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Natural disasters in the Cordillera Blanca, Peru.

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Presentation on theme: "Natural disasters in the Cordillera Blanca, Peru."— Presentation transcript:

1 Natural disasters in the Cordillera Blanca, Peru

2 Why human sacrificies in mountains? Archaeological sites and mummies have been found in the Andes at altitudes up to 6,700m Incas constructed the sites in the 15 th century to appease the mountain gods

3 The town of Huaraz flattened

4 Natural disasters in the Cordillera Blanca, Peru Major tectonic faults that are active Marked glacierization Geologically young, steep mountains Pro-glacial lakes Immediate vicinity of human settlements

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6 ALPAMAYO

7 HUANDOY

8 ARTESONRAJU

9 Mt HUASCARAN, PERU

10 1962 HUASCARAN AVY Large snow year 50 degree F increase in temp over a few minutes Caused avalanche 4,000 fatalities Yungay protected by ridge

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12 1970 Avalanche Triggered by 7.7 magnitude earthquake Rock face failure Incorporated 30 meters of snow and ice! Moraines confined flow initially Accelerated over a distance of 2.4 km Became airborne at change of slope

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21 Church before 1970 avalanche. Note palm trees in foreground.

22 Many years after the avalanche. Note palm trees survived.

23 Yungay is now completely abandoned. Cemetery has a monument to the dead.

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25 Guiness book of records as the most deaths ever from an avalanche

26 1970 HUASCARAN AVY Trigger was a large earthquake; 7.7 Caused avalanche with rock slide 20,000 fatalities Yungay destroyed

27 1941 Huaraz Disaster Moraine damming the proglacial Lake Palca (cocha = lake: Palcacocha) broke Resulting flood killed 6,000 people in Huaraz

28 HUARAZ, circa 1970

29 1970 Earthquake that caused the Huascaran disaster killed about 40,000 people in Huaraz. Streets of Huaraz after the 1970 Earthquake. Adobe houses collapsed, killing people inside.

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31 A potential disaster in the icy Andes: a regrettable blunder May 3, 2003: “NASA feels the heat as glacier pictures cause unrest in Peru”, according to Nature HUARAZ CASE STUDIES

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33 NASA press release A chunk of glacier was threatening to fall into an Andean lake and cause major flooding in a Peruvian city of 60,000. A fissure has appeared in the glacier that feeds the Lake Palcacocha near the city of Huaraz, 270 km north of Lima.

34 NASA press release If the piece breaks off, ensuing floods would take 15 minutes to reach the city. In 1941, the lake overflowed and caused massive destruction, killing 7,000 people.

35 NASA press release The city can be seen in the left-center part of the image. Lake Palcacocha is in the upper right corner of the image at the head of a valley, below the snow and glacier cap. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument, aboard NASA’s Terra satellite, is being tasked to obtain current images of the glacier to help monitor the situation.

36 ASTER image, 2001 Fissure NASA interprets as huge crevasse

37 ASTER image, 2003 Fissure NASA believes glacial release into the lake is imminent

38 Palcacocha, historical photograph

39 Palcacocha Rock band from glacial retreat, not crevasse.

40 LAGO PARON Located above Yungay Potential Pro-glacier flood

41 1940’s flood from glacier failure

42 Huge rock glacier dammed lake. Could collapse at any time.

43 Installed drainage tunnel Lowered lake level

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47 Summary: disaster 1962 Huascaran avalanche killed 4,000 1970 Huascaran avalanche killed 20,000 1941 proglacial lake outburst from Palcacocha killed 6,000 in Huaraz Lago Paron could have an outburst at any time from (a) collapse of rock glacier damn; (b) glacial ice fall into lake; c) combination of both

48 Summary: causes Major tectonic faults that are active Marked glacierization Geologically young, steep mountains Pro-glacial lakes Immediate vicinity of human settlements


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