Fix AG20

AG20 - apply 2021/7/12 Errata and sync with N.A.s latest fortran code. Validated test results with output from fortran code (modified to produce USGS flavors of Alaska and Cascadia.

Manually rebased on main after epistemic uncertainty changes.

Resolves #124 (closed)

changed the description

marked this merge request as ready

mentioned in merge request !209 (closed)

merged

mentioned in commit 47b15135

mentioned in merge request !216 (merged)