CEUS zone rate corrections

Resolves #56 (closed) #58 (closed)

stable-crust/zone/AR/Crowleys Ridge (south)/README.md

@@ -6,18 +6,22 @@ The Crowley's Ridge (South) source zone was introduced for the 2023 Conterminous
 The source zone was defined by Jessica Thompson Jobe, based on recent work by
 Thompson Jobe et al. (2020).
 
-The zone is modeled with vertical strike-slip faults parallel to the southwest/northeast axis of the
-zone polygon (i.e., strike = 5 degrees).
+The zone is modeled with vertical strike-slip faults parallel to the southwest/northeast
+axis of the zone polygon (i.e., strike = 5 degrees).
 
 The Mmax distribution was informed by Thompson Jobe et al. (2020).
 
 The total rate in the zone was based on estimated slip rates from Thompson Jobe et al. (2020).  
 
-|Weight| Rate     |
-|:----:|:--------:|
-| 0.25 | 2.12E-04 |
-| 0.25 | 8.94E-05 |
-| 0.25 | 3.77E-05 |
-| 0.25 | 1.59E-05 |
+| Magnitude |Weight| Rate     |
+|:---------:|:----:|:--------:|
+| 6.60      | 0.25 | 2.12E-04 |
+| 6.85      | 0.25 | 8.94E-05 |
+| 7.10      | 0.25 | 3.77E-05 |
+| 7.35      | 0.25 | 1.59E-05 |
 
-For the 2023 NSHM, we give this source a weight of 0.5.
+For the zone rate, we use the weighted average of the above rates for all magnitudes.
+
+In the 2023 NSHM, we assign this source a weight of 0.5 with the `null` branch of the
+logic tree representing the possibility that nothing happens. The rates in this zone
+are not scaled with latitude.