UTC time | 1975-05-26 09:11:51 |
---|---|
ISC event | 729431 |
USGS-ANSS | ComCat |
Local date | May 26, 1975 |
Local time | 10:11:51 |
Magnitude | 7.9 Mw [1] 8.1 Ms |
Depth | 33 km (21 mi) [1] |
Epicenter | 35°58′N17°39′W / 35.97°N 17.65°W [1] |
Type | Strike-slip |
Total damage | Limited [2] |
Max. intensity | MMI VI (Strong) [2] |
Tsunami | 2.1 m (6.9 ft) [1] |
The 1975 North Atlantic earthquake occurred on May 26 at 09:11 UTC. The epicenter was located in the North Atlantic, in an area between the Azores, Iberian Peninsula, and Morocco. It had a magnitude of Mw 7.9, or Ms 8.1. [3]
This was an intraplate earthquake that was located about 200 km south of the Gloria Fault, the presumed boundary between the African plate and the Eurasia Plate. It had a right-lateral strike-slip focal mechanism and was unusually large for an oceanic strike-slip event. [4] [5] Damage was reported in Madeira, which is about 250 km away. [6] [7] A tsunami of 0.3 m in maximum water elevation was recorded in Lagos, Portugal and an eyewitness reported a 2 m (6 ft 7 in) wave height at Ponta Delgada in the Azores. [4]
The 1946 Aleutian Islands earthquake occurred near the Aleutian Islands, Alaska on April 1, 1946. The shock measured 8.6, Mt 9.3 or 7.4. It had a maximum Mercalli intensity of VI (Strong). It resulted in 165–173 casualties and over US$26 million in damage. The seafloor along the fault was elevated, triggering a Pacific-wide tsunami with multiple destructive waves at heights ranging from 45–138 ft (14–42 m). The tsunami obliterated the Scotch Cap Lighthouse on Unimak Island, Alaska among others, and killed all five lighthouse keepers. Despite the destruction to the Aleutian Island Unimak, the tsunami had almost an imperceptible effect on the Alaskan mainland.
The 1957 Andreanof Islands earthquake occurred at 04:22 local time on March 9 with a moment magnitude estimated at 8.6 and a maximum Modified Mercalli intensity of VIII (Severe). It occurred south of the Andreanof Islands group, which is part of the Aleutian Islands arc. The event occurred along the Aleutian Trench, the convergent plate boundary that separates the Pacific plate and the North American plates near Alaska. A basin-wide tsunami followed, with effects felt in Alaska and Hawaii, and strong waves recorded across the Pacific rim. Total losses were around $5 million.
The Queen Charlotte Fault is an active transform fault that marks the boundary of the North American plate and the Pacific plate. It is Canada's right-lateral strike-slip equivalent to the San Andreas Fault to the south in California. The Queen Charlotte Fault forms a triple junction south with the Cascadia subduction zone and the Explorer Ridge. The Queen Charlotte Fault (QCF) forms a transpressional plate boundary, and is as active as other major transform fault systems in terms of slip rates and seismogenic potential. It sustains the highest known deformation rates among continental or continent-ocean transform systems globally, accommodating greater than 50mm/yr dextral offset. The entire approximately 900 km offshore length has ruptured in seven greater than magnitude 7 events during the last century, making the cumulative historical seismic moment release higher than any other modern transform plate boundary system.
The 1995 Antofagasta earthquake occurred on July 30 at 05:11 UTC with a moment magnitude of 8.0 and a maximum Mercalli intensity of VII. The Antofagasta Region in Chile was affected by a moderate tsunami, with three people killed, 58 or 59 injured, and around 600 homeless. Total damage from the earthquake and tsunami amounted to $1.791 million.
The 2000 New Ireland earthquakes occurred off the coast of New Ireland Province, Papua New Guinea on November 16 and 17.
Striking the Autonomous Region of the Azores on 1 January, the 1980 Azores Island earthquake killed 73 people and injured over 400, causing severe damage on the islands of Terceira and São Jorge. Resulting from a strike slip fracture, typical of other historical Azorean earthquakes, and measuring 6.9 on the moment magnitude scale, it also shook the islands of Pico and Faial.
The 1969 Portugal earthquake struck western Portugal and Morocco on 28 February at 02:40 UTC. Originating west of the Strait of Gibraltar, the earthquake registered a magnitude of 7.8 and the maximum felt intensity was VII on the Mercalli intensity scale. In total, 13 people died and 80 sustained minor injuries. It is the largest earthquake to hit Portugal since the 1755 Lisbon earthquake.
