Chile Earthquake Of 1960 - Research Paper Example

Chile Earthquake Of 1960 Introduction. In 1960, Chile recorded the largest earthquake in the 20th century on May 22, 1960 to 6 June. It originated from the Southern Chile coast and resulted to massive problems and fatalities in the country as the result of tsunamis that it created, in distant areas in Pacific coastal areas. The resulting tsunami affected Southern Chile, Japan, Hawaii, southeast Australia, the Philippines, the Aleutian Islands and eastern New Zealand (U.S. Geological Survey 4). The earthquake struck at 7.11 PM around 160 kilometers off the Chile’s coast and paralleled to Valdivia city. It agrees that, the shock had up to 9.5 magnitudes, though some researchers say that it may have been 9.6 or 9.4. The previous day, a series of foreshocks warned for incipient disaster. The major demolition in Concepcion was; as a result of magnitude 7.9. The source of fault-displacement of the earthquake covered over approximately 560-520miles (900-1,000km) area of Nazca Plate subducted underneath South American Plate (Geology.com 3). The epicenter was around 570 kilometers near Lumaco, south of Santiago, making Valdivia the most affected city. The immensity of the shifts of the seafloor that influenced the tsunamis big. Such that, nearly 15 hours later, the waves that arrived in the islands of Hawaiian, that is 6,200miles away, crested about 35feet at landfall in particular places (Thompson, 34). Most of the Chilean cities, including Puerto Montt, a noticeable subsidence happened. In Valdivia, almost half of the buildings were declared uninhabitable due to great damage they sustained. Even though the havoc caused by the shaking was not minor, most casualties resulted from 15 minutes later descent that rose up to 25 meters (80 feet) high on the Chilean coastline expanse. Puerto Aisen and Lebu cities bound it. The cities are also parallel to the subducting plate (Geology.com 3). The number of casualties and monetary losses that rose from the widespread disaster is not accurate. Different estimates of the total fatalities toll from the tsunamis and earthquake have been published, with another source estimating 6,000 dead and United States Geological Survey having 5,700 killed. The monetary costs lost have been estimated to be US$ 400 million to 800 million. Earthquake Events. The beginning Conception earthquake occurred at 06:02 UTC-4 on 21 May 1960, Curanilahue being its epicenter. The telecommunications to Sothern Chile were stunted making President Jorge Alessandri call off the traditional ceremony of memorial holiday of Battle of Iquique to manage the efforts of emergency assistance. The next day, the second and third Conception earthquakes took place at 06:32 UT-C AND 14:55 UT-C respectively, on 22nd may. The earthquakes formed a southward shift foreshock sequence towards Valdivia, the main shock, which happened 15 minutes later after the third Conception (Ker 5). Valdivia earthquake took place at 15:11 UT-C-4 on 22 May affecting entire Chile between Chiloe Island and Talca, over 150, 000 square miles (400,000sq km) (U.S. Geological Survey 4). The villages on the coast like Tolten disappeared. The Valdivia’s main port, Corral, the levels of water rose to 13 ft. (4m) Before it began to retreat. At 16:20 UT-C-4 an 8m wave hit the Chilean coast, mostly between Chiloe and Conception. Ten minutes later, another 10m (33ft) was reported (Ker 6). The time tsunami hit, and hundreds of people were reported dead. Another ship, Canelos, started to sink sinking at Valdivia’s River mouth after it was moved 0.93 miles (1.5km) forward and backward in the river; one can still see its mast from Niebla road. Many Spanish-colonial fortifications were completely demolished. Soil deepened local rivers, destroyed buildings and formed wetlands in areas like Choromayo and Rio Cruces. Cities extensive areas also had floods. Water systems and electricity in Valdivia were all demolished. Underground water was also flowing up past the soil. Due to landslides elements, the river turned brown with floating debris like entire houses. The earthquake did not hit entire territory with the same power. According to Mercalli scale, tectonically depressed areas witnessed heavier damage. The most affected regions were Puerto Octay, near northwest corner of Llanquihue Lake and Valdivia. In the central valley, Puerto Octay was the central north-south elliptical area with high intensity