diff --git a/Common/derived_types.f90 b/Common/derived_types.f90
index 33a228318bf266c549ea3ed6ff85c28338cd1f42..f8edfa46f658db15d3432c6e79b048fec897e9b6 100644
--- a/Common/derived_types.f90
+++ b/Common/derived_types.f90
@@ -44,11 +44,6 @@ module derived_types
      integer:: delta_out = huge(0)
      ! Minimum difference in time subscript where there is a direct
      ! successor. Huge means there is no direct succcessor.
-
-     integer radius4
-     ! extr%coord_proj + radius4 - 1 in all four directions is inside outermost
-     ! contour, extr%coord_proj + radius4 is outside.
-     ! radius4 /= 0 .eqv. out_cont%closed
   end type eddy
 
   type snapshot
@@ -86,7 +81,7 @@ module derived_types
      ! Field identifiers in the DBF files:
      integer extr_ssh, extr_date, extr_eddy_index, extr_speed
      integer extr_proj_date, extr_proj_eddy_index
-     integer out_r_eq_area, out_ssh, out_date, out_eddy_index, out_radius4
+     integer out_r_eq_area, out_ssh, out_date, out_eddy_index
      integer max_speed_r_eq_area, max_speed_ssh, max_speed_date, &
           max_speed_eddy_index
 
diff --git a/Common/read_field_indices.f90 b/Common/read_field_indices.f90
index 5ed90cddfeb64f4a9b29af8a92515573a9c74da2..bfdd8238c79643b399618b0161c62eed43f68d6d 100644
--- a/Common/read_field_indices.f90
+++ b/Common/read_field_indices.f90
@@ -34,10 +34,6 @@ contains
     call dbf_get_field_index_03(hshp%outermost, "date", hshp%out_date)
     call dbf_get_field_index_03(hshp%outermost, "eddy_index", &
          hshp%out_eddy_index)
-
-    ! We allow the field radius4 to be missing:
-    hshp%out_radius4 = dbfgetfieldindex(hshp%outermost, "radius4")
-
     call dbf_get_field_index_03(hshp%max_speed, "r_eq_area", &
          hshp%max_speed_r_eq_area)
     call dbf_get_field_index_03(hshp%max_speed, "ssh", hshp%max_speed_ssh)
diff --git a/Inst_eddies/Analysis/stat_SHPC.py b/Inst_eddies/Analysis/stat_SHPC.py
index d42e010dd58d22e09fedffbe0d28c159e498f2e2..090d946157eea4f3807582eb3c03cc481a87f217 100755
--- a/Inst_eddies/Analysis/stat_SHPC.py
+++ b/Inst_eddies/Analysis/stat_SHPC.py
@@ -20,12 +20,7 @@ with shapefile.Reader(path.join(args.SHPC, "Slice_0", args.orientation,
                                 "outermost_contour")) as outermost_contour:
     n_extr = len(extremum)
     field_names_outer = [f[0] for f in outermost_contour.fields[1:]]
-    with_radius_4 = 'radius4' in field_names_outer
 
-    if with_radius_4:
-        n_radius4 = np.zeros(3, dtype = int)
-        n_missing_speed = np.zeros(3, dtype = int)
-    
     for rec_extr, shape_rec_outer in zip(extremum.iterRecords(),
                                          outermost_contour):
         l = len(shape_rec_outer.shape.points)
@@ -33,32 +28,11 @@ with shapefile.Reader(path.join(args.SHPC, "Slice_0", args.orientation,
 
         if shape_rec_outer.record.r_eq_area >= 0: n_outer += 1
 
-        if with_radius_4:
-            if shape_rec_outer.record.radius4 == 0:
-                n_radius4[0] += 1
-            elif shape_rec_outer.record.radius4 == 1:
-                n_radius4[1] += 1
-            elif shape_rec_outer.record.radius4 >= 2:
-                n_radius4[2] += 1
-
-        if rec_extr.speed == 1e4 and with_radius_4:
-            if shape_rec_outer.record.radius4 == 0:
-                n_missing_speed[0] += 1
-            elif shape_rec_outer.record.radius4 == 1:
-                n_missing_speed[1] += 1
-            elif shape_rec_outer.record.radius4 >= 2:
-                n_missing_speed[2] += 1
-        else:
+        if rec_extr.speed != 1e4:
             n_valid_speed += 1
 
 print("number of extrema of SSH:", n_extr, "\n")
 
