How to map earthquakes worldwide with USGS data

Define the map before counting events

A world earthquake map needs an explicit minimum magnitude, start and end time, and source catalog. The USGS event service accepts filters such as starttime, endtime and minmagnitude; its GeoJSON feeds also offer fixed recent windows. Choose a UTC window and write it in the title. “Past week” changes every hour, so a static page must state exactly when its count was retrieved.

Magnitude is a measure of earthquake size, not the same thing as shaking intensity at a particular place. An epicentre marker cannot by itself tell you whether people felt the event, whether infrastructure was damaged, or how many people were exposed.

Publisher documentation: USGS — Earthquake Catalog API · USGS — Real-time GeoJSON feeds · USGS — Magnitude versus intensity

Treat the catalog as revisable evidence

An event record can be updated as more observations arrive. Keep the event identifier, event time, last-updated time, magnitude, depth and source URL with the marker. A new map load is not a new earthquake. If two views disagree, compare their time windows and the publisher's updated timestamp before concluding that one is wrong.

Global coverage and detection are not uniform at every magnitude. A high threshold makes a world map more readable, but it intentionally leaves out smaller events. The map therefore answers “which catalogued events met this filter?” rather than “where are all earthquakes happening?”.

• Choose a UTC start and end time plus a minimum magnitude, such as magnitude 5.
• Use the USGS catalog or GeoJSON feed, preserving each event's identifier and detail link.
• Label the map with retrieval time and distinguish event time from record update time.
• Open the event detail before making any claim about shaking, damage or impact.

Open a real map, then refresh the question

The Humaps example stores one unedited Atlas answer for worldwide magnitude-5-or-higher events in a specified seven-day window. Its count is historical. Use the live map or ask Atlas again for a current window; keep the USGS event links in any report you publish.