Index: /issm/trunk-jpl/src/c/Container/Observations.cpp
===================================================================
--- /issm/trunk-jpl/src/c/Container/Observations.cpp	(revision 12272)
+++ /issm/trunk-jpl/src/c/Container/Observations.cpp	(revision 12273)
@@ -78,5 +78,6 @@
 		}
 		else{
-			//We need to average with the current observations (not done yet)
+			/*We need to average with the current observations*/
+			this->quadtree->AddAndAverage(x[i],y[i],observations_list[i]);
 		}
 	}
Index: /issm/trunk-jpl/src/c/objects/Kriging/Observation.cpp
===================================================================
--- /issm/trunk-jpl/src/c/objects/Kriging/Observation.cpp	(revision 12272)
+++ /issm/trunk-jpl/src/c/objects/Kriging/Observation.cpp	(revision 12273)
@@ -15,10 +15,11 @@
 Observation::Observation(double x_in,double y_in,int xi_in,int yi_in,int index_in,double value_in){
 
-	this->x     = x_in;
-	this->y     = y_in;
-	this->xi    = xi_in;
-	this->yi    = yi_in;
-	this->index = index_in;
-	this->value = value_in;
+	this->x      = x_in;
+	this->y      = y_in;
+	this->xi     = xi_in;
+	this->yi     = yi_in;
+	this->index  = index_in;
+	this->value  = value_in;
+	this->weight = 1.;
 
 }
@@ -42,4 +43,5 @@
 	printf("   xi    : "); printbinary(this->xi); printf("\n");
 	printf("   yi    : "); printbinary(this->yi); printf("\n");
+	printf("   weight: %g\n",this->weight);
 	printf("   value : %g\n",this->value);
 }
Index: /issm/trunk-jpl/src/c/objects/Kriging/Observation.h
===================================================================
--- /issm/trunk-jpl/src/c/objects/Kriging/Observation.h	(revision 12272)
+++ /issm/trunk-jpl/src/c/objects/Kriging/Observation.h	(revision 12273)
@@ -14,4 +14,5 @@
 		int    xi,yi;
 		int    index;
+		double weight;
 		double value;
 
Index: /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.cpp
===================================================================
--- /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.cpp	(revision 12272)
+++ /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.cpp	(revision 12273)
@@ -198,4 +198,56 @@
 
 }/*}}}*/
+/*FUNCTION Quadtree::AddAndAverage{{{1*/
+void Quadtree::AddAndAverage(double x,double y,double value){
+
+	QuadtreeBox **pbox = NULL;
+	QuadtreeBox  *box  = NULL;
+	int           xi,yi;
+	int           level,levelbin;
+	int           index;
+	double        length,length2;
+
+	/*Get integer coodinates*/
+	this->IntergerCoordinates(&xi,&yi,x,y);
+
+	/*Initialize levels*/
+	level    = 0;
+	levelbin = (1L<<this->MaxDepth);// = 2^30
+
+	/*Get inital box (the largest)*/
+	pbox=&root;
+
+	/*Find the smallest box where this point is located*/
+	while((box=*pbox) && (box->nbitems<0)){ 
+
+		levelbin>>=1; level+=1; 
+
+		pbox = &box->box[IJ(xi,yi,levelbin)];
+	}
+
+	/*Add obervation in this box (should be full)*/
+	if(box && box->nbitems==4){
+		index  = 0;
+		length = pow(box->obs[0]->x - x,2.) + pow(box->obs[0]->y - y,2.);
+		for(int i=1;i<4;i++){
+			length2 = pow(box->obs[i]->x - x,2.) + pow(box->obs[i]->y - y,2.);
+			if(length2<length){
+				index  = i;
+				length = length2;
+			}
+		}
+
+		/*We found the closest observation, now average observation (do not change xi and yi to avoid round off errors*/
+		box->obs[index]->x = (box->obs[index]->weight*box->obs[index]->x + x)/(box->obs[index]->weight+1);
+		box->obs[index]->y = (box->obs[index]->weight*box->obs[index]->y + y)/(box->obs[index]->weight+1);
+		box->obs[index]->xi= int((box->obs[index]->weight*double(box->obs[index]->xi) + double(xi))/(box->obs[index]->weight+1));
+		box->obs[index]->yi= int((box->obs[index]->weight*double(box->obs[index]->yi) + double(yi))/(box->obs[index]->weight+1));
+		box->obs[index]->value   = (box->obs[index]->weight*box->obs[index]->value + value)/(box->obs[index]->weight+1);
+		box->obs[index]->weight += 1;
+	}
+	else{
+		_error_("Box is not full");
+	}
+}/*}}}*/
 /*FUNCTION Quadtree::Echo{{{1*/
 void  Quadtree::Echo(void){
Index: /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.h
===================================================================
--- /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.h	(revision 12272)
+++ /issm/trunk-jpl/src/c/objects/Kriging/Quadtree.h	(revision 12273)
@@ -53,4 +53,5 @@
 		~Quadtree();
 		void         Add(Observation *observation);
+		void         AddAndAverage(double x,double y,double value);
 		void         DeepEcho(void);
 		void         Echo(void);