U.S. DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

MARINE GEOLOGIC INVESTIGATIONS OF DISENCHANTMENT BAY, ALASKA, 

AFTER BREAKUP OF 1986 HUBBARD GLACIER ICE DAM

KVKARLUK CRUISE K1-91-YB 

21-28 JUNE 1991

by

Paul R. Carlson1 

Ross D. Powell2 

Ellen A. CowanS 

Daniel E. Lawson4

Open-File Report 92-706

This report is preliminary and has not been reviewed for conformity with U.S. 

Geological Survey editorial standards or with the North American Stratigraphic Code. 

Any use of trade, product, or firm names is for descriptive purposes only and docs not 

imply endorsement by the U.S. Government.

1992

1 - U.S. Geological Survey, Menlo Park, CA 94025

2- Geology Dept. Northern Illinois U., Dekalb, DL 60115 

3. Dept. of Geology, Appalachian St. U., DeKalb, IL 60115 

4- USA, CRREL, Hanover, NH 03755
We entered the ice-infested waters of Disenchantment Bay on the 42 

foot research vessel, the KARLUK precisely one hundred and one years 

after I.C. Russell visited Disenchantment Bay by canoe. He described the 

scene as follows--"the island (Haenke) occupies the position of the stage in 

a vast amphitheatre; the spectators are hoary mountain peaks, each a 

monarch robed in ermine and bidding defiance to the ceaseless war of the 

elements. How insignificant the wanderer who confronts such an audience, 

and how weak his efforts to describe such a scene!"
INTRODUCTION

Cruise K1-91-YB to Disenchantment Bay, which forms the upper part 

of Yakutat Bay, Alaska (Fig. 1), was designed to study the glacimarine 

sedimentary environment associated with the magnificent Hubbard 

Glacier, at the northern boundary of Disenchantment Bay. This study is a 

continuation of previous studies of morainal bank and proximal 

environments of tidewater glaciers in Glacier Bay, Alaska (Powell, 199la; 

Cowan and Powell, 1991; Carl son et al, 1983). These earlier studies relied 

upon sediment sampling and high-resolution seismic-reflection profiling to 

delineate sedimentary facies in tidewater glacier environments. The most 

recent work (Powell, 1991b; Powell et al., 1991) has made use of an 

additional powerful tool, a submersible Remotely Operated Vehicle (ROV) 

to make visual observations of the glacier's tidewater face, grounding line 

morainal banks, and the associated fjord floor. On cruise K1-91-YB we 

faced more severe ice and current conditions than we had encountered in 

Glacier Bay. In spite of these formidable obstacles, we were able to collect 

about 140 km of high-resolution seismic-reflection and 7 kHz bathymetric 

trackline profiles (Fig. 2). We also made six successful dives with the ROV 

system, on which, in addition to obtaining video footage, data were 

gathered by the attached conductivity, temperature, depth (CTD), optical 

backscatter (OBS), and current meters. In addition, water column vertical 

profiles were obtained using the ROV sensors at three sites. In this report, 

we will briefly discuss the data collected by the various systems deployed.

EQUIPMENT SYSTEMS

1. REMOTELY OPERATED VEHICLE.

The submersible ROV is a Phantom DHD2 with a 500m data transmission 

cable. The ROV has a CoHo low-light black and white video camera and 

two- 250 watt tungsten-halogen lights as basic equipment. The system 

was deployed with optional equipment that included a Sanyo CCTV color 

video camera, a Nikonis stereo still camera with strobe, an EDO side-scan 

sonar fish, a Marsh-McBirney electromagnetic current meter, a Downing 

and Assoc. optical backscatterance (OBS) turbidity monitor, and a Seacat 

SBE 19 CTD system.

2. HIGH-RESOLUTION SEISMIC-REFLECTION PROFILING

The Geopulse subbottom profiling system was operated at a power setting 

of 350 J and a firing rate of one-half second. The high-resolution seismic-
reflection profiles were collected using a Benthos 15/30 hydrophone, 

filtered between 300 and 1000 Hertz, on a EPC 4800 recorder at a one-half 

second sweep rate.

3. BATHYMETRY.

A 7 kHz Raytheon RTF 1000 hull-mounted transducer/transceiver was 

utilized to collect bathy metric and high-resolution profiles.

4. WATER-COLUMN SAMPLING

A 2.5 liter van Dorn water bottle was used to obtain water samples at 

various depths throughout the water column to measure concentrations of 

suspended matter at different locations in the fjord. Each sample was 

collected by hand lowering the bottle on separate casts.

5. NAVIGATION

Navigation throughout Disenchantment Bay was controlled by radar and 

Magellan GPS 2000 unit. Radar was the primary navigation system 

because the high, steep fjord walls prevented consistent GPS readings.

PHYSICAL SETTING

GEOGRAPHY

Disenchantment Bay occupies the northern part of Yakutat Bay, one 

of the prominent glacially formed bays adjacent to the north-eastern part 

of the Gulf of Alaska (Fig. 1). Yakutat Bay, a triangular shaped feature, is 

about 60 km long (from the Gulf of Alaska to Hubbard Glacier) and nearly 

30 km wide at the seaward end (Fig. 1). The most northerly part of the 

bay, the more elongate Disenchantment Bay (Figs. 1 & 3), is about 15 km 

long and 5 km wide with high steep bedrock walls that consist primarily of 

slightly metamorphosed Cretaceous sedimentary rocks of the Yakutat 

Group (Plafker and Miller, 1958). The 100 m-high, 7 km wide ice cliff of 

Hubbard Glacier, the widest tidewater terminus in North America, forms 

the northern end of Disenchantment Bay. Three smaller glaciers, Miller, 

Haenke, and Turner, calve into Disenchantment Bay from the northwest. 

Prominent along the eastern side of the bay is the 1.5 X 1 km Haenke 

Island which has a maximum elevation of about 170 m. Further northnortheast, small unnamed islands and rocks protrude above the bay water, 

some emergent only at low tide. The steep east wall of the bay continues 

north to nearly 60° N Latitude where Gilbert Point forms the north end of a 

massive peninsula that separates Russell Fjord from Yakutat Bay. The 

opening into Russell Fjord is presently narrower and shallower because of 

the recent advance of Hubbard Glacier.
GLACIAL HISTORY

Yakutat Bay owes much of its configuration to glaciation that has 

been modifying this fjord basin throughout most of Neogene and 

Quaternary time. As recently as 600-900 years ago (Plafker and Miller, 

1958), the ancestral Hubbard Glacier occupied the bay, extending slightly 

beyond the mouth into the Gulf of Alaska as indicated by a large arcuate 

terminal morainal bank that encompasses the bay entrance (Fig. 1). Two 

other possible morainal banks have been identified in Yakutat Bay. The 

"mid-bay moraine"? (Wright, 1972) may extend about two thirds of the 

way across the bay and the "upper-bay moraine", first identified by Gilbert 

(1904), extends easterly across the bay from Blizhni Point (Fig. 1). Plafker 

and Miller (1958) have suggested that this "upper-bay moraine" was 

formed during a more recent advance of the Hubbard Glacier -200 years 

ago.

