Shakira Zavala
Geography-1000-020-F12
Lauren Parker
E-Portfolio
Tracking Earthquakes and Volcanoes with Google Earth
Part 1: Tracking Earthquakes
Earthquakes are shaking of the ground caused by plate (tectonics) interactions because of
accumulated stress over time; release of stress results in the shaking of the ground. Stress is
released in the form of seismic waves. Following below are five plate boundary types: oceanicoceanic convergence, continental-continental convergence, oceanic-continental convergence,
transform, and divergent.
1. On Wednesday, October 24th, 2012 at 6:45pm a magnitude 6.5 Earthquake occurred in
Costa Rica, with a depth of 20.10 Km. It occurred on an oceanic-oceanic convergence
plate boundary. As one of the oceanic plates subducts beneath the other an oceanic trench
is formed, shallow and deep-focus earthquakes occur.
2. On Thursday, October 25th, 2012 at 1:05am a magnitude 5.2 Earthquake occurred in
Southern Italy, with a depth of 3.90 Km. It occurred on a continental-continental
convergent plate boundary. Under the conditions of continental collision, shallow-focus
earthquakes are common, no subduction takes place because continental crust is too
buoyant to subduct, but mountains are generally thrust upward.
3. On Tuesday, October 23rd, 2012 at 8:17pm a magnitude 4.1 Earthquake occurred in the
Caucasus region, Russia, with a depth of 20.60 Km. It occurred on an oceaniccontinental convergence plate boundary. The dense oceanic plate slowly and inexorably
sinks into the asthenosphere in the process of subduction. The subducting slab pulls on
the rest of the plate; such slab is probably the main cause of most plate movement,
pulling the rest of the plate in after itself, as it were. Shallow-focus earthquakes are
common at the trench, but as the subducting plate descends into the asthenosphere, the
earthquakes become progressively deeper.
4. On Wednesday, October 24th, 2012 at 12:56pm a magnitude 5.4 Earthquake occurred in
the Cayman Islands region, with a depth of 32.70 Km. It occurred on a transform plate
boundary. Transform faults are associated with a great deal of seismic activity,
commonly producing shallow-focus earthquakes.
5. On Thursday, October 25th, 2012 at 3:49pm a magnitude 5.4 Earthquake occurred in
Northern Peru, with a depth of 8.0 Km. It occurred on a divergent plate boundary. The
edges of lithospheric plates move apart at divergent boundaries. Such spreading centers
are associated with shallow-focus earthquakes.
Part 2: Tracking Volcanoes
Volcanism is a general term that refers to all the phenomena connected with the origin
and movement of molten rock. The high number of volcanoes occurring around the
Pacific Ocean Basin; is what is now called the “Pacific Ring of Fire,” along these plate
boundaries.
1. Yellowstone is a caldera, and is located in the state of Wyoming (USA).The
Yellowstone Plateau volcanic field developed through three volcanic cycles spanning
two million years that included some of the world’s larges known eruptions.
Yellowstone is on a Hot Spot and is presently the site of one of the world’s largest
hydrothermal systems including Earths largest concentration of geysers. Summit
elevation is 2805 m.
2. Mauna Loa is a shield volcano, and is located in Hawaii (Hawaiian Islands). Mauna
Loa is on a Hot Spot. It is the world’s largest volcano. Basaltic lava tends to flow
quite easily over the surrounding surface, forming broad, low lying shield volcanoes.
Summit elevation is 4170m.
3. Mt. Rainier is a composite volcano, and is located in Washington (USA). Mt. Rainier
is on a convergent plate boundary. Composite volcanoes emit higher silica,
intermediate lavas such as andesite often erupt explosively and tend to develop into
symmetrical, steep-sided volcanoes. Mt. Rainier, at 4392 m the highest peak in the
cascade range, forms a dramatic backdrop to the region.
4. Sunset Crater is a cinder cone volcano, and is located in Arizona (USA). Sunset
Crater is on a hotspot. Cinder cones are the smallest of the volcanic peaks, basaltic
magma is most common. Cinder cones are generally less than 450 meters, but Sunset
crater has a summit elevation of 2447 m.
Part 3:
Reflection
Plate tectonics is a theory of massive crustal rearrangement based on the
movement of continent-sized lithospheric plates. The correlation between earthquakes
and volcanoes with respect to the plate tectonics theory is that pate tectonics is the source
of these natural disasters. The different kind of plate boundaries that there are on earth
affects what happens when it comes to what type of natural disasters take place. Volcanic
activity is primarily associated with plate boundaries where subduction of oceanic
lithosphere is taking place; volcanoes are formed in association with the generation of
magma. Earthquakes are produced by shock waves resulting from a sudden displacement
along a fault and may also develop from a movement of magma or sudden ground
subsidence. This is how Plate Tectonics affect both earthquakes and volcanoes.
There is a spatial relationship between earthquakes and volcanoes in the sense that
both types of natural disasters are transforming the earth and have been doing it for
billions of years, and will continue. Both of these events occur mostly along tectonic
plate boundaries. This is the case in the Pacific Ring of Fire, where most of the world’s
volcanoes occur. These natural disasters can lead to another, like when magma moves up
the neck of a volcano, it can cause an earthquake if it has a high viscosity.
In doing this assignment I have learned how natural disasters are related, and how
they have shaped our earth over billions of years. It is kind of a scary thing to now know
that we (here in Utah) are along a fault that will cause a Big earthquake someday. I just
hope that I am somewhere else when that happens. I have learned that some countries are
more prepared than others for when these natural disasters do occur. I also have come up
with my own theory in doing this assignment. And that is that ultimately life on earth is
no longer going to exist, and this is going to be due to the natural disasters that earth
experiences. There is evidence that on other planets like on: Mars, the Moon, and
Mercury, those natural disasters have occurred but are no longer active. I believe that one
day life did exist on those other planets and the natural disasters ended it. I believe that
the same will happen here on earth, life on earth will end. It is a scary thing to think
about, but then again I don’t believe it will happen in my lifetime.
“Works Cited”
Hess Darrel.
Mcknight’s physical geography: a landscape appreciation/Darrel Hess; illustrated
by Dennis Tasa.-10th ed. P. cm.
URL: http://pubs.usgs.gov/publications/text/unanswered.html
Last updated: 05.05.99