Michael T
February 15, 2016
President of the United States
1600 Pennsylvania Avenue
Washington D.C. 2501
Dear Mr. President:
I am writing to answer your questions about earthquakes. I am Michael
Turpin, the USGS head scientist of earthquake studies. You have asked
many questions which I will answer in the following of this letter.
The most recent earthquakes are occurring at the edges of Plate Boundaries.
Plate Boundaries are the edges of the earth’s tectonic plates. The earth’s
Tectonic Plates are essentially giant slabs of rocks floating around on
denser, molten rock called the mantle, which lies between the earth’s crust
and the earth’s core. All the most powerful, frequent, and recent
earthquakes are happening upon the more actively moving and the largest
plate boundaries.
Yes, there are places more prone to earthquakes than other areas, because
of Plate Movement. There are three different types of plate movement. Those
are Divergent, Convergent, and Transform faults. Divergent plates move
apart from each other, Convergent plates ram each other, and transform
plates slide past each other.
These earthquakes are more likely to occur along the converging Plate
Boundaries than the divergent ones, because it causes a subduction area.
This causes a lot of friction between the plates. This means the earthquakes
will happen more often and more violently. Japan and Alaska are major
earthquake sites. This is because both of them are converging toward the
other, and thusly, the both of them have a lot of earthquakes.
Earthquakes and volcanoes are very much related. For one thing, both
phenomena are caused by Tectonic Plates rubbing together. Earthquakes
though, are caused by any kind of plate movement, while only convergent
plates and hotspots can cause a volcano. When a plate subducts, a lot of
heat is generated between the two slabs of rock. This melts some rock and
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February 15, 2016
creates superheated pockets of magma which force themselves out of
volcanoes because of the extreme pressure.
Earthquakes are caused by forces generated deep in the earth. These forces
are called convection currents. The convection currents are caused, in turn,
by heat and radioactive decay in the mantle. The process of convection is
heating, cooling, and sinking.
And so, Mr. President, that should answer all of your questions and then
some. If you have any other questions about earthquakes, just ask. You can
contact me at EQ_genius@USGS.org.
Sincerely,
Michael Turpin
USGS lead scientist