Index: /issm/trunk-jpl/src/m/classes/mesh.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/mesh.m	(revision 12977)
+++ /issm/trunk-jpl/src/m/classes/mesh.m	(revision 12978)
@@ -88,6 +88,6 @@
 			md = checkfield(md,'mesh.vertexonsurface','size',[md.mesh.numberofvertices 1],'values',[0 1]);
 			if (md.mesh.dimension==3),
-				md = checkfield(md,'mesh.z','>=',md.geometry.bed,'message','''mesh.z'' should be above the bed');
-				md = checkfield(md,'mesh.z','<=',md.geometry.surface,'message','''mesh.z'' should be below the ice surface');
+				md = checkfield(md,'mesh.z','>=',md.geometry.bed-10^-10,'message','''mesh.z'' lower than bedrock');
+				md = checkfield(md,'mesh.z','<=',md.geometry.surface+10^-10,'message','''mesh.z'' higher than surface elevation');
 			end
 			if (md.mesh.dimension==2),