The main objective of this work is to present a description of the precursory phenomena of the volcanic eruptions of two active volcanoes Nyiragongo and Nyamulagira. The volcanism of Virunga, like the whole volcanism in the divergence zones, is the Hawaiian type characterized by a passive overflowing of basaltic magma, i.e., very fluid and at very high temperature. The source data for our study are the earthquake data collected in the stations installed around the active volcanoes and that of Lwiro located at about 90 Km away of Virunga region. The discrimination in frequency content of...