The ponded basins between the morainal banks contain thicknesses 

of glacimarine sediment up to 350 m, which suggests maximum 

sedimentation rates that range from 20 to 70 cm/a (Carlson, 1989). The 

sediment on the morainal banks is a diamicton and in the basins ranges 

from clayey silt containing iceberg-rafted pebbles to silty clay (Wright, 

1972; Carlson et al., 1978).

Although most of Yakutat Bay has been ice-free and receiving 

glacimarine suspended sediment for more than 200 years, Disenchantment 

Bay has experienced periodic advances of the Hubbard Glacier terminus. 

Russell (1891) and Gilbert (1904) have suggested that visits to Yakutat Bay 

by Malaspina in 1792 and Vancouver in 1794 chronicled the presence of 

Hubbard Glacier south of Haenke Island. Tarr and Martin (1914) report 

that Russian maps showed the terminus to be a short distance north of 

Haenke Island in the early 1800s and also showed a lake to be present in 

Russell Fjord, indicating damming of the fjord entrance by Hubbard Glacier. 

By the time of the Harriman expedition's visit to Disenchantment Bay in 

1899, the Hubbard Glacier had retreated about 3.5 km north of Osier 

Island (Gilbert, 1904, plate VIII). Tarr and Martin (1914) showed maps of 

the terminus of Hubbard Glacier that in 1909 was about 1.9 km from Osier 

Island and 1910 was yet another 0.32 km distant.

For the next 60 years, the glacier slowly advanced, causing Post and 

Mayo (1971) to predict that "around 1990" Russell Fjord would again be 

dammed by the advancing terminus. On May 29, 1986, an ice dam 

blocked the entrance to Russell Fjord and Russell Lake filled with fresh 

water eventually to a height of 25.5 m (Mayo, 1989). On October 8, 1986, 

the ice dam failed catastrophically, producing a peak discharge of 105,000

5
m3 s-l averaged over one hour (Mayo, 1989). Although the outbreak 

occurred at night and could not be observed until about 5 hours later, the 

turbid outburst plume at that time had a measured surface speed at the 

center of the flow of 11.0 m s-l which provided enough momentum for the 

highly turbulent flow to reach the face of Turner Glacier about 6 km across 

Disenchantment Bay (Mayo, 1989). Seitz et al., (1986) reported that the 

turbid jokulhlaups plume was later visible at the mouth of Yakutat Bay, a 

distance of more than 50 km from the ruptured dam. Mayo (1989) also 

reported that 50 m of erosion of the highly jointed rocks of Osier Island 

and 200-300 m of an alluvial outwash fan attached to Gilbert Point were 

removed by the jokulhlaups. Trabant et al., (1991) predict that Russell 

Fjord at the present rate of glacial advance, will be closed off again during 

this decade. The rapid advance is due to a high accumulation-area to total - 

glacier-area ratio (0.95), and the presence of a morainal bank that controls 

ice loss from calving. They suggest that this time the dam might be 

sufficient to cause the lake to build to a height of 40 m, and to flow out of 

the south end into the Situk River drainage.

OCEANOGRAPHY

There are few oceanographic observations available for the Yakutat 

Bay area. The oceanography of Russell Fjord was reported by Reeburgh et 

al., (1976). As part of their study, temperature and salinity data were 

collected on April 5, 1973 from one station in upper Yakutat Bay located 

10 km downfjord from Haenke Island. Their measurements at 50 m depth 

are lower in temperature (by 1.6°C) and higher in salinity (by l.l%o) than 

those collected during our cruise in late June 1991. This difference can be 

explained by the location of their station which was closer to the mouth of 

the bay, by tidal cycle variations related to the "flushing" of Russell Fjord, 

and by annual variations in temperature and salinity in the Gulf of Alaska 

(Royer, 1975), the source water for Yakutat Bay. The depth of the 

outermost sill which controls exchange between the Bay and the Gulf of 

Alaska is at 70 m (Reeburgh et al., 1976). In April 1973, Reeburgh et al., 

(1976) measured surface water that was warmer (by 1.08° C) and higher 

in salinity (by 6.68 %o) than our measurements showed in June 1991. This 

difference results from the seasonal increase in meltwater discharge and 

by the closer proximity of our stations to the face of Hubbard Glacier.

PRELIMINARY RESULTS

CRUISE COMMENTS

The initial cruise plan was to concentrate on ROV dives in 

Disenchantment Bay intended to study the submerged face of Hubbard 

Glacier and the underlying morainal banks. Because of the great quantity
of ice that was constantly calving the accessible areas were limited. It 

soon became evident that the predesigned plan would be modified by the 

daily ice and current patterns. As a result of the severe ice and current 

conditions, our bathymetric and seismic-reflection survey lines were very 

disrupted (Fig. 2a&b) and there were parts of the Disenchantment Bay that 

never were reached during the cruise.

BATHYMETRY

The hull-mounted 7 kHz system was utilized continually on all 

profile lines and provided bati.ymetric data for the areas traversed. Prior 

to this cruise, the most complete and recent bathymetric data for 

Disenchantment Bay had been collected by the National Oceanic and 

Atmospheric Agency (NO A A) in 1978. The NOAA smooth sheet data, from 

Hydrographic Surveys 9778 and 9779 were contoured to provide detailed 

work sheets for our cruise K1-91-YB (Fig. 3).

Bathymetric data were collected previously from a helicopter along 

the face of the Hubbard Glacier where the risk to a small vessel would be 

very high due to the calving of ice from the 100-m-high ice cliff (Trabant 

et al., 1991). Water depths at the terminus ranged from as deep as 104 m 

along the northwestern 1/3 of the ice cliff to as shallow as 77 m along the 

southeastern 1/3 of the Hubbard Glacier ice face. The water shoals to 8 m 

at the entrace to Russell Fjord and depth increases near the ice face in 

Russell Fjord to as deep as 81 m.

Comparison between our data and the NOAA bathymetric data 

indicates shoaling has occurred throughout the deep basin (Fig. 4). The 

shoaling typically ranges from 2 to 6 m, with a maximum of 11 m at the 

base of the slope WNW of Osier Island. Although there is a general acrossand down-fjord trend, two large distinct areas of sediment accumulation 

can be identified. An area of maximum shoaling occurs within the upper 

part of the deep fjord basin, west and northwest of Osier Island. The 

amount of accumulation generally decreases west and southwest across the 

basin toward the Turner Glacier terminus. The second area of 

accumulation occurs within the deep basin west of Haenke Island where 

up to 5 m of shoaling has occurred (Fig. 4). In addition, localized areas of 

greater shoaling are apparent, occurring at the base of the fjord slope 

below Turner Glacier, and the southern most mapped area of the Bay.

