Index: /issm/trunk-jpl/src/m/classes/groundingline.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/groundingline.m	(revision 20259)
+++ /issm/trunk-jpl/src/m/classes/groundingline.m	(revision 20260)
@@ -31,9 +31,10 @@
 					md = checkmessage(md,['requesting grounding line migration, but bathymetry is absent!']);
 				end
-				pos=find(md.mask.groundedice_levelset>0.);
+				pos=find(md.mask.groundedice_levelset>0. & md.mask.ice_levelset<=0);
 				if any(abs(md.geometry.base(pos)-md.geometry.bed(pos))>10^-10),
 					md = checkmessage(md,['base not equal to bed on grounded ice!']);
 				end
-				if any(md.geometry.bed - md.geometry.base > 10^-9),
+				pos=find(md.mask.groundedice_levelset<=0. & md.mask.ice_levelset<=0);
+				if any(md.geometry.bed(pos) - md.geometry.base(pos) > 10^-9),
 					md = checkmessage(md,['bed superior to base on floating ice!']);
 				end