solely by expansion of fluid lava during solidification, 

that is, that positive and negative variations in the 

uplift due to structural warping and lateral flow cancel 
36 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

(/) 

a: 

UJ 

1-

UJ 

~ 

~ 

I 

1-

a.. 

UJ 

0 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 30.-Temperature profiles on September 25, 1963, and August 19, 1965, and a section through the lake on September 25 

1963. The 1963 profile was prepared from temperature measure~ 

ments in drill hole 1 on September 24 and 26, 1963 (solid line), 

extrapolated to the base of the lake (dashed line) by computations 

based on thermal modeling. The 1965 profile was measured in drill 

hole 9. 

out, the density of fluid lava in the lake in late September 1963 can be estimated from the measured 

changes in altitude of the surface during solidification. 

On September 25, 1963, the central part of the lake 

(using average values for all main stations on the grid 

except those very close to the margin-11, 23, 31, 32, 

and 34) consisted of2.2 m of crust, 9.4 m of molten lava 

of average temperature, 1,130°C, and 1.8 m of crust at 

the bottom of the lake. These figures are derived from 

the contour map of figure 1 and temperature profiles in 

drill hole 1 on September 24 and 26, 1963 (table 3), 

extrapolated to the base of the lake by computations 

based on thermal modeling similar to that illustrated 

in figure 39. The measured and extrapolated temperature profile is shown in figure 30, together with a profile in drill hole 9 on August 19, 1965, that was also 

used in the calculation. 

The calculations are based on the constancy of mass 

ofthe original lava and the derived solidified basalt. As 

mass equals density times volume, we can write the 

following equation: 

(1) 

where p equals density, V equals volume, and subscripts f and s stand for fluid lava and solidified basalt. 

The density of the solidified basalt, Ps, is known from 

measurements of drill core. The volume ratio, V8 /Vr, 

can be calculated from the measured uplift of the lake 

surface and the average depth of the lake as determined by photogrammetry and vertical-angle surveys. 

In order to adjust for the effects of thermal contraction, 

temperature measurements in drill holes can be used 

to reduce the rock density measured at room temperature to its value at the solidus (980°C) and to increase 

the observed uplift by the calculated thermal contraction of the lake during the period involved. In the calculations, we envisage a vertical segment of unit width 

through the lake that is representative of the central 

part of the lake. 

The average density at 25°C of basalt solidified from 

the molten lava present on September 25, 1963-that 

is, basalt at depths in the lake between 2.2 m and 

11.9 m-is 2.665 glee (table 5). The density at 980°C 

can be calculated using the coefficient of volume thermal expansion determined by the lake studies; av 

equals 3aL (Dane, 1941, p. 29), and thus equals 9 x 

10 -s;oc. The formulation is derived from the constancy 

of mass as follows: 

P9so 

P2s V2s 

V25 (1 +av~T) 

P2s 

1+av~T 

(2) 

where ~T equals the change in temperature from 25° to 

980°C. 

The ratio V8 !Vr (eq 1) of unit volumes of solidified 

basalt and fluid lava can be calculated from the change 

in thickness of the lake during solidification. In the 

lake, solidifying lava expanded in all three dimensions, 

as shown by changes in horizontal distance between 

stations on the lake surface (see section on ~~changes in 

Horizontal Distance during Solidification"). Accordingly, the ratio of volumes, V8 /Vr, is equal to the cube of 

the ratio of thicknesses, Ls!Lr, of solidified and fluid 

lava. The formulation is as follows: 

where Lr equals 9.4 m, the average thickness of fluid 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 37 

lava in the lake in late September, 1963; Uu equals 

0.14 75, the average recorded uplift of24 stations on the 

lake; and Uc equals 0.0233, the calculated decrease in 

altitude during this period caused by thermal contraction of the unit segment of solidified basalt and fluid 

lava. This decrease was calculated using the coefficient 

of linear thermal expansion (3 x 10-6) and includes the 

following elements: 0.0018 m subsidence due to thermal contraction of 9.4 m of fluid lava as it cooled from 

1,130oC to 1,065°C; 0.0161 m subsidence from thermal 

contraction as it continued to cool from 1,065°C to the 

average value of 495°C on August 19, 1965; 0.0039 m of 

subsidence due to thermal contraction of the original 

2.2 m of upper crust as it cooled an average of 590oC 

during this period; and 0.0015 m of subsidence due to 

the inferred 280°C of cooling of the original 1.8 m of 

lower crust. 

When these values are used, the ratio V8 1Vr is 

1.0555, and the calculated density of fluid lava is 

2.79±0.03 glee. A fairly large uncertainty is indicated 

because of possible errors in several of the figures used 

in the calculation. The measured average density may 

be greater than the true density because of relatively 

poor core recovery from more vesicular layers in the 

crust. The measured average cumulative uplift may 

include an unknown contribution from structural 

warping or lateral flow. The value for the average 

depth of the lake may differ from the true value by as 

much as 0.3 m because of errors in the vertical angle 

measurements from the rim of the crater. The value of 

2.79 glee reported here is 0.01 glee greater than the 

value reported earlier (Peck, 1969) from preliminary 

calculations. 

The calculated value for the density of fluid lava can 

be compared with values for the density of basaltic 

melt derived from the measured densities of basaltic 

glass or calculated from a chemical analysis of the 

glass. Fluid lava at 1,130°C in Alae lava lake contained 

an estimated 15 percent crystals, consisting of 11 percent olivine and pyroxene and 4 percent plagioclase 

(Wright and Peck, 1978). The content of gas bubbles 

is not known but is inferred to be :Y2 of 1 percent or less. 

Degassing of the initially oversaturated lava had 

largely finished by late September 1963 (p. 21-23 and 

figure 19). Vesiculation caused by crystallization over 

the temperature interval1,140° to 1,130°C should have 

yielded no more than % of 1 percent gas bubbles, if 

vesiculation was proportional to crystallization, as illustrated in figure 20. As the mass of fluid lava (mr) 

equals the mass of the melt fraction (mm) plus crystals 

(me) and gas bubbles (mg ), the density of the melt fraction (Pm) can be calculated from the densities of fluid 

lava (Pt), crystals (pc), and gas bubbles (pg) from the 

following relationship: 

mr=mm+mc+mg 

ptVr = PmVm +pcVc+PgVg 

Pm = PrVr-pcVc-pgVg 

Vm 

When one considers a unit volume of fluid lava, the 

volumes of melt, crystals, and gas bubbles (V m, Vc, and 

Vg) reduce to decimal proportions. The density of the 

exsolved gas is essentially zero, so that the term Pg Vg 

can be dropped (the content of gas bubbles enters the 

calculations by reducing the decimal proportion of 

melt). The densities of the crystals at 1,130°C are 3.2 

glee for olivine and pyroxene and 2.65 glee for plagioclase, judging from their densities at room temperature 

as determined by mineral separations (Wright and 

Peck, 1978) and published coefficients of volumetric 

thermal expansion (Skinner, 1966, p. 87). When one 

assumes a zero content of gas bubbles, the calculated 

density of the melt fraction is 2.74 glee. With % of 1 

percent gas bubbles the calculated density of melt is 

2. 76 glee. The measured density at room temperature 

of glass separated from two samples of pumice formed 

during the Alae eruption at 1,140°C and 1,160°C is 2.76 

glee (Wright and Peck, 1978). Vesicle-and crystal-free 

glass from differentiated melt collected at a temperature of 1,100°C from drill hole 69--i in Makaopuhi 

lava lake has a density at room temperature of 2.78 

glee. (T. L. Wright and N. L. Hickling, oral commun., 

1975). If these are reduced to the values at 1,130°C 

using the coefficient of volumetric thermal expansion 

of 9 x 10 -sloC, the densities of the melt fraction are 

2.73 and 2.75 glee; these densities are in good agreement with the density of the melt fraction calculated 

on the assumption that the proportion of exsolved gas 

is negligible. The density of glass from Alae pumice 

can also be calculated from a chemical analysis of the 

pumice using the method of Bottinga and Weill (1970), 

in which density is calculated from the partial molar 

volumes of the oxide components. Molar volumes at 

1,130°C were determined by linear extrapolations of 

the values listed for greater temperatures (1,250-

1,6000C, in Bottinga and Weill, 1970, table 5 and 

p. 175--176). The density for the melt at 1,130°C calculated by this method is 2. 704 glee, about 1 percent less 

than the values derived from the density measurements in the laboratory or calculated from the lavalake data. 

THE PATTERN OF COOLING IN 

THREE DIMENSIONS 

Some aspects of the three-dimensional pattern of solidification and further cooling of Alae lava lake were 

revealed by repeated temperature measurements in 

drill holes in different parts of the lake and by repeated 
38 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

0 50 100 METERS 

Contours in days after August 22, 1963 

FIGURE 31.-Approximate position of the outer margins of the 1,080°C isothermal surface in the lake as a 

function of time in days after August 22, 1963. The date when the margin passed beneath drill holes 3, 4, and 

8 (marked by a dot in fig. 31) was calculated by extrapolation of a plot of maximum temperatures versus time 

(fig. 14), and the position of the margin was estimated elsewhere by determining the time interval during 

which each surveying station underwent a late-stage, high-rate of uplift (fig. 23 and table 6). 

surveys of the altitude of the grid of stations on the 

lake surface. In the following section, the position with 

time of the outer margin of the 1,080°C isothermal surface (approximately the fluid-crust interface) and the 

1,000° isothermal surface (approximately the solidus) 

are shown in plan and those of the 1,000°C and 700°C 

surfaces are shown in cross section. The measured and 

inferred positions of the isothermal surfaces agree 

closely with the positions computed on the basis of 

two-dimensional numerical models, which are illustrated in figure 40. 

