Fix gridded seismicity optimization
Comparisons of hazard for the 2023 CONUS NSHM with gridded seismicity table-based optimizations turned on/off show that hazard across the intermountain west is lower with optimizations enabled. Differences are restricted to the region where focal mechanism weights are SS=0.5, R=0.0, N=0.5
. When building point sources from the tables of gridded seismicity rates, the weight of zero on reverse fault point sources is hitting a continue
and exiting the distance loop before getting to the normal fault table. Over this region hazard curve rates are exactly half what they should be.
This does not affect prior NSHMs that used UCERF3 because there were always non-zero weights associated with each possible focal mechanism. Also, if a strike slip table entry was empty/clear/0, the reverse and normal table entires would also be empty, so exiting the distance loop had no effect relative to continuing to the other tables. Investigation of this issue, however, highlights that the focal mechanism ratio applied to point sources generated from the optimization tables are wrong. See #237 (closed).