EARTHQUAKES

by: Hannah

Why is an earthquake a natural disaster?

Earthquakes are caused by a sudden shift deep under ground in the Earth's tectonic plates. On the surface, we see this as the shaking of the ground, causing damage to poorly built structures.

The most powerful earthquakes can destroy even the best built structers. . When they do it causes them to make an earthquake.

What does an earthquake do/damage?

Earthquakes release a lot of energy. They are able to destroy bridges, buildings, and even entire cities in just a few minutes, landslides and rockslides occur.
Cracks open in the ground, poles fall cutting off electrical,[etc], PEOPLE DIE!!!!!!!!

What are the most common areas for an earthquakes?

Haiti

China

Japan

Canada

Goergia

How do they form?

Stress in the earth's outer layer cause a pushing effect against the sides of the fault. Due to this motion, rocks slip or collide against each other releasing energy. This released energy travels in waves through the earth's crust and causes the shaking that we feel during an earthquake.

Under the surface of the earth, the two sides of a fault are constantly moving, relative to one another. This movement is known as a fault slip. The movement of these two sides is not smooth and is accompanied by a gradual build-up of elastic strain energy within the rocks along the fault.


Eventually, the strain along the fault becomes too much.The fault then ruptures with a sudden movement releasing all the energy it has built up. This energy is released in the form of vibrations called 'seismic waves'.

These waves travel along the surface and through the earth at varying speeds depending on the material through which they move.

Stress in the earth's outer layer cause a pushing effect against the sides of the fault. Due to this motion, rocks slip or collide against each other releasing energy. This released energy travels in waves through the earth's crust and causes the shaking that we feel during an earthquake.

Under the surface of the earth, the two sides of a fault are constantly moving, relative to one another. This movement is known as a fault slip. The movement of these two sides is not smooth and is accompanied by a gradual build-up of elastic strain energy within the rocks along the fault.

The Huaxian, China earthquake

The earthquake occurred near Huaxian, Shaanxi,China, about 50 miles (80 km) east-northeast of Xi'an, the capital of Shaanxi. More than 830,000 people were KILLED. Damage extended as far away as Taiyuan, the capital of Shanxi and about 270 miles (430 km) northeast of the epicenter. There are felt reports as far away as Liuyang in Hunan, more than 500 miles (800 km) away. Geological effects reported with this earthquake included ground fissures, uplift, subsidence, sandblows and landslides. Most towns in the damage area reported city walls collapsed, most to all houses collapsed and many of the towns reported ground fissures with water gushing out!