ML Amplitude Tomography from US Array Data for the Continental US

Session: Advances in Upper Crustal Geophysical Characterization [Poster]
Type: Poster
Date: 4/29/2020
Time: 08:00 AM
Room: Ballroom
Description: 

Seismic attenuation across the U.S. is estimated using station magnitude data from the U.S. Array. Station magnitudes are recalibrated back to amplitude and back projected in a two-dimensional tomography that includes station and event gain factors. Data from 25 to 600 km event-station distance were used. We find that the station and event gains are small but there are smaller station gains in the west than in the east. The western U.S. shows regions of extremely high attenuation that correspond to the Salton Trough, the Coast Ranges, Owens Valley, Columbia Plateau, Yellowstone, Snake River Plane and Rio Grande Rift. The Colorado Plateau rim is underlain by high attenuation. Most of these areas are regions of high thermal and tectonic activity or drastic regional changes in crustal structure. However, not all mountains (Sierra Nevada and northern Rocky Mountains) have high attenuation. In contrast, the US east of the Rocky Mountains is bland and contains none of the very high attenuation regions of the western US. Instead the central US has low attenuation with slightly higher attenuation to the north and south. Central Texas and the southern Appalachians are low attenuation regions.

Presenting Author: Thomas M. Hearn

Authors