All data comes from free, public, authoritative official sources. We state the coverage limits plainly here rather than letting the app look omniscient:
Hazard
Source
Coverage
Shown as
Earthquake
USGS
Global
Magnitude
Hurricane
GDACS
Global (major events only)
Category 0–5
Flood
GDACS
Global (major events only)
Alert level
Volcano
GDACS
Global (major events only)
Alert level 1–3
Tsunami
GDACS
Global (major events only)
Wave height (m)
Wildfire
GDACS
Global (major events only)
Hectares burned
Tornado
NWS
United States only
Tornado warning
Heat
NWS
United States only
Warning tier
Three honest caveats: GDACS lists only significant, currently active disasters, so hurricane / flood / volcano / tsunami / wildfire are quiet much of the time; tornado and heat are US-only because no free global real-time feed exists; and a hazard in progress has no post-event scientific rating (a tornado has no EF number yet), so we show the official alert wording instead of inventing a figure.
FAQ
Why does it say "Nothing to watch"?
You turned off every hazard type in Settings. Open Settings (gear, top right) and enable at least one.
Why does a type say "None in the last 48 hours"?
That type had no active event in the past 48 hours. Every type you follow keeps its own page. Read with the table above: outside the US, the tornado and heat pages stay calm by design — that is coverage, not a bug.
How is distance calculated?
From your location, as a great-circle straight-line distance to the event, computed on your device. The precise location used for this never leaves your device.
Why am I not getting notifications?
Make sure notifications are allowed both in the app's Settings and in iOS. The app is deliberately quiet: it alerts only when a new event is closer than the one displayed, or the displayed event's severity rises by 15% or more — and never twice for the same event within six hours.
Does enabling notifications upload my location?
It uploads a coarse location rounded to roughly an 11 km grid, so the server can tell whether a closer hazard appeared while the app is closed. We neither receive nor store precise coordinates. See the Privacy Policy.
How often does data update?
The app refreshes once a minute while on screen, and when it returns to the foreground. The server polls each source on its own cadence (earthquakes every minute, tornado/heat every two minutes).
Earth Radar is an awareness tool, not an emergency or early-warning service. In an emergency, follow official alerts.