Why we made this
When news of a big earthquake breaks, the first question is often “how far was that from me?” World earthquake maps rarely answer it. This page takes the USGS list of the past 24 hours and adds the distance and direction from your city to every quake, nearest first, and says plainly what the list leaves out.
Data
- Earthquakes: the USGS “All Earthquakes, Past Day” GeoJSON feed, updated every minute. Version 1.0 has been in production since 2013-05-22, with at least 30 days' notice before deprecation (Feed Life Cycle Policy). Your browser requests that one address directly.
- Field definitions: USGS ComCat documentation. Place names are USGS strings built from GeoNames.
- Coverage: the USGS FAQ says the lists should not be considered complete; outside the U.S. the map may not show quakes smaller than M5.0, and quakes under about M4.5 can be hard to locate.
- Example: Korea's weather agency reported 79 quakes of M2.0+ in Korea in 2025 (KMA press release); a USGS search of the same area returns 0 for 2025.
Sources checked: 2026-10-09.
Licences
- Earthquake data: U.S. Geological Survey (U.S. Public Domain, terms)
- Land outlines: Natural Earth 1:110m (Public domain, terms)
- TopoJSON: world-atlas v2 (Mike Bostock) (ISC, terms)
- 7 city coordinates: © OpenStreetMap contributors (Nominatim) (ODbL, terms)
- 17 Korean city halls: Kakao 장소검색 (danpung SPEC §2.9) (좌표값 인용)
- World city coordinates: Natural Earth populated places (Public domain, terms)
The math
Distance: a sphere of radius R = 6,371.0088 km (IUGG mean radius) and the haversine formula: a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2), clamped to 0–1, then d = 2R · atan2(√a, √(1−a)). This is the surface distance to the epicentre; depth is shown separately.
Accuracy, checked against GeographicLib (Karney 2013) on the WGS84 ellipsoid: at most 0.386% across 21 city pairs (Seoul–Sydney) and 0.555% across 20,000 random pairs (largest gap 37.8 km). So we say “within about 0.6%”.
| Pair | Haversine | WGS84 | Difference |
|---|---|---|---|
| Seoul–Busan | 325.068 | 324.871 | +0.197 |
| Seoul–Tokyo | 1,157.692 | 1,160.207 | −2.515 |
| Seoul–Los Angeles | 9,586.751 | 9,607.623 | −20.872 |
Direction: the initial great-circle bearing θ = atan2(sin Δλ · cos φ2, cos φ1 · sin φ2 − sin φ1 · cos φ2 · cos Δλ), in 16 compass points. Display: under 1,000 rounded to 1, otherwise to 10 (halves round up). Miles = km ÷ 1.609344, rounded the same way.
Place names
The English page shows the USGS place string exactly as published. Country borders, country names and sea names are not drawn on the map.
Shaking information
We never estimate shaking or say a distance is “fine”. Only values the USGS published for an event (felt reports, highest reported intensity, highest instrumental intensity, PAGER alert, tsunami flag) are shown, with their source. The tsunami flag does not mean a tsunami happened.
Privacy
The only outside request the page makes is the USGS feed address, sent with no query string, no referrer and no cookies, so your location has no way to travel with it. The city you pick is saved on this device as an id; your device location is rounded to two decimals (about 1 km), kept in memory and never saved. Google Analytics 4 receives only a bucket of how many quakes were shown, never a city, distance or coordinates. See the privacy policy.
Limits
- Small quakes outside the U.S. are often missing; your national agency is the official source for local quakes.
- USGS may revise magnitude or location later; automatic solutions are labelled.
- If the USGS feed is down, this page can't show the list and points you to the USGS map.
Disclaimer
This page is not an emergency alert. For warnings and evacuation, follow your official local agencies.