with the words of Thorne, with whom I shared an office for years at Caltech, and worked with for years at UCSC. He means it is hard to study because the effect, if non-zero, is very, very weak, and one needs decades of data to spot even a couple of small triggered events to see if they ever happen.

Or with the words of Susan. I'm quite familiar with her work as well. She's referring to the current controversy whether static or dynamic stress triggers aftershocks. Without putting words in her mouth, she thinks little of the 103 degree triggering claim.

If you're talking about the 103 and 140 discussion with Petra below, the P waves, although first, are the smallest of the seismic waves to come from a teleseism, dwarfed by both the S and surface waves, which do not have caustics at 103 and 140 degrees.