The approximate position in plan of the outer margin 

of the 1,080°C isothermal surface is shown as a function of days after August 22, 1963, in figure 31; the 

position is based on sparse temperature data from drill 

holes and on the surveying interval or intervals when 

each surveying station underwent a late stage, high 

rate of uplift. As discussed on p. 35, this phase of uplift 

at a station records the migration through the lake 

beneath the station of the outer margin of the lens of 

fluid lava and reflects the high rate of crystallization 

and vesiculation between 1,080°C and 1,050°C. Figure 

31 clearly shows the effect on the rate of solidification 

of the thinning of the lake over preeruption ridges beneath the north and southeast parts of the lake, as well 

as the rather rapid solidification of the lens of fluid lava 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HAWAII 39 

0 50 METERS 

Values at drill sites (solid dots) and on 

contours are in days after August 22, 1963 

FIGURE 32.-0uter margins of the l,Ooooc isothermal surface (approximately the solidus) in Alae lava lake as 

a function of days after August 22, 1963. The maximum lateral extent of the surface on different dates is 

based on precise level measurements of stations on the surface of the lake (fig. 22 and table 6) and on 

temperature measurements in drill holes (solid dots) that penetrated to the depths of the maximum temperature at the time of complete solidification. 

after 250 days. The outer margin of the 1,080°C 

isothermal surface after 300 days outlines fairly 

closely that part of the lake that was 14m or more 

thick. 

The position of the 1,000°C isothermal surface, approximately the solidus, is shown in plan and longitudinal section in figures 32 and 33. The location of the 

surface was determined from interpolation and extrapolation of temperature data from drill holes 5, 6, 8, 

9, and 12 and from the time at which each surveying 

station started to subside. The change from uplift to 

subsidence at a station reflected the completion of crystallization and vesiculation in the lake beneath that 

station (p. 33, 34 and fig. 28). Figure 32 shows, as does 

figure 31, the effect ofprelake highs beneath the north 

and southeast parts of the lake and the rapid completion of crystallization during the final 100 days. The 

position of the 1,000°C isothermal surface is known 

more precisely than the 1,080°C surface because more 

temperature data are available and because the time of 

the beginning of subsidence at each station can be accurately determined by plotting rates of change in altitude versus time for each station and interpolating 

the intersection with the zero rate axis. Figure 33 

shows the position of the isothermal surface in sections, the lower with the vertical scale equal to the 

horizontal scale and the upper with a 10 x -vertical 

exaggeration. In the lower part of the lake, the position 
40 

FEET METERS 

2580 

785 

z 

0 

i= 

<( 

a: 2560 UJ 780 (.!) 

(.!) 

<( 

X 

UJ 

X 

0 

w' 775 0 2540 :::J 

!:: 

1-

_I 

<( 

770 

2520 

SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

9 

II 

II 

II 

1 and 12 

7 and~ I 

r, ii \c ~~ 120 II II II II 

\~ !! =~:~= !! !!!: !t;)!i 1 \\\ r-- ~ II II II I II I 

\ 1 'r ..- i1 300 II I 11 

\\ \ II II II I I I I 

\\\1\ II 360 II II // II / )1/ \\'\. ~II II / /lv//9 1\\\ "'-. ·~ II ...-// // /1J// / \ \ '\. -..... II II ..-..- / / -1( / 

\\ "" ........ _jj.-- /-/...- - / \ '\. '-... '- ....._____ II ----- II ---..-...- ...-.....- II/ \ " ............................... _ ------- ____ -tr______ __--tt--::::::-------- ~-/t 

'-.. "-::._-......_ .._ ----- Jt------==--=-----tr' ..----- ----- II 

......_ --::::--- ------...+r- --- ----tr ..--- II ........... ____ ----:::----___.... -====------ --~--- ---- -... ___ ...--1!- ----- II 

------- ..Jt------ II -- -II II ____ ....____ __ 

~ 2600{800 ~~~~~~~~~~~~~3~60~~~~2~4~~~~~~1:2~0~~~;?~~ ~ 2500 

750 

0 50 100 METERS 

Values in days after August 22, 1963 

FIGURE 33.-Longitudinal cross section of Alae lava lake showing the positions of the l,Ooooc isothermal surface as a function of days after August 22, 1963. Isotherms dashed were extrapolated. Upper section, lOx vertical exaggeration; lower 

section, horizontal and vertical scales are equal. Numbered vertical lines are projected drill holes. 

of the isothermal surface (dashed) is largely inferred. 

Near the end of crystallization, the lens of partly molten lava is at a depth 60 percent of the distance from 

the upper surface and within the thickest part of the 

lake. Figures 32 and 33 show that final crystallization 

took place more rapidly in the thinner southeastern 

part of the lake than in the thicker, spatter-covered 

northwestern part; the figures are in good agreement 

with the computed position of the l,Ooooc isotherm in a 

generalized radial section of the lake after 300 days 

(fig. 40). 

altitude of stations on the lake surface are of little help 

in determining its location. The only relevant data 

from the altitude surveys is the position of the axis of 

maximum subsidence after solidification of the lake; 

the position puts an outer bound on the margin of the 

surface during two surveying periods. As in figure 33, 

the section shows the effect of lake thickness on the 

position of the isotherms-the last part to cool to 700°C 

was in the thickest part of the lake and at a depth 75 

percent of the lake thickness below the surface. Computed positions of the 700° isotherm at 300 and 600 

The depth of the 700°C isothermal surface in both days (fig. 40) are in close agreement. 

the upper and lower parts of the lake (fig. 34) is known 

from several drill holes in both the marginal (DH5 and 

6) and central (DHl, 3, 4, 7, 8, 9, and 12) parts of the 

lake. The position through time of the outer margin, 

however, is rather poorly known at distances from drill 

holes, because the data from repeated surveys of the 

THERMAL PROPERTIES OF ALAE BASALT 

Several thermal properties of Alae basalt were measured in the laboratory or were calculated from laboratory data on the constituent minerals. 
COOLING AND VESICULATION OF ALAE LA VA LAKE, HAWAII 41 

w 

Q 

::> 

1-

i= 

....J 

<( 

NORTHWEST 

FEET METERS 

2580 

780 

2550 

775 

2520 

700° C ISOTHERM 

0 50 100 METERS 

Values in days after August 22, 1963 

FIGURE 34.-Longitudinal cross section of Alae lava lake showing the position of the 700°C isothermal surface as a function 

of days after August 22, 1963 (lOx vertical exaggeration). Isotherms dashed were extrapolated. The position was determined from temperature profiles in drill holes, which are shown projected into the line of section as numbered vertical 

dashed lines. 

The thermal conductivity at ambient temperatures 

of Alae basalt can be determined from the graphs and 

formulation of Robertson and Peck (1974, figs. 7 and 8, 

eq 12), derived from detailed conductivity measurements at 35°C of vesicular basalt from Hawaii. The 61 

samples studied included 4 from the crust of Alae lava 

lake (Robertson and Peck, 1974 or 1969, nos. 613, 618, 

619, and 620). Conductivity was found to vary with 

porosity, olivine content, and the nature of the pore 

fluid (air or water). The conductivity of basalt samples 

which have the same pore fluid and similar olivine contents varies inversely with porosity, forming a linear 

plot against (1 - porosity)2. The conductivity (K) in air 

of Alae basalts can be calculated from the following 

equation (Robertson and Peck, 1974, eq 12, p. 4884): 

v'K = a + b ( yv'Ks + cf>YKa) 

where a and b are experimentally determined constants, y = solidity (that is, 1 - porosity), cp = porosity, 

K8 = conductivity of fully solid basalt, and Ka = conductivity of air. When one uses the experimentally determined values of 6.1 x 10-3 cal!cm sec ac for K 8 , 

0.063 x 10-3 cal!cm sec ac for Ka, 0.2 for a, and 0. 7 for 

b, the equation reduces to: 

K = (1.929-1.554cf>)2. 

The conductivity of Alae and other Hawaiian basalts 

which have 0--5 percent olivine, as calculated from this 

equation, is shown as a function of porosity in figure 

35. Alae basalt with 11 percent porosity, which forms 

the bulk of the lake, has a conductivity of 3.09 x 10-3 

cal/cm sec ac, but the conductivity values for more vesicular basalt decrease to 1. 71 x 10-3 cal!cm sec ac for 

the basalt with 40 percent porosity that forms the thin 

surficial crust of the lake. 

An appreciable increase in conductivity with temperature for solidified, vesicular Alae basalt is shown 

by laboratory measurements reported in this section 

and also by the results of thermal modeling discussed 

later (p. 45--4 7). This variation differs from that of previously published laboratory studies on the variation 

with temperature of the conductivity of basalt, apparently because of the effect of abundant vesicles. As 

summarized by Nafe and Drake (1968) and Robertson 
42 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

0.8 0.6 0.4 0.2 0 

POROSITY 

FIGURE 35.-Thermal conductivity at 35°C of air-saturated Alae 

basalt. Curve calculated using the formulation and experimentally 

determined constants of Robertson and Peck (1974, p. 4884), as 

discussed in the text. 

(unpub. data, 1976), most laboratory measurements of 

the variation with temperature of the conductivity of 

basalt indicate that conductivity values do not vary 

greatly with increasing temperature, although on the 

average they show a slight increase. Apparently the 

decrease in conductivity with increasing temperature 

of pyroxene and olivine is approximately counterbalanced by the increase in conductivity of plagioclase 

(Birch and Clark, 1940). Murase and McBirney (1973), 

however, found that the conductivities of Columbia 

River basalt and alkali olivine basalt from the 

Galapagos decrease about 50 percent from room temperature to 1,100°C. At greater temperatures conductivities increased sharply because of increased photon 

conductivity (Murase and McBirney, 1973, p. 3584). 

The studies summarized above were made on samples which have little or no porosity. In order to determine the effects of abundant vesicles on the variation 

of conductivity with temperature, Kaoru Kawada of 

the Earthquake Research Institute, Tokyo University, 

kindly measured the conductivity of four samples from 

Alae crater (written commun., 1966). Two of the samples (A-5-1 and A-11-1) were coarsely vesicular drill 

core from near the surface of the 1963 lava lake, one 

sample (DPH-28) was a coarsely vesicular hand sample from an open joint crack near the main drilling site, 

and the fourth sample (AM-51) was a finely vesicular 

hand sample from the petrographically similar prehistoric Alae lava lake, collected on the cliff face of the 

mezzanine 9.8 m below the surface of the lake. Conductivities were measured on cylindrical samples 2.5 em 

in diameter and 5.0 em in length in a furnace under 

controlled temperature. The temperature was increased in small increments by means of a heating 

filament inserted in a 0.25 em diameter hole along the 

axis of each sample, and temperatures were recorded 

by thermocouples in two 0.18 em diameter holes drilled 

0.3 and 1.2 em from the axis, half the length of each 

sample parallel to the axis and in the same plane. The 

experimental apparatus and techniques are described 

by Kawada (1966). 

