  | |
| UTC time | 1947-07-29 13:43:24 |
|---|---|
| ISC event | 897970 |
| USGS-ANSS | ComCat |
| Local date | July 29, 1947 |
| Local time | 18:43:24 |
| Magnitude | 7.3 Mw [1] |
| Depth | 60 km |
| Epicenter | 28°30′N94°00′E / 28.50°N 94.00°E [1] |
| Max. intensity | V (Strong) [2] |
The 1947 Assam earthquake occurred on 29 July at 13:43 UTC with an Mw of 7.3 and a maximum EMS-98 intensity of V (Strong).
The earthquake was located near the border between India and Tibet. Some sources put the epicenter in India, and some put it in Tibet. [3] [4] The released seismic moment was about 1.5×1020 Nm. [5] The mechanism of the earthquake is not well known. [6] In the Chinese literature, this earthquake was often located around the Nang County, Tibet. [7]
In Dibrugarh, Jorhat, and Tezpur, there were cracks in walls. Failure of electricity was reported in Guwahati. [4]
The border region was struck by the much larger 8.6 Mw Assam–Tibet earthquake three years later, on August 15, 1950.
The 1950 Assam–Tibet earthquake, also known as the Assam earthquake, occurred on 15 August and had a moment magnitude of 8.7. The epicentre was located in the Mishmi Hills. It is the strongest earthquake ever recorded on land and is tied with the 2012 Indian Ocean Earthquakes as the strongest Strike-slip earthquake to date.
Seismic magnitude scales are used to describe the overall strength or "size" of an earthquake. These are distinguished from seismic intensity scales that categorize the intensity or severity of ground shaking (quaking) caused by an earthquake at a given location. Magnitudes are usually determined from measurements of an earthquake's seismic waves as recorded on a seismogram. Magnitude scales vary on what aspect of the seismic waves are measured and how they are measured. Different magnitude scales are necessary because of differences in earthquakes, the information available, and the purposes for which the magnitudes are used.
This list of 20th-century earthquakes is a global list of notable earthquakes that occurred in the 20th century. 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. To prevent this list becoming unmanageable, only those of magnitude 6 and above are included unless they are notable for some other reason.
The 1968 Hyūga-nada earthquake occurred on April 1 at 09:42 local time. The earthquake had a magnitude of Mw 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 MJMA 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 1994 offshore Sanriku earthquake occurred on December 28, 1994, at 12:19 UTC. This was a magnitude Mw 7.7 earthquake with epicenter located in the Pacific Ocean at about 180 km east of Hachinohe, Aomori. The intensity reached shindo 6 in Hachinohe, Aomori, about 187.6 km from epicenter. It could be felt in Tokyo, about 632.9 km from epicenter, with shindo 2. The Japanese Meteorological Agency put the magnitude at MJMA 7.5. Slip associated with this earthquake continued for more than a year and it has been termed an 'ultra-slow earthquake'.
The 1966 Hualien earthquake occurred on March 13 at 00:31 local time of Taiwan. The epicenter was located in the offshore area between Yonaguni Island, Japan and Hualien, Taiwan.
The 2001 Geiyo earthquake occurred with a moment magnitude of 6.7 on March 24 at 15:27 local time near Hiroshima, Japan. One person in Hiroshima and one person in Ehime were reported dead. About 3,700 buildings were damaged in the Hiroshima area. Liquefaction was observed in Hiroshima and Ehime. Power outages occurred in the prefectures of Hiroshima, Ehime, Okayama, Yamaguchi, and Kōchi. The maximum intensity was shindo lower 6 in Hiroshima. This earthquake could be felt along the eastern and southern coasts of South Korea.
The 1968 Tokachi earthquake occurred on May 16 at 0:49 UTC in the area offshore of Aomori and Hokkaido. The magnitude of this earthquake was put at Mw 8.3. The intensity of the earthquake reached shindo 5 in Aomori, Aomori and Hakodate, Hokkaido.