We attribute much of the shoaling to sediment eroded and 

transported by the outburst flood of Russell Lake on October 8, 1986, (Seitz 

et. al., 1986; Mayo, 1989). The up-Bay area of maximum shoaling and the 

across-and down-fjord decrease lie along the path of the outburst flood as
described by Mayo, (1989) and Seitz et al., (1986) (Figs. 3&4). Following 

ice dam failure, the outburst flood rushed from between Osier Island and 

Gilbert Point, at speeds reaching 11 m S~l. The outburst flood continued 

across Disenchantment Bay as a highly turbulent "stream" that impinged 

upon the terminus of Turner Glacier (Mayo, 1989). Here the flow was 

deflected in a general down-fjord direction, west of Haenke Island (Fig. 3). 

Discharge velocity would have decreased with emergence into 

Disenchantment Bay and flow into and across the deep basin, which 

concurs with the across fjord thickness decrease. Eddies resulting from the 

outburst "stream" would have established gyres north and south of the 

flow where reduced velocity and turbulence would have favored 

sedimentation from the overflow plume (Figs. 3&4).

Because of the impressive scouring action of the jokulhlaups, a large 

amount of sediment was eroded and transported. In the Gilbert Point area, 

shore erosion of 50 to 300 m and up to 50 m of bedrock were eroded by 

the outburst flood (Mayo, 1989). Bedrock 2-3 m deep on Osier Island and 

a 200 to 300 m long alluvial fan deposit off Gilbert Point were eroded by 

the flood waters and transported into the upper bay area. In addition, 

over 500 m of glacier retreat near the outburst point resulted (Mayo, 

1989), widening the channel, and likely eroding morainal bank material in 

the process. The upper-bay area of sediment accumulation lies 

immediately down-flow from both erosional areas.

The area of 11 m shoaling lies downslope of the Hubbard Glacier's 

1986 terminus position which resulted from a rapid ice advance that 

shoved and transported significant volumes of marine sediment (Fig. 3). 

Mayo (1989) reported that a >600 m length of the ice margin near the 

entrance to Russell Fjord developed an emergent push moraine during this 

advance. Outburst flood induced erosion resulting in failure of this push 

moraine could account for some of this 11 m thick sequence.

The basin fill west of Haenke Island likewise lies along the path of 

the outburst flood waters during the period of maximum discharge 

following its deflection off the Turner Glacier terminus and the western 

fjord wall (Figs. 3&4). Subsequently, as discharge gradually decreased 

over the next 10 to 15 hours, the flow path would have returned to more 

central areas of the Bay. The deep waters south of the Turner Glacier 

terminus as well as reduced velocities resulting from decreased discharge 

would favor deposition.

Subaqueous slope failures and sediment flows along the western 

basin slope are also a possible consequence of the outburst flood. Such
flows would tend to follow the general gradient of the basin slope and floor 

into the basin west of Haenke Island. As described in the following 

section, seismic profiles in this basin have revealed both bed and subsurface features which appear to be sediment flow toes (Fig. 4). However, 

these deposits may have been generated by subaqueous flows during, or 

subsequent to the outburst flood, and derived from any number of 

locations within the Bay. Additional investigations, including coring, will 

be required to fully interpret the shoaling and seismic data collected 

during this cruise.

SUBBOTTOM PROFILES

This section describes some of the features visible on the highresolution seismic-reflection profiles collected in various parts of 

Disenchantment Bay (Fig. 2a) and the six lines obtained in the upper part 

of Yakutat Bay (Fig. 2b). Features resolved on the profiles include bedrock 

underlying the fjord sediment basin, sediment thickness, reflections within 

the sediment pile, the morainal bank on which the front of Hubbard Glacier 

rests, the "upper-bay moraine", and features such as mass movement 

deposits within the profiles.

The sedimentary fill accumulating in the bedrock basin of 

Disenchantment Bay reaches thicknesses of more than 150 m. 

The upper part of the sediment column is characterized by flat-lying 

continuous reflections, some of which can be traced across the width of the 

basin (Fig. 5). Note the bedrock walls delineating the sides of the 

sedimentary basin. At the base of the fjord walls, most of the highresolution profiles show hummocky disrupted reflections that indicate 

slide or debris flow deposits (Figs. 5&6). Other mass movement deposits 

can be seen at depth in the sediment. Two lines from the west side of 

upper Yakutat Bay (Figs. 7&8) exhibit well-defined mass movement scars 

with the resulting debris visible on the fjord floor at the base of the wall. 

Note that above the scar on Figure 8 there are a series of small step scarps 

that indicate the prevalence of mass movement. In this area, slides and 

debris flows are probably related to the rapid accumulation of sediment on 

the delta that forms Blihzni Point. These and other mass movements could 

have been triggered by seismic loading generated by the numerous 

earthquakes that occur in this technically active region. Along the west 

wall of the fjord south of Turner Glacier, two adjacent crossings show an 

irregular, hummocky buried deposit that may be a submarine slide or 

debris flow deposit (Fig. 9).
Profiles collected as close as feasible to the 100 m high ice face of 

Hubbard Glacier show the character of the distal slope of the morainal 

bank to be an irregular, hummocky surface with no visible internal 

reflections, the product of mass movement from this "pinning point" 

moraine (Fig. 10 a&b). The gradient of this pan of the morainal bank 

averages about 3° and attains a maximum steepness of about 4° along the 

profiled section of the bank. This contrasts to a gradient of about 14° for 

the proximal slope calculated from the near glacier end of our profile (183 

m depth) to the nearest shallowest water depth at the glacier face (81 m) 

as measured from a helicopter by Trabant et al., (1991).

South of the lower end of Disenchantment Bay lie prominent ridges 

that form the "upper-bay moraine", (Fig. 11). The most southern ridge is 

the steepest, having a gradient of 14.5° on the upper part of the morainal 

bank (similar in value to the Hubbard Glacier morainal bank), decreasing 

to 9.5° on the lower third of the bank, and then to 1° over some hummocky 

terrain that appears to be mass movement debris. If we calculate the 

gradient of slope across the lower third of the morainal bank, and the slide 

or debris flow deposit, we obtain a value of 2.6°, a gradient close to that 

measured for the distal part of the Hubbard morainal bank. Thus, we 

might conjecture that the "upper-bay moraine" is a possible morphologic 

model for the present morainal bank of Hubbard Glacier. Note the ponded 

glacimarine mud, containing iceberg-rafted pebbles (Carlson et al., 1978) in 

basins between minor morainal banks that are progressively smaller in the 

up-bay direction, presumably formed successively by the glacier during 

retreat.

