diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index 34e12d6c2..bbc7960a0 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -722,6 +722,7 @@
   "src/voice/session.test.mjs",
   "src/layers/alpr/records.js",
   "src/layers/earthquakes/records.js",
+  "src/layers/earthquakes/records.test.mjs",
   "src/sources/sourceSlot.js",
   "src/data/feedState.js",
   "src/app/localGeojsonServices.js",
diff --git a/src/layers/earthquakes/records.test.mjs b/src/layers/earthquakes/records.test.mjs
new file mode 100644
index 000000000..cd7b6a874
--- /dev/null
+++ b/src/layers/earthquakes/records.test.mjs
@@ -0,0 +1,261 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { normalizeEarthquakeSnapshot } from './records.js';
+
+test('normalizeEarthquakeSnapshot parses valid GeoJSON earthquake features', () => {
+  const geojson = {
+    type: 'FeatureCollection',
+    features: [
+      {
+        id: 'us7000m123',
+        type: 'Feature',
+        geometry: {
+          type: 'Point',
+          coordinates: [-122.4194, 37.7749, 10.5],
+        },
+        properties: {
+          mag: 4.2,
+          place: 'San Francisco Bay Area, CA',
+          time: 1711929600000,
+        },
+      },
+    ],
+  };
+
+  const rows = normalizeEarthquakeSnapshot(geojson);
+  assert.equal(Array.isArray(rows), true);
+  assert.equal(rows.length, 1);
+  assert.deepEqual(rows[0], {
+    stableId: 'us7000m123',
+    usgsId: 'us7000m123',
+    lon: -122.4194,
+    lat: 37.7749,
+    depthKm: 10.5,
+    mag: 4.2,
+    place: 'San Francisco Bay Area, CA',
+    time: 1711929600000,
+  });
+});
+
+test('normalizeEarthquakeSnapshot generates index-based stable IDs when id is missing or blank', () => {
+  const geojson = {
+    features: [
+      {
+        id: null,
+        geometry: { type: 'Point', coordinates: [139.6917, 35.6895, 25.0] },
+        properties: { mag: 3.5, place: 'Tokyo, Japan', time: 1711930000000 },
+      },
+      {
+        id: '',
+        geometry: { type: 'Point', coordinates: [-70.6693, -33.4489, 45.2] },
+        properties: { mag: 5.1, place: 'Santiago, Chile', time: 1711931000000 },
+      },
+    ],
+  };
+
+  const rows = normalizeEarthquakeSnapshot(geojson);
+  assert.equal(rows.length, 2);
+  assert.equal(rows[0].stableId, 'event-1');
+  assert.equal(rows[0].usgsId, null);
+  assert.equal(rows[1].stableId, 'event-2');
+  assert.equal(rows[1].usgsId, '');
+});
+
+test('normalizeEarthquakeSnapshot filters events below M2.5 without dropping the feed', () => {
+  const geojson = {
+    features: [
+      {
+        id: 'ev-sub',
+        geometry: { type: 'Point', coordinates: [10, 20, 5] },
+        properties: { mag: 2.49, place: 'Minor tremor' },
+      },
+      {
+        id: 'ev-null-mag',
+        geometry: { type: 'Point', coordinates: [11, 21, 5] },
+        properties: { mag: null, place: 'Uncalculated' },
+      },
+      {
+        id: 'ev-threshold',
+        geometry: { type: 'Point', coordinates: [12, 22, 5] },
+        properties: { mag: 2.5, place: 'Threshold event' },
+      },
+      {
+        id: 'ev-strong',
+        geometry: { type: 'Point', coordinates: [13, 23, 5] },
+        properties: { mag: 6.8, place: 'Major event' },
+      },
+    ],
+  };
+
+  const rows = normalizeEarthquakeSnapshot(geojson);
+  assert.equal(rows.length, 2);
+  assert.equal(rows[0].stableId, 'ev-threshold');
+  assert.equal(rows[0].mag, 2.5);
+  assert.equal(rows[1].stableId, 'ev-strong');
+  assert.equal(rows[1].mag, 6.8);
+});
+
+test('normalizeEarthquakeSnapshot normalizes optional fields to null when omitted or invalid', () => {
