Physical Sciences

Natural Disasters

Earthquakes


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Magnitude: 6.4
Location: Antofagastu, Chile
Date: March 4, 2010
Time: 7:39 pm
Distance: 88.00 km
Plate Boundary: Oceanic to Continental


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Magnitude: 5.7
Location: Hindu Kush region, Afghanistan
Date: February 28, 2010
Time: 3:51 am
Distance: 104.90 km
Plate Boundary: Continental to Continental


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Magnitude: 6.4
Location: Vanuatu
Date: March 5, 2010
Time: 1:02 am
Distance: 200.20 km
Plate Boundary: Oceanic to Oceanic


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Magnitude: 8.8
Location: Maule, Chile
Date: February 27, 2010
Time: 3:34 am
Distance: 35.00 km
Plate Boundary: Oceanic to Continental


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Magnitude: 6.4
Location: Taiwan
Date: March 4, 2010
Time: 8:18 am
Distance: 23.10 km
Plate Boundary: Oceanic to Oceanic

Volcanoes

 

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Shield Volcano

Santorini, Greece

Divergent Plate Boundary

 

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Cinder Cone

Sunset Crater, Arizona

Divergent Plate Boundary

 

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Composite Volcano

San Pedro, Chile

Oceanic to Continental Plate Boundary

 

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Hot Spot

Yellowstone, Wyoming

Intra-plate

The Volcano of Kilauea, Hawaii is currently listed as a watch. According to USGS there has been continued activity in two spots with frequently visible lava.

Reflection

According to the Theory of Plate Tectonics, there are various types of earthquakes and faults. The area that is most prone to having volcanoes as a result of earthquakes is along subduction zones. A subduction zone occurs along either an oceanic to oceanic fault, or oceanic to continental fault, where the oceanic plate ends up under another plate, and goes low enough to be melted from the earth’s core. The melted rock, magma, can then push up to the earth’s surface and become a full fledged volcano.  These types of volcanoes tend to occur along coast lines or form volcanic islands along the edge of the plate boundary.

When an earthquake occurs in the ocean, the denser oceanic plate sinks under either the lighter oceanic plate, or the lighter continental plate. The sinking causes the earth’s crust to go low enough to become heated by the earth’s core. The now heated rock then rises to the surface in the form of magma, to come out in a volcano. Some of the volcanoes are under the water, or new enough that they don’t really look like volcanoes, but over a period of time they can build up to form any one of three types, a cinder cone, shield, or composite volcano.


The spatial distribution of earthquakes and volcanoes tend to occur on fault lines and plate boundaries. They can occur intra-plate, in the case of volcanoes these are known as hot spots. The majority of volcanoes are found along coast lines, or along divergent plate boundaries, like the Riff V alley, or Mediterranean Sea. Earthquakes generally only occur along faults and plate boundaries. It is rare to get an earthquake in the middle of a plate, but it can happen, especially if there is a volcano or magma chamber located in the area.


There are a lot of thing I learned about Earthquakes and volcanoes that I didn’t know before taking this class. The first thing was that Yellowstone is a volcano hotspot that when it goes off it, it will blow itself up, and affect the entire earth either through ash cover, or climate change. I also learned that most volcanoes occurred along the coast line which is a subduction zone. Another new thing that I found out from this class was that there are multiple types of earthquakes. I originally thought that it was just the plates in the earth colliding. There are earthquakes that take place from collision, but there is also the pulling apart of plates and places where one plate, the heavier plate, goes under the other lighter plate.