The results are listed in table 7 and are plotted in 

figure 36 as ratios of the measured conductivities at 

high temperatures to the conductivities at room temperature. For three of the samples, conductivities increased nearly linearly with increasing temperature to 

the highest temperatures at which conductivities were 

measured (673°-950°C). The greatest rate of increase of 

conductivity with temperature, 0.09 percentrC, was 

shown by the highly vesicular samples A-5-1 and 

A-11-1, which had bulk porosities of28 and 25 percent 

respectively. A smaller increase, 0.03 percentfOC, was 

shown by the denser sample AM-51, which had a 

porosity of 7 percent. The fourth sample, DPH-28, 

which had a porosity of 24 percent, showed a nearly 

TABLE 7 .-Thermal conductivity of four samples of basalt from Alae crater as a function of temperature 

[Data from K. Kawada (written commun., 1966] 

A-5-P A-11-12 AM-51" DPH-284 

Temperature Conductivity Temperature Conductivity Temperature (~~?c~~~~i:c, Temperature Conductivity CCl (cal/cm sec °C) CCl (cal/cm sec eel (°Ci (°C) (cal/cm sec °C) 

28 ---------------- 1.19 X 10-3 46 2.21 X 10-3 32 2.07 X 10-3 40 2.86 X 10-3 

70 ---------------- 1.27 X 10-3 94 2.36 X 10-3 54 2.06 X 10-3 74 2.77 X 10-3 

73 ---------------- 1.23 X 10-3 194 2.53 X 10-3 62 2.05 X 10-3 149 2.70 X 10-3 

128 ---------------- 1.28 X 10-3 430 3.01 X 10-3 123 1.99 X 10-3 185 2.36 X 10-3 

139 ---------------- 1.27 X 10-3 551 3.27 X 10-3 274 2.17 X 10-3 268 2.23 X 10-3 

216 ---------------- 1.52 X 10-3 699 3.64 X 10-3 363 2.24 X 10-3 313 2.40 X 10-~ 

306 ---------------- 1.66 X 10-3 804 3.83 X 10-3 450 2.33 X 10-3 370 2.21 X 10-3 

433 ---------------- 1.70 X 10-3 946 4.03 X 10-3 451 2.25 X 10-3 495 2.11 X 10-3 

527 ---------------- 1.72 X 10-3 ---------- 528 2.27 X 10-3 ---------- 653 ---------------- 1.93 X 10-3 ---------- 673 2.49 X 10-3 ---------- 722 ---------------- 2.00 X 10-3 ---------- ---------- ---------- 839 ---------------- 2.12 X 10-3 ---------- ---------- ---------- 950 ---------------- 2.24 X 10-3 ---------- ---------- ----------

1

Drill core collected at a depth of0--0.1 min drill hole 5 in the 1963 Alae lava lake. Measured bulk density, 2.16 g/cm3 . Calculated porosity, 0.28. 2

Drill core collected at a depth of0--0.15 min drill hole 11 in the 1963 Alae lava lake. Measured bulk density, 2.25 g/cm3 . Calculated porosity, 0.25. 3

Hand sample collected from the cliff face of the prehistoric lava lake 16m below the mezzanine of Alae crater. Measured bulk density, 2.80 g/cm3 . Calculated porosity, 0.07. 4

Hand sample collected from an open joint crack in the 1963 Alae lava lake near drill hole 1. Measured bulk density, 2.28 g/cm3 • Calculated porosity, 0.24. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 43 

_j 

<((I) 

~w 

a: i= 1.5 W- I> 

1-i= 

u..U 

O::J 

Q~ 1.0 

1-Q 

<t:u 

a: 

200 400 600 800 1000 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 36.-The ratio of conductivity at high temperature to conductivity at room temperature of four samples of basalt from Alae 

crater. Data from K. Kawada (written commun., 1966). Samples 

A-5-l (circles), A-11-1 (dots), and DPH-28 (hexagons) are from 

the August 1963 lava lake; sample AM-51 (squares) was collected 

from a prehistoric lake exposed in the wall of the crater. The 

dashed line indicates ratios calculated on the basis of an increase 

in conductivity of 0.06 percentfDC, as deduced from thermal modeling (p. 45). 

linear decrease in conductivity, 0.05 percentrC, to 

495°C, the highest temperature measured. Kawada 

suggested that the decrease in conductivity of this 

sample may record the temperature effect for dense, 

nonporous basalt. Although the sample was highly vesicular, the vesicles were large compared with the 

sample size, and none may have been situated along 

the axial plane containing the heating element and 

sensing thermocouples. Low porosity in the axial plane 

is suggested by the relatively high conductivity of 2.86 

x 10-3 cal/cm sec oc measured at room temperature. A 

disparity between bulk porosity of the samples and the 

porosity in the axial planes is also suggested for two 

other samples, A-5-1 and AM-51, by a comparison of 

the relatively low conductivities measured at room 

temperature in these experiments with the measurements of Robertson and Peck (1974) and the resulting 

formulation on page 41. The marked increase in conductivity with temperature of three of the samples was 

confirmed by H. R. Shaw (written commun., 1975) by 

laboratory mea~urements of the diffusivity of vesicular 

basalt from Makaopuhi laval lake as a function of 

temperature, but is in contrast with the small changes 

with temperature found by other workers on nonporous 

samples. The difference may be due to radiative heat 

transfer across the vesicles, convective heat transfer by 

gases in the vesicles, or progressive closing of microfractures as the result of thermal expansion of the 

samples during heating. 

In situ thermal conductivity in the Alae lava lake 

may have been greater at higher temperatures because 

of the effect of an additional process, a decrease in conductivity with falling temperature in the cooling lava 

caused by successive formation of microfractures resulting from thermally induced stresses. The presence 

of relatively abundant (0.3 percent) microfractures in 

the crust of the lake is suggested by the disparity between the measured bulk coefficient of thermal expansion in the lake and coefficients determined in the laboratory on basalt and diabase of similar composition 

(p. 32, 33). Microfractures across grains and along 

grain boundaries are also evident in thin sections 

under the microscope. The effect of microfractures on 

rock conductivity has been demonstrated in the laboratory by measurements of conductivity with increasing 

pressure (Walsh and Decker, 1966) and was suggested 

as a possible factor in the conductivity of vesicular 

Hawaiian basalt by Naoyuki Fujii and George C. Kennedy (oral commun., 1974) after a review of the conductivity data. Robertson and Peck (1974) found that the 

intrinsic conductivity of nonporous basalt, as measured 

on finely crushed samples or calculated from mineral 

conductivities and the mode, was 40 percent greater 

than the effective conductivity determined from laboratory measurements on discs. They suggested that the 

difference was due to microvesicles and microfractures 

formed during initial cooling of the parent lava. 

The thermal modeling of the temperature data in 

Alae lava lake described in the section ~~Thermal Modeling" also indicates that the conductivity of solidified 

basalt in the lake increased with temperature. Theresults do not define the form of the relationship or the 

relative importance of radiative heat transfer, convective heat transfer, or microfracturing. The results do 

indicate that conductivity (K) at a given temperature 

(T, in °C) can be related approximately to the conductivity at room temperature (KRT) for temperatures less 

than 1,000°C by the linear relationship K x 

KRr(1+0.000{3T), where f3 equals 0.0006±0.0001. Values calculated by this function are represented by the 

dashed line in figure 36. The conductivity of Alae 

basalt at temperatures of more than l,Ooooc is not 

known. Thermal modeling using greatly different values for the conductivity of solid and molten basalt resulted in very small differences in temperatures, less 

than the accuracy of the field measurements. Laboratory studies by Murase and McBirney (1973) suggest 

that the conductivity of basalt at temperatures between the solidus and the liquidus is less than the conductivity at lower temperatures. 

The heat capacity of Alae basalt at six temperatures 

from 300° to 1,400°K was calculated by R. A. Robie 

(written commun., 1964) using the modal mineral 

composition (p. 3) and experimentally determined 

values of the specific heats of the minerals later published by Robie and Waldbaum (1968). The results are 
44 SOLIDIFICATION OF ALAE LA VA LAKE, HA WAil 

TABLE B.-Specific heats of minerals and calculated heat capacity of Alae basalt 

[Data from R. A. Robie (written commun., 19641] 

Temperature Specific heat cal!go Heat OK capacity 

Fayalite Fosterite Diopside Albite Anorthite Magnetite Ilmenite Basalt 

300 -------------------------- 0.1564 0.2011 0.1742 0.1876 0.1789 0.1569 0.1572 0.1783 

500 -------------------------- .1890 .2535 .2331 .2389 .2319 .1890 .1854 .2318 

800 -------------------------- .2108 .2822 .2617 .2688 .2614 .2610 .2017 .2608 

1000 -------------------------- .2218 .2949 .2731 .2826 .2747 .2072 .2092 .2724 

1200 -------------------------- .2320 .3060 .2825 .3029 .2864 .2072 .2165 .2849 

1400 -------------------~~----- .2418 .3165 .2911 .3066 .2974 .2072 .2223 .2927 

tabulated in table 8. Values range from 0.1783 cal/g oc 

at 300°K to 0.2927 cal/g oc at 1,400°K. A smooth curve 

for heat capacity (c) as a function of temperature (fig. 

37) was constructed on the basis of the calculated heat 

capacities and fitted to the following function of temperature (T in Kelvins) by R. A. Robie (written commun., 1975): 

c = 0.2356 + 4.3635 X 10 -sT - 6.3440 X 103 

T2 

Thermal diffusivity in the cooling Alae lava lake undoubtedly varied with time and depth. Diffusivity (D) 

is related to conductivity (K), density (p), and heat 

capacity (c) by the following relationship: 

D = K/pc 

Conductivity varies with vesicularity as well as tem-

(J)(J) 

!:!:!::J 

a:-

0~ ...Jw 

<((.) 

Uw 

zw 

-a: 

'(.9 

>-w !::o 

(.)~ 

~<( <(a: 

(.)(!) 

1-CI: 

<(W 

wo.. 

