THERMOPHYSICAL CHARACTERISTICS OF MANTLED TERRESTRIAL VOLCANIC SURFACES: INFRARED ANALOGS TO ARSIA MONS.

[摘要] Sediment/regolith history and mantling of underlying bedrock are important processes to understand for Mars science. The movement of dust over time significantly modifies and covers many bedrock surfaces on Mars. A reliable remote sensing tool for martian geology is thermal inertia, which allows for a detailed analysis of surface properties based on their response to heating and cooling. The future goal of this project is to use thermal inertia to identify eolian- mantled lava flows on Mars and derive a process for separating the spectral signature of the mantling from that of the lava. However, this method must be tested on a terrestrial proxy in order to gauge its effectiveness using ground and laboratory validation. An example of mantled volcanic terrain on Earth is the Mono Crater chain in California, which will serve as an analog for this work. Unfortunately, thermal inertia cannot be calculated from satellite-based imaging, so a proxy called apparent thermal inertia (ATI) was used. Two temporally similar day/night images of the Mono Craters were collected from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument in the thermal infrared (TIR) and visible near- infrared (VNIR). These data were used to create the ATI image. After comparing the ATI result to high-resolution aerial photos it was discovered that ATI appeared to correlate with block size and mantling material. Fieldwork was conducted in July of 2012 on and around North Coulee dome at the Mono Craters. Results The ATI result was found to be reliable, however shadowing on a sub- to super-pixel level was found to artificially increase ATI values in those regions.Future studies should mitigate this by incorporating a digital elevation (DEM) model and possibly radar backscatter into the ATI analysis to better determine block size. The success of the proxy study on Earth provides a foundation from which future work can be conducted on the Arsia Mons and Syria Planum mantled lava flows. Space-based thermal inertia investigations of these sites would provide insight to the history and eolian patterns of both regions and a greater understanding of the volcanic history and composition in these regions.

[发布机构] the University of Pittsburgh

[效力级别] Mantling