Index: /issm/trunk-jpl/src/c/analyses/StressbalanceAnalysis.cpp
===================================================================
--- /issm/trunk-jpl/src/c/analyses/StressbalanceAnalysis.cpp	(revision 16865)
+++ /issm/trunk-jpl/src/c/analyses/StressbalanceAnalysis.cpp	(revision 16866)
@@ -2228,5 +2228,6 @@
 		element->NodalFunctionsVelocity(vbasis,gauss);
 		surface_input->GetInputValue(&surface,gauss);
-		z=element->GetZcoord(gauss);
+		if(dim==3) z=element->GetZcoord(gauss);
+		else       z=element->GetYcoord(gauss);
 		pressure = rho_water*gravity*min(0.,z);//0 if the gaussian point is above water level
 
Index: /issm/trunk-jpl/src/c/classes/Elements/Element.h
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Element.h	(revision 16865)
+++ /issm/trunk-jpl/src/c/classes/Elements/Element.h	(revision 16866)
@@ -120,4 +120,5 @@
 		virtual void   GetVerticesCoordinatesTop(IssmDouble** xyz_list)=0;
 		virtual IssmDouble GetZcoord(Gauss* gauss)=0;
+		virtual IssmDouble GetYcoord(Gauss* gauss)=0;
 		virtual void   GetMaterialInputValue(IssmDouble* pvalue,Node* node,int enumtype)=0;
 
Index: /issm/trunk-jpl/src/c/classes/Elements/Penta.h
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Penta.h	(revision 16865)
+++ /issm/trunk-jpl/src/c/classes/Elements/Penta.h	(revision 16866)
@@ -102,4 +102,5 @@
 		void   GetSolutionFromInputsOneDof(Vector<IssmDouble>* solution,int enum_type);
 		IssmDouble GetZcoord(Gauss* gauss);
+		IssmDouble GetYcoord(Gauss* gauss){_error_("Not implemented");};
 		void   GetVectorFromInputs(Vector<IssmDouble>* vector,int name_enum);
 		void   GetVerticesCoordinates(IssmDouble** pxyz_list);
Index: /issm/trunk-jpl/src/c/classes/Elements/Seg.h
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Seg.h	(revision 16865)
+++ /issm/trunk-jpl/src/c/classes/Elements/Seg.h	(revision 16866)
@@ -151,4 +151,5 @@
 		void        GetInputValue(IssmDouble* pvalue,int enum_type){_error_("not implemented yet");};
 		void        GetMaterialInputValue(IssmDouble* pvalue,Node* node,int enumtype){_error_("not implemented yet");};
+		IssmDouble  GetYcoord(Gauss* gauss){_error_("Not implemented");};
 		IssmDouble  GetZcoord(Gauss* gauss){_error_("not implemented yet");};
 		Gauss*      NewGauss(void){_error_("not implemented yet");};
Index: /issm/trunk-jpl/src/c/classes/Elements/Tria.cpp
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Tria.cpp	(revision 16865)
+++ /issm/trunk-jpl/src/c/classes/Elements/Tria.cpp	(revision 16866)
@@ -1190,4 +1190,22 @@
 