On 13 March 1992, a moment magnitude 6.7 earthquake struck eastern Turkey. It had a maximum Mercalli intensity of IX (Violent) and occurred along the North Anatolian Fault. At least 498 people died, roughly 2,000 were injured, and an unknown number of people went missing. Total financial losses were between $13.5 million and $750 million.
The 1984 Northern Sumatra earthquake occurred with a moment magnitude of 7.2 on November 17 at 06:49 UTC. The epicentre was located off the coast of Sumatra, near the island of Nias, where building damage was reported. This earthquake could be strongly felt in parts of Northern Sumatra, including Padang and Medan. The focal mechanism corresponded to reverse faulting.
The 1953 Suva earthquake occurred on 14 September at 00:26 UTC near Suva, Fiji, just off the southeast shore of Viti Levu. This earthquake had an estimated magnitude of Ms 6.8 and Mw 6.4. The earthquake triggered a coral reef platform collapse and a submarine landslide that caused a tsunami. Eight people were reported killed.
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 1906 Aleutian Islands earthquake occurred at 00:11 UTC on August 17. It had an estimated seismic moment of 3.8 x 1028 dyn cm−1, equivalent to a magnitude of 8.35 on the moment magnitude scale. This earthquake was followed thirty minutes later by the 1906 Valparaíso earthquake in Chile, but the two events are not thought to be linked. Due to the remote location, there are no reports of damage associated with this earthquake. A transpacific tsunami reported from Japan and Hawaii was triggered by the Chilean event, rather than the Aleutian Islands earthquake.
The 1981 Playa Azul earthquake occurred on October 24, 1981, at 21:22 local time. It was located near Playa Azul, Michoacán, Mexico. The magnitude of the earthquake was Mw 7.2, or Ms 7.3. Three deaths were reported, two from Michoacán and one from Mexico City. Some buildings were damaged in both Michoacán and Mexico City. A small tsunami was registered in Acapulco with a maximum height of 9 cm.
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.
On January 30, 1973, at 15:01 (UTC–6), a magnitude 7.6 earthquake struck 35.3 km (21.9 mi) beneath the Sierra Madre del Sur range in the Mexican states of Colima, Jalisco and Michoacán. On the Mercalli intensity scale, the earthquake reached a maximum intensity of X (Extreme), causing serious damage in the region. At least 56 people were killed and about 390 were injured. The event is commonly referred to as the Colima earthquake.
The 1761 Lisbon earthquake and its subsequent tsunami occurred in the north Atlantic Ocean and south of the Iberian Peninsula. This violent shock which struck just after noon on 31 March 1761, was felt across many parts of Western Europe and in Morocco. Its direct effects were observed even far north in Scotland and Amsterdam, and to the south in the Canary Islands of Spain. The estimated surface-wave magnitude 8.5 event was the largest in the region, and the most significant earthquake in Europe since the Great Lisbon earthquake of 1755.
The Nemuro-Oki earthquake in scientific literature, occurred on June 17 at 12:55 local time. It struck with an epicenter just off the Nemuro Peninsula in northern Hokkaidō, Japan. It measured 7.8–7.9 on the moment magnitude scale (Mw ), 8.1 on the tsunami magnitude scale (Mt ) and 7.4 on the Japan Meteorological Agency magnitude scale (MJMA ).
The 1998 Azores Islands earthquake struck with an epicenter in the Atlantic Ocean, off the Azores Islands of Portugal at 05:19 local time. The 10 km (6.2 mi) deep mainshock, which measured 6.1 on the moment magnitude scale caused significant damage on Faial Island. At least 10 people died, 100 were injured, and 2,500 people were left without homes.
The 1816 North Atlantic earthquake occurred on 2 February somewhere between the Azores Islands and Lisbon, Portugal. The estimated moment magnitude 8.3–8.9 earthquake had an epicenter offshore in the Atlantic Ocean, and was felt in Lisbon at 00:40 local time. Little is known about the quake, but it is believed to be one of the largest to have struck the Atlantic.
The 1979 Saint Elias earthquake affected Alaska at 12:27 AKST on 28 February. The thrust-faulting Mw 7.5 earthquake had an epicenter in the Granite Mountains. Though the maximum recorded Modified Mercalli intensity was VII, damage was minimal and there were no casualties due to the remoteness of the faulting. Damage also extended across the border in parts of Yukon, Canada.