-if with_radius_4:
-    print("number of extrema with radius4 == 0 (no outermost contour or "
-          "insufficient area):", n_radius4[0])
-    print("number of extrema with radius4 == 1:", n_radius4[1])
-    print("number of extrema with radius4 >= 2:", n_radius4[2], "\n")
-
 print("number of outermost contours (outermost contour found, but may be with "
       "sufficient area or not):", n_outer)
 
@@ -66,15 +40,6 @@ print("average number of points of outermost contour per extremum:",
       n_points / n_extr, "\n")
 print("number of valid speed values:", n_valid_speed)
 
-if with_radius_4:
-    print("number of missing speed values with radius4 == 0:",
-          n_missing_speed[0])
-    print("number of missing speed values with radius4 == 1:",
-          n_missing_speed[1])
-    print("number of missing speed values with radius4 >= 2 (non null shape in "
-          "max_speed_contour and missing speed in extremum.dbf):",
-          n_missing_speed[2], "\n")
-
 n_max_speed = 0
 n_points_valid = 0
 n_points = 0
@@ -90,7 +55,7 @@ with shapefile.Reader(path.join(args.SHPC, "Slice_0", args.orientation,
             n_points_valid += l
 
 print("number of non-null maximum-speed contours (distinct from the "
-      "outermost contour, implies radius4 >= 2):",
+      "outermost contour):",
       n_max_speed)
 
 if n_max_speed != 0:
diff --git a/Inst_eddies/Tests/test_get_1_outerm.f90 b/Inst_eddies/Tests/test_get_1_outerm.f90
index 70c64be84a8b622ef9d68abc85d5852f91fda118..748d3282596a376f110285daede8126b7f0f766b 100644
--- a/Inst_eddies/Tests/test_get_1_outerm.f90
+++ b/Inst_eddies/Tests/test_get_1_outerm.f90
@@ -90,7 +90,6 @@ program test_get_1_outerm
      e%cyclone = cyclone
      e%speed_cont = null_ssh_contour()
      e%max_speed = missing_speed
-     e%radius4 = - 1
      call shpc_create(hshp, shpc_dir = "SHPC", cyclone = cyclone, slice = 0, &
           grid_lon_lat = grid_lon_lat)
      call write_eddy(e, hshp, date, i = 1)
diff --git a/Inst_eddies/set_max_speed.f90 b/Inst_eddies/set_max_speed.f90
index 51eaec69a25753f4811abac5fcc9006342ee17d3..b10be2e4e90d312f78fc6e609b5e608e6064e675 100644
--- a/Inst_eddies/set_max_speed.f90
+++ b/Inst_eddies/set_max_speed.f90
@@ -64,7 +64,6 @@ contains
     !---------------------------------------------------------------
 
     n_cont = size(cont_list)
-    e%radius4 = - 1
 
     do i = 1, n_cont
        speed(i) = mean_speed(u, v, cont_list(i)%polyline, e%extr%coord, &
diff --git a/Inst_eddies/shpc_create.f90 b/Inst_eddies/shpc_create.f90
index 1f17a973a8bb9a3e721b43479d7ff868bdcfbe8d..49062cc0dd24f238147ff1f6b1ade7b61ffca24f 100644
--- a/Inst_eddies/shpc_create.f90
+++ b/Inst_eddies/shpc_create.f90
@@ -56,8 +56,6 @@ contains
          ftinteger, nwidth = 5, ndecimals = 0)
     call dbf_add_field_03(hshp%out_eddy_index, hshp%outermost, 'eddy_index', &
          ftinteger, nwidth = 5, ndecimals = 0)
-    call dbf_add_field_03(hshp%out_radius4, hshp%outermost, 'radius4', &
-         ftinteger, nwidth = 2, ndecimals = 0)
 
     ! max_speed_contour shapefile:
     call shp_create_03(hshp%dir // "/max_speed_contour", shpt_polygon, &
diff --git a/Inst_eddies/write_eddy.f90 b/Inst_eddies/write_eddy.f90
index 168660bee012dbea1c2d63db2b24e367e3f85715..cd00840cd79b7dda05ff8afec0c98cab8cce253a 100644
--- a/Inst_eddies/write_eddy.f90
+++ b/Inst_eddies/write_eddy.f90
@@ -85,8 +85,6 @@ contains
     call dbf_write_attribute_03(hshpc%outermost, ishape, hshpc%out_date, date)
     call dbf_write_attribute_03(hshpc%outermost, ishape, hshpc%out_eddy_index, &
          i)
-    call dbf_write_attribute_03(hshpc%outermost, ishape, hshpc%out_radius4, &
-         e%radius4)
 
