Support

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Tremor Q&A

Where does the earthquake data come from?
Tremor aggregates four authoritative public feeds: the U.S. Geological Survey (USGS), the European-Mediterranean Seismological Centre (EMSC), the Japan Meteorological Agency (JMA), and GeoNet (New Zealand). Events from different sources are merged and deduplicated.

How recent is the data?
Feeds refresh continuously while the app is open. Tremor retains a rolling seven-day window of events. While Tremor aims to provide real-time information, some data feeds can have a slight delay in their reporting.

Why don't I see very small earthquakes?
Tremor shows events at or above your magnitude filter (default M2.0). Negative-magnitude microquakes are out of scope. Adjust the magnitude filter to see more or fewer events.

How do alerts work?
You can turn on notifications for significant world events (M6.0 and above, anywhere) or for quakes near you by going to Settings. Both are off by default. Enabling them asks for the relevant permissions, and you can turn them off anytime.

Why didn't I receive an alert?
Alerts are only sent for events that meet the criteria you've set in the app's settings. Be sure Tremor is running in the background on your device and Background Content Refresh (in iOS settings) is tured on. Tremor uses on-device notifications instead of push notifications to avoid having to store your private location data on a server. Note that alerts are not sent if your device is in low power mode.

Which devices are supported?
Tremor runs on iPad and Mac (iOS 26.0 and later).