Fig 2. Sites with unusually high behavior on February 3, 2008.

The green cross marks the location of the epicenters of the Lake Kivu earthquakes, while the two green circles mark the 25 and 50 km areas around the epicenters. Ten sites recorded unusually high call volume and movement frequency and belong to the same spatial cluster. One additional site recorded unusually high call volume, while two additional sites recorded unusually high movement frequency. Most of these sites are located within 50 km of the approximate location of the earthquakes epicenters which is indicative of the connection between the anomalous pattern of communication and the occurrence of the Lake Kivu earthquakes.