|UTC time||1992-09-02 00:16:01|
|Local date||September 2, 1992|
|Depth||45 km (28 mi)|
|Casualties||at least 116 killed|
The 1992 Nicaragua earthquake occurred off the coast of Nicaragua at 6:16 p.m. on September 2. Some damage was also reported in Costa Rica. At least 116 people were killed and several more were injured. The quake was located in an active zone of stress and deformation. It created tsunamis disproportionately large for its surface wave magnitude.
Nicaragua, officially the Republic of Nicaragua, is the largest country in the Central American isthmus, bordered by Honduras to the northwest, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the southwest. Managua is the country's capital and largest city and is also the third-largest city in Central America, behind Tegucigalpa and Guatemala City. The multi-ethnic population of six million includes people of indigenous, European, African, and Asian heritage. The main language is Spanish. Indigenous tribes on the Mosquito Coast speak their own languages and English.
Costa Rica, officially the Republic of Costa Rica, is a country in Central America, bordered by Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, the Pacific Ocean to the southwest, and Ecuador to the south of Cocos Island. It has a population of around 5 million in a land area of 51,060 square kilometers. An estimated 333,980 people live in the capital and largest city, San José with around 2 million people in the surrounding metropolitan area.
A tsunami or tidal wave,, also known as a seismic sea wave, is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water.
The 1992 Nicaragua earthquake was the first tsunami earthquake to be captured on modern broadband seismic networks.The initial surface wave magnitude was estimated at 7.2. The shock occurred on the subduction interface between the Cocos and Caribbean Plates, an active zone of stress and deformation, and due to the absence of sediment on the ocean floor off Nicaragua, the slip propagated up-dip all the way to the trench bottom, a creator of large tsunamis. This occurrence of slip of a plate interface filled with soft subducted sediments caused the rupturing process to be slower than the average subduction zone thrust earthquakes while the focus of the earthquake was much shallower than the typical subduction zone earthquake.
A tsunami earthquake triggers a tsunami of a magnitude that is very much larger than the magnitude of the earthquake as measured by shorter-period seismic waves. The term was introduced by Hiroo Kanamori in 1972. Such events are a result of relatively slow rupture velocities. They are particularly dangerous as a large tsunami may arrive at a coastline with little or no warning. A tsunami is a sea wave of local or distant origin that results from large-scale seafloor displacements associated with large earthquakes, major submarine slides, or exploding volcanic islands.
The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. The Cocos Plate also broke into two pieces, creating the small Rivera Plate. The Cocos Plate is bounded by several different plates. To the northeast it is bounded by the North American Plate and the Caribbean Plate. To the west it is bounded by the Pacific Plate and to the south by the Nazca Plate.
The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America.
The first shock of the earthquake occurred at 0:16 GMT and was followed by several strong aftershocks.The quake was most widely felt in the Chinandega and León departments of Nicaragua, though it was also felt elsewhere in Nicaragua at El Crucero, Managua and San Marcos and at San José in Costa Rica. It was the strongest seismic event to hit Nicaragua since the earthquake of 1972.
Chinandega is a department in Nicaragua, located on the border with Honduras. It covers an area of 4,822.42 km² and has a population of 429,557. The capital is the city of Chinandega.
Nicaragua is a unitary republic, divided for administrative purposes into fifteen departments and two autonomous regions :
El Crucero is a municipality in the Managua department of Nicaragua with 22,107 inhabitants.
At least 116 people were killed, most being children sleeping in their beds,with more than 68 missing and over 13,500 left homeless in Nicaragua. At least 1,300 houses and 185 fishing boats were destroyed along the west coast of Nicaragua. Total damage in Nicaragua was estimated at between 20 and 30 million U.S. dollars.
According to the Augusto César Sandino Foundation, the most affected were "inhabitants of small poor communities who live from diverse subsistence activities. Their houses, located beside the sea, were almost entirely destroyed. These people have lost their livelihoods, poor peasants who grow basic grains for their own consumption in marginal areas, and fisherpeople who have lost their fishing equipment, boats, storage sheds and warehouses. Their already extreme poverty has been exacerbated."