One question we posed before the cruise was whether or not we 

could find any remnant depositional features on the fjord floor that may 

have been caused by the outburst flood (jokulhlaup) when the ice dam at 

Russell Fjord failed. Several of the high-resolution seismic-reflection 

profiles that crossed the fjord floor west and southwest of Haenke Island 

showed a very subtle bump or scarp-like feature having a relief of about 

2 m (Fig. 12). On Figure 4, west-southwest of Haenke Island, we have 

plotted the occurrences of the shallow scarps that we thought possibly 

might represent the toes of debris or mud flows that could have been 

generated by the jokulhlaup. However, their plotted configuration does 

not necessarily point to the Russell Fjord entrance area as the origin of all 

of these features. The presence of the three glaciers along the west wall of 

the fjord and, of course, the mighty Hubbard Glacier at the head of the bay, 

all provide sources of rapidly deposited sediment that could fail and flow 

or slide down into the fjord.

10
A high-resolution acoustic profile near Haenke Island, contains a 

buried lens-shaped feature (Fig. 13) that also might be a debris flow 

deposit again a number of potential sources are nearby. This wedge or 

lens is buried beneath 2-3 m of the most recent sediment. If as reported 

in several fjords, including Yakut at Bay (Carl son, 1989), the rate of 

sediment accumulation is >100 cm/a and in extreme cases several times 

that rate (Molnia et al., 1984; Cowan et al., 1988; Powell, 1991a), then the 

upper 2-3 m thick layer could have been deposited since 1986. 

Consequently, the lens could have been part of the slug of sediment 

discharged into Disenchantment Bay when the joku'hlaupss from Russell 

Fjord occurred on October 8, 1986.

WATER COLUMN AND BOTTOM SEDIMENT DATA FROM ROV DIVES

Real-time CTD and OBS data and video imagery, were collected and 

transmitted through the ROV's umbilical to the ship during each of the six 

dives (Fig. 14). Temperature, salinity, sigma-t, and OBS turbidity 

measurements were plotted against depth for each ROV descent through 

the water column. Current velocity and direction also were measured; 

however, many of these values are unuseable due to current and iceinduced movement resulting in ROV instability. The descent rate was 

uniform, therefore, these profiles are similar to oceanographic casts. 

However, most of the profiles were collected from ice-proximal locations 

that were targeted for visual observation rather than evenly spaced 

stations for oceanographic study. Water samples were collected at various 

depths at sites 2, 3, 5 and 6, (Fig. 14) with a 2.5 L van Dorn bottle.

At dive site 1, located near the lower end of Disenchantment Bay 

(Fig. 14), the water column had a salinity minimum from 8.9 to 11 m depth 

that resulted from an interflow (Fig. 15). The sigma-t value within this 

layer was 0.72 units less than the overlying water column above 8.9 m. 

There was also an abrupt increase in OBS turbidity units at 9.9 m that 

remained high until a depth of 15.6 m. A suspended sediment 

concentration of 7.2 g/L would be necessary to offset this low sigma-t 

layer at this depth. No water samples were collected during this dive, 

therefore, no suspended sediment concentrations are reported. However, 

concentrations as high as 7 g/L are within the range of suspended 

concentrations measured from an interflow in a fjord in Glacier Bay (Cowan 

et al., 1988). The fact that OBS turbidity values remained at a moderate 

level until 50 m depth indicates that sedimentation from the interflow was 

quite rapid. Current speeds were measured at depths at 

19, 62, 76, and 86 m. Corresponding speeds were 60, 81, 80, and 61 cm/s.

1 1
The profile at dive site 2 (same location as site 1; Fig. 14) indicates a 

26 m thick overflow (Fig. 16a). The overflow had the lowest salinity and 

temperature and the highest OBS turbidity readings measured on this dive. 

The highest sediment concentrations (Table 1) are within the overflow, but 

they remain high down to 60 m depth where there is a gradual decrease in 

turbidity to about 90 m depth. Video observations show that the base of 

the higher turbidity zone is marked by large, "wispy" billows of mud and 

marine snow (phytoplankton and some zooplankton). Beneath the 26 m 

thick surface layer, the temperature gradually increases to a maximum of

about 6.8° C between depths of 80 and 105 m. Salinity similarly increases 

below 26 m depth. Salinity gradually increases, temperature decreases, 

and OBS fluctuates at low values (mostly due to marine snow) below 100 

m depth. This profile is similar to those described from other glacial fjords 

in British Columbia and Alaska (Cowan and Powell, 1990; Pickard, 1961, 

1967). The distinct halocline indicates that the freshwater supply, mainly 

from glaciers at the head of the Bay and from Russell Fjord, is sufficient to 

drive circulation in the upper part of the water column. The high 

suspended sediment concentrations are also associated with the overflow 

indicating that it originates from meltwater discharge. Current velocities 

could only be measured at 216 m depth (74 cm/s), and at the bed (101 

cm/s). The video imagery of the bed at this site shows a relatively flat, 

featureless, soft, sandy mud.

Dive site 3 (Fig. 14) is similar in water column profile to site 2, but 

more proximal to Hubbard Glacier. The overflow is thinner, about 17 m 

thick, but has OBS turbidity values three times higher than at site 2 

(compare - Fig. 16 a&b). Dive site 3 is closer to Hubbard Glacier, an 

important freshwater and sediment source, than site 2. The water column 

below the halocline is similar to that at site 2 (Figs. 16 a&b). Current 

speeds at the seabed were low (26 cm/s). Water column video 

observations suggest that current flow was mainly vertical; the horizontal 

component averaged 20 cm/s. Problems with ice, wind, and tidal currents 

affecting the Karluk's station keeping, caused this dive to be aborted 

before ice face and morainal bank observations could be made.

The profile for dive site 4 (Fig. 14) was collected over the slope 

adjacent to the entrance to Russell Fjord. During the descent the tide was 

ebbing and surface currents were flowing out of Russell Fjord past the dive 

site. The more uniform temperature on descent than measured at the 

other sites indicated a well-mixed water column. Salinity gradually 

increases throughout the profile (Fig. 17a). Turbidity is highest in the 

overflow, reaching peaks at about 4 m and 15 m depth. Within the 

overflow, sediment concentrations fluctuated in response to ebb-induced

12
turbulence that was seen on the video as billowing turbid clouds. An 

ascent profile (Fig. 17b) was collected 20 minutes later, after the tide had 

turned to flood and surface water began to move from the Bay into Russell 

Fjord. The effects of this reversal included an increase in salinity above 52 

m and a decrease in OBS turbidity beneath the overflow plume, (compare 

Figs. 17 a&b). Temperatures remained relatively uniform and similar to 

the descent profile. The video showed that at dive site 4 the bed at 62 m 

depth consists primarily of "soupy" mud with slightly irregular relief. 

