Support

Tremula shows events as soon as data loads. If you see this on first launch, the app may still be fetching. Pull down to refresh. If it persists, check that you have an internet connection. The app caches the last known data so you'll always see something after your first successful load.

Your location is used to center the map, show nearby earthquakes and weather alerts, calculate aurora context, request nearby fire/hotspot context, and estimate how far the ISS is from you. Some NASA-backed requests go through Tremula's Cloudflare Worker so API keys stay out of the app. You can also use Tremula without location permission; it will show broader/global events instead of local context.

USGS earthquake data typically appears in the app within minutes of an event occurring. Tremula refreshes when you open the app, when you manually reload, and periodically while the app is active. Some checks may also happen through iOS Background App Refresh, but iOS decides exactly when background refresh is allowed to run.

Aurora visibility depends on the Kp index (geomagnetic activity level). At Kp 5+, aurora can be visible from latitudes around 50°N and above. At Kp 7+, it can reach as far south as 45°N. Tremula shows the current Kp level and a plain-language description so you always know what the sky is doing. For best viewing: find a dark location, look north, and go out after midnight.

Yes. After your first successful data load, Tremula caches all events locally. If you lose internet connection, you'll see the last known data with a banner indicating when it was last updated. Meteor shower calendar data is always available offline since it's built into the app.

Tremula can notify when it checks active alerts, but iOS does not guarantee exact hourly background execution. For the most current view, open Tremula or tap reload. Make sure Notifications and Background App Refresh are enabled in iPhone Settings.

During onboarding, Tremula will ask for notification permission. If you declined and want to enable it later, go to your iPhone's Settings → Tremula → Notifications and turn on Allow Notifications. Tremula can send notifications for significant events and alerts, including strong earthquakes, active weather warnings, aurora/space-weather activity, and other notable Earth or sky events.

The Kp index measures global geomagnetic activity on a scale of 0–9. 0 = completely quiet. 3 = minor activity, aurora near poles. 5 = geomagnetic storm, aurora to ~50°N. 7+ = severe storm, aurora visible across much of North America and Europe. NOAA updates this number every 3 hours.