outside Valdivia’s Basin. Piles of plates remained in place in a hotel in Todods Los Santos Lake, East of Puerto Octay. Cordon Caulle, a volcanic vent that was close to Puyehue volcano erupted two days after the earthquake. Tectonically, the earthquake was as a result of the megathrust earthquake from mechanical stress release between the South American Plate and Nazca plate, on the Peru-Chile trench. Relatively, the focus was shallow at 21miles (33km), in a view that earthquakes in Argentina and Chile can reach depths of 70 kilometers. Zones of subduction are known to create strong earthquakes on earth as their unique structures allow more stress to form before the energy is released (Shake map Atlas 8). The earthquakes caused many landslides, mostly in steep southern Andes glacial valleys. Within Andes, many landslides around Liquine-Ofqui Fault happened on forested mountains. The landslides did not lead to fatalities or economic losses since they were uninhabited with only few roads. One landslide led to the destruction due to its blockage of Rinihue Lake outflow. Nearly 100 kilometers on the south of Rinihue Lake, the mountain landslide around Golgol River, led to the damming of the river. When the river burst up from the earthen dam, it caused floods down to Puyehue Lake. The landslides also demolished part of international Route 215-CH that connects Argentina with Bariloche through Cardenal Antonio Samore Pass (Ker 6). The Chilean coast from Aysen Region (45 degrees South) to Mocha Island (38 degrees South) was greatly affected by tsunami. Across South Chile, a tsunami caused great destruction to port infrastructure and few boats and massive loss of life. Talcahuano port, further north, did not experience any major damage; only floods. Some small boats and tugboats got stranded on Island of Rocuant near Talcahuano. People in Ancud sought refuge in boats, after the May 21 Conception earthquake. A police boat, Gloria, was towing some other boats after the second stroke on May 22. Gloria became stressed between Cochinos Island and Cerro Guaigen as the sea regressed. The boats were stranded as it was wrecked when tsunami wave struck. The small port, Bahia Mansa new infrastructures were destroyed by the Tsunami that raised it to nearly 10 m.a.s.l around that area. Isabella boat that was in Bahia Mansa at that time left the port but experienced the loss of its anchors (Ker 5). In Corral Bay and Valdivia River several vessels were destroyed due to the earthquake, among them being Carlos, Haverbeck, Canelos, Melita and the remnants salvages of Penco. When the quake struck, Canelos was anchored at Corral filling a cargo of wood and other things destined to North Chile. The Canelos engine was warmed up for events viewing. After drifting hours around Valdivia River and Corral Bay, the wrecked ship was abandoned by its crew at 18.00 PM. Two people who on board died. Another ship anchored at corral, Santiago, managed to leave at the time of the quake though in a bad state. It was wrecked off the shores of Mocha Island on May 24 (U.S Geological Survey 6). La Milagrosa, the schooner, departed from Quele to Fitzroya wood shingles in a small port in southern Corral, to load a cargo in May 22. The ship was wrecked by currents and tsunami waves for four days while it was shipping towards the south. Outside Corral, six minors were rescued on board of two boats. They were dehydrated and unconscious. The boats found were for navigation in Corral Bay and Valdivia River but had drifted towards the high sea. Following the earthquake, a more than one meter seiche was seen on Panguili Lake. On May 22, a seiche was also observed in Nahuel Huapi Lake, on the side of Argentina of Andes, more than 200 kilometers away from Valdivia. Earthquake-triggered sediment slide produced a wave at the lake bottom that killed two individuals and demolished San Carlos de Bariloche city pier (U.S Geological Survey 8). During the earthquake in Chile, west of Tralcan Mountain landslides blocked the Rinihue Lake outflow. Rinihue Lake is the lowest lakes chains among the seven that receives a constant inflow from River Enco. The blocked river, which drains the lake, goes through several towns before it reaches the Valdivia city near the coast. Due to San Pedro River blockage, the level of Lake Rinihue water rose to approximately 20 million cubic meters. Therefore, 4,800 million cubic meters of water was released to River San Pedro, easily overpowering its capacity to flow in 400 cubic meters per second. The disaster would have flooded violently on the settlements on the affected areas with less than five hours if the dam suddenly burst. 