U.S. Department of the Interior

U.S. GEOLOGICAL SURVEY

A Compilation of Sulfur Dioxide and Carbon Dioxide Emission-Rate Data
from Cook Inlet Volcanoes (Redoubt, Spurr, Iliamna, and Augustine),
Alaska During the Period from 1990 to 1994

by

Michael P. Doukas^1^

Open-File Report 95-55

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 does not imply endorsement by the U.S.
Government.

^1^Anchorage, Alaska

Table of Contents Page

Introduction\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...
3

Discussion
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4

Acknowledgments
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4

References
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4

Figures

Figure 1. Map of the Cook Inlet area,
Alaska\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\.....
6

Figure 2. Graph of average SO~2~ and CO~2~ emission rates

(metric tonnes per day) from Redoubt Volcano
\...\...\...\...\...\...\...\...\...\... 7

Figure 3. Graph of average SO~2~ and CO~2~ emission rates

(metric tonnes per day) from Spurr volcano
\...\...\...\...\...\...\...\...\...\...\..... 8

Figure 4. Graph of average SO~2~ emission rates

(metric tonnes per day MT/D) from Iliamna volcano
\...\...\...\...\...\...\... 9

Figure 5. Graph of average SO~2~ and CO~2~ emission rates

(metric tonnes per day) from Augustine volcano
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Tables

Table 1. Beginning dates of SO~2~ and CO~2~ measurements

at Cook Inlet volcanoes
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11

Table 2. Listing of average SO~2~ emission rates
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**INTRODUCTION**

Airborne sulfur dioxide (SO~2~) gas sampling of the Cook Inlet volcanoes
(Mt. Spurr, Redoubt, Iliamna, and Augustine, fig. 1) began in 1986 when
several measurements were carried out at Augustine volcano during the
eruption of 1986 (Rose and others, 1988). More systematic monitoring for
SO~2~ began in March 1990 and for carbon dioxide (CO~2~) began in June,
1990 at Redoubt Volcano (Brantley, 1990 and Casadevall and others, 1994)
and continues to the present. This report contains all of the available
daily SO~2~ and CO~2~ emission rates determined by the U.S. Geological
Survey (USGS) from March 1990 through July 1994. Intermittent
measurements (four to six month intervals) at Augustine and Iliamna
began in 1990 and continues to the present. Intermittent measurements
began at Mt. Spurr volcano in 1991, and were continued at more regular
intervals from June, 1992 through the 1992 eruption at the Crater Peak
vent to the present.

A correlation spectrometer (COSPEC) was used to measure SO~2~ in the
Cook Inlet volcanic plumes. The upward-looking COSPEC was mounted in a
fixed-wing aircraft and flown below and at right angles to the plume.
The first traverse (or orbit) during a measurement was used to determine
the size, location and direction of the volcanic plume. In some cases no
SO~2~ plume was detected by the instrument and a value of zero was
reported as the SO~2~ rate. Even though SO~2~ may have been sensed by
the operator\'s nose (more sensitive than the instrument), a rate of
zero was still reported. Typically, three to six traverses were made
underneath the plume to determine an average SO~2~ burden (concentration
multiplied by the pathlength) within a cross-section of the plume.
Knowing the burden, the plume width and plume velocity (assumed to be
the same as ambient wind speed), the emission rate of SO~2~ was
calculated. The resultant value of SO~2~ is reported after values of
more than one standard deviation from the average have been removed. All
emission rates are reported in metric tons/day (t/d) above the
background level upwind of the volcano. The use of correlation
spectroscopy for determining the SO~2~ output of volcanoes is well
established and the technique has been discussed in detail by a number
of investigators (Malinconico, 1979; Casadevall and others, 1981;
Stoiber and others, 1983).

