Earthquakes: The Dynamic Earth

Earthquakes - The Dynamic Earth

Precise definition of earthquakes:

Earthquake is a natural disaster that occurs when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault, also known as the fault plane. The area below the earth’s surface where the earthquake starts is called the hypocentre, and the area above it on the surface is called the epicentre.

More than a million earthquakes rattle the world each year. But, most are so small that they can only be detected by sensitive instruments called seismogram.

Scientific theory that explains why earthquake occurs:

The earth consists of four major layers: The inner core, outer core, mantle and crust. The crust and the top of the mantle make up a thin skin on the surface of the planet. However, the skin is not all in one piece; it is made up of several pieces, called tectonic plates. These huge plates are

When a plate collides with another plate, pressure builds up until the rocks suddenly crack and shift.

The fractures that form between these shifting rocks are called faults. Not all faults are the same. There are three basic kinds: normal, thrust or reverse and transcurrent or strike-slip faults.

Normal fault is when the land on one side of the break slips downward, and so the land on other side is higher. Normal faults are currently forming in the Basin and Range region of the western United States. They are also responsible for the Sea of Cortez, or the Gulf of California, that separates Baja California from the rest of Mexico.

Thrust or reverse fault is when one block of crust is on top of another. These faults are commonly found in collisions zones, where tectonic plates -push up mountain ranges such as the Himalayas and the Rocky Mountains.

Strike-slip or the transcurrent fault is when two lands are sliding past each other horizontally, with little to no vertical