Articles using Mw magnitude scale

The 1980 El Asnam earthquake occurred on October 10 at 13:25:23 local time with a moment magnitude of 7.1 and a maximum Mercalli intensity of X (Extreme). The shock occurred in the Algerian town of El Asnam (now known as Chlef). The shocks were felt over 550 km (340 mi) away, with the initial earthquake lasting 35 seconds. It was the largest earthquake in Algeria, and was followed three hours later by a magnitude 6.2 aftershock. The earthquake created about 42 km (26 mi) of surface rupture and had a vertical slip of up to 4.2 m (14 ft). No foreshocks were recorded. The earthquake was found to have occurred very close to the epicenter of the 1954 Chlef earthquake using joint epicenter determination techniques. It occurred at a previously unknown reverse fault.The earthquake was the largest in the Atlas range since 1790.In addition to the earthquake, weak tsunami waves were recorded on tide gauges.The earthquake occurred at a populated region of Algeria, affecting 900,000 people. It destroyed 25,000 houses and made 300,000 inhabitants homeless. In addition to destroying homes, the earthquake also demolished critical infrastructure, including the main hospital, the central mosque, and a girls' school. The hospital was damaged significantly enough that victims had to be transported more than 160 km (100 mi) away to the next nearest hospital. Both events caused considerable damage with at least 2,633 killed and 8,369 injured. The earthquake caused approximately $5.2 billion in damage, which was 22% of Algeria's GDP at the time.

The 1991 Costa Rica earthquake, also known as the Limon earthquake or Bocas del Toro earthquake, occurred at 3:57 pm local time (21:56:51 UTC) on April 22. The epicenter of the 7.7 Mw earthquake was in Pandora, Valle La Estrella, in the Caribbean region of Limon, Costa Rica, 225 kilometres (140 mi) southeast of San José. The earthquake was the strongest recorded in Costa Rica's history, and was felt throughout the country as well as in western Panama.

The 1994 Kuril Islands earthquake – also known as the Hokkaido Toho-oki earthquake – occurred on October 5 at 00:23:00 local time. The magnitude of this earthquake was put at Mw8.3, or MJMA8.1. The epicenter was located at about 70 km east of Shikotan Island. The shaking and tsunami caused road and building damage. At least 10 people were reported dead.

The 1997 Umbria and Marche earthquake occurred in the regions of Umbria and Marche, central Italy on the morning of 26 September. It was preceded by a foreshock almost as strong as the main quake. The foreshock occurred at 02:33 CEST (00:33 UTC), rated Mw5.7, and the second – the main shock – occurred at 11:40 CEST (09:40 UTC), rated Mw 6.0. Their epicentre was in Annifo. The mainshock was assigned X (Extreme) and foreshock VIII (Severe) on the Mercalli intensity scale.There were several thousands of foreshocks and aftershocks from May 1997 to April 1998, more than thirty of which had a magnitude more than 3.5. Eleven people are known to have died following the shocks.

The 1922 Vallenar earthquake occurred with a moment magnitude of 8.5–8.6 and a tsunami magnitude of 8.7 in the Atacama Region of Chile, near the border with Argentina on 11 November at 04:32 UTC. It triggered a destructive tsunami that caused significant damage to the coast of Chile and was observed as far away as Australia.

An earthquake affected several villages in the Kerman province of Iran on February 22, 2005, at 05:55:23 local time. The shock measured 6.4 on the moment magnitude scale and had a maximum Mercalli intensity of VIII (Severe). Zarand is located 740 km southeast of Tehran. The maximum recorded peak ground acceleration was 0.51 g at Shirinrud dam. The United States' National Earthquake Information Center and the Belgian' Centre for Research on the Epidemiology of Disasters both show that 612 died and 1,411 were injured in the event.

The January 2001 El Salvador earthquake struck El Salvador on January 13, 2001, at 17:33:34 UTC. The 7.6 (later estimated to be 7.7 or 7.9) quake struck with the epicenter 60 miles (100 km) SW of San Miguel, El Salvador (13.04°N 88.66°W) at a depth of 60 km (31 mi).