Iceberg-rafted clasts up to cobble size are scattered across the bed. Video 

of the bed showed a strong current with large floes and marine snow in 

turbulent transport flowing down Disenchantment Bay away from the 

entrance of Russell Fjord. Initially the current exhibited episodic turbulent 

pulses ranging in speed from 40 to 50 cm/s, but after about 15 minutes 

the turbulent flow decreased to a non-turbulent, uniform flow of about 26 

cm/s, still moving out of Russell Fjord during the initial tidal flooding stage.

Dive site 5 (Fig. 14) was occupied for visual observations of the 

suspended paniculate matter (SPM) in the water column. As is common in 

glacial fjords, the turbidity maximum in the overflow occurs below the 

surface (Fig. 18), coinciding with the lowest temperature in the overflow 

(Cowan and Powell, 1990). The base of the overflow, about 20 m depth, is 

marked by a sharp halocline and thermocline and a decrease in SPM 

concentration, below which, a few floes occur with marine snow. Below 

110 m, floes are few and OBS turbidity values are low and variable. A 

slight increase in the number of floes occurs at about 170 m depth, 

coinciding with a weak, lower temperature, nepheloid layer. The fjord 

floor at 220 m depth consists of soft, "soupy" mud with cm-scale relief. The 

video shows ripples that are cut by a small scarp 1-4 cm high trending 

perpendicular to ripple crests that strike at about 243° MN. Isolated 

cobble- to small boulder-size ice berg-rafted clasts are scattered over the 

fjord floor. Shrimp were common and four bottom fish were imaged. 

Near-bottom currents in the nepheloid layer were flowing at 21 cm/s 

between 207 and 297° MN. At 207 m depth, a current speed of 

22 cm/s was measured. At 120 m depth, turbulent bursts up to 80 cm/s 

punctuated quieter flow conditions of 23 cm/s.

The profiles at dive site 6, (Fig. 14) were also collected in a 

more distal location for determining water column characteristics 

(Figs. 19 a&b). This dive was about two hours later than the dive at 

site 5. Characteristics of the upper part of the water column in the 

overflow were similar in both profiles; however, the rest of the column 

was different. At dive site 6, there were four significant increases in OBS

13
turbidity values that correlated with video observations of increased 

numbers of floes in the water column (Fig. 19a). The layer between 20 and 

30 m was probably produced by particles settling from the base of the 

overflow. Between 40 and 60 m, an OBS turbidity peak was associated 

with a lower density layer or interflow. The upper part of the interflow is 

characterized by the highest current velocities (Fig. 19b). Current 

velocities ranging from 18 to 65 cm/s were measured during ascent at 

dive site 6 (Fig. 19b). At 40 m depth, currents were strong enough to 

cause the ROV to spin continuously. The current speeds are relatively 

uniform throughout the water column except for the higher velocity layer 

between 40 and 60 m.

The difference in sigma-t values between the layer at 40-60 m and 

the overlying denser layer is small (0.2315 units), but it represents an 

unstable density profile if only the water density is considered. However, 

this difference could be offset by the addition of suspended sediment in a 

concentration of approximately 2.3 g/L. Water samples collected from this 

station had suspended sediment concentrations of less than 100 mg/L, but 

none were collected within the 40-60 m depth layer. At about 50-55 m 

depth the temperature, salinity, and OBS values show relatively abrupt 

changes. Note that the OBS turbidity values do not drop sharply at the 

base of the layer as do the salinity values, indicating that panicles were 

settling out from the interflow at 40-60 m depth.

Below the interflow, the water column was dominated by marine 

snow but there were also two well defined layers of floes. These layers 

were observed on video and also identified by peaks in OBS turbidity 

values between 85 and 97 m, and between 155 and 160 m depth. Each of 

these layers occurs just above a small density contrast on the sigma-t 

profile (Fig. 19a).

Below about 225 m depth the numbers of floes increased to the 

bottom, reflected by increasing OBS values. This increase defines a 9 mthick nepheloid layer of colder, more saline water. The top of the 

nepheloid layer appeared "billowy" on the video. At about 1-2 m above 

the fjord bottom the water column was quite turbid. The bed is very 

"soupy" mud. The bottom current was flowing at about 24 cm/s in a 

down-fjord direction.

CONCLUSIONS

1. Comparing Kl-91 bathymetic profiles to NOAA 1978 bathymetry shows 

shoaling of the deep fjord floor by 2-6 meters. An exception is at the base

14
of the slope west of the Russell Fjord entrance area where 8-11 meters of 

shoaling has occurred. This decrease in water depth ostensibly is due to 

the breakup of the Hubbard Glacier ice dam in October 1986, resulting in 

large scale erosion, sediment transport into Disenchantment Bay, and 

redeposition.

2. High-resolution seismic-reflection profiles across the deep floor of 

Disenchantment Bay WSW of Haenke Island show subtle, low-relief 

seafloor scarps that may be the toes of flows generated by the jokulhlaup 

of October 8, 1986. Some of these flows also may have come from 

moraines of the Hubbard Glacier or the side-wall glaciers.

3. High-resolution seismic-reflection profiles indicate that more than 150 

m of sediment has accumulated in Disenchantment Bay basin since 

deglaciation. This sedimentation is a result of a combination of processes 

that include slide and gravity flow deposition that originates from the 

steep fjord side walls and from the morainal banks that are terminal 

moraines of Hubbard Glacier. Other important processes include 

particulate settling from the meltwater discharge plumes issuing from 

Hubbard and the smaller side-wall glaciers of Disenchantment Bay and 

Russell Fjord and iceberg rafting of sediment.

4. The present gradient of the Hubbard Glacier morainal bank decreases 

down fjord from ~14° to 3°. The "upper-bay moraine", located in the upper 

part of Yakutat Bay, has similar gradients 14.5° at the top part and 

averaging 2.6° over the lower part of the moraine. This similarity in 

morphology suggests that the "upper-bay moraine" is a satisfactory model 

for the modern morainal bank.

