sheet_solve_velocity Subroutine

  subroutine sheet_solve_velocity(this, basal_drag, success)
    !* Author: Chris MacMackin
    !  Date: May 2017
    !
    ! Computes the ice sheet velocity at the current time with the
    ! current ice thickness.
    !
    class(ice_sheet), intent(inout)          :: this
    class(scalar_field), intent(in)          :: basal_drag
      !! A paramter, e.g. coefficient of friction, needed to calculate
      !! the drag on basal surface of the glacier.
    logical, intent(out)                     :: success
      !! True if the integration is successful, false otherwise
  end subroutine sheet_solve_velocity