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BHINEBI:

Hona hemen gure txosten, eredutzat hartuz:

Irune Elicegui Iara Duran Irene Arin

INDEX

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What’s inside the Earth? 3

The lithosphere

Tectonic plates 4

What’s a tectonic plate? The major tectonic plates in the World

Continents 5

What’s continental drift? Earthquakes Volcanoes

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WHAT’S INSIDE THE EARTH?

The lithosphere

The lithosphere is underlain by the asthenosphere, the weaker, hotter, and deeper part of the upper mantle. The concept of the lithosphere as Earth’s strong outer layer was developed by Barrell, who wrote a series of papers introducing the concept. The concept was based on the presence of significant gravity anomalies over continental crust, from which he inferred that there must exist a strong upper layer (which he called the lithosphere) above a weaker layer which could flow (which he called the asthenosphere). The division of Earth's outer layers into lithosphere and asthenosphere should not be confused with the chemical subdivision of the outer Earth into mantle, and crust. All crust is in the lithosphere, but lithosphere generally contains more mantle than crust.

There are two types of lithosphere:

-Oceanic lithosphere, which is associated with Oceanic crust.

-Continental lithosphere, which is associated with Continental crust.

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TECTONIC PLATES

What’s a tectonic plate? (Plate movement)

Plate tectonics describes the large scale motions of Earth's lithosphere.

The lithosphere is broken up into what are called tectonic plates — in the case of Earth, there are seven major and many minor plates. The lithospheric plates ride on the asthenosphere. These plates move in relation to one another at one of three types of plate boundaries: convergent or collision boundaries, divergent or spreading boundaries, and transform boundaries. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries. The lateral movement of the plates is typically at speeds of 50—100 mm annually. The major tectonic plate of the world:

The main plates are:

African Plate covering Africa - Continental plate Antarctic Plate covering Antarctica - Continental plate Australian Plate covering Australia - Continental plate Indian Plate covering Indian subcontinent and a part of

Indian Ocean - Continental plate Eurasian Plate covering Asia and Europe - Continental plate North American Plate covering North America and north-east

Siberia - Continental plate South American Plate covering South America - Continental

plate Pacific Plate covering the Pacific Ocean - Oceanic plate

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CONTINENTS

Made tens of millions of years, had only one continent on our planet, called Pangea. The theory of plate tectonics explains how the different plates that make up the Pangea were divided into two continents Laurasia and Gondwana, and divided up to the conformation having the continents.

The movement of plates has caused the formation and break-up of continents over time, including occasional formation of a supercontinent that contains most or all of the continents. The supercontinent Rodinia is thought to have formed about 1 billion years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around 600 million years ago. The eight continents later re-assembled into another supercontinent called Pangaea; Pangaea eventually broke up into Laurasia (which became North America and Eurasia) and Gondwana (which became the remaining continents).

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EARTHQUAKES

An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacing the ground. Earthquakes are caused mostly by rupture of geological faults, but also by volcanic activity, landslides, mine blasts, and nuclear experiments. An earthquake's point of initial rupture is called its focus or hypocenter. The term epicenter refers to the point at ground level directly above this.

TIPES OF EARTHQUAKES

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VOLCANOES

Volcanoes are simply vents at the earth's surface through which lava and other volcanic products are erupted. Although many volcanoes are cone-shaped, different types of volcano exist according to their location an d the products they are made up of.

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