update doc of source.moment_magnitude

trichter · Aug 11, 2020 · 1c6f054 · 1c6f054
1 parent 7c881b0
commit 1c6f054
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/qopen/source.py b/qopen/source.py
@@ -168,7 +168,14 @@ def lstsqab(fc, a, opt=False):
 
 
 def moment_magnitude(M0):
-    """Moment magnitude Mw from seismic moment M0"""
+    """
+    Moment magnitude Mw from seismic moment M0
+
+    Based on Kanamori (1997), an alternative definition is based on
+    Hanks and Kanamori (1999) with an offset of -6.03.
+
+    :param M0: seismic moment in Nm
+    """
     return 2 / 3 * np.log10(M0) - 6.07