Carbon dioxide in the Cook Inlet volcanic plumes was measured by an
infrared spectrometer (MIRAN) tuned to the 4.26 micrometers CO~2~
absorption band. Volcanic CO~2~ is defined as that gas detected within a
volcano\'s plume that is in excess of the concentration of ambient CO~2~
in the atmosphere. An external sample tube was attached to the fuselage
of a twin-engine aircraft to deliver outside air to the gas cell of the
MIRAN. The aircraft was then flown at several different but increasing
elevations through the plume. These traverses were at right angles to
the plume trajectory and defined plume area and CO~2~ concentration in a
vertical cross-section of the plume. Plume area, CO~2~ density at the
mean altitude of the plume, and the plume velocity (assumed to be equal
to the ambient wind speed), were then used to calculate the CO~2~
emission rate. The resulting calculated CO~2~ emission rate is not an
average of several measurements (as is the case for SO~2~ emission
values), but one value. During times of low emission rates and low wind
speeds, orbits within a kilometer of the vent were required, which gave
low results because of slow instrumental response times. Thus, some
CO~2~ measurements reported here are indicated to be minimum values. All
emission rates are reported in metric tons/day (t/d) above the
background level upwind of the volcano. The use of infrared spectroscopy
for determining the CO~2~ output of volcanoes is discussed in detail by
Harris and others (1981).

**DISCUSSION**

From March 1990 to October 1994, more than one hundred fixed-wing
aircraft flights were made by the USGS in order to measure and
characterize gas emissions from the Cook Inlet volcanoes. The beginning
dates for measurements of SO~2~ and CO~2~ emissions at Cook Inlet
volcanoes are listed in Table 1. Sulfur dioxide was detected on the
majority of these flights. Sixty-four flights were made to Redoubt
Volcano, most of which were made during the eruption of 1989-90 (table
1). Sulfur dioxide burden in the Redoubt plume fell below detection
limits in May 1991 (fig. 2). Carbon dioxide was measured twice at
Redoubt volcano in June of 1990 (fig. 2) and four times from 1992 to
1994. On a few occasions, two or three separate SO~2~ gas-measurement
flights to Redoubt volcano were made in a single day. In these cases all
of the emission-rate values are listed for that day but are considered
separate measurements (11, April, 1990 \[2 flights\]; 15, August, 1990
\[3 flights\]; 7, September, 1990 \[2 flights\]). Forty flights were
made to Mt. Spurr volcano most of which were made during the 1992
eruption series (table 3). Sulfur dioxide burden at Mt. Spurr volcano
(the Crater Peak vent) fell below detection limits in October of 1992
(fig. 3). Carbon dioxide levels were measured from September 1992 to the
present at Mt. Spurr volcano (Fig. 3, table 1). Inflight measurements at
Mt. Spurr volcano will continue until CO~2~ levels are near background
levels. Nine flights were made to Iliamna volcano (fig. 4, table 1).
Seven flights were made to Augustine volcano (fig. 5, table 1). Carbon
dioxide measurements were attempted at Augustine and Iliamna volcanoes
during 1993 and 1994, with no gas detected above atmospheric
concentrations. Portions of this database have been presented earlier by
Casadevall and others (1994) and Doukas and Gerlach (in press).

**ACKNOWLEDGMENTS**

I acknowledge the efforts of the numerous individuals who contributed to
the success of the USGS airborne gas measurement program in Alaska by
participating in the gas flights. Funding for this work has been
provided by the USGS Volcano Hazards Program.

**REFERENCES CITED**

Casadevall, T.J., Johnston, D.A., Harris, D.M., Rose, W.I., Malinconico,
L.L., Stoiber, R.E., Bornhorst, T.J., Williams, S.N., Woodruff, L. and
Thompson, J.M., 1981, SO~2~ emission rates at Mount St. Helens from
March 29 through December, 1980, [in]{.underline} Lipman, P.W., and
Mullineaux, D.L., eds., The 1980 eruptions of Mount St. Helens,
Washington: U.S. Geological Survey Professional Paper 1250, p. 193-200.

