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A Compilation of Sulfur Dioxide and Carbon Dioxide Emission-Rate Data from Mount St. Helens during 1980-88

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   McGee, Kenneth A. , and Casadevall, Thomas J. , 1994, A Compilation of Sulfur Dioxide and Carbon Dioxide Emission-Rate Data from Mount St. Helens during 1980-88: U.S. Geological Survey Open-File Report 94-212, U.S. Geological Survey, Reston, VA.

   Online Links:

   • <http://pubs.usgs.gov/of/1994/of94-212/>

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.250

   East_Bounding_Coordinate: -122.125

   North_Bounding_Coordinate: 46.250

   South_Bounding_Coordinate: 46.125

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 01-May-1980

   Ending_Date: 18-Sep-1988

   Currentness_Reference: U.S. Geological Survey Open-File Report 94-212

5. What is the general form of this data set?

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      Indirect_Spatial_Reference:

      Typically, three to six traverses were made underneath the plume to determine the SO2 burden (concentration x pathlength) within a cross-section of the plume. Knowing the burden along with the plume width and plume velocity (assumed to be the same as ambient wind speed), we could then calculate the emission rate of SO2.
      

   2. What coordinate system is used to represent geographic features?

7. How does the data set describe geographic features?

   Sulfur dioxide emission rate estimate

   Typically, three to six traverses were made underneath the plume to determine the SO2 burden (concentration x pathlength) within a cross-section of the plume. Knowing the burden along with the plume width and plume velocity (assumed to be the same as ambient wind speed), we could then calculate the emission rate of SO2. (Source: The use of correlation spectroscopy for determining the sulfur dioxide 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).)

   Sulfur dioxide emission rate estimate

   Material flux in tonnes/day (Source: Casadevall, T.J., Johnston, D.A., Harris, D.M., Rose, W. I., Malinconcio, L.L., Stoiber, R.E., Bornhorst, T.J., Williams, S.N., Woodruff, Laurel and Thompson, J.M., 1981, SO2 emission rates at Mount St. Helens from March 29 through December, 1980, in 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.)

   Frequency of measurement: Irregular

   Range of values
   Minimum:	3
   Maximum:	no value exceeds 10000
   Units:	tonnes/day
   Resolution:	1

   Carbon dioxide emission rate estimate

   Carbon dioxide in the Mount St. Helens plume was measured by an infrared spectrometer tuned to the 4.26 um CO2 absorption band. An external sample tube was attached to the fuselage of a twin-engine aircraft to deliver outside air to the gas cell of the spectrometer. The aircraft was then flown at several different elevations through the plume at right angles to plume trajectory to define plume area and carbon dioxide concentration in a vertical cross- section of the plume. These two parameters along with the density of CO2 for the altitude of the plume and the plume velocity (assumed as above to be equal to ambient wind speed) were then used to calculate the CO2 emission rate (Harris and others, 1981). (Source: Harris, D.M., Sato, Motoaki, Casadevall, T.J., Rose, W.I. and Bornhorst, T.J., 1981, Emission rates of CO2 from plume measurements, in Lipman, P.W. and Mullineaux, D.L., eds., The 1980 eruptions of Mount St. Helens, Washington: U.S. Geological Survey Professional Paper 1250, p. 201-207.)

   Carbon dioxide emission rate estimate

   Material flux in tonnes/day (Source: Harris, D.M., Sato, Motoaki, Casadevall, T.J., Rose, W.I. and Bornhorst, T.J., 1981, Emission rates of CO2 from plume measurements, in Lipman, P.W. and Mullineaux, D.L., eds., The 1980 eruptions of Mount St. Helens, Washington: U.S. Geological Survey Professional Paper 1250, p. 201-207.)

   Frequency of measurement: Irregular

   Range of values
   Minimum:	3, but no actual value is smaller than 262
   Maximum:	no value exceeds 25000
   Units:	tonnes/day
   Resolution:	1

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Kenneth A. McGee
   • Thomas J. Casadevall

2. Who also contributed to the data set?

3. To whom should users address questions about the data?
   Kenneth A. McGee
   David A. Johnston Cascades Volcano Observatory
   U.S. Geological Survey
   5400 MacArthur Boulevard
   Vancouver, WA 98661
   USA
   

   (206) 696-7695 (voice)
   kenmcgee@pwavan.wr.usgs.gov
   

Why was the data set created?

Presentation of airborne measurements of volcano emissions during and following the 1980 eruption of Mount St. Helens, Washington.

How was the data set created?

