1970 Peru Earthquake


Peru located in South America is home of the ancient Incas. Peru is neighbors with Brazil, Ecuador, and Chile. About 29.5 million people are populating Peru. Since it borders the Pacific Ocean it is known to get some tsunamis or floodings but mainly, earthquakes. On May 31, 1970 a massive magnitude 7.9 earthquake hit Chimbote (Figure 1), Peru around mid afternoon. Chimbote was the epicenter of this massive earthquake and damages were reported from Lima to Chiclayo. But the cities near Chimbote and near the coast were the ones that suffered the most damage from this 7.9 earthquake. In the coastal regions of Peru, like Casma south of Chimbote, had about almost 100 percent damage on its buildings and structures but surprisingly had little deaths to a 13,000 population in Casma.



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Figure 1: Chimbote, the epicenter of the earthquake.
("Historic Earthquakes." U.S. Geological Survey Earthquake Hazards Program. Web. 08 Mar. 2010. <http://earthquake.usgs.gov/earthquakes/world/events/1970_05_31.php>.)


Unlike Casma, Chimbote suffered 3,000 casualties but its buildings and structures did not get a lot of damage. They reported from those small building damages is where the deaths came from due to weak structure and material. This horrific earthquake was caused because as the South American continental plate drifted (normal fault) causing the Pacific plate to subduct causing it to bend and building pressure where it finally released all its stress.

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Figure 2: Chimbote's roads after the deadly earthquake.
("Cracks! | LiveScience."
LiveScience | Science, Technology, Health & Environmental News.)





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Figure 3:Huaraz, aftermath of the earthquake.
("Geologic Hazards Slides, Volume 1 - Earthquakes - General Topics."
Welcome... Web. 08 Mar. 2010. <http://www.smate.wwu.edu/teched/geology/eq-general.html>)

Subduction


Subduction is when the weaker plate pushes down under the stronger plate. Thus faulting happens and when this happen usually rocks move into fractures. When subduction happens a lot of movement is happening causing an earthquake. Also from all the movement and friction it causes the weaker plate, the one that subducted under the stronger plate, to melt.


Yungay Landslide


As Chimbote took its beating, Yungay was just completely destroyed. Yungay was a small city that lived around small hills and mountains. Of those mountains, there was the biggest mountain, was the icy Huascaran . The Huascaran was behind a small mountain, were Yungay residents thought that if the Huascaran had an avalanche or a rock slide that the small mountain in front of it would cause a shield affect and protect the city. Well when the 1970 earthquake hit Chimbote, the Huascaran shook and a big piece of it broke off and slid down the mountain towards Yungay. As it reached the small mountain in front of it, the small mountain caused a catapult effect and launched that land, snow, rock,and dirt to slide up in the air and Yungay residents running to the farthest point they can get when then the land slide covered the whole city of Yungay (Figure 4). Nothing left but dirt, snow, debris, rocks and the tips of the some palm trees (Figure 5). The debris avalanche traveled at 200 miles per hours for a distance of seven miles​. Adobe construction was especially susceptible to damage (Cluff, 1971). In addition to failing structures threatening lives, buses smashed from all landslide and rocks that crushed them. Many died as people still yelled and scream for help under all that dirt and mud. Only 100 survived this horrific landslide cause by the earthquake. The total death in Yungay was about 20,000 dead.




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Figure 4: Huascarans effect after the 1970 earthquake.
("Mass-Wasting." University of Wisconsin - Green Bay. Web. 08 Mar. 2010. <http://www.uwgb.edu/DutchS/EarthSC202Notes/masswast.htm>)




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Figure 5: Yungay after the horrific landslide.
("Yungay |."
...en Perú - Travel Culture History News. Web. 09 Mar. 2010. <http://enperublog.com/2006/06/22/yungay/>)




Witness


My dad was there when the 1970 earthquake happen. My dad, Max, was 14 years old when his mother and him, where in Caraz, which is 2 hours from Chimbote (the epicenter) (Figure 6), when the earthquake hit Chimbote. He said he remembers being in the plaza of Caraz when the earthquake hit watching the ground payers rumbling and jumping from the ground. Seeing all the roofs from the building around him collapse and hearing people screaming. He saw the air get completely covered with dust from the mountains around him that have collapsed. It went from 3 in the afternoon to night. Then he heard a loud noise, he thought one of the mountains with snow around him was falling so he ran with all the people to a hill. He said he later found out that noise was a piece of the Huascaran falling on top of Yungay which was 20 minutes from where he was from. After the earthquake had finally stopped and even after a couple of aftershocks he went with his mother to Yungay because he had an uncle that lived there and wanted too see if he was okay. He remember arriving to Yungay and seeing nothing but ice,rock, debris,and mud mixed with blood as they walked through wood logs. He remembers hearing people still screaming for help as they were trapped under the landslide that had covered Yungay.



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Figure 6: Callejon de Huayalas (Huayalas District)
("Andes Website - Climbing Expeditions to the Cordillera Blanca, Peru."
Andes Website - Trekking, Hiking, Skiing and Climbing in the Andes Mountains of South America. Web. 09 Mar. 2010. <http://www.andes.org.uk/tailor-made-and-private-expeditions/cordillera-blanca-climber-dossier.asp>.)


Total Dead


The damage from this natural disaster is remarkable. The earthquake was responsible for 50,000 injuries. It destroyed over 200,000 structures, leaving 800,000 Peruvians without homes. (Cluff, 1971). The death toll overall of this massive earthquake was 66,000.




Works Cited

"Andes Website - Climbing Expeditions to the Cordillera Blanca, Peru." Andes Website - Trekking, Hiking, Skiing and Climbing in the Andes Mountains of South America. Web. 09 Mar. 2010. <http://www.andes.org.uk/tailor-made-and-private-expeditions/cordillera-blanca-climber-dossier.asp>

"CIA - The World Factbook -- Peru." Welcome to the CIA Web Site Central Intelligence Agency. Web. 18 Feb. 2010. <https://www.cia.gov/library/publications/the-world-factbook/geos/pe.html>.

"Cracks! | LiveScience." LiveScience | Science, Technology, Health & Environmental News.

Cluff, L.S. (1971). Peru Earhtquake of May 31, 1970 Engineering Geology Observations. Bulletin of the Seismological Society of America. Retrieved March 11, 2010 from http://www.iris.edu/seismo/quakes/1970/Cluff1971.pdf

"Historic Earthquakes." U.S. Geological Survey Earthquake Hazards Program. Web. 18 Feb. 2010. <http://earthquake.usgs.gov/earthquakes/world/events/1970_05_31.php>.

"Geologic Hazards Slides, Volume 1 - Earthquakes - General Topics." Welcome... Web. 08 Mar. 2010. <http://www.smate.wwu.edu/teched/geology/eq-general.html>

"Great Earthquakes and Subduction along the Peru Trench." SAO/NASA ADS: ADS Home Page. Web. 08 Mar. 2010. <http://adsabs.harvard.edu/abs/1989PEPI...57..199B>

"Mass-Wasting." University of Wisconsin - Green Bay. Web. 08 Mar. 2010. <http://www.uwgb.edu/DutchS/EarthSC202Notes/masswast.htm>.

Max Milla; "Peru Earthquake 1970." Personal interview. 03 Mar. 2010.

"Subduction." Oracle ThinkQuest Library. Web. 09 Mar. 2010. <http://library.thinkquest.org/17457/platetectonics/5.php>.

"Yungay |." ...en Perú - Travel Culture History News. Web. 09 Mar. 2010. <http://enperublog.com/2006/06/22/yungay/>