Running Head: JAPANESE TSUNAMI 1. Geological Perspective of the Japanese Tsunami

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1 Running Head: JAPANESE TSUNAMI 1 Geological Perspective of the Japanese Tsunami

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3 JAPANESE TSUNAMI 3 Abstract Humanity is characterized with flaws, so is planet earth. Earthquakes shake the ground every now and then. They have been fascinating humankind for some time now, and despite advances in technology, earthquakes are still unpredictable. Since time immemorial, various models have been developed to explain this geological phenomenon. Geologists have proposed a model that portrays earthquakes as resulting from plate movement in the earth s crust due to the excessive pressure and heat from the mantle. The heat from the lower mantle continues to push and pull the plates. This pressure eventually breaks the plates sending shock waves to the land and oceans. Due to its proximity to the Pacific Ring of Fire, Japan is one victim with its latest occurrence as Tohuku Tsunami. Therefore, this paper tries to examine the Japanese Tsunami from a geological point of view.

4 JAPANESE TSUNAMI 4 Introduction On 11 March 2011, a monster earthquake ensued miles off the East seashore of the Island of Honshu, Japan. This seismic activity was named Tsunami; a Japanese phrase for seismic sea wave. The massive seismic activity weighed 9.0 on the Richter scale. This activity occurred forth a zone where major tectonic plates meet. A seismic sea wave is characterized by large wavelengths, long periods, long water walls and long tides (Gerard, n.d.). They are known to pose a danger to aquatic life, deforming the coastline, and causing earthquakes on land (Lassieur, 2003). Geologists claim that seismic sea waves move in series comprising of long walls of water that can extend into the land at greater velocities. Tsunamis are known to reshape the earth s surface. A notable change was in the shifting Japan`s island by 2.4 meters. The earthquake happened as the Earth's crust split forth a stretch of 400 km long by 160 km breadth (CNN, 2011). The oceanic and continental plates moved slid about 18meters. Geophysicists also claim the seismic sea wave also shifted the earth`s axis by 10 centimeters (CNN, 2011). The same phenomenon resulted in the formation of 9-meter walls of water that cleaned up across plantations and immersed towns. They are characterized with triggering aftershocks, so is the Tohoku Tsunami. According to CNN, Tohuku Tsunami triggered 160 aftershocks scaling 5.0 on the Richter scale in 24 hours of its inception (2011). Causes The main cause of earthquakes is faulting. Tsunami is common along subduction zones with the Pacific plate ramming under Asia. It is a zone characterized with the sinking of one plate beneath the other into the mantle (like the Peru-Chile encroachment). This movement is not always suave, friction get`s them stuck at the boundaries while the other part is in motion (Ammon, 2001). It gets to a point when the rock at the edges cannot strain

5 JAPANESE TSUNAMI 5 further, and rocks split. The two tectonic plates move. When it happens, pressure heightens. The phenomenon results in the release of energy as seismic waves which worsen with an increase in distance from the epicenter. Factors influencing Seismic activity The intensity of the tremble arises from various factors namely; magnitude, depth of focus, topography, distance from the epicenter and geological properties of the zone (Ammon, 2001). The closer a place to the center of action the more severe is the shaking. Tohuku is said to have caused havoc in Japan than in any country due to its nearness to the focus. The amplitude and period of seismic activity are dependent on quake measurement on Richter scale (Murck, 2012). The closer a region is near the focus the more the shaking. When a seismic activity takes place in deep seas the action is less felt than when it`s in shallow waters. The rock properties of the rock forming the crust are vital in predicting seismic activities in future. Softer rocks and sediment soils result in liquefaction when exposed to any strong seismic activities (Gerard, n.d.). Rifts, hills, mountains and other physical features of a place affect the seismic activity of a place. Mountainous regions tend to have a severe shaking. Zones, where faulting has taken place, have more severe shakes. Effects of the Quake According to World Bank reports Japan ranks third best economy in the world. It has embraced a market economy, state-of-art technology, and best fiscal properties around. Due to the role it plays in global economics, this disaster sent everyone into tumult. The effects of the Tsunami could be felt around the globe. Some of the most affected sectors of the economy are energy, food production, automobile, textile and maritime industries (UN, 2012). Its macro-environment was greatly affected. The GDP per capita of Japan dropped, exports decreased in the same year.

6 JAPANESE TSUNAMI 6 Due to the massive damages on the national infrastructure, the Japanese government sought refuge in massive public borrowing and foreign debts (UN, 2012). Since the power generation stations were struck by the Tsunami, the Japanese government had to abandon nuclear power generation, therefore, increasing production costs as well (UN, 2012). The Tsunami action on Fukushima nuclear plant caused further displacement due to radioactivity leakage into the surroundings. In conclusion, the Tsunami activity in Japanese was a disaster awakening. It prepared the world against the wrath of Mother Nature. Lessons can be learned from this disaster. Although it experienced the toughest disaster on the planet, it did not experience many casualties like other earthquakes in history. It posed a challenge to geophysicists to develop tools that can predict the time, magnitude and effect of seismic activities.

7 JAPANESE TSUNAMI 7 Reference List Charles, Ammon (2001). Earthquake Effects. Penn state Earthquake Seismology. Retrieved from Lecture Notes, Online Website: html Fryer, Gerard. (n.d). Reply to-ask-an Earth-Scientist. Hawaii Institute of Geophysics and Planetology. Retrieved from lecture notes: Lassieur, Allison (2011). Earthquakes. Mankato: Capstone Books. Murck, Barbara (2012). Visualizing Geology. Hoboken: John Willey & Sons. World Economic Situation and Prospects 2012 (2012). United Nations. Retrieved from: f Voigt, Kevin (2011). Quake Moved Japan Coast 8 Feet, Shifted Earth`s Axis. CNN.COM. Retrieved from: ml?_s=pm:world