07-19-2014, 11:50 AM
Brian,
actually, I'll agree with the Denali fault one. If there are not deep sedimentary basins (like Los Angeles basin), the shaking does drop off sharply with distance from strike-slip faults, at least in California. This was demonstrated by Jim Brune's work on precariously-balanced rocks in southern California: they are seen something like >20 km from the distributed strike-slip faults.You don't see such a narrow strip in California because there are too
many faults: for example, thrust faults east of the San Andreas along the west side of the Central Valley (think Coalinga, vs, San Andreas at Parkfield).
Hmm, might there be such faults in Alaska that have been missed (or at least their activity?).
Chris
actually, I'll agree with the Denali fault one. If there are not deep sedimentary basins (like Los Angeles basin), the shaking does drop off sharply with distance from strike-slip faults, at least in California. This was demonstrated by Jim Brune's work on precariously-balanced rocks in southern California: they are seen something like >20 km from the distributed strike-slip faults.You don't see such a narrow strip in California because there are too
many faults: for example, thrust faults east of the San Andreas along the west side of the Central Valley (think Coalinga, vs, San Andreas at Parkfield).
Hmm, might there be such faults in Alaska that have been missed (or at least their activity?).
Chris