c
c-----------------------------------------------------------------------
c  Second order horizontal pressure gradient.
c-----------------------------------------------------------------------
c
          z=p5*(vdepth(i,k,jrn)+vdepth(i,k+1,jrn))
c
#ifdef cubspl
          call splintslab(tdepth(1,1,jrs),rho(1,1,jrs),
     *                    d2rhodz2(1,1,jrs),imt,km,i,klow(i,1),
     *                    khi(i,1),z,r(1),xtrp(1))
          call splintslab(tdepth(1,1,jrs),rho(1,1,jrs),
     *                    d2rhodz2(1,1,jrs),imt,km,i+1,klow(i,2),
     *                    khi(i,2),z,r(2),xtrp(2))
          call splintslab(tdepth(1,1,jrn),rho(1,1,jrn),
     *                    d2rhodz2(1,1,jrn),imt,km,i,klow(i,3),
     *                    khi(i,3),z,r(3),xtrp(3))
          call splintslab(tdepth(1,1,jrn),rho(1,1,jrn),
     *                    d2rhodz2(1,1,jrn),imt,km,i+1,klow(i,4),
     *                    khi(i,4),z,r(4),xtrp(4))
#else
          call lintslab(tdepth(1,1,jrs),rho(1,1,jrs),imt,km,i,
     *                  klow(i,1),khi(i,1),z,r(1),xtrp(1))
          call lintslab(tdepth(1,1,jrs),rho(1,1,jrs),imt,km,i,
     *                  klow(i,2),khi(i,2),z,r(2),xtrp(2))
          call lintslab(tdepth(1,1,jrn),rho(1,1,jrn),imt,km,i,
     *                  klow(i,3),khi(i,3),z,r(3),xtrp(3))
          call lintslab(tdepth(1,1,jrn),rho(1,1,jrn),imt,km,i+1,
     *                  klow(i,4),khi(i,4),z,r(4),xtrp(4))
#endif
#ifndef noxtrp
c
          call extrap(4,z,r,xtrp)
#endif
c
          hpx(i,k)=((r(4)-r(3))*cstr(j+1)+(r(2)-r(1))*cstr(j))*dxu2r(i)
          hpy(i,k)=((r(4)-r(2))+(r(3)-r(1)))*dyu2r(j)