Twicalli: An Earthquake Detection System Based on Citizen Sensors Used for Emergency Response in Chile

Barbara Poblete

Abstract: In this talk I will describe "Twicalli", a real-time earthquake detection system based on citizen sensors. This system is publicly available for over a year, at http://twicalli.cl, and is currently in use as a decision support tool by the National Seismology Office and by the Hydrographic and the Oceanographic Service in Chile. The novelty of our system relies on the fact that it has a very good precision and recall tradeoff for earthquakes of all magnitude ranges that were reported on Twitter. Our earthquake detection methodology is simple, efficient, unsupervised, and it can detect earthquakes reported globally in any language and any region. This complements existing approaches that are either: i) supervised and customized to a particular geographical region, which makes them very expensive to scale geographically and keep up-to-date, or ii) unsupervised with low earthquake recall.The evaluation of our system, performed during a 9-month period, shows that our solution is competitive to the best state-of-the-art methods, providing very good precision and recall performance for a wide range of earthquake magnitudes.