modified to use new zi (zisodisp) structure

src/isostasy.f90

-subroutine isostasy (params,weightel,ov,surface,mat,zisodisp)
+subroutine isostasy (params,weightel,ov,surface,mat,zi)
 
 ! first go at imposing isostasy
 ! this routine assumes that the original surface are flat
@@ -15,7 +15,8 @@ type(octreev) ov
 double precision weightel(ov%nleaves)
 type(sheet) surface(params%ns)
 type(material) mat(0:params%nmat)
-double precision zisodisp(2**params%levelmax_oct+1,2**params%levelmax_oct+1)
+type(ziso) zi
+!double precision zisodisp(2**params%levelmax_oct+1,2**params%levelmax_oct+1)
 
 double precision xc,yc,zc,eps
 integer i,j,ii,jj,kk,ie,dlev,is,iproc,nproc,ierr,ic
@@ -261,7 +262,7 @@ enddo
   endif
 
 ! Store the total displacement of the basal node plane 
-if (params%isobc) zisodisp=zisodisp-work
+if (params%isobc) zi%zisodisp=zi%zisodisp-work
 
 ! transforms the displacements into velocities and add this contribution to the velocity
 ! solution of the Stokes equation before interpolation onto the surfaces and their advection