diff --git a/src/geophires_x/GeoPHIRESUtils.py b/src/geophires_x/GeoPHIRESUtils.py
index d1d4b10e..02ff2f2e 100644
--- a/src/geophires_x/GeoPHIRESUtils.py
+++ b/src/geophires_x/GeoPHIRESUtils.py
@@ -85,7 +85,7 @@
         0.4,
         0.4,
         0.4,
-        0.4,
+        0.5, # Extrapolate from fig 2 in https://geothermal-energy-journal.springeropen.com/articles/10.1186/s40517-019-0119-6
     ]
 )