 }/*}}}*/
+/*FUNCTION Tria::GetVerticesCoordinatesBase(IssmDouble** pxyz_list){{{*/
+void Tria::GetVerticesCoordinatesBase(IssmDouble** pxyz_list){
+
+	int        indices[2];
+	IssmDouble xyz_list[NUMVERTICES][3];
+
+	/*Element XYZ list*/
+	::GetVerticesCoordinates(&xyz_list[0][0],this->vertices,NUMVERTICES);
+
+	/*Allocate Output*/
+	IssmDouble* xyz_list_edge = xNew<IssmDouble>(2*3);
+	this->EdgeOnBedIndices(&indices[0],&indices[1]);
+	for(int i=0;i<2;i++) for(int j=0;j<2;j++) xyz_list_edge[i*3+j]=xyz_list[indices[i]][j];
+
+	/*Assign output pointer*/
+	*pxyz_list = xyz_list_edge;
+
+}/*}}}*/
 /*FUNCTION Tria::NormalSection{{{*/
 void Tria::NormalSection(IssmDouble* normal,IssmDouble* xyz_list){
@@ -1577,4 +1595,21 @@
 	/*We found the enum.  Use its values to fill into the vector, using the vertices ids: */
 	input->GetVectorFromInputs(vector,&vertexpidlist[0]);
+}
+/*}}}*/
+/*FUNCTION Tria::GetYcoord {{{*/
+IssmDouble Tria::GetYcoord(Gauss* gauss){
+
+	IssmDouble y;
+	IssmDouble xyz_list[NUMVERTICES][3];
+	IssmDouble y_list[NUMVERTICES];
+
+	::GetVerticesCoordinates(&xyz_list[0][0],vertices,NUMVERTICES);
+	for(int i=0;i<NUMVERTICES;i++) y_list[i]=xyz_list[i][1];
+	int backup = this->element_type;
+	this->element_type = P1Enum;
+	TriaRef::GetInputValue(&y,y_list,gauss);
+	this->element_type = backup;
+
+	return y;
 }
 /*}}}*/
@@ -2044,4 +2079,12 @@
 }
 /*}}}*/
+/*FUNCTION Tria::JacobianDeterminantBase{{{*/
+void Tria::JacobianDeterminantBase(IssmDouble* pJdet,IssmDouble* xyz_list_base,Gauss* gauss){
+
+	_assert_(gauss->Enum()==GaussTriaEnum);
+	this->GetSegmentJacobianDeterminant(pJdet,xyz_list_base,(GaussTria*)gauss);
+
+}
+/*}}}*/
 /*FUNCTION Tria::JacobianDeterminantSurface{{{*/
 void Tria::JacobianDeterminantSurface(IssmDouble* pJdet,IssmDouble* xyz_list,Gauss* gauss){
@@ -2263,4 +2306,12 @@
 	GetAreaCoordinates(&area_coordinates[0][0],xyz_list_front,xyz_list,4);
 	return new GaussTria(area_coordinates,order_vert);
+}
+/*}}}*/
+/*FUNCTION Tria::NewGaussBase(int order){{{*/
+Gauss* Tria::NewGaussBase(int order){
+
+	int indices[2];
+	this->EdgeOnBedIndices(&indices[0],&indices[1]);
+	return new GaussTria(indices[0],indices[1],order);
 }
 /*}}}*/
@@ -2360,4 +2411,20 @@
 	if(found)*pvalue=value;
 	return found;
+}
+/*}}}*/
+/*FUNCTION Tria::NormalBase {{{*/
+void Tria::NormalBase(IssmDouble* bed_normal,IssmDouble* xyz_list){
+
+	/*Build unit outward pointing vector*/
+	IssmDouble vector[2];
+	IssmDouble norm;
+
+	vector[0]=xyz_list[1*3+0] - xyz_list[0*3+0];
+	vector[1]=xyz_list[1*3+1] - xyz_list[0*3+1];
+
+	norm=sqrt(vector[0]*vector[0] + vector[1]*vector[1]);
+
+	bed_normal[0]= + vector[1]/norm;
+	bed_normal[1]= - vector[0]/norm;
 }
 /*}}}*/
Index: /issm/trunk-jpl/src/c/classes/Elements/Tria.h
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/Tria.h	(revision 16865)
+++ /issm/trunk-jpl/src/c/classes/Elements/Tria.h	(revision 16866)
@@ -117,5 +117,5 @@
 		void        GetVectorFromInputs(Vector<IssmDouble>* vector, int name_enum);
 		void        GetVerticesCoordinates(IssmDouble** pxyz_list);
-		void        GetVerticesCoordinatesBase(IssmDouble** pxyz_list){_error_("not implemented yet");};
+		void        GetVerticesCoordinatesBase(IssmDouble** pxyz_list);
 		void        GetVerticesCoordinatesTop(IssmDouble** pxyz_list){_error_("not implemented yet");};
 		void        InputCreate(IssmDouble* vector,IoModel* iomodel,int M,int N,int vector_type,int vector_enum,int code);
@@ -266,8 +266,9 @@
 		void           GetGroundedPart(int* point1,IssmDouble* fraction1, IssmDouble* fraction2,bool* mainlyfloating);
 		IssmDouble     GetGroundedPortion(IssmDouble* xyz_list);
+		IssmDouble     GetYcoord(Gauss* gauss);
 		IssmDouble     GetZcoord(Gauss* gauss){_error_("not implemented");};
 		void           NormalSection(IssmDouble* normal,IssmDouble* xyz_list);
 		void           NormalTop(IssmDouble* normal,IssmDouble* xyz_list){_error_("not implemented yet");};
-		void           NormalBase(IssmDouble* normal,IssmDouble* xyz_list){_error_("not implemented yet");};
+		void           NormalBase(IssmDouble* normal,IssmDouble* xyz_list);
 		IssmDouble     GetMaterialParameter(int enum_in);
 		Input*         GetInput(int inputenum);
@@ -291,5 +292,5 @@
 		void           JacobianDeterminantLine(IssmDouble* Jdet, IssmDouble* xyz_list,Gauss* gauss){_error_("not implemented yet");};
 		void           JacobianDeterminantSurface(IssmDouble*  pJdet, IssmDouble* xyz_list,Gauss* gauss);
-		void           JacobianDeterminantBase(IssmDouble* pJdet,IssmDouble* xyz_list_base,Gauss* gauss){_error_("not implemented yet");};
+		void           JacobianDeterminantBase(IssmDouble* pJdet,IssmDouble* xyz_list_base,Gauss* gauss);
 		void           JacobianDeterminantTop(IssmDouble* pJdet,IssmDouble* xyz_list_base,Gauss* gauss){_error_("not implemented yet");};
 		IssmDouble     MinEdgeLength(IssmDouble* xyz_list){_error_("not implemented yet");};
@@ -298,5 +299,5 @@
       Gauss*         NewGauss(IssmDouble* xyz_list, IssmDouble* xyz_list_front,int order);
       Gauss*         NewGauss(IssmDouble* xyz_list, IssmDouble* xyz_list_front,int order_horiz,int order_vert);
-		Gauss*         NewGaussBase(int order){_error_("not implemented yet");};
+		Gauss*         NewGaussBase(int order);
 		Gauss*         NewGaussLine(int vertex1,int vertex2,int order){_error_("not implemented yet");};
 		Gauss*         NewGaussTop(int order){_error_("not implemented yet");};