BHINEBI:
Hona hemen gure txosten, eredutzat hartuz:
Irune Elicegui
Iara Duran
Irene Arin
INDEX
 What’s inside the Earth?
 The lithosphere
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 Tectonic plates
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 Continents
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 What’s a tectonic plate?
 The major tectonic plates in the World
 What’s continental drift?
 Earthquakes
 Volcanoes
WHAT’S INSIDE THE EARTH?
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 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.
TECTONIC PLATES
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
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:
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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
CONTINENTS
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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).
EARTHQUAKES
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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
VOLCANOES
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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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