The 1976 Moro Gulf earthquake and tsunami occurred on near the islands of Mindanao and Sulu, in the Philippines. It measured 8.0 on the moment magnitude scale occurring at a depth of 20 km (12 mi). The earthquake was accompanied by a destructive tsunami that resulted in a majority of the estimated 5,000 to 8,000 fatalities. It was the deadliest and strongest earthquake in the Philippines in 58 years since the 1918 Celebes Sea earthquake.
This list of 20th-century earthquakes is a list of earthquakes of magnitude 6 and above that occurred in the 20th century. Sone smaller events which nevertheless had a significant impact are also included. After 1900 most earthquakes have some degree of instrumental records and this means that the locations and magnitudes are more reliable than for earlier events.
The 2002 Mindanao earthquake struck the Philippines at 05:16 Philippine Standard Time on March 6. The world's sixth most powerful earthquake of the year, it registered a magnitude of 7.5 and was a megathrust earthquake. It originated near the Cotabato Trench, a zone of deformation situated between the Philippine Sea Plate and the Sunda Plate, and occurred very near to the Philippines' strongest earthquake for the 20th century, the 1918 Celebes Sea earthquake.
The 2010 Mindanao earthquakes occurred in the southern Philippines in the Moro Gulf. This was a complex sequence of events including three main events of magnitude 7.3 or greater on the 23rd of July, and two significant aftershocks of magnitude 6.6 on the 24th and 29th. All of these were deep focus earthquakes, at depths from 565 km (351 mi) to 634 km (394 mi). This resulted in minimal, but very widespread shaking at the surface, with a maximum intensity of IV on the PEIS scale; consequently there were no reports of casualties or damage.
The 1881 Nicobar Islands earthquake occurred at about 07:49 local time on 31 December, with an epicentre beneath Car Nicobar. It occurred as two separate ruptures, the largest of which had an estimated magnitude of 7.9 on the moment magnitude scale and triggered a tsunami that was observed around the Bay of Bengal. It is probably the earliest earthquake for which rupture parameters have been estimated instrumentally.
The 1944 Tōnankai earthquake occurred at 13:35 local time on 7 December. It had an estimated magnitude of 8.1 on the moment magnitude scale and a maximum felt intensity of greater than 5 Shindo. It triggered a large tsunami that caused serious damage along the coast of Wakayama Prefecture and the Tōkai region. Together, the earthquake and tsunami caused 3,358 casualties.
The 1968 Hyūga-nada earthquake occurred on April 1 at . The earthquake had a magnitude of 7.5, and the epicenter was located in Hyūga-nada Sea, off the islands of Kyushu and Shikoku, Japan. The magnitude of this earthquake was also given as 7.5. A tsunami was observed. One person was killed, and 22 people were reported injured. The intensity reached shindo 5 in Miyazaki and Kōchi.
The 1762 Arakan earthquake occurred at about 17:00 local time on 2 April, with an epicentre somewhere along the coast from Chittagong to Arakan in modern Myanmar. It had an estimated moment magnitude between 8.5 and 8.8 and a maximum estimated intensity of XI (Extreme). It triggered a local tsunami in the Bay of Bengal and caused at least 200 deaths. The earthquake was associated with major areas of both uplift and subsidence. It is also associated with a change in course of the Brahmaputra River to from east of Dhaka to 150 kilometres (93 mi) to the west via the Jamuna River.
The 1941 Andaman Islands earthquake struck the Andaman Islands on June 26 with a magnitude of 7.7 to 8.1. Details of this event are poorly known as much of Southeast Asia was in the turmoil of World War II. The quake caused severe damage in the Andaman Islands. The tsunami it triggered was reported along the Andaman and Nicobar Islands, India and British Ceylon. There may have been damage and deaths in Bangladesh, Myanmar, and Thailand due to the tsunami.
The 1897 Mindanao earthquakes occurred on September 20, 1897, at 19:06 UTC and September 21, 1897, at 05:12 UTC. The estimated epicentres of the two earthquakes are identical, lying just off the southwestern coast of Mindanao in the Philippines, south of Basilan island. The earthquakes were originally given estimated magnitudes of 8.6 and 8.7 on the surface wave magnitude scale by Charles Richter, but these were revised downwards by Katsuyuki Abe to 7.4 and 7.5 , respectively. Contemporary reports noted that with few exceptions, all the masonry buildings in Zamboanga and Basilan were left in ruins.
The Cotabato Trench is an oceanic trench in the Pacific Ocean, off the southwestern coast of Mindanao in the Philippines. Along this trench the oceanic crust of the Sunda Plate beneath the Celebes Sea is being subducted beneath the Philippines Mobile Belt. It forms part of a linked set of trenches along the western side of the Philippines formed over east-dipping subduction zones, including the Manila Trench and the Negros Trench. At its northern end the rate of convergence across this boundary is about 100 mm per year. It is a relatively young structure, forming during the late Miocene to Pliocene. This age is consistent with the estimated age of the sedimentary rocks in the accretionary wedge associated with the trench and the age of adakitic arc rocks on Mindanao thought to date the onset of subduction.
During April 1819, the area around Copiapó in northern Chile was struck by a sequence of earthquakes over a period of several days. The largest of these earthquakes occurred on 11 April at about 15:00 local time, with an estimated magnitude of 8.5. The other two events, on 3 April between 08:00 and 09:00 local time and on 4 April at 16:00 local time, are interpreted as foreshocks to the mainshock on 11 April. The mainshock triggered a tsunami that affected 800 km of coastline and was also recorded at Hawaii. The city of Copiapó was devastated.
The 1979 Yapen earthquake occurred on September 12 at 05:17:51 UTC. It had an epicenter near the coast of Yapen Island in Irian Jaya, Indonesia. Measuring 7.5 on the moment magnitude scale and having a depth of 20 km (12 mi), it caused severe damage on the island. At least 115 were killed due to shaking and a moderate tsunami.
The southern margin of the Gulf of Corinth was struck by a major earthquake on 26 December 1861 at 08:28 a.m. local time. It had an estimated magnitude in the range 6.6–6.7 and a maximum felt intensity of IX (destructive) on the European macroseismic scale (EMS). It caused widespread damage on both sides of the Gulf and led to up to 20 deaths and a further 126 people being injured, 18 of them seriously. A series of tsunami waves were reported, with a maximum run-up of 2.1 m.
A Mw 7.9 earthquake struck offshore between Mindanao and Sulawesi on 14 March 1913. It had a maximum Modified Mercalli intensity of IX (Violent). A majority of the 138 fatalities occurred on Sangihe Island attributed to a mudflow.
