Earthquakes are caused by movements within the Earth's crust and uppermost mantle. They range from weak events detectable only by seismometers, to sudden and violent events lasting many minutes which have caused some of the greatest disasters in human history. Below, earthquakes are listed by period, region or country, year, magnitude, cost, fatalities, and number of scientific studies.
The 1946 Nankai earthquake was a great earthquake in Nankaidō, Japan. It occurred on December 21, 1946, at 04:19 JST. The earthquake measured between 8.1 and 8.4 on the moment magnitude scale, and was felt from Northern Honshū to Kyūshū. It occurred almost two years after the 1944 Tōnankai earthquake, which ruptured the adjacent part of the Nankai megathrust.
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 1931 Fuyun earthquake (富蕴地震) occurred on August 10 at 21:18 UTC. The epicenter was near Fuyun County of northern Xinjiang, China. It was a 8.0 earthquake and had a surface rupture of 171 km with a maximal horizontal displacement of 14 m along the Koktokay-Ertai fault zone (可可托海-二台断裂带). The Koktokay-Ertai fault has a slip rate of 4±2 mm per year. The rupture of this earthquake was caused by right-lateral strike-slip movement with normal component. The rupture is well preserved and becomes one of the main features of the Koktokay National Geopark (可可托海国家地质公园) located in Koktokay.
The 1935 Helena earthquake occurred at in Montana, with an epicenter near Helena. It had a magnitude of 6.2 on the surface-wave magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. The temblor on that date was the largest of a series of earthquakes that also included a large aftershock on October 31 of magnitude 6.0 and a maximum intensity of VIII. Two people died in the mainshock and two others died as a result of the October 31 aftershock. Property damage was over $4 million.
The 2006 Mozambique earthquake occurred at 22:19 UTC on 22 February. It had a magnitude of 7.0 on the moment magnitude scale and caused 4 deaths and 36 injuries. The epicenter was near Machaze in Manica Province of southern Mozambique, just north of the Save River. It was the largest historical earthquake in Mozambique and the first earthquake in southern Africa to have an identified surface rupture.
The 1918 Celebes Sea earthquake occurred on August 15 at 12:18 UTC near the Moro Gulf coast of Mindanao. It had a magnitude of 8.3 on the moment magnitude scale and a maximum perceived intensity of X (Extreme) on the Mercalli intensity scale. It triggered a tsunami of up to 7 m in height and the combined effects of the earthquake and tsunami led to the deaths of 52 people.
The 1976 Sabah earthquake occurred at 10:56 am on 26 July near Lahad Datu in the eastern portion of Sabah, Malaysia. The moment magnitude 6.3 earthquake is one of the strongest in Malaysia to be recorded by seismic instruments. It had a focal mechanism corresponding to strike-slip faulting. While slightly larger than the 2015 Sabah earthquake, the 1976 event caused less extensive damage, in the form of cracks on several buildings and ground cracks.
The 2004 Baladeh earthquake occurred on May 28 in northern Iran. This dip-slip earthquake had a moment magnitude of 6.3 and a maximum Mercalli intensity of VIII (Severe). Total deaths for the event amounted to 35, with 278–400 injured, and $15.4 million in damage.
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.
On 29 November, at 14:10 UTC, a magnitude 7.7 earthquake struck off the southern coast of Taliabu Island Regency in North Maluku, Indonesia. At least 41 people were killed on the nearby islands and a tsunami was triggered. Several hundred homes, buildings and offices were damaged or destroyed.
On November 14, 1986, a strong earthquake with a recorded magnitude of 7.4 struck Hualien City in Taiwan. The earthquake killed 15 people and injured 44. Landslides occurred along a highway between Su'ao and Hualien. The Taiwan–Guam and Taiwan–Okinawa undersea telecommunication cables were damaged. The earthquake triggered a tsunami with a maximum height of 0.3 m. The tsunami sank 10 fishing boats in Hualien and Yilan and was attributed to six injuries.
United States, south of Unimak Island, Alaska (Magnitude 8.6) April 1
Dominican Republic, Samaná Bay (Magnitude 7.5) August 4 1,790 deaths
