Powerful earthquakes strike Algeria annually , ranging in Mercalli intensity scale intensity from VI ( '' Strong '' ) to XI ( '' Extreme '' ) . Chlef was hit by another major earthquake in 1980 which killed 3,500 people . The Atlas Mountains area faces aseismic deformation ( change in shape not originating from movement of faults ) , with only marginal plate shifting each year . Both Chlef earthquakes originated from the same reverse fault zone
major earthquake
1980 El Asnam earthquake
1954 Chlef earthquake