5. The tidewater glacier meltwater discharge and tidal currents dominate 

the water column properties of Disenchantment Bay. Interflows, possibly 

from high suspended matter discharge from Hubbard Glacier and perhaps 

the ebb-flow from Russell Fjord, create small density inversions in the 

water column. ROV dives and water samples also recorded the presence of 

a 26 m thick overflow near Hubbard Glacier. Suspended sediment 

concentrations were highest at the dive site closest to Hubbard Glacier 

(Table 1). Concentrations reached 602 mg/L in the overflow. On the slope 

west of the Russell Fjord entrance, ROV imagery showed strong, turbulent, 

down-fjord transport of large floes and marine snow at 5-7 m above the 

bottom. In the deep water of the fjord axis west of Haenke Island, a 

9-m-thick nepheloid layer was defined by the ROV data.

15
ACKNOWLEDGMENTS

We greatly appreciate the professional skippering of 

Jim Christmann, Santa Cruz, CA as a last-minute, skillful, substitute 

captain. Mike Boyle enthusiastically provided much needed electonics 

expertise and willing assistance in all phases of the cruise. We thank 

Sue Hunt and Judi Alien for their thorough logistical help, and we 

appreciate the assistance given to us by members of the U.S. National 

Forest Service in Yakutat. A sincere thank you goes to Gayle Ranney of 

Fishing and Flying in Yakutat for providing great help with 

communications, transportation, and logistical advice. Water depths were 

picked from the 7kHz bathymetric profiles by Christen Nail, a student at 

Appalachian State University. Funding for the cruise was provided by 

National Science Foundation Grant DPP 8822098 to R. Powell, by CRREL for 

D. Lawson's participation, and by the U.S. Geological Survey. Reviews by 

Dennis Trabant and Homa Lee were very helpful. We appreciate the 

assistance of Carolyn Degnan and Jean Riordan in plotting and merging the 

shoreline and tracklines and preparing the bathymetric and track!ine maps 

used in the field and in the open-file report.

REFERENCES

Atwood, T.A., Bruns. T.R., Carlson, P.R., Molnia, B.F., and Plafker, G., 1981.

Bathymetric map of the eastern Gulf of Alaska. Scale, 1:250,000.

U.S. Geological Survey Miscellaneous Field Study Map MF-859, 3

sheets. 

Carlson, P.R., 1989. Seismic reflection characteristics of glacial and

glacimarine sediment in the Gulf of Alaska and adjacent fjords.

Marine Geology, v. 85, p. 391-416. 

Carlson, P.R., Molnia, B.F., Hampson, J.C., Jr., Post, A., and Atwood, T.J.,

1978, Post-deglaciation sedimentation in Yakutat Bay, Alaska.

Transactions, American Geophysical Union, EOS, v. 59, p. 296. 

Carlson, P.R., Wheeler, M.C., Molnia, B.F., Post, A., and Powell, R.D., 1983,

Map showing post-neoglacial thickness and bathymetry in Tarr Inlet,

Glacier Bay, Alaska. U.S. Geological Survey Miscellaneous Field

Studies Map, MF-1456. 

Cowan, E.A., and Powell, R.D., 1990. Suspended sediment transport and

deposition of cyclically interlaminated sediment in a temperate

glacial fjord, Alaska, U.S.A. In Glacimarine Environments: Processes

and Sediments, Dowdeswell, J.A. and Scourse, J.D. (eds). Geological

Society of London Special Publication 53, p. 75-89.

1 6
Cowan, E.A., and Powell, R.D., 1991. Ice-proximal sediment

accumulation rates in a temperate glacial fjord, southeast

Alaska. In Anderson, J.B. and Ashley, G.M. (eds.), Glacial Marine

Sedimentation Paleoclimatic Significance. Geological Society of

America Special Paper 261, p. 75-93. 

Cowan, E.A., Powell, R.D., and Smith, N.D., 1988. Rainstorm induced event

sedimentation at the tidewater front of a temperate glacier. Geology,

v. 16, p. 409-412. 

Gilbert, G.K., 1904. Glaciers and glaciation: Harriman Alaska Expedition,

v. 3, New York, Doubleday, Page & Co. 

Mayo, L.R., 1989, Advance of Hubbard Glacier and 1986 outburst of

Russell Fiord, Alaska, U.S.A. Annals of Glaciology, v. 13, p. 189-194. 

Molnia, B.F., Atwood, TJ., Carlson, P.R., Post, A., and Vath, S.C., 1984.

Map of marine geology of upper Muir and Wachusett inlets, Glacier

Bay, Alaska: sediment distribution and thickness, bathymetry and

interpreted seismic profiles. U.S. Geological Survey, Open-file

Report 84-632, scale 1:40,000. 

Plafker, G. and Miller, D.J., 1958. Glacial features and surficial deposits of

the Malaspina District, Alaska. U.S. Geological Survey Miscellaneous

Geologic Investigations Map 1-271. 

Pickard, G.L., 1961. Oceanographic features of inlets in the British

Columbia mainland coast. Journal of the Fisheries Research

Board of Canada, 18, p. 907-999. 

Pickard, G.L., 1967. Some oceanographic characteristics of the larger

inlets of southeast Alaska. Journal of the Fisheries Research

Board of Canada, 24, p. 1475-1506. 

Post, A., and Mayo, L.R., 1971. Glacier-dammed lakes and outburst

floods in Alaska. U.S. Geological Survey Hydrologic Atlas

HA-455, 10 p., 3 pi. 

Powell, R.D., 199la Grounding-line systems as second order controls on

fluctuations of temperate tidewater termini. In Anderson, J.B. and

Ashley, G.M., (eds). Glacial Marine Sedimentation Paleoclimatic

Significance. Geological Society of America Special Paper 261,

p. 75-93. 

Powell, R.D., 1991b Grounding-line systems as feedbacks for marine

glacier stability: further evaluations from ROY submersible

observations. 13th INQUA Congress, Beijing, China, Abstracts

Volume: p. 287. 

Powell, R.D., Lawson, D.E., Cowan, E.A., Hunter, L.E., Cai, J., and Carlson,

P.R., 1991, Submersible observations of grounding lines and

morainal banks of tidewater termini of temperate glaciers.

Annual Geological Association of Canada Program with Abstracts,

p. 101.

17
Reeburgh, W.S., Muench, R.D., and Cooney, R.T., 1976. Oceanographic

conditions during 1973 in Russell Fjord, Alaska. Estuarine and

Coastal Marine Sciences, 4, p. 129-145. 

Royer, T.C., 1975. Seasonal variations of waters in the northern Gulf of

Alaska. Deep-Sea Research, 22, p. 403-416. 

Russell, I.C., 1891. An expedition to Mount St. Elias. National Geographic

Magazine, v. 3, p. 53-191. 

Seitz, W.G., Thomas, D.S., and Tomlinson, B., 1986. The storage and

release of water from a large glacier-dammed lake: Russell Lake

near Yakutat, Alaska. U.S. Geological Survey Open-File Report

86-545, 9p. 