I 

0.30 r-----.,..----.,..----...,...----.-----.---~ 

0.28 

0.26 

0.24 

0.22 

0.20 

0.18 

200 400 600 800 1000 1200 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 37.-Calculated heat capacity of Alae basalt as a function of 

temperature. 

perature, as discussed above, and hence with depth in 

the lake and probably with time at a given depth during solidification. The same is true of density. Both the 

heat capacity and conductivity vary with temperature, 

hence they vary also with time and depth. Increased 

conductivity with decreased porosity and increased 

temperature, however, is at least partly offset by the 

increased density of less porous basalt and the increased heat capacity at greater temperature. Changes 

in diffusivity of solidified basalt with time and depth in 

the lava lake are illustrated in figure 38; the figure 

shows computed diffusivities for solidified basalt on 2 

days during solidification (Sept. 6 and Dec. 30, 1963) 

and 3 days thereafter. Diffusivity values were computed using a numerical formulation (p. 45-4 7) for a 

lake 49 feet (14.9 m) thick having a latent heat of 80 

cal/g, a conductivity that increased 0.06 percentfOC and 

varied with porosity as described on page 41, a variable 

heat capacity described on pages 43, 44 and a density 

structure in the lake as tabulated in table 5. A lowconductivity vesicular cell at shallow depth was not 

included. Calculated diffusivities increased downward 

in the upper 3-5 m of the crust because of the increase 

in density and temperature with depth. On December 

30, 1963, for example, the calculated diffusivity increased from 0.0049 cm2/sec at 0.15 m depth to 0.0064 

cm2/sec at a depth of 3.8 m. The average diffusivity of 

the upper crust (average of values at 0.3 m intervals) 

increased from 0.0055 cm2/sec on September 6, 1963, to 

0.0058 on September 3, 1964. The computed average 

diffusivity of the lake after complete crystallization in 

late September 1964 decreased from a maximum value 

of 0.0060 cm2/sec on December 8, 1964, to 0.0058 cm2/ 

sec in August 1965 and May 1966, but thereafter increased to 0.0060 on August 31, 1967, as temperatures 

continued to fall. 

The latent heat of Alae basalt can be deduced from 

numerical analysis of the thermal data (p. 45, Peck and 

others, 1977), and can also be calculated using estimated and experimentally determined heats of fusion 

of the component minerals. Unfortunately, the reliability of the calculated value is limited because of uncertainty in the values of heats of fusion of the major 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 45 

0.------------,------------.-----------, 

·-·-·\- I 

2 

4 

C/) 6 a: 

UJ 

1-

UJ 

~ 

~ 

I. 8 

1-

a.. 

UJ 

0 

10 

12 

-.:·· ... l. Sept 6 ..... ..... \ . -.. -_.--, 7 963 

.......... '\..... -------

\'1 ............... 

I '-

\ '",, <l 

'\ \o ',tQ(' 

'\

(.1)(\ J:> ''Vlo I c;P C:: \ • ..... 

\ . . \& ~ \"$ ~ \~ ,'-? \~- \ 

~ \ ~ I _,. -..I I 

'<D \$ 

I 

\ 

I 

\ 

I 

\ 

I 

\ 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I I 

\ 

\ 

\ 

I 

I 

I 

I 

I 

I 

I 

I 

pyroxene, and plagioclase, and the retention of nearly 

7 percent silicic glassy residuum at the end of crystallization. The calculated values are in good agreement 

with the value of 80± 10 cal/g deduced from numerical 

analysis of the temperature data (p. 45). 

THERMAL MODELING 

Temperature profiles in Alae lava lake were 

analyzed (Peck, Hamilton, and Shaw, 1977) using 

the one- and two-dimensional computer programs for 

cooling lava lakes devised by Shaw, Hamilton, and 

Peck (1977). The effort was an extension of a preliminary analysis conducted with J. C. Jaeger (written 

commun., 1967) that was summarized by Peck (1974). 

Computed temperature profiles were compared with 

representative profiles measured in the central part of 

the lake on 12 separate days from September 6, 1963, 

to August 31, 1967. The effect of rainfall on temperatures in the lake was computed by withdrawing 620 

calories from the 100°C isotherm for each centimeter of 

measured rainfall. The latent heat was distributed in 

three temperature intervals in accordance with modal 

data on crystal abundance within partly molten lava 

near the base of the crust-that is, 30 percent from 

1,140° to 1,080°C, 41 percent from 1,080° to 1,050°C, 

and 29 percent from 1,050° to 980°C. The upper surface 

was held at 70°C for the first 5 months and at 40°C 

thereafter, and temperatures in the lake were reduced 

by conductive cooling to a surface at a temperature of 

4 

I 

5 6 

DIFFUSIVITY, IN SQUARE CENTIMETERS 

PER SECOND X 103 

20°C at a depth 100 feet (30.5 m) below the bottom of 

7 the lake. A cell length of 1 foot (0.3 m) and a time 

interval of 3.237 x 104 seconds 0.385 day) were 

selected for the computations. 

FIGURE 38.-Calculated diffusivity of solidified Alae basalt 

(<1,000°C) as a function of depth and time. Curves are based on 

computed values at 0.3 m intervals, as described in the text. 

constituents augite and labradorite. Calculations were 

made using the modal data on page 3 and the normative composition of the 6.75 percent residual silicic 

glass (Wright and Weiblan, 1968). Values for heats of 

fusion were taken from Robie and Waldbaum (1968) 

and Bradley (1962), and were supplemented by a value 

of 22.4 kcal/gfwt for augite Wo. 4En. 4 Fs. 2 estimated 

by D. R. Wones (written commun., 1964, 1975) and two 

rather different estimates for anorthite-29.4 kcal/ 

gfwt (Wones) and 18.7 kcal/gfwt (Yoder, 1975). When 

these values are used, the calculated latent heat of 

completely (100 percent) crystalline Alae basalt would 

be 94 cal/g or 85 cal/g, depending on the value used for 

anorthite. The calculated latent heat that would be released during crystallization in the lake, however, is 

substantially less, 77 or 67 cal/g, because of the crystallization prior to the eruption of 13 percent olivine, 

During the initial runs using one-dimensional models, thermal and physical properties of basalt in the 

lake were assumed to be constant, and a lake thickness 

of 48 feet (14.6 m) was chosen to simulate the deeper, 

central part of the lake. Ten measured profiles during 

the first 2 years of cooling were reproduced with average deviations of 20°C using a constant diffusivity of 

0.006 cm2/sec and a latent heat of 90 cal/g. A better 

match, particularly of temperature profiles in the 

upper crust during initial cooling and at the base of the 

lake after complete solidification, was obtained using 

numerical models incorporating variable thermal and 

physical properties, as well as slightly different values 

for lake thickness and latent heat. The following modifications were made to the initial model. 

1. A variable diffusivity was included by assigning values for density and conductivity at 

room temperature to each 1-foot (0.3 m) cell 

in the lake; this density was based on the 

measured density (table 5) and the relationship between conductivity and porosity de-
46 SOLIDIFICATION OF ALAE LA VA LAKE, HAW All 

5 

(/) 

a: 

w 

1-

w 

~ 

z 10 

£ 

1-

a.. 

w 

Cl 

20 

300 600 900 1200 

TEMPERATURE, IN DEGREES CENTIGRADE 

FIGURE 39.-Computed (solid) and observed (symbols) temperature profiles in Alae lava lake. Temperature data are marked in table 3 

and the dates indicated in figure 10. The dates for the profiles and the drill holes in which the temperatures were measured are as 

follows: 0, Sept. 6, 1963, DH 1; 1, Nov. 5 and 8, 1963, DH 3; 2, Dec. 30, 1963, DH 4; 3, Mar. 24, 1964, DH 4; 4, July 2, 1964, DH 8; 5, 

Sept. 3, 1964, DH 8; 6, Dec. 8, 1964, DH 9; 7, Jan. 21, 1965, DH 9; 8, Mar. 2, 1965, DH 9; 9, Aug. 19, 1965, DH 9; 10, May 27, 1966, 

DH 12; 11, Aug. 31, 1967, DH 12. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 47 

scribed on p. 41. Heat capacity, conductivity, 

and diffusivity were calculated for each cell 

by an iterative process, using the relationship between heat capacity and temperature 

given on page 43, and a linear increase of 

0.06 percentfCC of conductivity with increasing temperature. 

2. Heat loss by rainfall was computed using the 

measured density structure of the lake. 

3. The lake thickness was increased to 49 feet 

(14.9 m), a better approximation of the 

deepest part of the lake near drill hole 9, and 

the latent heat for the basalt was decreased 

accordingly to 80 cal/g. 

4. Low-conductivity and density values were assigned to one of the cells to simulate the 

highly vesicular and cavernous zone found at 

shallow depth in the lake. 

The computed profiles for a lake 49 feet (14.9 m) thick 

and measured profiles in Alae lava lake are shown in 

figure 39. The measured profiles are based on temperatures measured at depth intervals of 0.3 m or less for 

the first four profiles and 0.9 m or less for the last eight. 

Temperatures read from smoothed plots of the profiles 

are shown by symbols at 0.3 intervals on the figure, 

and the dates of the profiles are indicated in figure 10. 

The last two profiles (10 and 11), which were measured 

in drill hole 12 on May 27, 1966, and August 31, 1967, 

are not strictly comparable with the computed profiles 

or with the other measured profiles. The lake was an 

estimated 1% m shallower at this site, and the upper 

part of the hole was heated by gases rising along a 

fracture intersected in the drilling. However, this was 

the only drill hole open through the lake during the 

last 2 years. Using the numerical model described 

above and illustrated in figure 39, average deviations 

(at 0.3 m intervals) between computed and measured 

temperatures for the 10 representative profiles during 

the first 2 years are less than 2°C. Measured temperatures for the first three profiles are matched with average deviations of one-hal:FC. Measured and computed 

maximum temperatures after solidification (profiles 6 

to 9) and basal contact temperatures for profiles 7 to 9 

are matched within 2°C. The computed contact temperature for profile 6 is 27oC less than observed; this 

difference may reflect errors in the measurement of the 

values for depths or temperatures near the base of the 

lake for that profile. The poorest match of computed 

and measured temperatures is for profile 4, for which 

computed temperatures on the average are 55°C greater than observed. The profile was measured in drill 

hole 8 only 2 weeks after the hole was drilled, and 

temperatures in the upper part of the hole were probably still strongly depressed because of the coolant 

water used in the drilling. Computed and measured 

temperatures August 31, 1967 (profile 11), 4 years 

after formation of the lake, agree with an average deviation of 0.5°C, and the computed and measured 

temperatures (at the base of the lake) differ by only 

1 °C. The value of the observed maximum of 86°C 

suggests that the lake cooled to less than 1 oooc several 

months before the date of the measurement. In the 

computer model the lake cooled to 100°C in mid-April 

1967, 4% months before the final temperature measurements. Computed temperatures in the lake using a 

((no-rain" model are as much as 366°C greater than 

observed on August 31, 1967, and the lake takes a total 

of 19.5 years to cool to 100°C. 

