INFERRING VOLCANIC ACTIVITY AND SUBSURFACE CONDITIONS AT MAMMOTH MOUNTAIN, CALIFORNIA BY MAPPING REMOTELY SENSED SPATIAL AND TEMPORAL VARIATIONS IN CO2-INDUCED TREE KILLS

High Concentrations of cold Carbon dioxide (CO₂) emitted from the flanks of Mammoth Mountain volcano, on the southwestern ring fracture of the Long Valley Caldera, eastern California, are believed 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.

To evaluate volcanic activity and interpret subsurface conditions at Mammoth Mountain, this study maps the spatial and temporal variations in the distribution of magmatic CO₂-induced tree kills using remote sensing technology. Digital mapping of the time-varied CO₂-induced tree kills incorporates available multi-and hyper-spectral image sets from NASA, including: AVIRIS, TIMS, NS001 (TM Simulator), and MASTER data for the study area. Spectral measurements have been made in the field to establish the reflectance characteristics of the field area, to provide ground truth measurements and improve the quality of the remote sensing analyses. Developing an understanding of the temporal migration of CO₂ emission-induced tree kills may assist in constructing a picture of the structure and volcanic activity beneath Mammoth Mountain and aid in analysis of future volcanic unrest.