Most of the casualties and damage were caused by a tsunami affecting the west coasts of Nicaragua and Costa Rica, and it was one of three tsunamis to occur within a span of six months. Ms , and the duration of the rupture process was 100 s, unusually long for its size. The moment magnitude was 7.6, larger than the 20-s Ms of 7; this Ms –Mw difference is a characteristic of tsunami earthquakes. Tide gages were set up at Corinto and Puerto Sandino, which showed an impulsive tsunami originating 61 minutes after the earthquake. It ran inland 1,000 meters to Masachapa, the hardest hit major town of all, with 9 fatalities.Runup heights were measured shortly after the earthquake and reached heights of up to 9.9 meters, though the average height was 3 to 8 meters. The tsunami was disproportionately large for its surface wave magnitude, or
The moment magnitude scale is a measure of an earthquake's magnitude based on its seismic moment, expressed in terms of the familiar magnitudes of the original "Richter" magnitude scale.
Puerto Sandino is a coastal town in western Nicaragua. Prior to the 1979 revolution it was known as Puerto Somoza. Due to its crude oil supply line, it is a major port, and also plays a large role in Nicaragua's fishing industry. Puerto Sandino is an extremely popular location for surfing.
From the onset of the disaster authorities provided initial assistance.President Violeta Chamorro stated in her speech to her nation on September 2, 1992, that no international assistance was needed. However, the Red Cross did assist in some operations while the National Civil Defence carried out much of the relief operations, with wounded people being transported to the Hospital Leon and Lenin-Fonseca Hospital.
Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to gravity into the mantle. Regions where this process occurs are known as subduction zones. Rates of subduction are typically in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries.
The Japan Trench is an oceanic trench part of the Pacific Ring of Fire off northeast Japan. It extends from the Kuril Islands to the northern end of the Izu Islands, and is 8,046 meters (26,398 ft) at its deepest. It links the Kuril-Kamchatka Trench to the north and the Izu-Ogasawara Trench to its south with a length of 800 km. This trench is created as the oceanic Pacific plate subducts beneath the continental Okhotsk Plate. The subduction process causes bending of the down going plate, creating a deep trench. Continuing movement on the subduction zone associated with the Japan Trench is one of the main causes of tsunamis and earthquakes in northern Japan, including the megathrust Tōhoku earthquake and resulting tsunami that occurred on 11 March 2011. The rate of subduction associated with the Japan Trench has been recorded at about 7.9-9.2 cm/yr.
The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
The Manila Trench is an oceanic trench in the Pacific Ocean, located west of the islands of Luzon and Mindoro in the Philippines. The trench reaches a depth of about 5,400 metres (17,700 ft), in contrast with the average depth of the South China Sea of about 1,500 metres (4,900 ft). It is created by subduction, in which the Sunda Plate is subducting under the Philippine Mobile Belt, producing this almost N-S trending trench. The convergent boundary is terminated to the north by the Taiwan collision zone, and to the south by the Mindoro terrane. It is an area pervaded by negative gravity anomalies.
The 1957 Andreanof Islands earthquake took place on March 9 with a moment magnitude of 8.6 and a maximum 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. Total losses were around $5 million.
The 2006 Pangandaran earthquake and tsunami occurred on July 17 at 15:19:27 local time along a subduction zone off the coast of west and central Java, a large and densely populated island in the Indonesian archipelago. The shock had a moment magnitude of 7.7 and a maximum perceived intensity of IV (Light) in Jakarta, the capital and largest city of Indonesia. There were no direct effects of the earthquake's shaking due to its low intensity, and the large loss of life from the event was due to the resulting tsunami, which inundated a 300 km (190 mi) portion of the Java coast that had been unaffected by the earlier 2004 Indian Ocean earthquake and tsunami that was off the coast of Sumatra. The July 2006 earthquake was also centered in the Indian Ocean, 180 kilometers (110 mi) from the coast of Java, and had a duration of more than three minutes.
