Comparison and validation of Airborne Thematic Mapper thermal imagery using ground-based temperature data for Grímsvötn caldera, Vatnajökull, Iceland
Published:January 01, 2007
S. F. Stewart, H. Pinkerton, G. A. Blackburn, M. T. Guðmundsson, 2007. "Comparison and validation of Airborne Thematic Mapper thermal imagery using ground-based temperature data for Grímsvötn caldera, Vatnajökull, Iceland", Mapping Hazardous Terrain Using Remote Sensing, R. M. Teeuw
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Grímsvötn, Iceland's most active volcano, is also one of the most powerful geothermal areas in Iceland. This subglacial volcano is located in the centre of Vatnajökull, Europe's largest temperate ice cap, and it erupted most recently in 1998 and 2004. As part of continuing research on heat flux, morphological changes and volcanic processes at Grímsvötn, thermal anomalies were mapped using remote sensing Natural Environmental Research Council (NERC) Airborne Research and Survey Facility (ARSF) data. The 2001 Airborne Thematic Mapper (ATM) thermal images of the Grímsvötn subglacial caldera reveal distinct areas of geothermal activity and provide an overview of the thermal anomalies associated with water and rock exposures. A crater lake located on the 1998 eruption site is shown to have a surface temperature of 30–35 °C. There is a good correlation between the ARSF data and ground-based temperature measurements. The thermal images also revealed previously undetected areas of high heat flow. Factors that complicate the interpretation and comparison of different datasets from an ice-covered area include recent cornice collapses and variations in atmospheric humidity. To reduce uncertainty in future missions, temperature measurements should be made at points whose position is well constrained using differential global positioning system. In addition, humidity and temperature measurements should be made at the time of flight.
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Mapping Hazardous Terrain Using Remote Sensing
The dangers that we face from geohazards appear to be getting worse, especially with the impact of increasing population and global climate change. This collection of papers illustrates how remote sensing technologies - measuring, mapping and monitoring the Earth’s surface from aircraft or satellites - can help us to rapidly detect and better manage geohazards. The hazardous terrains examined include areas of landslides, flooding, erosion, contaminated land, shrink-swell clays, subsidence, seismic activity and volcanic landforms. Key aspects of remote sensing are introduced, making this a book that can easily be read by those who are unfamiliar with remote sensing. The featured remote sensing systems include aerial photography and photogrammetry, thermal scanning, hyperspectral sensors, airborne laser altimetry (LiDAR), radar interferometry and multispectral satellites (Landsat, ASTER). Related technologies and methodogies, such as the processing of Digital Elevation Models and data analysis using Geographical Information Systems, are also discussed.