Earth Science: Forces Within the Earth

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Please see my response to your questions attached, which are also presented below. I also provided a couple of diagrams that I thought you might find helpful, which are in the attached response. Have a great summer and take care.

RESPONSE:

Q1: How do forces within the earth especially in the Lithosphere, asthenosphere, and Mesosphere determine and /or cause earthquakes, volcanoes, tidal waves, faults, fold fractures, continental plate movement and rock formation? Please explain.

Below is a diagram that you can refer to - which will make it easier to understand the answers. Please refer to the diagram as you read the answers (see diagram in attached response)

1. What Causes An Earthquake?

A sudden tremor or movement of the earth's crust causes an earthquake, which is part of the lithosphere. The movement of the lithosphere originates naturally at or below the surface (i.e., plate tectonics). The word natural is important here, since it excludes shock waves caused by French nuclear tests, man made explosions and landslides caused by building work. Earthquakes occur in the crust or upper mantle that is called the lithosphere, which ranges from the earth's surface to about 800 kilometers deep (about 500 miles). However, deep earthquakes occur in the forces associated with plate tectonic in the aesthenosphere.

In fact, there are two main causes of earthquakes. Firstly, they can be linked to forces associated with explosive volcanic eruptions; they are in fact very common in areas of forces associated with volcanic activity where they either proceed or accompany eruptions. Secondly, the forces of Tectonic activity associated with plate margins and faults (i.e., aesthenosphere) trigger earthquakes. The majority of earthquakes worldwide are of this type. In other words, an earthquake is caused by a sudden slip on a fault. Forces in the earth's outer layer, called the lithosphere, push the sides of the fault together. Stress builds up and the rocks slips suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. An EQ occurs when plates grind and scrape against each other. (http://www.zephryus.demon.co.uk/geography/resources/earth/cause.html).

2. What causes a volcano?

The forces that cause a volcano are inside the earth's core - which is called magma, which is a red-hot liquid rock. (See diagram above for location). Volcanoes happen when magma rises to the surface of the earth ...