100,000 people lives were in danger, and so efforts were made to evacuate Valdivia and many individuals left. To avoid city destruction, various military units, many workers from CORFO, ENDESA and MOP began the efforts to manage the lake (Barrientos and Ward 7). Twenty-seven bulldozers were put in action though they had severe troubles moving the mud around the dams. Dykes had to be built with shovels from June and onwards. The flow into Lake Rinihue was minimized by extending the work to drainages of other seven parts of the lakes. With the exception of Clafquen Lake, other dams were later removed. By 23rd June, the main dam was down to 15 meters for 24 meters, allowing 3,000 cubic meters flow of water from the lake with a considerable destructive power. Thirty eight hours after the main shock, 28 may, in Valdivia; Cordon Caulle started a rhyodacitic fissure eruption. The eruption had few eye witnesses due to its sparsely populated and isolated in Andean valleys, hence, fewer media attention. The eruption spread to 5.5kilometer long and N135 degrees trending fissure where 21 people vents have been discovered. The vents created an output of nearly 0.25km3 both inform of tephra and lava flows. The eruption stopped on 22 July (Barrientos and Ward 7). Consequences. The subsequent aftershocks and earthquake created landslides that killed many persons. The toll on the casualties was never reported accurately for the region. Approximately, the casualties ranged from 490 to 6,000 with no distinction of how many deaths were as a result of tsunami waves and those caused by earthquakes. Tsunamis caused most fatalities, and earthquakes caused most property damage. For example, Valparaiso city, a city of 200,000 people, many buildings were demolished (Barrientos and Ward 8). Three thousand people were reportedly injured and 717 missing in Chile. Chilean government officials estimated 2 million people to have been left homeless. 130,000 houses were demolished, one in every three, in the quake. Approximately, about 40% of Valdivia houses were demolished leaving about 20,000 persons homeless. Buildings built of concrete were the most affected structures, which in most cases entirely collapsed because of earthquake engineering inefficiency. Traditionally wooden houses fared well though were uninhabitable in most places, and they did not breakdown. Buildings on less tectonically elevated areas experienced lesser damage, compared to those situated on lowlands. The lowland houses absorbed large amounts of energy and suffered floods. Many city blocks with demolished buildings remained uninhabited until the 1990s and 2000s. A number of them are currently being used as parking lots. Some of the blocks, before the earthquake, had buildings built on concrete after the Great Valdivia fire that happened in 1909 (Ker 6). In the view of urban development, Valdivia experienced minor loss, but important Cau-Cau Bridge that has never been re-built. Other bridges had small damages. Coral Bay’s land subsidence advanced navigability because shoal banks, formed by Madre de Dios earlier sediments and other gold mines, were compacted and sank. As the earthquake demolished Valdivias flood barriers, it exposed other general land subsidence areas to flooding (Ker 4). A field hospital was quickly set up by United States following the events of earthquakes. It also aided Valdivia’s geological survey and, as a result, the city’s first geological map was created. After the earthquake, Mexico built a public school, Escuela Mexico. Seaside farms of the Southern coast of Chile were destroyed by tsunami that struck around that area, killing numerous people and livestock. The quake also demolished industrial structures and Barns. Dairy farm was among the few industries that were affected in the area. The firm received investments and subsidies after the earthquake. Through long-term policy, it received support from the state after the earthquake (Ker 5). In addition, there were other geologic phenomena associated with the tsunami and earthquake. There were extensive subsidence reported, altering the local flooding and the shoreline. Landslides and rock fall in the Andes created a lake on the Rio San Pedro. On 24t May, 1960, there was Puyehue volcano