1. From what previous works were the data drawn?

2. How were the data generated, processed, and modified?

   Date: 1980 (process 1 of 1)

   Airborne monitoring of Mount St. Helens by the USGS began in May 1980 for sulfur dioxide emissions and in July 1980 for carbon dioxide emissions. A correlation spectrometer, or COSPEC, was used to measure sulfur dioxide in Mount St. Helens' plume. The upward-looking COSPEC was mounted in a fixed-wing aircraft and flown below and at right angles to the plume. Typically, three to six traverses were made underneath the plume to determine the SO2 burden (concentration x pathlength) within a cross-section of the plume. Knowing the burden along with the plume width and plume velocity (assumed to be the same as ambient wind speed), we could then calculate the emission rate of SO2.
   Carbon dioxide in the Mount St. Helens plume was measured by an infrared spectrometer tuned to the 4.26 um CO2 absorption band. An external sample tube was attached to the fuselage of a twin-engine aircraft to deliver outside air to the gas cell of the spectrometer. The aircraft was then flown at several different elevations through the plume at right angles to plume trajectory to define plume area and carbon dioxide concentration in a vertical cross- section of the plume. These two parameters along with the density of CO2 for the altitude of the plume and the plume velocity (assumed as above to be equal to ambient wind speed) were then used to calculate the CO2 emission rate (Harris and others, 1981).

   Person who carried out this activity:
   

   Kenneth A. McGee
   David A. Johnston Cascades Volcano Observatory
   U.S. Geological Survey
   5400 MacArthur Boulevard
   Vancouver, WA 98661
   USA
   

   (206) 696-7695 (voice)
   kenmcgee@pwavan.wr.usgs.gov
   

   Data sources used in this process:

   • Malinconico, L.L., 1979, Fluctuations in SO2 emission during recent eruptions of Etna: Nature, v. 278, p. 43-45.
   • Stoiber, R.E., Malinconico, L.L. and Williams, S.N., 1983, Use of the correlation spectrometer at volcanoes, in Tazieff, H. and Sabroux, J.C., eds., Forcasting Volcanic Events: Amsterdam, Elsevier, p. 425-444.
   • Harris, D.M., Sato, Motoaki, Casadevall, T.J., Rose, W.I. and Bornhorst, T.J., 1981, Emission rates of CO2 from plume measurements, in Lipman, P.W. and Mullineaux, D.L., eds., The 1980 eruptions of Mount St. Helens, Washington: U.S. Geological Survey Professional Paper 1250, p. 201-207.

   Data sources produced in this process:

   • Casadevall, T.J., Johnston, D.A., Harris, D.M., Rose, W. I., Malinconcio, L.L., Stoiber, R.E., Bornhorst, T.J., Williams, S.N., Woodruff, Laurel and Thompson, J.M., 1981, SO2 emission rates at Mount St. Helens from March 29 through December, 1980, in 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.

3. What similar or related data should the user be aware of?

   McGee, Kenneth A. , 1992, Volcanic-plume data from Mount St. Helens during 1980-88: U.S. Geological Survey Open-File Report 92-361, U.S. Geological Survey, Reston, VA.

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

   The use of correlation spectroscopy for determining the sulfur dioxide 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).
   

2. How accurate are the geographic locations?

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   The data listing in this report contains all of the available daily SO2 and CO2 emission rates determined by the USGS from May 1980 through the end of the measurements in September 1988. On a few occasions, two gas-measurement flights were made in a single day. In those cases, two emission-rate values are listed for that day. Portions of this database have been presented earlier by Casadevall and others (1981, 1983), Harris and others (1981), McGee (1992a), and McGee and Sutton (in press). Other data pertaining to these measurements such as plume dimensions and wind information were earlier listed in McGee (1992b).
   

5. How consistent are the relationships among the observations, including topology?

   From May 1980 to September 1988, more than 1000 fixed-wing aircraft flights were made by the U.S. Geological Survey in order to measure and characterize gas emissions from Mount St. Helens. Sulfur dioxide was detected on the majority of these flights. However, toward the end of this time period, and particularly during the final two years of measurements, the sulfur dioxide burden was often below the detection limit of the COSPEC. On those days, the sulfur dioxide emission rate was arbitrarily assigned a value of 3 tonnes/day in the database. Carbon dioxide was routinely measured starting in July 1980. These measurements were discontinued in August 1981 after CO2 levels had declined to near background levels.
   

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: none

Use_Constraints: none

1. Who distributes the data set? (Distributor 1 of 1)
   Peter N. Schweitzer
   Mail Stop 918 National Center
   U.S. Geological Survey
   12201 Sunrise Valley Drive
   Reston, VA 20192
   USA
   

   (703) 648-6533 (voice)
   (703) 648-6560 (FAX)
   pschweitzer@usgs.gov
   

2. What's the catalog number I need to order this data set?

   USGS Open-File Report 94-212

3. What legal disclaimers am I supposed to read?

   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.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Text and data tables in format TEXT Size: 0.338 megabytes
     Network links:	<http://pubs.usgs.gov/of/1994/of94-212/Core/raw/table.txt>

   • Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 12-May-1995

Metadata author:

Peter N. Schweitzer
U.S. Geological Survey
Mail Stop 918 National Center
12201 Sunrise Valley Drive
Reston, VA 20192
USA

(703) 648-6533 (voice)
(703) 648-6560 (FAX)
pschweitzer@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)