Tsunami advisories
Threat-level bulletins are shown near recent earthquakes when timing and distance make a link plausible.
Worldwide coverage
Official sources, one map
Tremor ingests earthquake reports from global catalogs and local or national seismic networks. Global sources such as USGS, EMSC, and GEOFON/GFZ provide broad coverage, while local networks add smaller regional events that global catalogs often miss.
When multiple agencies report the same quake, Tremor groups the reports and prefers local or national network solutions over global aggregators for the primary marker. Source attribution remains visible so the origin of each report stays clear.
Freshness and accuracy
Fast updates, official values
The sync worker checks recent feeds continuously, with the core loop running about once per minute. Some agencies publish slower or revise events after analyst review, so magnitude, depth, location, and status can change as official data improves.
Tremor is designed for situational awareness, not as an emergency alert authority. The source status page shows provider freshness, and official civil-protection instructions should always take priority during an event.
Hazard overlays
Context around the quake
Volcano activity
Active or elevated volcanoes appear as a separate layer so nearby volcanic hazards stay visible.
Wildfire hotspots
Recent fire detections help show where earthquake response may overlap with other active hazards.
Weather and pressure
Weather alerts, tropical systems, pressure centers, and plate boundaries provide extra map context.
I'm safe
A lightweight check-in after an event
The I'm safe feature lets someone create an anonymous passkey account, tap a check-in button after an event, and share a read-only status link with people they choose.
The server stores a random account id, the passkey public key, a random share token, an optional label, and check-in timestamps. There are no tracking cookies, and a lost passkey means creating a new account.