eruption. The earthquake ended the era of prosperity in the coastal town of Queule that had developed significantly during 1950s. Its economy majored in agriculture; fishing and industry had drastically grown during that time. Queule was linked by road to the rest of the nation in 1957. The town had developed into a Balneario. Therefore, the earthquake was a blow to the economy of the region. Government Actions. After the Valdivia earthquake in 1960, the government formed a committee to solve issues caused by earthquakes. It continued to perform, to improve national approaches on emergencies. It was named ONEMI (National Emergency and Information Office) in 1974, and the law authorized it as an independent government office (Pula, Patricia and Lowell 6). The office coordinates the work of rescuing in the areas hit by earthquakes, assist reconstruction and resume order. The central government can react quickly through the office when confronted with catastrophe, including volcanic eruptions, earthquakes and tsunamis. The constitution of the country also has fundamental laws that describe the responsibilities and roles of the central government in dealing with events of catastrophe. The laws of the local government also set out rules and duties of local officials upon dealing with disasters. In 2002, Chile introduced a plan that describes concrete measures local and central governments should take in each phase of dealing with a disaster (Pula, Patricia and Lowell 6). The Chilean buildings have to comply with strict building regulations set out by the government so as to withstand earthquakes. Therefore, construction companies build with earthquakes in mind to reduce the risk of destruction during earthquakes or any other catastrophe. The government has also formed anti-disaster drills national wide. In 1995, the drill participants’ number had reached 350,000. School children practice the drills three times annually in an operation known as DEYSE. International technological cooperation programme was started in the dairy sector due to the earthquake. More specifically, Danish and the German governments assisted in the creation of Centro Tecnologico de la Leche in the South of the University of Chile. Erik Dahmen argues that the earthquake is a result of creative destruction for Southern Chile farmers (Geology.com 3). Previous and Later Earthquakes. In 1575, it was evident that a similar landslide and earthquake occurred in Valdivia. 1960 earthquake had similar power and also led to a Rinihuazo. According to Marino de Lobera chronicle, Valdivia’s Corregidor in 1575, the outflow of the lagoon Renigua was blocked by a landslide. The landslide caused floods several months later in April. He says that the settlers of Spanish had evacuated and waited on high regions until the dam got its way through, though many aboriginals perished in the water that flooded (Geology.com 7). At local time 03:34 in Feb 27, 2004, a magnitude earthquake of 8.8 occurred between Santiago and Conception, off the coast of Maule region of Chile. The quake was reported to be centered nearly 22 miles (35km) deep and many miles off the shores. The 2010 Chile earthquake can be consequential or related to the 1960 disaster (Geology.com 8). Conclusion From the discussion, Chilean earthquake in 1960 caused great destruction and affected its economy and, therefore, the government had to form strategies to prepare the country in other disasters should happen. Works Cited Barrientos S.E and Ward S.N. : “The 1960 Chile earthquake: inversion for slip distribution from surface deformation” Geophysical journal International 103 (3) Dunbar Pula K, Lockridge, Patricia A and Whiteside Lowell S. Catalog of significant earthquakes 2150 B.C-1991 AD. : United States, U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration. 1992 Geology.com 2002. World’s Largest Recorded Earthquake. Retrieved from http://geology.com/records/largest-earthquake/ Date of Access 22 October 2014 Hamilton, Sue L. Earthquakes. Minneapolis, Minn.: ABDO Pub. Co., 2012. Print. Shake Map atlas. Earthquake.usgs.gov. 2009-10-14. Retrieved 2012-06-11. U.S Geological Survey “The largest Earthquake in the World- Articles”. . Archived from the original on 7th January. 2007. Retrieved 11 January 2007. Than Ker (2 March 2010) “Chile Earthquake Altered Earth Axis, Shortened Day”. National Geographical News. Thompson, Jerry. Cascadias Fault. Berkeley, CA: Counterpoint, 2011. Print. Read More