Cooling at the margins of Alae lava lake was 

analyzed using a two-dimensional numerical model 

formulated by Shaw, Hamilton, and Peck (1977). The 

results are presented by Peck, Hamilton, and Shaw 

(1977) and summarized below. A generalized radial 

section of the southern quarter of the lake was divided 

into cells 15m long and 1.5 m thick (Shaw and others, 

1977, fig. 6), and the model cooled in 150 time steps 

of 8.318 x 105 sec (9.63 days) duration. A constant 

value of diffusivity of 0.006 cm2/sec and a latent heat of 

80 cal/g were used in the calculations, and heat loss 

from rain was taken into account using a constant 

value for the average density of the lake. The results 

are illustrated in figure 9 of Peck, Hamilton, and Shaw 

(1977), which shows the positions of several isotherms 

(including the 1,080°, 1,000°, and 700°) after 300 days, 

and in figure 40, which shows the positions of the 

1,000° isotherm after 120, 240, and 360 days. The computed temperature distribution in cross section, which 

is in close agreement with temperatures measured in 

drill holes and inferred from level surveys (figs 31-34), 

indicates that temperatures in the central part of the 

lake were not influenced by cooling at the margins. 

Throughout the first year, temperatures in the computer model were decreased more than 1 oc only in the 

outer 15 m of the lake, and in the fourth year only in 

the outer 45 m. The variation of90 days in the dates of 

complete solidification in the central part of the lake 

(figs. 32 and 33) can be attributed to lateral variations 

of about 2 m in the depth of the lake. Heat transfer to 

the margins, however, may have been a more significant factor in the cooling of Alae lava lake than in the 

model because of factors that were not incorporated in 

the model. This conclusion is suggested by the existence of a belt of maximum subsidence in the lake detected by repeated level surveys during the first year 

after solidification (fig. 26). The belt, which presumedly 

represents the part of the lake undergoing the most 

rapid cooling and thermal contraction, does not manifest itself in the two-dimension thermal model. Possi- ~ 
48 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

120 

240 (f'J 

a: 

w 

Iw 

~ 

] _____ _j 

0 30 METERS I I 

Contours in days after August 22, 1963 

FIGURE 40.-Computed position of the 1,ooooc isotherm in a 

generalized radial section of Alae lava lake after 120, 240, 

and 360 days. Computations based on a two-dimensional 

model having a latent heat of 80 cal/g and a constant diffusivity of 0.006 cm2 /sec. Solid boundary shows the margins 

of the lake in a generalized section based on measured surface profiles and the topographic map of the crater (fig. 1 ). 

Dashed boundary shows the margin of cells in the simplified 

model used in the numerical calculations (Shaw and others, 

1977, fig. 6B). 

bly, cooling in the lake itself was accelerated because of 

shallow circulation in the margin of the lake of water, 

less than 100°C, derived from rain that fell on the lake 

margin, bordering talus, and crater walls. 

CONCLUSIONS 

The 15-m-thick Alae lava lake solidified in 10¥2 

months and cooled to less than 100°C 3 years later. 

Study of the lake, combined with study of Makaopuhi 

lava lake (Wright and others, 1968; Wright and 

Okamura, 1977) and Kilauea Iki lava lake (Richter 

and Moore, 1966) provide a unique body of data on the 

cooling and crystallization of Kilauean tholeiite. Alae 

was the smallest of the three lakes, cooled in the least 

time, and showed the simplest pattern of solidification 

and cooling. Major conclusions of this study are as follows: 

1. Solidification of Alae lava lake took place by the 

slow increase in thickness of upper and lower 

crusts with time (fig. 10). Growth of the upper 

crust during the first 3 months was linear with 

respect to the square root of time; the thickness 

(in meters) was equal to 0.00132\/t- 0.18, where 

t equals time in seconds after the eruption. 

2. Crystallization of tholeiitic basalt in the lake took 

3. 

place over a temperature interval of 160°C from 

the emplacement temperature of 1,140°C to the 

solidus temperature of 980°C. The interface between fluid lava and solid crust was at 1,065°C. 

Measured temperatures at the base of the lake 

were as much as 700±10°C, 60 percent ofthe initial temperature of the lake (table 4). 

The lava vesiculated as it cooled and crystallized 

because of the exsolution of gases, raising the 

upper surface of the lake (fig. 22) and forming 

porous basalt that decreased in porosity (and increased in density) downward from the surface 

(fig. 16, table 5). Initially, gas was exsolved because of supersaturation of the newly erupted 

lava; later vesiculation was caused by crystallization and resulted in minute, angular pores (fig. 

18). Repeated leveling surveys combined with 

temperature measurements in the drill holes 

permit delineation of the approximate outline in 

plan of the lens of fluid lava (fig. 31) and the 

outline in plan and section of the fluid lava and 

partly molten crust (figs. 32, 33). Comparison of 

these figures with computer runs based on twodimensional thermal modeling (fig. 40) indicates 

that solidification rates in the central part of the 

lake were not affected by cooling at the lake 

margin. 

4. The lake continued to cool for 3 years after solidification. Thermal contraction of the cooling basalt 

caused subsidence of the lake surface (fig. 26). 

The bulk linear coefficient of thermal expansion 

(3± 1 x 10-6 fOC) determined by the lake's studies 

is markedly less than values measured in the 

laboratory on similar rocks, presumedly because 

ofmicrofracturing caused by differential thermal 

contraction. 

5. Measured temperatures in the cooling lake can be 

matched within the limits of error of the measurements and of the lateral variability of temperature in the lake by computations based on 

numerical models (fig. 39), indicating that the 

lake cooled largely by conductive heat transfer. 

Vaporization of the abundant rainfall, however, 

strongly affected temperatures in the upper crust 

during solidification and throughout the lake 

thereafter. Near joint cracks, temperatures were 

affected by downward circulation of cool air from 

the upper surface and by upward flow of hot 

gases from the interior of the lake. 

6. Thermal properties of the Alae basalt measured in 

the laboratory or calculated from laboratory data 

are in good agreement with values deduced from 

the thermal modeling. Values for the properties 

are as follows: 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 49 

(a) Conductivity (K, in cal!cm sec °C) increased with 

decreasing porosity (£/>) and with increasing 

temperature (Tin °C), and can be represented by 

the following expression; 

K = (1.929-1.554£/>)2 (1 +0.0006T) 

(b) Heat capacity (c) can be represented by the following function of temperature (T, in Kelvins): 

c = 0.2356+4.3635 X 10-5T - 6.3440 X 103JT2 

(c) Thermal diffusivity varied with time and depth 

in the lake from about 0.005 to 0.006 cm2/sec 

with changing conductivity, density, and heat 

capacity. 

(d) The latent heat for 80 percent crystallization of 

the basalt was 80± 10 cal! g. 

The results of this investigation are pertinent to interpretations of the cooling histories of other basaltic 

lakes and flows, but they should be applied with caution. Such factors as mineralogical composition and 

vesicularity strongly affect thermal properties. Different modes of formation of the lake or flow may result in 

different initial temperature distributions. Temperatures in the upper part of Makaopuhi lava lake, for 

example, were decreased markedly by repeated crustal 

foundering during drain back of lava into the vent at 

the end of the eruption. Separate lakes and flows are 

subjected to different amounts of rainfall. Furthermore, the cooling effect of rain may be markedly less in 

thicker lakes, where a significant fraction of the vaporized rainwater condenses at shallow levels in the 

crust rather than escaping to the atmosphere. 

REFERENCES CITED 

Ault, W. U., Eaton, J. P., and Richter, D. H., 1961, Lava temperatures in the 1959 Kilauea eruption and cooling lake: Geol. Soc. 

America Bull., v. 72, no. 5, p. 791-794. 

Ault, W. U., Richter, D. H., and Stewart, D. B.. 1962, A temperature 

measurement probe into the melt of the Kilauea Iki lava lake in 

Hawaii: Jour. Geophys. Research, v. 67, no. 7, p. 2809-2812. 

Birch, Francis, and Clark, Harry, 1940, The thermal conductivity of 

rocks and its dependence upon temperature and composition: 

Am. Jour. Sci., v. 238, no. 8, p. 529-558, no. 9, p. 613-635. 

Bottinga, Y., and Weill, D. F., 1970, Densities ofliquid silicate systems calculated from partial molar volumes of oxide components: Am. Jour. Sci., v. 269, no. 2, p. 169-182. 

Bradley, R. S., 1962, Thermodynamic calculations on phase equilibria involving fused salts, Part 2, Solid solutions and applications 

to the olivines: Am. Jour. Sci., v. 260, no. 7, p. 550-554. 

Carslaw, H. S., and Jaeger, 1959, Conduction of Heat in Solids: London, Oxford at the Clarendon Press, 510 p. 

Daly, R. A., Manger, G. E., and Clark, S. P., Jr., 1966, Density of 

rocks, in Clark, S P., Jr., ed., Handbook of Physical Constants 

(rev. ed.): Geol. Soc. America Memoir 97, p. 19-26. 

Dane, E. B., Jr., 1941, Density at high pressure; thermal expansion, 

in Birch, Francis, Schairer, J. R., and Spicer, H. C., Handbook of 

Physical Constants: Geol. Soc. America Spec. Paper 36, p. 27-37. 

Decker, R.W., and Peck, D. L., 1967, Infrared radiation from Alae 

lava lake, Hawaii, in Geological Survey research 1967: U. S. 

Geol. Survey Prof. Paper 575-D, p. D169-D175. 

Finlayson, J. B., Barnes, I. L., and Naughton, J. J., 1968, Developments in volcanic gas research in Hawaii, in The crust and upper 

mantle of the Pacific area: Am. Geophys. Union Geophys. Mon. 

12, p. 428-438. 

Kawada, Kaoru, 1966, Studies of the thermal state of the earth. The 

17th Paper: Variation of thermal conductivity of rocks, Part 2: 

Bull. Earthquake Research Inst., Tokyo Univ., v. 44, p. 1-21. 