Tarr, R.S., and Martin, L., 1914. Alaskan glacier studies. National

Geographic Society, Washington, D.C., 498 p. 

Trabant, D.C., Krimmel, R. M., and Post, A. 1991. A preliminary forecast

of the advance of Hubbard Glacier and its influence on Russell Fjord,

Alaska. U.S. Geological Survey Water Resources Investigations

Report 90-4172, 34p. 

Wright, F.F., 1972. Marine Geology of Yakutat Bay, Alaska. U.S. Geological

Survey Professional Paper 800-B, p. B9-B15.

1 8
140*30' 140*00' 139'30'

Kilometers 

20 m Contour Interval

r> Glacier

Bay-Mouth 

Moraine 

(600-900 yrs BP)

Pacific Ocean

- 60*00'

- 59*30'

Figure 1. Map showing location of Yakutat Bay, Disenchantment Bay, and 

Hubbard Glacier along northern Gulf of Alaska coast line. Detailed 

bathymetry is from Atwood et al., 1981. Areas of figures 2a and b 

are delineated by bold rectangles.

19
-1 39° 40' _., 39° 3 8' -139° 36' -139° 34' -139° 32' -1 39tr3$'9 ° 29 ' 

60=2', , ^ , v , r-^ , 60°2'

60 C

59 C 58'

59 r 56'

59 C 54'

-f

-h

60(

59°58'

59°56'

59°54'

_ ! 39 c 40, -139° 38' -139° 36' -139° 34' -139° 32' -1 391^§'g o 2g .

Figure 2a. Trackline map showing high-resolution seismic-reflection 

coverage in Disenchantment Bay. Numbered thicker lines locate 

illustrated profiles. See figure 1 for location.

20
~ 139-1 §9° 44' -139° 42' -139° 40' -139° 38' -1 39Tri^'9 ° 35 '

59°55'

59°54'

59°52'

59°50'

59°48'

59°46'

59°45'

Upper Yakutat Bay

59°55'

59°54'

59°52'

59°50'

59°48'

59°46'

59°45'

-1 39Tr4§'9C44/ -139° 42' -139° 40' -139°38' -1 391}§'9035,

Figure 2b. High-resolution seismic-reflection profile lines in upper

Yakutat Bay. Numbered thicker lines locate illustrated profiles. 

See figure 1 for general location in greater Yakutat Bay.

21
04

Miller Glacier

Haenke Glacier

\ Hubbard Glacier

60'00

2km

59° 56'

139" 35 139« 30'

Figure 3. Detailed bathymetry of Disenchantment Bay. Contoured from 

NOAA depth soundings (Hydrographic Surveys 9778 & 9779) 

collected in 1978. Contour intervals are 20 m on the fjord walls and 

10 m on deep basin floor, supplemented by 5 m intervals at 

>230 m depth. Location of ice face of Hubbard Glacier approximated 

from July 20, 1990 aerial photographs furnished by Robert Krimmel, 

USGS, Tacoma, Washington. Arrows show generalized path of 

outburst flood waters (October 8, 1986) based on descriptions by 

Mayo (written memorandum, November 19, 1986; 1989). 22
DISENCHANTMENT BAY

0 1km 

3=SHOALING AMOUNT (M)

 ^FJORD FLOOR OUTLINE 

^-4 2 M CONTOUR WTERVAL

e LOW-RELEF SCARP - HACHURES 

PONT UP SLOPE FROM FLOW TOE

Figure 4. Map of deep fjord basin floor in Disenchantment Bay showing 

amount of shoaling that has occurred between 1978 (see contoured 

bathymetry Fig. 3) and 1991 (cruise Kl-91). Also included are 

locations of low-relief scarps mapped from high-resolution 

seismic-reflection profiles. Ice margin positions: June, 1986

(Mayo, 1989); July, 1990 (aerial photo-see Fig. 3).

23
0.1

K)

0.2 -

West Wall 

Slide or Debris Flow Deposit

Haenke Island 

Bedrock Platform

*T

Figure 5. Geopulse profile across width of deep basin floor showin

(>150 m) sequence of sediment. Note slide or debris flow d

base of west wall; disrupted, discontinuous reflections at dep

sediment (>25 m) in west half of basin also are indicative of 

movement deposit. See figure 2a for location. Vertical exa

(V.E.)~7x
..XT

to

(J1

0.4

\

\ 

Figure 6. Geopulse profile showing hummocky, chaotic mass 

debris reflections at base of west wall near Turner Glacier

profile is just north of profile shown in figure 5, illustrat

abundance of mass movement deposits that contribute to 

fill. See figure 2a for location. V.E.~7x
(s) TIME TWO-WAY 

o

(m) DEPTH WATER 
0.1

Small Step Scarps

Slide or Debris Flow Scarp .0.5

Slide or Debris Flow Deposit

Slide or Debris Flow Deposit

Figure 8. Geopulse profile that shows a small scarp and a series 

small step scarps on west wall of the fjord and an accumul

of mass movement debris in basin at base of wall. See figu

for location. V.E.~7x.
0.2

0.4 -

 < " ti$r^^ "Buried Debris from Wa" of R°rd^"^p^W

; ! !*f**r " ' jt.-iv i I : :'''V: i:^:;^: rv'^;

 ' - -*« -.^t'^-- -'--- ,-- - .-I !.-....... .. ....... ....,'.:v:;.:._!.'' 

O

M 

l-i

3 

O

iU 

o

M)

§

f

u

'

ro

CD

Figure 9. The west side of two adjacent Geopulse profiles shows a 

mass movement deposit at the base of the fjord wall near Tu

Glacier. See figure 2a for location. V.E.~7x.
(s) TIME TWO-WAY 

o P 

(m) DEPTH WATER 
TIME TWO-WAY 

 *&»,; ;,«.jfev i*z- V----1 f . -.*- -.. - '.: 

jSh>3itr, " -.T»* - ::,':. -J-vr"V j-..'- -. :

^^:-r:M%^ :.v%--fc~--W>i*fl-? ! -.:-:r>-?,.:~-f--

. K. * ^_!MM. _~k_-^ . !., _ -- 

(m) DEPTH WATER 
P

u>

(s) TIME TWO-WAY 

o o 

i~ N) 

00

e

3

O v* 

*- *» « ^ 

N- e a, ? 

. c e> e» 

w o 5* 

O 5 * 

MMI r> A 

w C C v» 

S <^ ea 

T3 O 

w3 a S 

S *< 3 

_ » ^^ 

O 00 (9 

2. sr *» 

? e 2 

2- 8 3 ® 

w *> o e» 

-. S! C ^ 

O o. 5 ; 

**» 5* 3 O 

rt ^ a 

*o ^ s. ^ 

cv"0 O < 

2" -. 

