[S-SS10] 地震活動とその物理

[SSS10-P10] Statistical Study of recent earthquake Swarms (2000-2020) in Northeastern Algeria

*Sofiane Taki-Eddine Rahmani¹、Issam Abacha¹、Oualid Boulahia¹、Khaled Roubeche¹、El-Mahdi Tikhamarine²、Hichem Bendjama¹ (1.Center of Research in Astronomy, Astrophysics, and Geophysics、2.University Ferhat Abbes of Setif-1, Faculty of Sciences, Department of Physics)

キーワード：Earthquake Swarms, Time Clustering, , Induced Seismicity, ETAS

Northeastern Algeria is known by its high seismic activity as reflected by several hundreds of events occurring every year. Recently this area has been the seat of several seismic sequences such as the 2010 Beni-Ilmane earthquake sequence, the 2012-2013 Bejaia earthquake sequences and more recently the 2020 Mila sequence. On the other hand, it is also observed that the seismic activity of this part of Algeria is dominated by swarms, with high concentrations in time and space, from a few days to several months, ranging from a few kilometers to ten kilometers, and sometimes showing a migration of several kilometers in several weeks. Based on some statistical laws (Gutenberg-Richter, Gamma, Omori and ETAS model) we found that, the earthquake swarms are related to the increase in the water body of the reservoir after a heavy precipitation (Beni-Haroun (B-H) dam on 2012), and to the increase in the interstitial pressure due to the fluid injection (the 2007 Mila crisis and Grouz reservoir crisis) or due to the water circulation in hydrothermal systems (Ain Azel, El-Hachimia, Azzaba and Djemila swarms). Here, 10 swarms occurring in the region were analyzed using statistical laws and finally the results have been discussed.