Nat Haz Lec Notes 2-7-08

Nat Haz Lec Notes 2-7-08 - everything in its...

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Nat Hazards Volcano Video Notes: 2/7/08 - the earth’s inner core reaches temperatures of 12,000 degrees F - magma rises to the earth’s surface through breaks in the earth’s crust o when magma breaks through crusts it becomes lava o most lava comes up where one plate dives below another, or when two plates spread apart - Hawaiin Islands are examples of volcanoes causing land to uprise from the ocean - Kilewea is the most active volcano on earth - Ash accumulates on the sides of volcanoes o When it rains, it becomes hazardous because it becomes mud and can turn into mud flows that rage at large speeds and cause floods - Key to the future is the past: o 1914 – volcanoes bury 6 villages and cause deaths o most volcanoes lay quiet by centuries, then take society by surprise - magma contains gases that expand violently when they reach earth’s atomosphere o lava to thick to flow can ooze up slowly and form extremely hot rock, the rock can collapse and cause an avalanche of hot rock, ash and consumes
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Unformatted text preview: everything in its path-pyroclastic flows – virtually unpredictable and rare o only seen in photographs-Volcano in Tanzania o Had black lava-Nov 13 th 1985 – Colombian Volcano – Nevada Del Ruiz o Mud flows cover 23,000 people and villages o Predictions were made, but were covered up-USGS – Cascades Volcanoes Observatory-Summit Mt. Penatubo o USGS team arrives at airforce base o June 5 th- swarms of earthquake formulate a level 3 alert o June 7 th – Penatubo emits large amounts of ash – level 4 alert o June 10 th – large evacuation – Airforce Base members leave o June 12 th – volcano erupts – more than 80,000 people leave their homes o Tens of thousands were saves as the largest evacuation due to prediction-benefits of volcanoes o build new land o create mountains o recycle gases and minerals o volcanoes bring atoms to the surface of earth-...
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This note was uploaded on 05/01/2008 for the course GEOG 260Lg taught by Professor Curtis during the Spring '07 term at USC.

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