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

Metadata Updated: November 12, 2020

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. 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). 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).

Access & Use Information

License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Date February 5, 2016
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) January 1, 1994 (publication)
Frequency Of Update irregular

Metadata Source

Harvested from DOI Open Data

Additional Metadata

Resource Type Dataset
Metadata Date February 5, 2016
Metadata Created Date November 12, 2020
Metadata Updated Date November 12, 2020
Reference Date(s) January 1, 1994 (publication)
Responsible Party (Point of Contact)
Contact Email
Guid
Access Constraints Use Constraints: none, Access Constraints: none
Bbox East Long -122.125
Bbox North Lat 46.250
Bbox South Lat 46.125
Bbox West Long -122.250
Coupled Resource
Frequency Of Update irregular
Licence 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.
Metadata Language
Metadata Type geospatial
Progress completed
Spatial Data Service Type
Spatial Reference System
Spatial Harvester True
Temporal Extent Begin 1980-05-01
Temporal Extent End 1988-09-18

Didn't find what you're looking for? Suggest a dataset here.