The 1948 Litang earthquake (1948年理塘地震) occurred on May 28, 1948 at 07:11 UTC. It was located near Litang, China. Now situated in the Sichuan Province, Litang County was then called Lihua (理化) County and belonged to the defunct Xikang Province. The earthquake had a magnitude of Mw 7.2, or Ms 7.3.
The 2000 Tottori earthquake occurred on 6 October 2000, at 13:30:20 local time with a moment magnitude of 6.7 and a maximum Mercalli intensity of VIII (Severe). The epicenter was near Yonago and Matsue. About $150 million in damage was caused and between 130-182 people were injured.
The 1976 Longling earthquake in Yunnan Province, People's Republic of China, was a doublet earthquake, with two main shocks striking just east of Longling at 12:23:20 and 14:00:22 UTC. The magnitudes were estimated at 6.7 and 6.6, respectively, on the Mw(GCMT) scale, and 6.9 and 7.0 on the Ms scale; Chinese sources put these at 7.4 and 7.3 on the Ms7 scale. The region is noted for the quantity and intensity of its earthquakes, and the complexity of its tectonics, which are closely related to the collision between the Indian and Eurasian tectonic plates.
The Haiyuan Fault is a major active intracontinental strike-slip (sinistral) fault in Central Asia.
The 1988 Lancang–Gengma earthquakes, also known as the 11.6 earthquakes by the Chinese media were a pair of devastating seismic events that struck Lancang and Gengma counties, Yunnan, near the border with Shan State, Burma. The earthquake measured moment magnitude (Mw ) 7.0 and was followed 13 minutes later by a 6.9 Mw shock. These earthquakes were assigned a maximum China seismic intensity of IX and X, respectively. Between 748 and 939 people were killed; more than 7,700 were injured. Both earthquakes resulted in US$270 million in damage and economic losses. Moderately large aftershocks continued to rock the region, causing additional casualties and damage.
The 1902 Turkestan earthquake devastated Xinjiang, China, near the Kyrgyzstan border. It occurred on August 22, 1902, at 03:00:22 with an epicenter in the Tien Shan mountains. The thrust earthquake measured 7.7 on the moment magnitude scale (Mw ) and had a depth of 18 km (11 mi).
The 2021 Maduo earthquake, also known as the 5.22 earthquake struck Madoi County in Qinghai Province, China on 22 May at 02:04 local time. The earthquake had a moment magnitude and surface-wave magnitude of 7.4. Highway bridges, roads and walls collapsed as a result of the earthquake. According to an anonymous source, at least 20 people were killed, 300 were injured, and 13 were missing. Officials stated that there were no deaths but 19 people sustained minor injuries. It was the strongest in China since 2008. It was assigned a maximum intensity of X in Machali, Maduo County on the China seismic intensity scale and Modified Mercalli intensity scale. This earthquake was preceded by another unrelated earthquake that occurred 5 hours earlier in Yunnan.
The 1982 Urakawa earthquake was a Mw 6.9 earthquake that struck off the coast of Urakawa, Japan on 11:32 (JST), March 21, 1982. The epicenter was 42.1°N 142.6°E. The earthquake was the largest earthquake in the history of the region. The earthquake caused 167 injuries and damage in Tomakomai and Sapporo.
The Shōnai offshore earthquake occurred at around 14:00 on December 7, 1833. It struck with an epicenter in the Sea of Japan, off the coast of Yamagata Prefecture, Japan. A tsunami was triggered by the estimated MJMA 7.5–7.7 earthquake. One hundred and fifty people were killed and there was severe damage in the prefecture.
The eastern margin of the Sea of Japan is a zone of concentrated geological strain which extends several hundred kilometers and north–south along the eastern margin of the Sea of Japan. The margin has undergone convergence tectonics since the end of the Pliocene. It is believed to be an incipient subduction zone which defines the tectonic boundary between the Amurian and Okhotsk plates. This geological zone is seismically active and has been the source of destructive tsunamis. The feature runs off the west coast of Honshu, passes west of the Shakotan Peninsula on Hokkaido and through the Strait of Tartary, between Sakhalin and mainland Russia.