+  const geojson = {
+    features: [
+      {
+        id: 'ev-sparse',
+        geometry: { coordinates: [-100, 40] }, // depth omitted
+        properties: { mag: 3.0, place: 12345, time: 'invalid' }, // place not string, time not number
+      },
+    ],
+  };
+
+  const rows = normalizeEarthquakeSnapshot(geojson);
+  assert.equal(rows.length, 1);
+  assert.equal(rows[0].depthKm, null);
+  assert.equal(rows[0].place, null);
+  assert.equal(rows[0].time, null);
+});
+
+test('normalizeEarthquakeSnapshot returns null for malformed structures or non-array features', () => {
+  assert.equal(normalizeEarthquakeSnapshot(null), null);
+  assert.equal(normalizeEarthquakeSnapshot(undefined), null);
+  assert.equal(normalizeEarthquakeSnapshot({}), null);
+  assert.equal(normalizeEarthquakeSnapshot({ features: 'not-an-array' }), null);
+  assert.equal(normalizeEarthquakeSnapshot({ features: null }), null);
+});
+
+test('normalizeEarthquakeSnapshot returns null for invalid geometries or out-of-range coordinates', () => {
+  const baseFeature = {
+    id: 'test',
+    geometry: { type: 'Point', coordinates: [0, 0, 0] },
+    properties: { mag: 3.0 },
+  };
+
+  // Non-Point geometry
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: {
+            type: 'LineString',
+            coordinates: [
+              [0, 0],
+              [1, 1],
+            ],
+          },
+        },
+      ],
+    }),
+    null,
+  );
+
+  // Missing or short coordinates
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        { ...baseFeature, geometry: { type: 'Point', coordinates: [0] } },
+      ],
+    }),
+    null,
+  );
+
+  // Longitude out of range [-180, 180]
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: { type: 'Point', coordinates: [180.1, 0, 0] },
+        },
+      ],
+    }),
+    null,
+  );
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: { type: 'Point', coordinates: [-180.1, 0, 0] },
+        },
+      ],
+    }),
+    null,
+  );
+
+  // Latitude out of range [-90, 90]
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: { type: 'Point', coordinates: [0, 90.1, 0] },
+        },
+      ],
+    }),
+    null,
+  );
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: { type: 'Point', coordinates: [0, -90.1, 0] },
+        },
+      ],
+    }),
+    null,
+  );
+
+  // Non-finite depth
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [
+        {
+          ...baseFeature,
+          geometry: { type: 'Point', coordinates: [0, 0, NaN] },
+        },
+      ],
+    }),
+    null,
+  );
+
+  // Magnitude > 10
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [{ ...baseFeature, properties: { mag: 10.1 } }],
+    }),
+    null,
+  );
+
+  // Non-object or array properties
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [{ ...baseFeature, properties: 'invalid' }],
+    }),
+    null,
+  );
+  assert.equal(
+    normalizeEarthquakeSnapshot({
+      features: [{ ...baseFeature, properties: [] }],
+    }),
+    null,
+  );
+});
+
+test('normalizeEarthquakeSnapshot returns null when feed contains duplicate IDs', () => {
+  const geojson = {
+    features: [
+      {
+        id: 'duplicate-id',
+        geometry: { type: 'Point', coordinates: [0, 0, 0] },
+        properties: { mag: 3.0 },
+      },
+      {
+        id: 'duplicate-id',
+        geometry: { type: 'Point', coordinates: [1, 1, 1] },
+        properties: { mag: 4.0 },
+      },
+    ],
+  };
+
+  assert.equal(normalizeEarthquakeSnapshot(geojson), null);
+});