As I was so worried last Saturday of a Tsunami hitting the Philippines, my husband was there to comfort me that I should not worry because we are too way from where the sea is situated. This morning while we were chatting, my husband wrote some information about the movement of the earth.
Here’s what he wrote:
Well that got me to thinking, I have tutored students before in earth science and one of the lessons was in Plate Tectonics. What are plate tectonics? Plate Tectonics is a theory that describes the movement of the Earths “lithosphere” (the outermost rocky shell of the earths surface).
The lithosphere is broken up in to man plates, some major and some minor. The Philippines sits on the diamond shaped Filipino Plate and is boarded on the west by the Pacific Plate and on the east by the Eurasian Plate. If you look at most of the worlds volcanoes, they are situated along the borders of these plates. The pacific has a series of Volcanoes called the “Ring of Fire”. By clicking on the link you will see that most of the volcanoes are located near tectonic plates.
90% of the world’s earthquakes and over 3/4ths of the larges occur along the ring of fire. The next most active is the Alpide with only 17% of the world’s largest earthquakes.
The Ring of Fires is a direct consequence of plate tectonics because the plates are moving.
So what is an Earthquake? An earthquake is the shaking of the Earth along a fracture in the Earth’s crust called a fault. Most earthquakes occur along the previous mentioned plates. Scientists believe that most earthquakes are caused by the slow movements of these plates.
The Magnitude of earthquakes is the measure used to tell the strength of an earthquake. The magnitude is a measurement of either the amplitude or duration of specific types of recorded seismic waves. The intensity of an earthquake is the measurement of ground shaking at a specific location.
There is a lot more to this and if you want to learn more you can research Plate Tectonics or tell Mary Anne you want me to try to write more. If you want to know where earthquakes have occurred in the last seven days, you can go click on the USGS site.
You might be surprised how many and where they are.