Download Lexie Carletti

Lexie C
December 16, 2007
The President of the United States
The White House
1600 Pennsylvania Avenue NW
Washington, DC 20500
Dear Mr. President:
I am honored that you have chosen me to be your resource for these questions. As you may know
many earthquakes occur much around the United States and with preparedness, awareness, and
knowledge you can save many Americans lives. So with the help of these answers they will
teach you how to better inform the public on earthquake safety and general information.
First of all, you asked me where the most recent earthquakes are occurring and if they are more
likely to occur in certain areas. As I have been tracking earthquakes the past three weeks I found
that earthquakes happen mostly in Indonesia, Fiji, Japan, Alaska, and Chile. In other words these
places all happen along the Ring of Fire. The Ring of Fire is a basically a section of plates
forming a ring where many earthquakes and volcanoes occur. It is made up of western North
America, western South America, and eastern and southern Asia. If the earthquakes aren’t
occurring in the Ring of Fire they happen along plate boundaries where plates scrape and grind
against each other. So, earthquakes are most likely to take place in the Ring of Fire or along plate
boundaries.
Secondly, another question you needed guidance on was is there a way to determine what parts
of the world are most prone to earthquakes. Yes, in fact the part of the world that is most prone
to earthquake activity is people living along the Ring of Fire or plate boundaries. However,
earthquakes can sometimes be unpredictable so it just depends on when the plate will snap and
release. People that live here are in a danger zone and it is risky. Here people must take safety
precautions such as reinforcing highway pillars with spiral reinforcing rods or putting buildings
on flexible circular moorings with steel and rubber springs.
Next, you also were wondering if there is a relationship between earthquake and volcanoes.
There is in fact a relationship between earthquakes and volcanoes. A certain type of a plate
boundary is called a subduction zone. Here an oceanic plate and a continental plate collide and
the denser oceanic plate sinks or subducts under the other plate. Then, the oceanic plate starts to
melt from intense heat and causes magma chambers. When these magma chambers get to full
they explode and we get volcanoes. Sometimes when volcanoes erupt earthquakes happen too.
Hawaii is a great example of this because it has many earthquakes and the islands are full of
volcanoes. Japan is also another example plus many others.
Finally, your last question was what is causing earthquakes. The cause of earthquakes is plate
tectonics. Plate tectonics is the shifting and movement of plates and as a result is earthquakes.
Heat within the core and radioactive decay in the mantle cause convection currents. Convection
currents are material heating, rising, cooling, and sinking all in a circular motion like watching
pasta on a stovetop cooking. These currents cause the movement and shaking of the earth we see
daily. They move continents because plates are floating on the asthenosphere and the currents
churn it up so the plates move. Also, plates sometimes move on faultlines when there is so much
pressure they occasionally “slip” and distress.
In conclusion, I must say this was a superb privilege that you gave to me. I hope that you found
the answers you were looking from my research. I now have a great reputation to live up too.
Remember you can always reach me at my office and I would be happy to help you with other
earthquake information.
Sincerely,
Lexie Carletti
Lead Scientist-USGS
Earthquake Division