Index: /issm/trunk-jpl/src/c/shared/Enum/EnumDefinitions.h
===================================================================
--- /issm/trunk-jpl/src/c/shared/Enum/EnumDefinitions.h	(revision 17221)
+++ /issm/trunk-jpl/src/c/shared/Enum/EnumDefinitions.h	(revision 17222)
@@ -679,4 +679,5 @@
 	TransientIslevelsetEnum,
 	ExtrapolationVariableEnum,
+	IceMaskNodeActivationEnum,
 	/*}}}*/
 	MaximumNumberOfDefinitionsEnum
Index: /issm/trunk-jpl/src/c/shared/Enum/EnumToStringx.cpp
===================================================================
--- /issm/trunk-jpl/src/c/shared/Enum/EnumToStringx.cpp	(revision 17221)
+++ /issm/trunk-jpl/src/c/shared/Enum/EnumToStringx.cpp	(revision 17222)
@@ -638,4 +638,5 @@
 		case TransientIslevelsetEnum : return "TransientIslevelset";
 		case ExtrapolationVariableEnum : return "ExtrapolationVariable";
+		case IceMaskNodeActivationEnum : return "IceMaskNodeActivation";
 		case MaximumNumberOfDefinitionsEnum : return "MaximumNumberOfDefinitions";
 		default : return "unknown";
Index: /issm/trunk-jpl/src/c/shared/Enum/StringToEnumx.cpp
===================================================================
--- /issm/trunk-jpl/src/c/shared/Enum/StringToEnumx.cpp	(revision 17221)
+++ /issm/trunk-jpl/src/c/shared/Enum/StringToEnumx.cpp	(revision 17222)
@@ -653,4 +653,5 @@
 	      else if (strcmp(name,"TransientIslevelset")==0) return TransientIslevelsetEnum;
 	      else if (strcmp(name,"ExtrapolationVariable")==0) return ExtrapolationVariableEnum;
+	      else if (strcmp(name,"IceMaskNodeActivation")==0) return IceMaskNodeActivationEnum;
 	      else if (strcmp(name,"MaximumNumberOfDefinitions")==0) return MaximumNumberOfDefinitionsEnum;
          else stage=7;
Index: /issm/trunk-jpl/src/m/classes/mask.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/mask.m	(revision 17221)
+++ /issm/trunk-jpl/src/m/classes/mask.m	(revision 17222)
@@ -39,4 +39,12 @@
 			WriteData(fid,'object',obj,'fieldname','groundedice_levelset','format','DoubleMat','mattype',1);
 			WriteData(fid,'object',obj,'fieldname','ice_levelset','format','DoubleMat','mattype',1);
+
+			% get mask of vertices of elements with ice
+			isice=md.mask.ice_levelset<=0.;
+			vlist = zeros(md.mesh.numberofvertices,1);
+			pos=find(sum(isice(md.mesh.elements),2)>0);
+			vlist(md.mesh.elements(pos,:))=1;
+			WriteData(fid,'data',vlist,'enum',IceMaskNodeActivationEnum(),'format','DoubleMat','mattype',1);
+
 		end % }}}
 	end
Index: /issm/trunk-jpl/src/m/classes/mask.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/mask.py	(revision 17221)
+++ /issm/trunk-jpl/src/m/classes/mask.py	(revision 17222)
@@ -1,2 +1,3 @@
+import numpy
 from fielddisplay import fielddisplay
 from EnumDefinitions import *
@@ -43,3 +44,10 @@
 		WriteData(fid,'object',self,'fieldname','groundedice_levelset','format','DoubleMat','mattype',1)
 		WriteData(fid,'object',self,'fieldname','ice_levelset','format','DoubleMat','mattype',1)
+
+		# get mask of vertices of elements with ice
+		isice=numpy.array(md.mask.ice_levelset<=0.,int)
+		vlist = numpy.zeros((md.mesh.numberofvertices,1), dtype=int)
+		pos=numpy.nonzero(numpy.sum(isice[md.mesh.elements-1],axis=1))[0]
+		vlist[md.mesh.elements[pos,:]-1]=1
+		WriteData(fid,'data',vlist,'enum',IceMaskNodeActivationEnum(),'format','DoubleMat','mattype',1);
 	# }}}
Index: /issm/trunk-jpl/src/m/enum/EnumDefinitions.py
===================================================================
--- /issm/trunk-jpl/src/m/enum/EnumDefinitions.py	(revision 17221)
+++ /issm/trunk-jpl/src/m/enum/EnumDefinitions.py	(revision 17222)
@@ -630,3 +630,4 @@
 def TransientIslevelsetEnum(): return StringToEnum("TransientIslevelset")[0]
 def ExtrapolationVariableEnum(): return StringToEnum("ExtrapolationVariable")[0]
+def IceMaskNodeActivationEnum(): return StringToEnum("IceMaskNodeActivation")[0]
 def MaximumNumberOfDefinitionsEnum(): return StringToEnum("MaximumNumberOfDefinitions")[0]