where do earthquakes occur?Earthquakes occur where tectonic plates meet and collides. The plates are moving approximately few centimeters a year in different directions. The areas of the world where many plates boarder one another is a natural earthquake zone. These various boundaries can also be called fault lines. Fault lines are the surface lines of a fracture in the earth's crust and plates as a result of powerful earthquakes. These fault lines created by earthquakes will become the source of future earthquakes as the two separated parts rub and compress to create new tension. The Elastic-Rebound Theory explains how strain and stress gradually builds up in the fault lines as two plates rub ("Earthquake", 5 April 2013). The surfaces of the two plates coming together determines the power of the energy being strained. Aseimical surfaces of the plates in contact are smooth. Asperties surfaces are irregular and rough, causing more pent up stress and energy when two plates are locked together at the bumps. When the strain and stress can not be contained by the weight of the plates anymore, then the seismic waves are released with force and causes an earthquake. Earthquakes caused by boundries with the rough surfaces cause bigger earthquakes. The energy caused by the rupture of the moving plates is called the seismic energy. On the average, 90% of the seismic energy released by the earthquake is obsorbed by the mantel or converted into heat. The extra heat earthquake creates beneath the earth’s surface causes volcanoes to erupt and hot springs to emerge. Fortunately for us humans, only 10% of the earthquake’s energy is actually released into the crust but effects of that 10% can be very damaging ("Earthquake", 5 April 2013).
Top 7 Major Tectonic Plates:
1. North America 2. South America 3. Eurasia 4. Africa 5. Indo - Australia 6. Pacific 7. Antarctica (Briney, Amanda, 2013) |
Earthquake zonesRing of Fire: This is a 40,000 km area in the Pacific Rim with the largest number of earthquakes and volcanoes in the world. There are numerous tectonic plate boundaries and fault lines in this area. Much of the fault surface is rocky and cause great seismic tension to collect. 81% of the world's strongest earthquakes occur in the Ring of Fire. Of course, the fault lines of Japan are located in this area ("The Top 5 Deepest Ocean Trenches", 2012)
Alpide Belt: This is the mountain range area along the southern boarder of Eurasia. African, Arabian and Indian plates are colliding northward with the Eurasian plate to create this number 2 earthquake zone. 17% of the world's largest earthquakes occur in this area. ("The Top 5 Deepest Ocean Trenches", 2012)
Mid - Atlantic Ridge: This is a divergent tectonic plate area along the Atlantic Ocean. It has the longest under water mountain range in the world. The Mid - Atlantic Ridge tectonic movements produces 2% of the largest earthquakes in the world. ("The Top 5 Deepest Ocean Trenches", 2012)
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