Index: /issm/trunk-jpl/src/c/classes/Elements/TriaRef.cpp
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/TriaRef.cpp	(revision 22982)
+++ /issm/trunk-jpl/src/c/classes/Elements/TriaRef.cpp	(revision 22983)
@@ -116,4 +116,17 @@
 	Matrix2x2Determinant(Jdet,&J[0][0]);
 	if(*Jdet<0) _error_("negative jacobian determinant!");
+
+}
+/*}}}*/
+void TriaRef::GetJacobianDeterminant3D(IssmDouble* Jdet, IssmDouble* xyz_list,Gauss* gauss){/*{{{*/
+	/*The Jacobian determinant is constant over the element, discard the gaussian points. 
+	 * J is assumed to have been allocated of size NDOF2xNDOF2.*/
+	IssmDouble J[2][2];
+
+	/*Get Jacobian*/
+	GetJacobian(&J[0][0],xyz_list,gauss);
+
+	/*Get Determinant*/
+	Matrix2x2Determinant(Jdet,&J[0][0]);
 
 }
Index: /issm/trunk-jpl/src/c/classes/Elements/TriaRef.h
===================================================================
--- /issm/trunk-jpl/src/c/classes/Elements/TriaRef.h	(revision 22982)
+++ /issm/trunk-jpl/src/c/classes/Elements/TriaRef.h	(revision 22983)
@@ -20,4 +20,5 @@
 		void GetJacobian(IssmDouble* J, IssmDouble* xyz_list,Gauss* gauss);
 		void GetJacobianDeterminant(IssmDouble* Jdet, IssmDouble* xyz_list,Gauss* gauss);
+		void GetJacobianDeterminant3D(IssmDouble* Jdet, IssmDouble* xyz_list,Gauss* gauss);
 		void GetJacobianInvert(IssmDouble*  Jinv, IssmDouble* xyz_list,Gauss* gauss);
 		void GetNodalFunctions(IssmDouble* basis,Gauss* gauss,int finiteelement);