The movement of the plates is divided in three ways: they move together (converge), the move apart (diverge), or they move past each other [About.com – Geology]. “Earthquakes occur along faults, where huge blocks of rock are grinding past each other. Tectonic motions produce directional pressure, which causes rocks on either side of a large fracture to move past each other. The movement is rarely smooth; usually the blocks stick because of friction, which slows their movement. Eventually, the friction is overcome and the blocks slip abruptly, releasing pent-up energy with a huge “snap”—an earthquake” (The Plate Tectonic Model – Page 107).
Plate Tectonics Press Release Assignment Geology/101 An earthquake is the shaking of the ground cause by an abrupt shift of rock along a fracture in the Earth, called a fault. An earthquake is caused by the breaking and shifting of rock beneath the Earth’s surface. Ground shaking from earthquakes can collapse buildings and bridges; disrupt gas, electric, and phone services; and sometimes trigger landslides, avalanches, flash floods, fires, and huge, destructive ocean waves (tsunamis) (www.fema.gov/hazard/earthquake/facts). So the question that everyone wants to know is why does the planet move when the plates move? The planet moves whenever the two plates get tangled together.
I shall use examples of the Kobe Earthquake 1995, Boxing Day Tsunami 2004 and the Haiti Earthquake 2010. The earthquake of 2004 was caused by subduction of the Australian plate and the Eurasian Plate ,a 15-20m slip occurred along the fault line which then caused an earthquake measuring a 9.1 on the Richter scale. This a very high recording on the Richter scale so therefore it would always cause devastating hazards , but human factors could be seen as making the impacts far worse. The earthquake in the ocean had caused a tsunami to occur within the Indian Ocean. The wave reached up to 30 metres high causing devastation to the 13 countries surrounding the ocean.
PROJECT IN EARTH SCIENCE SUBMITTED BY: JOSEPH RUEL SAMILLANO SUBMITTED TO: MS: ELIZABETH BAYONA WHAT IS TSUNAMI? A tsunami is a series of ocean waves that sends surges of water, sometimes reaching heights of over 100 feet (30.5 meters), onto land. These walls of water can cause widespread destruction when they crash ashore. These awe-inspiring waves are typically caused by large, undersea earthquakes at tectonic plate boundaries. When the ocean floor at a plate boundary rises or falls suddenly it displaces the water above it and launches the rolling waves that will become a tsunami.
'The extent to which volcanic processes represent hazards depends on where and when they occur.' Discuss this statement. Volcanic processes become a hazard when they impact upon the human and built environments, killing and injuring people, burying and collapsing buildings, destroying infrastructure and bringing agricultural activities to a halt. Volcanic hazards are influenced by several factors including location, time and frequency of eruptions, and the materials ejected. It is the viscosity of magma that largely determines the nature and power of an eruption and the resultant severity of the hazard.
Each year, around 60 major volcanoes erupt globally. How hazardous each eruption is depends on a variety of physical and human factors. This essay will analyse how physical volcanic properties interact with human variables to make certain volcanoes more hazardous than others. This will be identified through the numerous recorded eruptions from different countries at different stages of development. Since the degree of impact an earthquake has is measure on both the Richter and the Mercalli scale, it must be reasonable to assume that the power of an eruption is representative to the degree of how potentially hazardous the event may be.
A natural hazard is a natural event that has the ability to adversely affect people and their property. In an earthquake the primary hazard is the ground shaking which leads to injury or loss of life. Although humans have no control over the duration of time that
Earthquakes are tremors in the earth’s crust which are caused mainly by tension between the tectonic plates. The most destructive earthquakes are often at destructive plate boundaries, where the more dense oceanic plate is being subducted under the less dense continental plate. These plates will build up pressure over time before slipping releasing huge amounts of kinetic energy. However earthquakes are apparent along other plate boundaries. Conservative plate boundaries, such as the Pacific and North American plate, move at 2-3cm/year causing damage to cities along the fault, such as Los Angeles.
Discuss the view that the impact of earthquake hazards depends primarily on human factors. (40 marks) Earthquakes are caused by the movement of tectonic plates when the energy from friction is released on the earth’s surface. They occur at all plate boundaries; destructive, constructive and conservative. Every earthquake will be different, and there are many factors influencing the extent to which it will have an impact on the surrounding area and its population. In most earthquakes physical and human factors will play a part in how an area and the population are affected.
It is this side-to-side load which causes the worst damage, often collapsing poor buildings on the first shake. The side-to-side load can be worse if the shocks come in waves, and some bigger buildings can vibrate like a huge tuning fork, each new sway bigger than the last, until failure. This series of waves is more likely to happen where the building is built on deep soft ground, like Mexico City. A taller or shorter building nearby may not oscillate much at the same frequency. Often more weight has been added to a building or structure at most frequently at greater heights; say another floor and another over that; walls built round open balconies and inside partitions to make more, smaller, rooms; rocks piled on roofs to stop them blowing away; storage inside.