Create iceSheetGeoJson.json

1 file changed +90 −0

Diff

diff --git a/iceSheetGeoJson.json b/iceSheetGeoJson.json
new file mode 100644
index 0000000..0806622
--- /dev/null
+++ b/iceSheetGeoJson.json
@@ -0,0 +1,90 @@
+const iceSheetGeoJson = {
+    lgm_laurentide: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-125, 48], [-120, 45], [-115, 42], [-110, 40], [-100, 38], [-95, 37.5], [-90, 38], [-85, 39], [-80, 40], [-75, 40.5], [-70, 41], [-65, 42], [-60, 43], // Southern Edge (West to East)
+            [-55, 48], [-50, 55], [-50, 60], [-55, 65], [-60, 70], [-70, 75], [-80, 78], [-90, 80], [-100, 80], [-110, 78], [-120, 75], [-130, 70], [-135, 65], [-130, 60], [-125, 55], // Northern/Western Edge
+            [-125, 48]
+        ]]
+    },
+    lgm_cordilleran: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-140, 62], [-135, 58], [-130, 55], [-125, 50], [-120, 47], // Eastern Edge (South to North, approximate)
+            [-122, 45], [-125, 46], [-130, 48], [-135, 52], [-140, 55], [-145, 58], [-142, 60], // Western Edge (South to North, approximate Pacific coast)
+            [-140, 62]
+        ]]
+    },
+    lgm_fennoscandian: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-10, 50], [0, 48], [10, 48], [20, 50], [30, 52], [40, 53], [50, 55], [60, 58], // Southern Edge (West to East, into Russia)
+            [70, 60], [75, 65], [70, 70], [60, 72], [50, 75], [40, 78], [30, 75], [20, 72], [10, 70], [0, 65], [-5, 60], [-10, 55], // Northern Edge (East to West)
+            [-10, 50]
+        ]]
+    },
+    lgm_barents_kara: { // Often considered with Fennoscandian but had distinct centers
+        "type": "Polygon",
+        "coordinates": [[
+            [30, 68], [40, 65], [50, 62], [60, 60], [70, 60], [80, 62], [90, 65], // Southern edge over land
+            [95, 70], [90, 75], [80, 80], [70, 82], [60, 82], [50, 80], [40, 78], [30, 75], // Northern extent in Arctic Ocean
+            [30, 68]
+        ]]
+    },
+    lgm_greenland: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-75, 80], [-60, 83], [-40, 85], [-20, 83], [-15, 75], [-20, 70], [-25, 65], [-30, 60], [-40, 58], [-50, 57], [-60, 58], [-70, 60], [-78, 65], [-80, 70], [-78, 75],
+            [-75, 80]
+        ]]
+    },
+    lgm_iceland: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-25, 63], [-20, 62.5], [-15, 63], [-13, 64], [-14, 66], [-18, 67], [-22, 67], [-26, 66], [-25, 64],
+            [-25, 63]
+        ]]
+    },
+    lgm_alpine: { // European Alpine Ice Cap
+        "type": "Polygon",
+        "coordinates": [[
+            [5, 45.5], [7, 45], [9, 44.5], [11, 44.5], [13, 45], [15, 45.5], // Southern extent
+            [16, 46.5], [15, 47.5], [13, 48], [11, 48.5], [9, 48.5], [7, 48], [5.5, 47.5], // Northern extent
+            [5, 45.5]
+        ]]
+    },
+    lgm_patagonian: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-75, -38], [-72, -37], [-69, -38], [-68, -40], [-67, -45], [-66, -50], [-65, -54], // Eastern extent
+            [-68, -56], [-72, -55], [-75, -52], [-76, -48], [-77, -45], [-76, -42], // Western extent (Pacific side)
+            [-75, -38]
+        ]]
+    },
+    lgm_antarctic_west: { // West Antarctic Ice Sheet - grounded further out
+         "type": "Polygon",
+         "coordinates": [[
+            [-60, -70], [-50, -72], [-40, -75], [-50, -78], [-70, -80], [-90, -82], [-110, -80], [-130, -78], [-150, -75], [-170, -72], // Ross Sea / Ronne-Filchner grounding line approximations
+            [-170, -70], [-150, -68], [-130, -66], [-110, -65], [-90, -64], [-70, -65], [-60, -68], // Seaward edge
+            [-60, -70]
+         ]]
+    },
+    lgm_antarctic_east: { // East Antarctic Ice Sheet - generally similar but with some coastal expansion
+         "type": "Polygon",
+         "coordinates": [[
+            [20, -65], [40, -64], [60, -64], [80, -65], [100, -66], [120, -66], [140, -65], [160, -64], [170, -65], // Coastal edge
+            [170, -75], [160, -80], [140, -85], [120, -88], [100, -88], [80, -85], [60, -80], [40, -75], [20, -70], // Inland (approximating current bulk with some expansion)
+            [20, -65]
+         ]]
+    }
+    // Note: More localized ice caps in areas like the Tibetan Plateau, New Zealand Alps, British-Irish Ice Sheet (sometimes shown separate from Fennoscandian) could be added for even greater detail.
+    // The British-Irish Ice Sheet is complex; part could be merged with Fennoscandian thinking or drawn separately:
+    ,
+    lgm_british_irish: {
+        "type": "Polygon",
+        "coordinates": [[
+            [-12, 50], [-8, 49], [-5, 49.5], [0, 50], [2, 52], [0, 55], [-2, 58], [-5, 60], [-8, 61], [-10, 60], [-13, 58], [-14, 55], [-12, 52],
+            [-12, 50]
+        ]]
+    }
+};
\ No newline at end of file