REMOTE SENSING EVALUATION OF MAMMOTH MOUNTAIN, CALIFORNIA: MAPPING SPATIAL AND TEMPORAL VARIATIONS IN VOLCANOGENIC CO2 INDUCED TREE KILLS

Mammoth Mountain volcano, on the southwestern ring fracture of the Long Valley Caldera in eastern central California, has shown signs of volcanic unrest since the early 1980s. High concentrations of cold Carbon dioxide (CO₂), believed to be volcanogenic in nature, are being emitted from the flanks of the mountain. The emitted CO₂ is interpreted to be the cause of over 170 acres of dead trees in that area since 1990. Shallow magmatic intrusions, inferred from seismic activity, ground deformation, and changes in fumarolic gas composition on and around Mammoth Mountain beginning in 1989, have been interpreted as the source of the CO₂ gas.

Airborne remote sensing data for the field area, collected using muti- and hyperspectral (NS001 (TMS), MASTER, ASTER and AVIRIS) sensors, is being evaluated to map the spatial and temporal variation in the distribution of magmatic CO₂-induced tree kills between 1989 and present. Field spectral measurements have been incorporated into the remote sensing evaluation to establish the reflectance characteristics of the field area, to provide ground truth measurements and improve the quality of the remote sensing analyses. The results of the temporal remote sensing assessment have been integrated into a geographic information system with a detailed geologic map of the field area to highlight relationships between surface geology and areas of tree mortality. These evaluations will assist in constructing a picture of the structure and volcanic activity beneath Mammoth Mountain and aid in analysis of future volcanic unrest.