Casadevall, T.J., Doukas, M.P., Neal, C.A., McGimsey, R.G., and Gardner,
C.A., 1994, Emission rates of sulfur dioxide and carbon dioxide from
Redoubt Volcano, Alaska during the 1989-1990 eruptions: Journal of
Volcanology and Geothermal Research, v. 62, p. 519-530.

Brantley, S.R., 1990, The eruption of Redoubt Volcano, Alaska, December
14, 1989 - August 31, 1990: U.S. Geological Survey Circular 1061, p. 33.

Doukas, M.P. and Gerlach, T. M., (in review), Sulfur dioxide scrubbing
during the 1992 eruption of Crater Peak, Spurr volcano, Alaska.
[in]{.underline} Keith, T.E.C., ed., The 1992 eruptions of Crater Peak
vent, Spurr volcano, Alaska: U.S. Geological Survey Bulletin.

Harris, D.M., Sato, M., Casadevall, T.J., Rose, W.I., and Bornhorst,
T.J., 1981, Emission rates of CO2 from plume measurements,
[in]{.underline} Lipman, P.W. and Mullineaux, D.L., eds., The 1980
eruptions of Mount St. Helens, Washington: Washington: U.S. Geological
Survey Professional Paper 1250, p. 201-207.

Malinconico, L.L., 1979, Fluctuations in SO~2~ emission during recent
eruptions of Etna: Nature, v. 278, p. 43-45.

Rose, W.I., Heiken, G., Wohletz, K., Eppler, D., Barr, S., Miller, T.,
Chuan, R.L., and Symonds, R.B., 1988, Direct rate measurements of
eruption plumes at Augustine volcano: A problem of scaling and
uncontrolled variables: Journal of Geophysical Research, v. 93, no. B 5,
p. 4485-4499.

Stoiber, R.E., Malinconico, L.L., Williams, S.N., 1983, Use of the
correlation spectrometer at volcanoes, [in]{.underline} Tazieff, H. and
Sabroux, J.C., eds., Forecasting Volcanic Events: Amsterdam, Elsevier,
p. 425-444.

Figure 1. Index map showing the location of the Cook Inlet volcanoes
included in this report. Filled triangles = volcanoes of this report;
open triangles = location of other nearby volcanoes.

Figure 2. Graph of sulfur dioxide and carbon dioxide emission rates (in
metric tonnes per day, MT/D) from Redoubt Volcano, March 1990 to April
1993. Open boxes = average sulfur dioxide emission rate for a single
flight; closed triangles = carbon dioxide emission rate; vertical solid
line = onset of 1989-1990 eruptions of Redoubt Volcano.

Figure 3. Graph of sulfur dioxide and carbon dioxide emission rates
(MT/D) from Spurr volcano, July 1991 to July 1994. Open boxes = average
sulfur dioxide emission rate; closed triangles = carbon dioxide emission
rate; vertical solid lines = 1992 eruptions of Spurr volcano.

Figure 4. Graph of sulfur dioxide emission rates (MT/D) from Iliamna
volcano, March 1990 to April 1993. Open boxes = average sulfur dioxide
emission rate; closed triangle = CO~2~ emission rate.

Figure 5. Graph of sulfur dioxide and carbon dioxide emission rates
(MT/D) from Augustine volcano, March 1990 to July 1994. Open boxes =
average sulfur dioxide emission rate; closed triangle = CO~2~ emission
rate.

Table 1. Beginning dates of SO~2~ and CO~2~ measurements at Cook Inlet
volcanoes.

Volcano

> SO~2~-start
>
> number of measurements
>
> CO~2~ - start
>
> number of measurements

Redoubt

> March, 1990
>
> 64
>
> June, 1990
>
> 7

Spurr

> July, 1991
>
> 40
>
> Sept., 1992
>
> 25

Iliamna

> March, 1990
>
> 9
>
> Oct., 1992
>
> 3

Augustine

> March, 1990
>
> 7
>
> July, 1994
>
> 2

Table 2. SO~2~ and CO~2~ Emission Rates From Cook Inlet volcanoes
(metric tons per day), number of traverses per flight (n), standard
deviation (s.d.) for SO~2;~ no measurements (n.m.), minimum value (\>).

