Analyzing Change in Yellowstone's Terrestrial Emittance with Landsat Imagery

Abstract

Yellowstone National Park (YNP) contains the world's largest concentration of geothermal features and is legally mandated to protect and monitor these natural features. Remote sensing is a component of the current geothermal monitoring plan. Landsat satellite data have a substantial historical archive and will continue to be collected into the future, making it the only available thermal imagery for historical analysis and long-term monitoring of geothermal areas in the entirety of YNP. Landsat imagery from Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) sensors was used to examine change trajectories for terrestrial emittance among spatial groupings from 1986 to 2007. Trajectories of locations with known change events were also examined. Relationships between the spatial groupings and several change vectors (distance to geologic faults, distance to large water bodies, and distance to earthquake swarms) were explored. The analysis showed the strongest relationship between absolute difference in terrestrial emittance and earthquake swarms, with 34% of the variation explained. Certain known change events were reflected in the change trajectories, while the Landsat imagery was not able to detect other known events. This suggests that Landsat imagery might be a useful tool for monitoring geothermal responses in YNP, but cannot be expected to suffice as the sole monitoring tool.