About Tremo

Tremo is a free platform to see earthquakes in real time, get alerts based on what you'd feel at your places, understand the science of earthquakes and get prepared. It was born in Colombia, a country that shakes every day, and works worldwide.

Our principles

Honesty: we never promise to predict earthquakes or warning seconds that don't exist.
Zero false alarms: we only alert with data from official networks, once per quake and based on estimated intensity.
Privacy: your exact location never leaves your phone.
For everyone: 14 languages, free, no mandatory sign-up.

Data sources

Colombian Geological Survey (SGC) — felt earthquakes in Colombia and maximum reported intensity.
U.S. Geological Survey (USGS) — worldwide ComCat catalog (public domain).
EMSC – European-Mediterranean Seismological Centre — SeismicPortal, integrating agencies from many countries.

When several networks report the same quake, we show it once and give priority to the local agency.

Scientific methods

Estimated intensity: Allen, Wald and Worden (2012) intensity prediction equation.
Wave times: mean speeds P ≈ 6.0 km/s and S ≈ 3.5 km/s in the crust (7.9 and 4.4 km/s at larger distances).
Lab: Gutenberg-Richter law with maximum-likelihood b-value (Aki 1965; Utsu), completeness by maximum curvature (Wiemer and Wyss 2000; Woessner and Wiemer 2005), Reasenberg and Jones (1989) aftershocks, Gardner and Knopoff (1974) declustering, BPT renewal model (Matthews et al., 2002) and Brier-score evaluation.

Maps and resources

Plate boundaries: Bird (2003), PB2002, via fraxen/tectonicplates (ODC-By).
Interactive maps with Leaflet (BSD-2). Nunito typeface (SIL Open Font License).

Who's behind it

Tremo is a project by qhero.net. Ideas, bugs or partnerships? Write to [email protected].