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Use of thermal infrared imaging for monitoring renewed dome growth at Mount St. Helens, 2004: Chapter 17 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

Professional Paper 1750-17

This report is Chapter 17 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006. For more information, see: Professional Paper 1750
By:
, , , ,
Edited by:
David R. Sherrod, William E. Scott, Peter H. Stauffer

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Abstract

A helicopter-mounted thermal imaging radiometer documented the explosive vent-clearing and effusive phases of the eruption of Mount St. Helens in 2004. A gyrostabilized gimbal controlled by a crew member housed the radiometer and an optical video camera attached to the nose of the helicopter. Since October 1, 2004, the system has provided thermal and video observations of dome growth. Flights conducted as frequently as twice daily during the initial month of the eruption monitored rapid changes in the crater and 1980-86 lava dome. Thermal monitoring decreased to several times per week once dome extrusion began. The thermal imaging system provided unique observations, including timely recognition that the early explosive phase was phreatic, location of structures controlling thermal emissions and active faults, detection of increased heat flow prior to the extrusion of lava, and recognition of new lava extrusion. The first spines, 1 and 2, were hotter when they emerged (maximum temperature 700-730°C) than subsequent spines insulated by as much as several meters of fault gouge. Temperature of gouge-covered spines was about 200°C where they emerged from the vent, and it decreased rapidly with distance from the vent. The hottest parts of these spines were as high as 500-730°C in fractured and broken-up regions. Such temperature variation needs to be accounted for in the retrieval of eruption parameters using satellite-based techniques, as such features are smaller than pixels in satellite images.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Use of thermal infrared imaging for monitoring renewed dome growth at Mount St. Helens, 2004: Chapter 17 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006
Series title:
Professional Paper
Series number:
1750-17
Year Published:
2008
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Volcano Hazards Program
Description:
13 p.
Larger Work Type:
Report
Larger Work Subtype:
USGS Numbered Series
First page:
347
Last page:
359
Number of Pages:
13
Country:
United States
State:
Washington
Other Geospatial:
Mount St. Helens