Murase, Tsutomu, and McBirney, A. R., 1973, Properties of some 

common igneous rocks and their melts at high temperatures: 

Geol. Soc. America Bull., v. 84, p. 3563-3592. 

Nafe, J. E., and Drake, C. L., 1968, Physical properties of rocks of 

basaltic composition, in Hess, H. H., and Poldervaart, Arie, eds.; 

Basalts, v. 2: New York and London, lnterscience Pub., p. 483-

502. 

Peck, D. L., 1969, Density of molten lava in Alae lava lake, Hawaii 

[abs.]: EOS, v. 50, no. 4, p. 339. 

--1974, Thermal properties of basaltic magma; results and practical experience from study of Hawaiian lava lakes-summary, 

in Colp, J. L., and Furumoto, A. S., eds., The Utilization of Volcano Energy: Sandia Laboratories, Albuquerque, p. 287-295. 

Peck, D. L., Hamilton, M. S., and Shaw, H. R., 1977, Numerical 

analysis of lava lake cooling models; Part II, Application to Alae 

lava lake, Hawaii: Am. Jour. Sci., v. 277, p. 415-437. 

Peck, D. L., and Kinoshita, W. T., 1976, The eruption of August 1963 

and the formation of Alae lava lake, Hawaii: U.S. Geol. Survey 

Prof. Paper 935-A, p. Al-A33. 

Peck, D. L., and Minakami, Takeshi, 1968, The formation of columnar joints in the upper part of Kilauean lava lakes, Hawaii: 

Geol. Soc. America Bull., v. 79, no. 9, p. 1151-1165. 

Peck, D. L., Moore, J. G., and Kojima, George, 1964, Temperatures in 

the crust and melt of Alae lava lake, Hawaii, after the August 

1963 eruption of Kilauea volcano-a preliminary report, in 

Geological Survey research 1964: U.S. Geol. Survey Prof. Paper 

501-D, p. D1-D7. 

Peck, D. L., Wright, T. L., and Moore, J. G., 1966, Crystallization of 

tholeiitic basalt in Alae lava lake, Hawaii: Bull. Volcano!., v. 29, 

p. 629-655. 

Rawson, D. E., 1960, Drilling into molten lava in the Kilauea Iki 

volcanic crater, Hawaii: Nature, v. 188, p. 930-931. 

Richter, D. H., and Moore, J. G., 1966, Petrology of the Kilauea Iki 

lava lake, Hawaii: U. S. Geol. Survey Prof. Paper 537-B, 26 p. 

Richter, Dorothy, and Simmons, Gene, 1974, Thermal expansion behavior of igneous rocks: Int. Jour. Rock Mechanics and Mining 

Science, v. 11, p. 403-411. 

Robertson, E. C., and Peck, D. L., 1974, Thermal conductivity of 

vesicular basalt from Hawaii: Jour. Geophys. Research, v. 79, 

no.32, p.4875-4888. 

Robie, R. A., and Waldbaum, D. R., 1968, Thermodynamic properties 

of minerals and related substances at 298.15°K (25.0°C) and one 

atmosphere (1.013 bars) pressure and at higher temperatures: 

U. S. Geol. Survey Bull. 1259, p. 1-256. 

Shaw, H. R., 1969, Rheology of basalt in the melting range: Jour. 

Petrology, v. 10, no. 3, p. 511-535. 

Shaw, H. R., Hamilton, M. S., and Peck, D. L., 1977, Numerical 

analysis of lava lake cooling models; Part I, Description of the 

model: Am. Jour. Sci., v. 277, p. 384-414. 

Shaw, H. R., Wright, T. L., Peck, D. L., and Okamura, R., 1968, The 

viscosity of basaltic magma: An analysis of field measurements 

in Makaopuhi lava lake, Hawaii: Am. Jour. Sci., v. 266, no. 4, 

p. 225-264. 

Skinner, B. J., 1966, Thermal expansion, in Clark, S.P., Jr., ed., 

Handbook of Physical Constants (rev. ed.): Geol. Soc. America 

Mem. 97, p. 75-96. 

Stearns, H. T., and Macdonald, G. A., 1946, Geology and groundwater resources of the Island of Hawaii: Hawaii Div. Hydrog-
50 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

raphy, Bull. 9, 363 p. 

Swanson, D. A., Duffield, W. A., Jackson, D. B., and Peterson, D. W., 

1973, The complex filling of Alae crater, Kilauea volcano, 

Hawaii: Bull. Volcanol., v. 36 (1972) no. 1, p. 105-126. 

Swanson, D. A., Jackson, D. B., Duffield, W.A., and Peterson, D. W., 

1971, Mauna Ulu eruption, Kilauea Volcano: Geotimes, v. 16, 

no. 5, p. 12-16. 

Swanson, D.A., and Peterson, D. W., 1972, Partial draining and crustal subsidence of Alae lava lake, Kilauea Volcano, Hawaii, in 

Geological Survey research 1972: U.S. Geol. Survey Prof. Paper 

800--C, p. C1-C14. 

Walsh, J. B., and Decker, E. R., 1966, Effect ofpressure and saturating fluid on the thermal conductivity of compact rock: Jour. 

Geophys. Research, v. 71, no. 12, p. 3053-3061. 

Wright, T. L., Kinoshita, W. T., and Peck, D. L., 1968, March 1965 

eruption of Kilauea volcano and the formation of Makaopuhi 

lava lake: Jour. Geophys. Research, v. 73, no. 10, p. 3181-3205. 

Wright, T. L., and Okamura, R. T., 1977, Cooling and crystallization 

of tholeiitic basalt, 1965, Makaopuhi lava lake, Hawaii: U.S. 

Geol. Survey Prof. Paper 1004, 78 p. 

Wright, T. L., and Peck, D. L., 1978, Crystallization and differentiation of the Alae magma: U.S. Geol. Survey Prof. Paper 935-C (in 

press). 

Wright, T. L., Peck, D. L., and Shaw, H. R., 1976, Kilauean lava 

lakes: natural laboratories for study of cooling, crystallization, 

and differentiation of basaltic magma: Am. Geophys. Union 

Geophys. Mon. 19, p. 375-390. 

Wright, T. L., and Weiblen, P. W., 1968, Mineral composition and 

paragenesis in tholeiitic basalt from Makaopuhi lava lake, 

Hawaii [abs.]: Geol. Soc. America, Spec. Paper 115, p. 242. 

Yoder, H. S., Jr., 1975, Heat of melting of simple systems related to 

basalts and eclogites: Carnegie Inst. Wash. Year Book 74, 

p. 515-519. 
TABLE 3 
52 SOLIDIFICATION OF ALAE LA VA LAKE, HAWAII 

TABLE 3.-Temperatures in Alae lava lake 

rremperatures measured with thermocouples of chromel-alumel unless noted otherwise. 

Profiles used in constructing fig. 10 are marked by an asterisk C* ). Square root of time 

in days after 06h Aug. 22, 1963, in parentheses] 

Drill hole No. Time 1 Temperature (oC) 

TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole No. Time 1 Depth2 

(ft) 

September 11, 1963 (4.50) 

Temperature (oC) 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 53 

TABLE 3.-Temperatures in Alae lava lake-Continued TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole Time' D~K\h2 Temperature Drill hole Time' Depth2 Temperature No. (oC) No. (ft) (oC) 

October 2, 1963 (6.42) October 24, 1963 (7.95) 

DH3 __ 11h31m-13h14m ____ 7.5 906 DH3 __ 09h55m-10h22m ____ 0.8 255 

8.0 985 1.3 336 

8.5 1,026 1.8 409 

9.0 1,056 2.3 481 

9.5 1,050 3.3 602 

11h35m ____________ 7.5 926 3.8 655 

8.0 1,000 4.3 701 

8.5 1,037 4.8 745 

9.0 1,063 5.8 824 

9.5 1,053 6.3 865 

11h45m ____________ 7.5 955 6.8 903 

8.0 1,018 7.3 939 

8.5 1,047 DHL_ 10h40m ------------ 3.4 589 

9.0 1,069 3.9 639 

9.5 1,058 4.4 691 

12h00m ____________ 7.55 983 4.9 740 

8.05 1,031 DH3 __ 15h00m-16h04m ____ 10.0 41,043 

8.55 1,056 11.0 41,077 

9.05 1,074 11.5 41,079 

9.55 1,062 12.5 41,108 

12h22m ------------ 7.6 1,002 13.0 41,113 

8.1 1,039 13.5 41,117 

8.6 1,063 14.0 41,121 

9.1 1,078 

9.6 1,065 November 5, 1963 (8.68) 12h37m __ ---------- 7.6 1,011 

8.1 1,044 

8.6 1,067 *DHL_ 15h00m ____________ 1.4 291 

9.1 1,079 2.4 427 

9.6 1,066 3.4 534 12h45m ____________ 7.6 1,016 4.4 637 

8.1 1,046 5.4 726 

8.6 1,068 *DH3 __ 13h46m-14h16m ____ 1.0 185 

9.1 1,079 2.0 365 

9.6 1,065 3.0 509 13h00m ____________ 7.7 1,022 4.0 616 

8.2 1,051 5.0 710 

8.7 1,070 5.8 778 

9.2 1,078 6.8 855 

9.7 1,064 7.8 925 

13h10m -------- ____ 7.9 1,033 8.8 987 

8.4 1,058 9.8 1,035 

8.9 1,075 

9.4 1,076 

9.9 1,066 November 7, 1963 (8.79) 13h12m ____________ 8.1 1,043 

8.6 1,065 DH3 __ 12h43m ____________ 9.2 596 9.1 1,075 10.2 688 9.6 1,071 11.2 823 10.1 1,075 12.2 992 13h14m ____________ 8.1 1,045 13.2 1,050 8.6 1,066 12h46m ____________ 9.2 634 9.1 1,079 10.2 718 9.6 1,070 11.2 852 10.1 1,084 12.2 1,011 

13.2 1,053 12h48m ____________ 9.4 680 

October 17, 1963 (7 .50) 10.4 747 

11.4 874 

*DHL_ 11h39m-11h52m ____ 0.5 141 12.4 1,035 

1.0 239 13.4 1,050 12h51m ____________ 9.5 708 

1.5 332 10.5 776 

2.0 416 11.5 893 2.5 492 12.5 1,044 3.4 596 13.5 1,045 3.9 654 12h55m ____________ 9.5 724 

4.4 705 10.5 796 

4.9 758 11.5 908 5.4 798 12.5 1,049 

13.5 1,047 

See footnotes at end of table. 
54 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

TABLE 3.-Temperatures in Alae lava lake-Continued TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole Timet Depth2 Temperature Drill hole Timet Depth2 Temperature No. (ft) (°Ci No. (ft) (oCJ 

---~----------

DH3 ____ 13h00m ____________ 9.5 740 November 8, 1963 (8.85) 10.5 816 

11.5 924 

12.5 1,053 DH3 __ 11h36m-12h48m ____ 1.0 94 

13.5 1,048 2.0 97 

13h05m ____________ 9.5 754 3.0 94 

10.5 832 4.0 269 

11.5 934 5.0 436 

12.5 1,057 6.0 593 

13.5 1,051 7.0 741 

13h10m ____________ 9.5 765 8.0 858 

10.5 845 8.9 944 

11.5 948 9.0 944 

12.5 1,059 9.4 979 

13.5 1,052 9.9 1,008 13h15m ____________ 9.5 776 10.0 1,005 

10.5 858 10.4 1,034 

11.5 958 10.8 1,053 

12.5 1,061 10.9 1,055 

13.5 1,054 11.4 1,071 13h19m ____________ 9.5 784 11.8 1,085 

10.5 866 11.9 1,086 

11.5 964 12.4 1,095 

12.5 1,063 12.8 1,112? 

