Daniel Parker
Tracking Volcanoes and Earthquakes Using Google Earth
Part 1: Tracking Earthquakes
1. Continental Rift Boundary
-4.3 magnitude earthquake
-Saturday, October 20, 2012 05:48:51 PM
-Near Potosi, Bolivia
-Occurred near a continental rift boundary
-208 km was the focus depth
-The two plates pulled apart from each other and this happens at continental rift boundaries.
2. Continental Convergent Boundary
-Magnitude 6.2 earthquake
-Sunday, October 21, 2012 10:00:32 AM
-Near the small island of Vanuatu
-Occurred near a continental convergent boundary
- Focus depth of 35.60 km
- 2 plates smashing into each other and this occurred because Vanuatu is located in the "ring
of fire", where lots of volcanic and earthquake activity occur.
3. Continental Transform Boundary
- 5.3 magnitude earthquake
- Saturday, October 20, 2012 11:55:09 PM
- Occurred in Central California, east of Fresno
- 9.20 km focus depth
- Two plates are sliding past each other moving in opposite directions causing
stress and strain to build up and release energy in the form of an earthquake.
4. Oceanic Convergent
-4.6 magnitude earthquake
- Tuesday, October 23, 2012 19:11:52
- Occurred off the west coast of Northern Sumatra
- 29 km focus depth
- When earthquakes happen at this type of boundary, subduction occurs where one oceanic
plate is sub ducted under the other, causing a trench.
- This particular earthquake occurred because the location is the Sumatra oceanic trench
5. Subduction Zone
-4.8 magnitude earthquake
- Saturday, October 20, 2012 05:56:40 AM
- Occurred just south of Panama
- 10 km focus depth
- Happens when an oceanic plate is sub ducted underneath a continental plate
- Occurred at this particular location because of the panama plate boundary. This includes a
subduction zone border.
Part 2: Tracking Volcanoes
1. Composite Volcano
- Mount St. Helens
-It is a Stratovolcano (AKA Composite)
- On the Juan de Fuca Plate, this is a convergent plate boundary
- The Juan de Fuca Plate is being sub ducted underneath the North
American plate, causing this volcano.
2. Shield Volcano
-
Newberry volcano
-
One of the largest Shield volcanoes in North America
-
The Newberry volcano is a potentially active hotspot
-
The cause of the volcanic activity is greatly debated
3. Caldera Volcano
-
Yellowstone Caldera
-
A Caldera Volcano
-
It sits on top of the yellowstone hotspot
-
The force behind this creation is controversial as well
-
One side says that it is an interaction between the lithosphere and upper mantle
-
Others say it originated deep in the mantle
4. Cinder Cone Volcano
-
Nazko Volcano
-
Type of Volcano is Cinder Cone
-
It is on a hotspot in the middle of the North American plate
-
Located on the Anahim Volcanic Belt
Part III : Assignment Reflection
Most scientists today follow the theory of Plate Tectonics. Plate tectonics essentially is
the motion within the lithosphere, which is the outer-most layer of earth. There are 10 major
tectonic plates around the earth’s surface. These sparsley sized plates move about earth’s
surface in varying ways whether it be pulling apart, sliding past each other or violently
colliding with one another. These motions are essentially earthquakes. Earthquakes are not
randomly located around the surface, they tend to be concentraded in narrow zones. This
supports the Plate Tectonic Theory by saying where these earthquakes occurr, are esentially
at the plate borders. All this activity is definitely not limited to the continental part of the
Earth. Ocean plates are also included in this theory, mostly in the process of sea-floor
spreading. Plate tectonics help us predict earthquakes because we have seen them occurr at
the plate boundaries.
Drastic results occurr when earthquakes happen at these plate boundaries. Not only
are huge mountain ranges a direct result from earthquakes, volcanoes are as well. Volcanoes
form with two of the plate boundary type, Divergent and convergent. Most of the worlds
volcanoes are located on or near the plate boundaries, with the exception of hot spots. In
Divergent boundaries, the two plates move away from one another forming a break in which
magma rises to fill the gap. Convergent boundaries occur when two plates collide with one
another. Only if one of the plates is made up of oceanic crust, will a volcano occur. The reason
for this is subduction, in which the denser oceanic crust slides underneath the less dense crust
which then forms a trench. The descending slab causes magma to rise upward.
Looking at a map of earthquakes and also one of volcanoes around the world, you’ll
see that they match very closely. As stated above, you can clearly see that where there is
seismic activity along those boundaries, that’s where you’ll be able to locate most volcanoes,
with the exception of hotspots. When volcanoes are formed and in its active stage of life, it will
experience earthquakes caused by magma moving within its chamber. When you have giant
amounts of rock moving together, you’ll experience earthquakes.
Knowing that when volcanoes experience increased seismic activity, in which the
magma is moving and shifting, is a sign that eruption is very likely to occurr. Monotoring the
activity of volcanoes and the magnitude of the earthquakes we can predict when an eruption
can happen. This allows us to alert the right authorities to proceed with an evacuation if
necessary.
Before doing this assignment and attending my class, there were loads of information
that I had no idea about. I didn’t know any of the different types of fault types (normal,
reverse, thrust, strike-slip) , volcanoes (cinder cone, shield, composte, lava dome.) I didn’t
know what a hotspot was (volcanic activity in the middle of the lithosphere), I didn’t know
that yellowstone was just a gigantic volcano. I didn’t know what the ring of fire was and just
thought it was a song by Johnny Cash. There was a lot of material that I learned.
How we can determine quite accurate where an earthquake took place facsinated me.
By using 3 locations all around the United States, they all work together to locate where it
occurred. When an earthquake is released, S and P waves and sent through the surface of the
earth. The 3 locations then triangulate those waves and determine the location. What amazed
and frightened me at the same time is the possible eruption of Yellowstone’s supervolcanoe.
When it erupts, which is a 1 in 10,000 chance in our lifetime, it would ultimately be the end of
most living things on earth. The immediate effect would blow a huge crater in the middle of
the United States which would obviously kill everyone around it instantly. Tons of ash would
be erupted into the air, which would then affect the climate of the earth and slowly destroy
life as we know it.
Works Cited
(n.d.). Retrieved from Huffinton Post: http://www.huffingtonpost.com/2012/06/04/yellowstonesupervolcano-eruption-unlikely_n_1569214.html
(n.d.). Retrieved from soest.hawaii.edu: http://www.soest.hawaii.edu/GG/ASK/plate-tectonics.html
(n.d.). Retrieved from earthquake.usgs.gov:
http://earthquake.usgs.gov/learn/topics/plate_tectonics/rift_man.php
Hess, D. (2011). Physical Geography a Landscape Appreciation.