The 1896 Sanriku earthquake was one of the most destructive seismic events in Japanese history. The 8.5 magnitude earthquake occurred at 19:32 on June 15, 1896, approximately 166 kilometres (103 mi) off the coast of Iwate Prefecture, Honshu. It resulted in two tsunamis which destroyed about 9,000 homes and caused at least 22,000 deaths. The waves reached a then-record height of 38.2 metres (125 ft); this would remain the highest on record until waves from the 2011 Tōhoku earthquake exceeded that height by more than 2 metres.
The 1906 Ecuador–Colombia earthquake occurred at 15:36 UTC on January 31, off the coast of Ecuador, near Esmeraldas. The earthquake had a moment magnitude of 8.8 and triggered a destructive tsunami that caused at least 500 casualties on the coast of Colombia.
The 1963 Kuril Islands earthquake occurred at 05:17 UTC, on October 13. The earthquake had a magnitude of 8.5 and was followed by a Mw=7.8 event seven days later. Both earthquakes triggered tsunamis that were observed around the northern part of the Pacific ocean.
The 1969 Yangjiang earthquake occurred on 26 July, at 6:49 am, Beijing local time. It had a magnitude of 6.4 on the Moment magnitude scale and a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale It struck the city of Yangjiang and caused over 10,700 houses to collapse, severely damaging a further 36,000. The earthquake also caused landslides and sandblows were observed along the coast and along some rivers in the area of Yangjiang. The earthquake was also felt in Hong Kong. There were an unconfirmed total of 3,000 deaths.
The 1978 Miyagi earthquake occurred at 17:14 local time on 12 June. It had a surface wave magnitude of 7.7, JMA magnitude 7.4, and triggered a small tsunami. The earthquake reached a maximum intensity of Shindo 5 in Sendai and caused 28 deaths and 1,325 injuries.
The 1996 Chimbote earthquake occurred on February 21 at 07:51 local time about 130 km off the coast of northern Peru, near the Peru–Chile Trench. It was an earthquake of magnitude Mw 7.4.
The 1994 Java earthquake occurred on June 3 at 01:17:37 local time off the coast of Indonesia. The epicenter was off the eastern part of the southern Java coast, near the east end of the Java Trench.
The 1942 Guatemala earthquake occurred at 17:37 local time on August 6 and had ratings of 7.7 on the moment magnitude scale and 7.9 on the surface wave magnitude scale. The epicenter was located off the southern coast of Guatemala, and it was one of the strongest earthquakes ever recorded there.
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 1942 Peru earthquake occurred on August 24 at 17:50 local time and was located near the border of the departments of Ica and Arequipa, Peru. It had a magnitude of Mw 8.2 or Ms 8.4.
The 1787 New Spain earthquake, also known as the San Sixto earthquake, occurred on 28 March at 11:30 local time. It caused a large tsunami that affected the coast of the Puebla Intendancy and the Oaxaca Intendancy in Southwestern Mexico. With an estimated magnitude of 8.6 on the moment magnitude scale, it was more powerful than any instrumentally recorded Mexican earthquake.
The 1956 Amorgos earthquake occurred at 03:11 UTC on July 9. It had a magnitude of 7.7 on the moment magnitude scale and a maximum perceived intensity of IX on the Mercalli intensity scale. The epicentre was to the south of the island of Amorgos, the easternmost island of the Cyclades in the Aegean Sea. There was significant damage on Amorgos and the neighbouring island of Santorini. It was the largest earthquake in Greece in the 20th century. It was followed 13 minutes later by a magnitude 7.2 earthquake near Santorini. It triggered a major tsunami with a maximum run-up of 30 m. The combined effects of the earthquake shaking and the tsunami caused the deaths of 53 people with a further 100 injured.