13.5 1,056 12.9 1,099, 1,100 13h26m ____________ 9.5 796 13.4 1,104 

10.5 879 13.8 1,110 

11.5 974 13.9 1,114; 1,115; 1,115 

12.5 1,065 14.8 1,123 

13.5 1,057 14.9 1,124; 1,126; 1,125 13h30m ____________ 9.5 807 15.9 1,129; 1,130; 1,131 

10.5 887 16.9 1,134; 1,132; 1,132 

11.5 981 17.9 1,136; 1,135 

12.5 1,069 

13.5 1,062 

13h31m ------------- 12.5 1,070 November 20, 1963 (9.50) 13.5 1,062 13h33m ____________ 12.5 1,070 

13.5 1,062 *DH3 __ 10h16m-10h25m ____ 1.1 171 

13h34m ____________ 9.5 811 2.6 408 

10.5 894 4.1 550 

11.5 986 5.6 694 

12.5 1,071 7.1 803 

13.5 1,063 8.6 908 13h37m ____________ 12.5 1,071 10.1 983 

13.5 1,063 13h39m ____________ 9.5 817 

10.5 901 November 27, 1963 (9.86) 11.5 992 

12.5 1,072 

13.5 1,064 DH4 __ 14h30m ____________ 11.3 810 

13h41m ____________ 12.5 1,073 12.3 897 

13.5 1,064 13.3 948 

13h43m ____________ 9.5 824 14.3 974 

10.5 907 15.3 702 

11.5 999 14h48m _ ----------- 11.3 827 

12.5 1,074 12.3 918 

13.5 1,065 13.3 969 

13h45m ____________ 12.5 1,074 14.3 997 

13.5 1,065 15.3 760 

13h46m ____________ 11.55 1,001 

12.55 1,075 

13.55 1,065 November 28, 1963 (9.91) 13h4 7m ____________ 12.55 1,075 

13.55 1,066 13h48m ____________ DH4 __ 10h42m-10h57m ____ 6.0 481 12.6 1,076 

13.6 1,067 7.0 586 

13h49m ____________ 12.6 1,078 8.0 693 

13.6 1,067 9.0 797 

13h50m ____________ 12.7 1,080 10.0 886 

13.7 1,067 11.2 981 

13h51m ____________ 13.0 1,081 12.2 1,035 

14.0 1,064 13.2 1,065 

14.2 1,068 

15.2 1,058 

See footnotes at end of table. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAW All 55 

TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole No. Time 1 

December 2, 1963 (10.11) 

DH4__ 12h25m-13h30m ____ 3.0 

3.5 

4.0 

4.5 

5.0 

5.5 

6.0 

6.5 

7.0 

7.5 

8.0 

8.5 

9.0 

9.5 

10.0 

10.5 

11.0 

11.5 

12.0 

12.5 

13.0 

13.5 

14.0 

14.5 

15.0 

15.5 

16.0 

16.5 

17.0 

17.5 

18.0 

December 5, 1963 (10.26) 

DH4__ 10h12m-13h22m ____ 1.0 

2.0 

3.0 

4.0 

5.0 

6.0 

7.0 

8.0 

9.0 

10.0 

11.0 

12.0 

13.0 

14.0 

15.0 

16.0 

December 16, 1963 (10.78) 

DH4__ 10h45m-15h28m ____ 1.0 

See footnotes at end of table. 

2.0 

3.0 

4.0 

5.0 

6.0 

7.0 

8.0 

9.0 

10.0 

11.0 

12.0 

13.0 

13.3 

13.8 

14.0 

14.3 

323 

377 

425 

470 

514 

559 

612, 598 

657 

698 

740 

781 

820 

849, 853 

884 

917 

946 

974 

1,001 

1,013; 1,022 

1,033 

1,048 

1,059 

1,066 

1,071 

1,062; 1,075 

1,071 

1,079 

1,088 

1,094 

1,099 

1,100 

4127 

4240 

4357 

4456 

4546 

4635 

4715 

4793 

4864 

4926 

4981 

41,010 

41,048 

41,069 

41,086 

41,102 

158 

284 

399 

493 

573 

653 

724 

794 

857 

911 

953 

995 

1,034 

1,045 

1,060 

1,061 

1,064 

TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole No. Time1 Depth2 

(ft) 

DH4__ 10h45m-15h28m____ 14.8 

15.0 

15.3 

15.8 

16.3 

16.8 

17.3 

17.8 

17.0 

1,073 

1,075 

1,079 

1,087 

1,089 

1,094 

1,095 

1,098 

41,096; 1,086 

December 18, 1963 (10.79) 

*DH4__ llh21m-12h21m ____ 0.0 

1.0 

2.0 

3.0 

4.0 

5.0 

6.0 

7.0 

8.0 

9.0 

10.0 

11.0 

12.0 

13.0 

13.5 

13.85 

14.0 

14.5 

14.85 

15.5 

15.85 

16.5 

16.85 

17.5 

17.85 

67 

172 

289 

394 

484 

567 

643 

713 

779 

837 

904 

950 

995 

1,031 

1,049 

1,062 

1,058 

1,069 

1,078 

1,083 

1,091 

1,094 

1,101 

1,100 

1,106 

December 30, 1963 ( 11.41) 

*DH4 __ 10h16m-13h25m ___ _ 0.0 

1.0 

2.0 

3.0 

4.0 

5.0 

6.0 

7.0 

8.0 

9.0 

10.0 

11.0 

11.75 

12.0 

12.25 

12.5 

12.75 

13.0 

13.25 

13.5 

13.75 

13.85 

14.0 

14.25 

14.5 

14.75 

14.85 

15.0 

15.25 

15.5 

15.75 

15.85 

16.0 

358 

196 

302 

395 

477 

547 

639 

700 

758 

812 

861 

926, 934 

968 

970, 980, 975 

990 

999 

1,005 

1,005; 1,018; 1,015; 1,009 

1,024; 1,025 

1,031; 1,032; 1,036 

1,036; 1,043 

1,042 

1,042; 1,048; 1,044; 1,043 

1,053; 1,050 

1,057; 1,056; 1,060 

1,062; 1,064 

1,064 

1,063; 1,063; 1,064; 1,063 

1,065; 1,068 

1,069; 1,074; 1,073 

1,079; 1,077 

1,076 

1,083; 1,084 
56 SOLIDIFICATION OF ALAE LAVA LAKE, HAWAII 

TABLE 3.-Temperatures in Alae lava lake-Continued TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole Time' Depth2 Temperature Drill hole Time' Depth2 Temperature No. (ft) (oC) No. (ft) (oC) 

December 30, 1963 (11.41)-Continued DH5 __ 10h35m-13h25m ____ 16.85 899 

18.5 917, 912 

19.85 913 

*DH4 __ 10h16m-13h25m ____ 16.25 1,085; 1,086 21.5 902, 897 

16.5 1,088; 1,089; 1,089 22.85 876 

16.75 1,091 24.5 842, 836 

16.85 1,092 25.85 801 

17.0 1,097 27.5 750, 745 

17.25 1,098 28.85 701 

17.5 1,100; 1,100 *DH4 __ 14h05m-15h28m ____ 1.0 95, 96 

17.75 1,101 2.0 93,97 

17.85 1,103 3.0 176, 195 

DH5 __ 14h09m-15h14m ____ 0.0 345 4.0 307, 318 

1.0 128 5.0 399,407 

2.0 217 6.0 504, 506 

3.0 292 7.0 569, 572 

4.0 365 8.0 631, 633 

5.0 434 9.0 687, 690 

6.0 526 9.2 716 

7.0 594 10.0 738, 739 

8.0 655 10.2 769 

9.0 713 11.2 818 

10.0 766 12.2 865 

11.0 842 13.2 907 

12.0 887 

13.0 928 March 24, 1964 (14.71) 14.0 963 

15.0 993 

15.5 1,021 DH5 __ 10h51m-12h07m ____ 1.5 110 

16.0 1,032 3.0 140 

16.5 1,038 4.5 218 

17.0 1,045 6.0 342 

17.5 1,049 7.5 449 

18.0 1,052 9.0 555 

18.5 1,050 10.5 625 

19.0 1,050 12.0 683 

19.5 1,044 13.5 719 

20.0 1,041 15.0 752 ---~ --------~---------------------~--~~-~- 15.5 779, 781 

January 29, 1964 (12.70) 16.9 781 

18.5 808, 809 

19.9 811 

*DH4 __ 12h11m-14h48m ____ 1.0 95 21.5 799, 799 

2.0 161 22.9 785 

3.0 272 24.5 752, 752 

4.0 374, 362 25.9 722 

5.0 453, 436 27.5 673, 672 

6.0 533, 528 28.9 633 

7.0 602, 596 *DH4 __ 12h35m-13h15m ---- 1.0 96 

8.0 683,670,660 2.0 97 

9.0 743, 728 3.0 95 

9.3 765 4.0 97 

10.0 796, 781 5.0 187 

10.3 818 6.0 330 

11.0 846 6.5 381 

11.3 867 7.0 425 

12.0 891 7.5 471 

12.3 912 8.0 512 

13.3 953 8.5 552 

9.0 583 

9.5 618 

February 17, 1964 (13.43) 10.0 644 

10.5 674 

DH5 __ 10h35m-13h25m ____ 1.5 100, 97 

3.0 101, 97 April 13, 1964 (15.37) 4.5 101, 97 

6.0 441 

7.5 563, 555 *DH4 __ 12h42m-13h23m ____ 0.0 337 

9.0 641, 633 1.0 94 

10.5 711, 704 2.0 96 

12.0 767, 760 3.0 97 

13.5 817,809 4.0 125 

15.0 853, 844 5.0 205 

15.5 879, 877 6.0 307 

7.0 376 

See footnotes at end of table. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 57 

