Stress field variations along the Maghreb region derived from inversion of major seismic crisis fault plane solutions

Seismicity of Algeria from 1365 to 2013: Maximum Observed Intensity Map (MOI2014)

“…Special attention should be paid to offshore and coastal seismicity causing strong and destructive events, such as Djidjelli (1856; Harbi et al, 2011) andZemmouri (2003;Harbi, Maouche, Ousadou, et al, 2007;Ayadi et al, 2008), which were responsible for significant damage. The seismicity of the northern region of Algeria is dominated by thrust focal mechanisms to the west and centrally and by strike-slip faults to the east (e.g., Bezzeghoud et al, 2014;Ousadou et al, 2014).…”

“…(Benouar, 1994;Mokrane et al, 1994;Harbi, Maouche, Ousadou, et al, 2007;Harbi, Maouche, Vaccari, et al, 2007) in which significant earthquakes have occurred over the last 50 years, such as El Asnam (1954, M 6.5; 1980, M 7.3), Constantine (1985, M 6.0), and Al Hoceima (1994, M 5.8; 2004, M 6.0) (e.g., Bezzeghoud et al, 1995;Bezzeghoud and Buforn, 1999;Bounif et al, , 2004Cakir et al, 2006, Ousadou et al, 2014. However, there is no record of the intensities for the events used to draw the map in Figure 3.…”

The large Algerian earthquakes (267 A.D.-2017)

“…In other hand, analysis of the focal mechanisms indicates a reorientation of the stress regime between the western part and eastern part of Algeria from compressive to a strike slip movement, associated with a reorientation of the stress axes (Ousadou et al, 2014). The study of many recent moderate events in the eastern part of Algeria as the Bejaia event (2013)(2014), (Abacha, 2015) or the Ain Azel-Merouana (Setif region) (2015) (Chami et al, 2015) or the last Biskra event will contribute more to see how the stress pattern evolves from west to east.…”

“…From west to east, active faults are visible as en echelon system represented by inverse faults or faults related to fold mainly oriented NNE-SSW or strike slip faults oriented NNW-SSE. In the eastern part, recent earthquakes on E-W active faults indicate a reorientation of the most compressive stress axis σ 1 in a NNW-SSE to N-S (Buforn et al, 1995;Ousadou et al, 2014;Abacha, 2015).…”

The Rupture Process and Location of the 2003 Zemmouri–Boumerdes Earthquake (Mw 6.8) Inferred from Seismic and Geodetic Data

“…and Yielding (1985) relocated the 1980 main event and several of the largest 1980 aftershocks. The aftershock zone extended over a length of approximately 40 km in the NE-SW direction (Ouyed et al, 1981) and ranged between depths of 5 and 14 km following the relocation procedure using HypoDD performed by Ousadou et al (2014). Three segments were identified on the rupture zone as shown by the aftershock distribution and surface fault traces (Ouyed et al, 1981).…”