In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults. Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep.
In geology, aseismic creep or fault creep is measurable surface displacement along a fault in the absence of notable earthquakes. Aseismic creep may also occur as "after-slip" days to years after an earthquake. Notable examples of aseismic slip include faults in California.
An earthquake occurred on 31 May 1935 between 2:30 am and 3:40 am at Quetta, Balochistan, British India, close to the border with southern Afghanistan. The earthquake had a magnitude of 7.7 Mw and anywhere between 30,000 and 60,000 people died from the impact. It was recorded as the deadliest earthquake to strike South Asia until 2005. The quake was centred 4 km south-west of Ali Jaan, Balochistan, British India.
The 2008 Ziarat earthquakes hit the Pakistani province of Balochistan on October 29 with a moment magnitude of 6.4. The US Geological Survey reported that the first earthquake occurred 60 km (37 mi) north of Quetta and 185 km (115 mi) southeast of the Afghanistan city of Kandahar at 04:09 local time at a depth of 15 km (9.3 mi), at 30.653°N, 67.323°E. It was followed by another shallower magnitude 6.4 earthquake at a depth of 14 km (8.7 mi) approximately 12 hours after the initial shock, at 30.546°N, 67.447°E. 215 people were confirmed dead. More than 200 were injured, and 120,000 were rendered homeless. Qamar Zaman Chaudhry, director general of Pakistan Meteorological Department, stated the quake epicenter was 70 miles (110 km) north of Quetta, and about 600 km (370 mi) southwest of Islamabad.
A 6.2 magnitude earthquake occurred in Afghanistan on October 22, 2009 at 19:51:27 UTC. The maximum Mercalli intensity was V (Moderate) at Fayzabad, Badakhshan.
The 2019 Kashmir earthquake struck regions of Pakistan with an epicentre in Azad Kashmir on 24 September at 16:02 local time. It had a magnitude of 5.4 and a maximum felt intensity of VII on the Modified Mercalli intensity scale or VIII on the European macroseismic scale. There was severe damage in Mirpur District, causing the deaths of 40 people and injuring a further 850. The epicentre of the shallow quake was near the city of Mirpur, Pakistan. The tremors were felt in the Kashmir region, Punjab (Pakistan), Punjab (India), Uttarakhand and northern parts of India including New Delhi.
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 Main Frontal Thrust (MFT), also known as the Himalayan Frontal Thrust (HFT), is a geological fault in the Himalayas that defines the boundary between the Himalayan foothills and Indo-Gangetic Plain. The fault is well expressed on the surface thus could be seen via satellite imagery. It is the youngest and southernmost thrust structure in the Himalaya deformation front. It is a splay branch of the Main Himalayan Thrust (MHT) as the root décollement.
The 2021 Assam earthquake struck 11 km away from Dhekiajuli, Assam, India at 07:51 (IST) on April 28, 2021 with a moment magnitude of 6.0 at 34.0 km (21.1 mi) depth. The quake struck with an epicenter 140 km north of the main city of Guwahati. It resulted in two fatalities and at least 12 injuries.
The 2020 Kashgar earthquake, also known as the Jiashi earthquake occurred on 19 January 2020 at 21:27:56 China Standard Time in Xinjiang Province, China. According to the United States Geological Survey, the earthquake had a moment magnitude of 6.0 and a surface wave magnitude of 6.4 according to the China Earthquake Network Center. It struck at a shallow depth of 5.6 km according to the USGS while the CENC has the figure at 16 km. Local emergency management agencies said the earthquake damaged more than 1,000 homes and businesses in the nearby populated towns and villages. One person is known to have died while two other children were injured.
The 1555 Kashmir earthquake occurred at around midnight in the month of Ashvin in the Hindu calendar, or September in the Gregorian calendar, although the exact day of occurrence is not known. The earthquake seriously impacted the Kashmir Valley in present-day Pakistan and northwestern India. A moment magnitude (Mw ) of 7.6 to 8.0 and Modified Mercalli intensity of XII (Extreme) has been estimated for the earthquake. Thought to be one of the most destructive in the Kashmir Valley, the earthquake caused serious widespread damage and ground effects, killing an estimated 600–60,000 individuals.
The 1889 Chilik earthquake occurred on July 11 on the Gregorian calendar, or June 30 on the Julian calendar at 15:14 local time in the Tien Shan mountains. The earthquake measured an estimated Mw 7.9–8.0 on the moment magnitude scale and was assigned a maximum intensity of X (Devastating) on the MSK 64 and Rossi-Forel scales. Over 92 people across Kazakhstan, Kyrgyzstan and China were killed.
An earthquake struck Pakistan's province of Balochistan near the city of Harnai on 7 October 2021. The moment magnitude 5.9 Mww quake struck in the early morning at 03:01 local time, killing at least 42 people and injuring 300 others. The earthquake occurred just one day before the anniversary of the 2005 Kashmir earthquake.
The 1654 Tianshui earthquake occurred on July 21 in Tianshui, Gansu Province, Ming dynasty sometime between 21:00 and 23:00 local time. The event had an estimated moment magnitude of 7.0 and was assigned a maximum intensity of XI on the China seismic intensity scale. Resulting in extreme damage and affecting at least four provinces, the quake killed approximately 30,000 people.
The 1885 Kashmir earthquake, also known as the Baramulla earthquake occurred on 30 May in Srinagar. It had an estimated moment magnitude of Mw 6.3–6.8 and maximum Medvedev–Sponheuer–Karnik scale intensity of VIII (Damaging). At least 3,081 people died and severe damage resulted.
The 1803 Garhwal earthquake occurred in the early morning of September 1 at 01:30 local time. The estimated 7.8-magnitude-earthquake had an epicenter in the Garhwal Himalaya near Uttarkashi, British India. Major damage occurred in the Himalaya and Indo-Gangetic Plain, with the loss of between 200 and 300 lives. It is among the largest Himalaya earthquakes of the 19th-century, caused by thrust faulting.
The 1980 Nepal earthquake devastated the Nepal–India border region on the evening of July 29. The epicenter of the 6.6 earthquake was located in Nepal, northwest of Khaptad National Park. At least 200 people died and 5,600 were injured in the disaster. Extensive damage occurred on both sides of the border, amounting to 245 million USD.
In November 2002, two medium-sized earthquakes struck northern Pakistan, causing major damage in Baltistan region and killing 41 people.
The 1977 Bob–Tangol earthquake struck Kerman province of Iran on December 20, 1977, at 03:04 Iran Standard Time. The earthquake measured 5.9 and struck at a depth of 22.7 km (14.1 mi). A maximum Modified Mercalli intensity of VII was evaluated based on damage. It had a strike-slip focal mechanism, which was unusual as the source structure was a thrust fault. It was part of a sequence of strong earthquakes along the 400 km (250 mi) Kuh Banan Fault. Between 584 and 665 people perished while a further 500–1,000 were injured; thousands were also made homeless. Casualties from the earthquake was considered moderate due to the sparsely populated area it affected. Preceded by foreshocks the month before, many residents became wary of a larger earthquake and took refuge outside their homes, contributing to the moderate death toll. However, there were none immediately before the mainshock so many were still in their homes when it struck. Aftershocks were felt for several months, some causing additional damage.
The New Guinea Trench is a trench along the northern coast of New Guinea. It may represent the seafloor expression of an active subduction zone.