TABLE 3.-Temperatures in Alae lava lake-Continued TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole Time' Depth2 Temperature Drill hole Time' Depth2 Temperature No. (ft) (oC) No. (ft) (oC) 

*DH4 __ 12h42m-13h23m ____ 8.0 451 

9.0 517 June 17, 1964 (17.36) 

10.0 578 

10.5 605 DH5 __ 13h45m-14h18m ____ 0.0 3 DH5 52 __ 13h40m-14h33m ____ 3.0 179 

6.0 331 3.0 236 

9.0 492 6.0 356 

12.0 608 9.0 456 

15.0 669 12.0 513 

16.3 725 16.4 578 

19.3 744 19.4 579 

22.3 729 22.4 557 

25.3 678 25.4 510 

28.3 598 

July 2, 1964 (17.79) 

April 16, 1964 (15.47) 

*DH8 __ 11h00m-12h55m ____ 1.5 96 

DH6 __ 12h28m-14h17m ____ 1.5 111 3.0 99 

3.0 153 4.5 110 

4.5 111 6.0 231 

6.0 177 7.5 322 

7.5 307 9.0 407 

9.0 428 10.5 483 

10.5 530 12.0 556 

12.0 638 13.5 621 

13.5 703 15.0 690, 706 

15.0 808 16.3 765 

16.5 897 18.0 843 

18.0 959 19.3 894 

19.5 988; 1,004 21.0 956 

20.5 1,023 22.3 996 

21.0 1,015 24.0 1,032 

22.5 1,023; 1,032 25.3 1,047 

23.5 1,039 27.0 1,049 

24.0 1,028 28.3 1,044 

25.5 1,019; 1,027 

26.5 1,023 July 27, 1964 (18.48) 27.0 1,007 

28.5 982, 989 

29.5 978 *DH8 __ 15h16m-15h55m ____ 0.0 343 

30.0 955 3.0 102 

31.5 926 6.0 256 

32.5 905 9.0 431,436 

12.0 573, 580 

May 22, 1964 (16.59) 15.0 698, 710 

18.0 827 

DH6 __ 12h20m-13h00m ____ 0.0 339 

21.0 920 

1.45 96 

4.45 97 September 3, 1964 ( 19.49) 

7.45 97 

10.45 554 *DH8 __ 13h20m-15h30m ____ 0.0 53 

13.45 728 1.5 92 

17.25 908 3.0 112 

20.25 996 4.5 174 

23.25 1,046 6.0 272 

26.25 1,044 7.5 377 

29.25 1,005 10.5 513 

13.5 632 

June 9, 1964 (17.13) L6.5 742 

19.5 834 

*DH7 __ 13h15m-15h10m ____ 0.0 337 

.3 78 December 8, 1964 (21.81) 3.3 161 

6.3 274 

7.8 367 DH12 10h05m-10h57m ____ 0.0 336 

9.3 423 3.0 273 

9.35 449 6.0 414 

10.8 523 9.0 544 

12.35 609 12.0 639 

13.8 686 15.0 716 

15.35 761 18.0 774 

16.8 828 21.0 828 

18.35 889 24.0 863 

21.35 981 27.0 871 

See footnotes at end of table. 
58 SOLIDIFICATION OF ALAE LAVA LAKE, HAW All 

TABLE 3.-Temperatures in Alae lava lake-Continued TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole Time' D~K~h2 Temperature Drill hole Time' Depth2 Temperature 

No. (°C) No. (ft) (oC) 

December 8, 1964 (21.81)-Continued DHll 13h52m ____________ .0 342 

3.0 145 

DH12 __ 10h05mr10h57m ____ 30.0 867 6.0 250 

33.0 861 9.0 355 

36.0 822 12.0 473 

39.0 779 15.0 579 

42.0 730 DH5 __ 15h15mr15h40m ____ .0 330 

45.0 690 3.0 159 

*DH9 __ 12h07mr13h12m ____ .0 330 6.0 231 

3.0 152 9.0 289 

6.0 291 12.0 322 

9.0 420 15.0 326 

12.0 537 16.3 321 

15.0 644 19.3 297 

21.0 800 22.3 264 

24.0 852 25.3 229 

27.0 888 28.3 192 

30.0 902 

33.0 897 

35.8 889 March 2, 1965 (23.65) 

38.8 856 

41.8 814 *DH9 __ 10h20mrllh50m ____ 0.0 331 44.8 776 

47.8 718 3.0 154 

DH5 __ 15h12mr15h37m ____ 3.0 221 6.0 231 

6.0 318 9.0 316 

9.0 369 12.0 393 

12.0 391 15.0 525 

15.0 384 21.0 701 

16.3 377 24.0 761 

19.3 347 25.5 788 

22.3 310 27.0 805 

25.3 270 28.5 818 

28.3 229 30.0 828 

31.5 832 

January 21, 1965 (22. 79) 33.0 833 

34.5 831 

DH12 10h00mrllh15m ____ 0.0 350 

36.0 828 

37.5 814 

3.0 221 39.0 806 

6.0 351 42.0 773 

9.0 479 45.0 733 

12.0 594 48.0 676 

15.0 682 DH12 12h45mr14h15m ____ .0 334 

18.0 749 3.0 237 

21.0 801 6.0 367 

24.0 833 9.0 457 

27.0 848 12.0 557 

30.0 845 15.0 640 

34.7 820 18.0 708 

37.7 783 21.0 764 

40.7 735 22.5 782 

43.7 673 24.0 798 

46.7 610 25.5 810 

*DH9 __ llh55mr12h49m ____ .0 340 27.0 815 

3.0 131 28.5 817 

6.0 214 30.0 815 

9.0 283 31.5 811 

12.0 441 34.5 792 

15.0 562 34.7 791 

18.0 670 37.7 756 

21.0 751 40.7 709 

24.0 804 43.7 655 

27.0 843 46.7 598 

30.0 860 DH5 __ 15h30mr15h55m ____ .0 322 

35.7 855 3.0 136 

38.7 829 6.0 209 

41.7 791 9.0 256 

44.7 745 12.0 281 

47.7 692 15.0 280 

DH10 13h20m ____________ .0 340 15.8 274 

3.0 96 18.8 250 

6.0 225 21.8 220 

9.0 403 24.8 189 

12.0 552 27.8 187 

15.0 660 

See footnotes at end of table. 
COOLING AND VESICULATION OF ALAE LAVA LAKE, HAWAII 59 

TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole No. 

*DH9 __ 

DH5 __ 

*DH12 

*DH12 

Time1 

August 19, 1965 (27.01) 

10h05m-12h20m ____ 6.0 

9.0 

12.0 

15.0 

18.0 

21.0 

24.0 

27.0 

30.0 

31.5 

33.0 

34.5 

35.9 

37.5 

38.9 

40.5 

41.9 

43.5 

44.9 

47.9 

12h40m-13h50m ____ 3.0 

6.0 

9.0 

12.0 

15.0 

15.8 

18.8 

21.8 

24.8 

27.8 

14h40m-16hl2m ____ 3.0 

6.0 

9.0 

12.0 

15.0 

20.0 

23.0 

24.5 

26.0 

27.5 

29.0 

30.5 

32.0 

33.5 

35.0 

36.5 

38.0 

41.0 

44.0 

47.0 

May 27, 1966 (31.78) 

11h00m-14h05m ____ 2.8 

5.8 

8.8 

11.8 

193 

237 

273 

295 

Temperature 

(°CI 

125 

181 

249 

339 

406 

474 

538 

596 

637 

658 

664 

679 

684 

687 

686 

682 

675 

666 

653 

616 

51 

56 

74 

88 

94 

94 

93 

85 

75 

66 

185 

253 

319 

390 

456 

559 

606 

629 

642 

656 

663 

670 

669 

671 

669 

658 

654 

626 

585 

543 

*U.S. GOVERNMENT PRINTING OFFICE: 1978- 789-107/65 9-II 

TABLE 3.-Temperatures in Alae lava lake-Continued 

Drill hole No. 

*DH12 __ 

*DH9 __ 

DH9 __ 

*DH12 

Time 1 Depth2 

(ftl 

Temperature (oC) 

llh00m-14h05m____ 14.8 315 

17.8 338 

20.8 355 

23.8 377 

26.8 402 

29.8 431 

32.8 456 

33.8 462 

34.8 467 

35.8 471 

36.8 473 

37.8 475 

38.8 477 

39.8 475 

40.8 474 

41.8 472 

42.8 468 

43.8 464 

44.8 456 

45.8 451 

46.8 448 

14h20m-15h30m ____ .6 62 

3.6 30 

6.6 40 

9.6 66 

11.1 68 

12.6 110 

15.6 121 

18.6 116 

21.6 164 

24.6 165 

(Blocked by sublimates at 24.6 ft) 

August 31, 1967 (38.35) 

14.6 

17.6 

20.6 

23.6 

26.6 

5.0 

8.0 

11.0 

14.0 

17.0 

20.0 

23.0 

26.0 

29.0 

32.0 

35.1 

38.1 

41.1 

44.1 

47.1 

74 

74 

74 

72 

70 

63 

63 

65 

65 

68 

68 

68 

68 

68 

76 

76 

80 

84 

87 

90 

1 All times are given in hours and minutes, Hawaii Standard Time. 2 1 foot equals 0.3048 m. 3Measured with a mercury thermometer. 4Measured with a thermocouple of platinum-platinum plus 10 percent rhodium.