**REDOUBT VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

20-Mar-90 4609 5 534 n.m.

21-Mar-90 2033 8 261 n.m.

22-Mar-90 1609 6 148 n.m.

23-Mar-90 2502 6 97 n.m.

24-Mar-90 3798 4 182 n.m.

01-Apr.-90 3892 9 1151 n.m.

06-Apr.-90 3662 6 619 n.m.

07-Apr.-90 2819 7 584 n.m.

08-Apr.-90 4145 8 433 n.m.

11-Apr.-90 4826 7 1381 n.m.

11-Apr.-90 2510 8 190 n.m.

14-Apr.-90 1691 8 286 n.m.

17-Apr.-90 5855 8 752 n.m.

22-Apr.-90 3464 8 584 n.m.

25-Apr.-90 6121 8 967 n.m.

27-Apr.-90 3601 8 939 n.m.

03-May-90 3258 6 540 n.m.

04-May-90 4115 9 323 n.m.

19-May-90 3116 9 402 n.m.

20-May-90 4177 9 534 n.m.

22-May-90 4150 10 894 n.m.

25-May-90 2492 11 404 n.m.

01-June-90 1249 6 99 n.m.

02-June-90 1489 4 421 1200

05-June-90 3814 4 261 2400

07-June-90 1601 7 313 n.m.

09-June-90 2340 6 198 n.m.

11-June-90 2462 3 39 n.m.

30-June-90 657 6 100 n.m.

04-July-90 868 6 174 n.m.

12-July-90 1591 9 132 n.m.

16-July-90 1131 6 205 n.m.

19-July-90 2179 6 121 n.m.

03-Aug.-90 1660 6 219 n.m.

13-Aug.-90 1008 5 115 n.m.

14-Aug.-90 2376 6 138 n.m.

TABLE 2. continued

**REDOUBT VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

15-Aug.-90 1002 6 183 n.m.

15-Aug.-90 742 6 37 n.m.

15-Aug.-90 2609 5 368 n.m.

31-Aug.-90 469 5 161 n.m.

07-Sept.-90 188 4 21 n.m.

07-Sept.-90 680 3 81 n.m.

13-Sept.-90 723 4 78 n.m.

25-Sept.-90 297 6 43 n.m.

28-Sept.-90 897 6 89 n.m.

03-Oct.-90 366 8 21 n.m.

15-Oct.-90 586 4 36 n.m.

21-Oct.-90 510 9 76 n.m.

27-Oct.-90 162 8 36 n.m.

08-Nov.-90 577 8 158 n.m.

23-Jan.-91 297 2 140 n.m.

21-Mar.-91 35 7 10 n.m.

04-Apr.-91 149 9 45 n.m.

10-Apr.-91 29 5 11 n.m.

06-May-91 73 5 25 n.m.

22-May-91 24 4 7 n.m.

31-May-91 0 2 0 n.m.

21-Aug.-91 0 2 0 n.m.

14-May-92 0 1 0 n.m.

14-Oct.-92 0 2 0 0

23-Oct.-92 0 1 0 0

15-Nov.-92 0 1 0 0

24-Apr.-93 0 2 0 0

07-July-94 0 2 0 0

**SPURR VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

22-July-91 0 1 0 n.m.

21-Aug.-91 0 2 0 n.m.

29-Aug.-91 0 2 0 n.m.

03-Sept.-91 85 2 18 n.m.

22-Nov.-91 0 2 0 n.m.

14-May-92 88 2 10 n.m.

TABLE 2. continued

**SPURR VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

08-June-91 21 2 4 n.m.

29-June-92 5 5 3 n.m.

10-Sept.-92 0 0 0 n.m.

21-Sep-92 23 5 12 n.m.

23-Sep-92 24 4 7 n.m.

24-Sep-92 79 3 11 n.m.