" - 

i?a ' 

s

^»

S

ts> 

S)

(m) DEPTH WATER 
0.3 ~ 

of Debris or Mud Flow

0.4 *

U)

K)

Figure 12. High-resolution Geopulse profile of deep fjord floor we

southwest of Haenke Island showing subtle scarp of debris o

flow. See figure 2a for location. V.E.~7x.
>- 0.4

$ 

g0.3|-

 :! <& 

i Hydrophone Hit 

, Floating Ice

i

, Lens (Debris Flow Deposit) ens

»

--- ~~Z^~ 

 _^ --------- " 

0.4

Figure 13. High-resolution Geopulse profile showing buried le

flow deposit within deep fjord floor sediment fill. See fi

for location. V.E.~7x.
*« 04

Miller Glacier

i Hubbard Glacier

60° 00'

/ D-6

68-73)

2km

Figure 14. Location map of ROV dive sites D-l through D-6 and water 

column samples (57-73).

34
0

TEMPERATURE(°C) SALINITY (% ) SIGMA-T OBS (

0 6 22_ 32 17 25 0 ___

¥v^

33

W 

Q

90

T I I I I I I I I I il 

CJ

U1

Figure 15. Profiles of temperature, salinity, sigma-t, and OBS col

from dive site 1 on June 24, 1991. Dive began at 0905 hou

(Alaska day light time) and ended short of the bottom. (Lo

throughout). See figure 14 for locations of all dive sites.
TEMPERATURE(°C) SALINITY (%«» OBS (TURBIDITY)

0 6 22

^ -V

e, r

i

32 C

i r -i. i i i i i i

100 i r i i i- 1 i i L

-\ i

1

240

Figure 16a. Profiles of temperature, salinity, and OBS collected

from dive site 2 on June 24, 1991. Descent began at 1016 hours.

TEMPER ATURE(°C) SALINITY (%o>

0

6 22 32

OBS (TURBIDITY)

w Q

120

I I I I J i 1 I I

380 iiiniiiiiiiiiiTiT

I

Figure 16b. Profiles of temperature, salinity, and OBS collected from 

dive site 3 on June 24, 1991. ROV descent was located 

approximately 50 m away from Hubbard ice face and began at

1445 hours. Dive did not reach bottom.

36
TEMPERATURE (°C) SALINITY (%*) 

0 ___ 6 22

I 1 I I T

OBS (TURBIDITY) 

32 1 0 70

II I 1 > I I IT I I I ! I

70

Figure 17a. Profiles of temperature, salinity, and OBS collected during 

descent at dive site 4 on June 27, 1991, adjacent to Russell Fjord 

breakout site. Descent began at 1049 hours, during ebb tide.

0

TEMPERATURE (°C) SALINITY (%*> 

0 6 22

X

fc

w

Q

1 I I

32

I 1 I I Ml \TT

OBS (TURBIDITY)

0_____ 90

1 I I I I 1 1

70

Figure 17b. Profiles of temperature, salinity, and OBS turbidity

collected from dive site 4 on June 27, 1991, adjacent to Russell 

Fjord breakout site. This profile was collected during ascent from 

fjord floor at 1111 hours.

37
TEMPERATURE (°C) SALINITY (%<» SIGMA-T OBS (TU

0

I

ac

£

W

3

40

P <

1 1 1 1 .;'

 

_ * _

i

\

i

i

*M 1 Mi

* ,

1

1

^* 

1

r

t ; c

/.

_ ^

i «

 f

12 3

i i i ri. i i i i

%

 l t

^* * mm

tf

\

t

Ml * ^

 ,

11 » %***

t

1V-

/1-

1

.

_ .

-

2 :20 25 0 

1- - . 1 1 1 i.

 , ^* * ^m t t

s

1

 ,

\

\

^* \^m

1

1

V

/

|

m* 

mm 

 -

 » m

mm m

mm m

1 1 I 

^* 

 1 ' 

V

)

** * 

f

1

\%

" N*

" /'

- (

i

 * V

-I' 

. i

Figure 18. Profiles of temperature, salinity, sigma-t, and OBS

turbidity collected from dive site 5 on June 27, 1991. The 

began at 1257 hours and reached bottom at 1322 hours.

00
0

TEMPERATURE(°C) SALINITY (%o> SIGMA-T 

Q__ 622 ___ 3220

r X

a

Q -

OBS (T

25 0 

240

1 1 1 I 1

mm "» mm

1

1

V ,

 1 « 

\

V

- 4-

j

; /' 

"

: I'

1 1 1 1 1 1 1. 1 1

 

 ,

%

J'

_ '.' .

: 1

 i 

i

1 1 ' ! 1

 « ^

%

*»,

I t "

y

r . j

-

.

_

-

" 

i i r 

^ 

I ;

"" *' . 

. ?*' 

.<

- < 

;i. 

-/

7-L.

Figure 19a. Profiles of temperature, salinity, sigma-t, and OBS co

from dive site 6 on June 27, 1991. Dive began at 1447 hou

reached bottom at 1507 hours.

OJ 

<£>
0

CURRENT VELOCITY (cm/s) 

0 100

240

T

Figure 19b. Current speed measured on ascent at dive site 6. Data 

are mean values of 20 to 24 readings at each depth. Current 

velocity at 40 m depth could not be measured because ROV 

was constantly spinning on its tether. Speed exceeded other 

depths, but magnitude is unknown.

40
Table 1. Water Samples Collected from Disenchantment Bay RV KARLUK 

Cruise K1-91-YB (See Fig. 14 for locations).

DATE

6-24-91 

6-24-91 

6-24-91 

6-24-91

6-24-91 

6-24-91 

6-24-91 

6-24-91 

6-24-91

6-27-91

6-27-91 

6-27-91 

6-27-91 

6-27-91 

6-27-91 

6-27-91

DEPTH ODNCEhrrRATION 

TIME _(m)_ __(mg/L)__

1057 30 159

1102 20 182

1106 10 196

1110 5 155

1434 0 602

1545 11 530

1550 20 337

1602 36 270

1619 5 63

1354 0 85

1607 0 19

1628 23 89

1635 17 78

1640 10 67

1642 5 62

1648 35 67

DCATKDN

Dive 2

Dive 2

Dive 2

Dive 2

Dive 3

Dive 3

Dive 3

Dive 3

Dive 3

Dive 5

Dive 6

Dive 6

Dive 6

Dive 6

Dive 6

Dive 6

SAMPLE

NUMBER

HG91-57

HG91-58

HG91-59

HG91-60

HG91-61

HG91-63

HG91-64

HG91-66

HG91-62

HG91-67

HG91-68

HG91-69

HG91-70

HG91-71

HG91-72

HG91-73

41