  | |
| 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 | EMS-98 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 moment magnitude scale is a measure of an earthquake's magnitude based on its seismic moment. Mw was defined in a 1979 paper by Thomas C. Hanks and Hiroo Kanamori. Similar to the local magnitude/Richter scale (ML ) defined by Charles Francis Richter in 1935, it uses a logarithmic scale; small earthquakes have approximately the same magnitudes on both scales. Despite the difference, news media often use the term "Richter scale" when referring to the moment magnitude scale.
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.
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 based 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.
The 1920 Haiyuan earthquake occurred on December 16 in Haiyuan County, Ningxia Province, Republic of China at 19:05:53. It was also called the 1920 Gansu earthquake because Ningxia was a part of Gansu Province when the earthquake occurred. It caused destruction in the Lijunbu-Haiyuan-Ganyanchi area and was assigned the maximum intensity on the Mercalli intensity scale. About 258,707-273,407 died, making it one of the most fatal earthquakes in China, in turn making it one of the worst disasters in China by death toll.
Body-waves consist of P-waves that are the first to arrive, or S-waves, or reflections of either. Body-waves travel through rock directly.
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 1905 Kangra earthquake occurred in the Kangra Valley and the Kangra region of the Punjab Province in India on 4 April 1905. The earthquake measured 7.8 on the surface wave magnitude scale and killed more than 20,000 people. Apart from this, most buildings in the towns of Kangra, Mcleodganj and Dharamshala were destroyed.
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 1941 Colima earthquake occurred on April 15 at 19:09 UTC. The epicenter was located in the State of Michoacán, Mexico.
The 1959 Kamchatka earthquake occurred on May 4 at 19:15 local time with a moment magnitude of 8.0–8.3, and a surface wave magnitude of 8.25. The epicenter was near the Kamchatka Peninsula, Russian SFSR, USSR. Building damage was reported in Petropavlovsk-Kamchatsky. The maximum intensity was VIII (Damaging) on the Medvedev–Sponheuer–Karnik scale. The intensity in Petropavlovsk-Kamchatsky was about VIII MSK.
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 1966 Toro earthquake, or the 1966 Ruwenzori earthquake, occurred on March 20 at 01:42 UTC. The earthquake was located near the border between Uganda and the Democratic Republic of the Congo (DRC), to the south of Lake Albert. Some sources put the epicenter in Uganda while some put it in the Democratic Republic of the Congo. The earthquake had a magnitude of Mw 6.8 and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale.
The Main Himalayan Thrust (MHT) is a décollement under the Himalaya Range. This thrust fault follows a NW-SE strike, reminiscent of an arc, and gently dips about 10 degrees towards the north, beneath the region. It is the largest active continental megathrust fault in the world.
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 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.