25-Sep-92 300 4 54 11000

28-Sep-92 194 4 25 12000

29-Sep-92 749 3 75 8700

02-Oct.-92 452 2 0 n.m

03-Oct.-92 220 4 114 4800

04-Oct.-92 212 4 72 3500

05-Oct.-92 356 4 173 2900

10-Oct.-92 243 3 100 n.m

14-Oct.-92 47 3 4 2400

15-Oct.-92 64 2 4 n.m.

16-Oct.-92 105 4 16 \>2000

19-Oct.-92 0 1 0 \>0

23-Oct.-92 24 2 3 2100

29-Oct.-92 0 1 0 \>0

10-Nov.-92 0 1 0 0

11-Nov.-92 0 3 0 0

12-Nov.-92 0 1 0 1100

13-Nov.-92 0 1 0 1000

15-Nov.-92 0 1 0 1000

08-Dec.-92 0 1 0 \>1000

11-Dec.-92 0 1 0 \>500

15-Dec.-92 0 1 0 3200

18-Dec.-92 0 1 0 \>1000

23-Dec.-92 0 1 0 \>1000

21-Jan.-93 0 1 0 \>1000

18-Feb.-93 0 1 0 \>400

24-Apr.-93 0 1 0 \>930

07-July-94 0 1 0 0

TABLE 2. continued

**ILIAMNA VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

20-Mar-90 0 2 0 n.m.

05-June-90 0 2 0 n.m.

31-May-91 24 4 5 n.m.

13-June-91 18 2 4 n.m.

21-Aug.-91 41 3 9 n.m.

21-Nov.-91 0 3 0 n.m.

23-Oct.-92 35 2 6 0

24-Apr.-93 38 2 5 0

07-July-94 19 2 6 0

**AUGUSTINE VOLCANO**

Date SO~2~ n s.d. CO~2~

Rate Rate

20-Mar-90 0 2 0 n.m.

13-June-91 4 3 1 n.m.

21-Aug.-91 0 2 0 n.m.

20-Nov.-91 0 2 0 n.m.

14-May-92 0 2 0 n.m.

23-Oct.-92 0 1 0 0

07-July-94 0 2 0 0

**Open-File Report 95-55, A Compilation of Sulfur Dioxide and Carbon
Dioxide Emission-Rate Data from Cook Inlet Volcanoes (Redoubt, Spurr,
Iliamna, and Augustine), Alaska during the Period from 1990 to 1994.**

By Michael P. Doukas. 1995. 15 p.

Open-File Report 95-55

This report contains all of the available daily sulfur dioxide and
carbon dioxide emission rates from Cook Inlet volcanoes as determined by
the U.S. Geological Survey (USGS) from March 1990 through July 1994.
Airborne sulfur dioxide gas sampling of the Cook Inlet volcanoes
(Redoubt, Spurr, Iliamna, and Augustine) began in 1986 when several
measurements were carried out at Augustine volcano during the eruption
of 1986. From March 1990 to October 1994, more than one hundred
fixed-wing aircraft flights were made by the USGS in order to measure
and characterize gas emissions from the Cook Inlet volcanoes. Systematic
monitoring for sulfur dioxide and carbon dioxide began in March 1990 at
Redoubt volcano and continues to the present. Intermittent measurements
at Augustine and Iliamna volcanoes began in 1990 and continues to the
present. Intermittent measurements began at Spurr volcano in 1991, and
were continued at more regular intervals from June, 1992 through the
1992 eruption at the Crater Peak vent to the present.

REQUEST FOR OPEN-FILE REPORT RELEASE

To: Branch of Technical Reports

Following is the needed information for announcements of an open-file
report in the monthly list of \"New Publications of the Geological
Survey\": and for preparation of an open-file report release notice.

Title: A Compilation of Sulfur Dioxide and Carbon Dioxide Emission-Rate
Data from Cook Inlet Volcanoes (Redoubt, Spurr, Iliamna, and Augustine),
Alaska during the period from 1990 to 1994.

Author(s): Michael P. Doukas

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