     ! max_speed_contour.dbf:
     if (e%speed_cont%area >= 0) then
diff --git a/Overlap/read_eddy.f90 b/Overlap/read_eddy.f90
index d988bd2cb442382eff9030aeb89a71355df788bc..37e0741e9654b49b9ebec164d3997d54a09eadce 100644
--- a/Overlap/read_eddy.f90
+++ b/Overlap/read_eddy.f90
@@ -69,14 +69,6 @@ contains
 
     call dbf_read_attribute_03(e%out_cont%ssh, hshp%outermost, hshp%out_ssh, &
          ishape)
-
-    if (hshp%out_radius4 /= - 1) then
-       call dbf_read_attribute_03(e%radius4, hshp%outermost, hshp%out_radius4, &
-            ishape)
-    else
-       e%radius4 = - 1
-    end if
-
     call shp_read_object_03(hshp%outermost, ishape, psobject)
     p = shpobj2pol(psobject)
     call shpdestroyobject(psobject)
diff --git a/Overlap/recv_snapshot.f90 b/Overlap/recv_snapshot.f90
index 9490eb950dabe9f31f144bc7efc3831a1c1d4428..b50dd44f6dea70e2f0fb74d861361c3aae6b1d7c 100644
--- a/Overlap/recv_snapshot.f90
+++ b/Overlap/recv_snapshot.f90
@@ -37,7 +37,6 @@ contains
        call ezmpi_recv(s%list(i)%max_speed, source, tag)
        call ezmpi_recv(s%list(i)%delta_in, source, tag)
        call ezmpi_recv(s%list(i)%delta_out, source, tag)
-       call ezmpi_recv(s%list(i)%radius4, source, tag)
     end do
 
     allocate(s%extr_map(1 - copy:nlon + copy, nlat))
diff --git a/Overlap/send_snapshot.f90 b/Overlap/send_snapshot.f90
index a2e3c04d38f6793f4791daa9be9fdc2507db5cd2..708a6b45fcb68acc7f9f6952ef386bb62d8417b7 100644
--- a/Overlap/send_snapshot.f90
+++ b/Overlap/send_snapshot.f90
@@ -34,7 +34,6 @@ contains
        call ezmpi_send(s%list(i)%max_speed, dest, tag)
        call ezmpi_send(s%list(i)%delta_in, dest, tag)
        call ezmpi_send(s%list(i)%delta_out, dest, tag)
-       call ezmpi_send(s%list(i)%radius4, dest, tag)
     end do
 
     call ezmpi_send(s%extr_map, dest, tag)
diff --git a/test_write_null.f90 b/test_write_null.f90
index cc31e48293c52c9be7922678d4ae7d992e11ec6e..5d5ec424a45acf9e7a5b4663560b18d4e2505bf9 100644
--- a/test_write_null.f90
+++ b/test_write_null.f90
@@ -47,8 +47,6 @@ program test_write_null
         call dbf_write_attribute_03(hshpc%outermost, ishape, hshpc%out_date, 0)
         call dbf_write_attribute_03(hshpc%outermost, ishape, &
              hshpc%out_eddy_index, i)
-        call dbf_write_attribute_03(hshpc%outermost, ishape, &
-             hshpc%out_radius4, 0)
         call dbf_write_attribute_03(hshpc%max_speed, ishape, &
              hshpc%max_speed_r_eq_area, - 100.)
         call dbf_write_attribute_03(hshpc%max_speed, ishape, &
@@ -79,8 +77,6 @@ program test_write_null
         call dbf_write_attribute_03(hshpc%outermost, ishape, hshpc%out_date, 0)
         call dbf_write_attribute_03(hshpc%outermost, ishape, &
              hshpc%out_eddy_index, i)
-        call dbf_write_attribute_03(hshpc%outermost, ishape, &
-             hshpc%out_radius4, 0)
      end do
 
      do i = 1, n_eddies