Earthquakes

EarthquakesFernando Viscarret

Pablo PueyoXavi Viñeta

Pablo Visiers

Why they occurs:

• An earthquake (also known as a quake, or tremor) is a violent movement of rocks in the Earth crust.

• Earthquakes are usually quite brief, but may repeat over a long period of time.

The release of energy.

What causes?

• Earthquakes are caused by tectonic movements in the Earth crust.

• The main cause are the tectonic plates.

• One rides over the other, causing orogeny (mountain building), earthquakes and volcanoes.

Earthquakes shake buildings inCalifornia.

The earthquake fault types

• There are three main types of fault that may cause an earthquake: normal, reverse thrust and strike- slip. Normal faults occur mainly in areas where the crust is being extended. The three

basic fault types of earthquakes.

The earthquake clusters

• Most earthquakes clusters form part of a sequence, related to each other in terms of location and time. Most earthquake clusters consist of small tremors which cause little to no damage, but there is a theory that earthquakes can recur in a regular pattern.

The effects and the precipitation of earthquakes.

• Earthquakes are caused when a massive amount of Energy is the Earth’s crust is released at one time.

• They cause seismic waves that then go on to cause damage. This is a summary of their effects, causes and prediction

The earthquake produces seismic waves, Human impacts: Loss of lifeBuilding collapseLoss of amenity/basic necessities water, electricity, shelterFiresDiseaseRoad / bridge damage

Which are the cities that suffer the earthquakes

• Jakarta and much of Indonesia suffered from a major earthquake, this year in September.

• Mexico is prone to earthquakes, and Mexico city is very densely populated with many poorly designed structures.

Indonesia Earthquake 2009

Earthquake Strkes Mexico's Pacific Coast

The aftershocks

• An aftershock is an earthquake that occurs after a previous earthquake, the mainshock.

• are formed as the crust adjusts to the effects of the main shock

Earthquake swarms

• Are sequences of earthquakes striking in a specific area within a short period of time.

• They are different from earthquakes because they followed by a series of aftershocks.

• By the fact that no single earthquake in the sequence is obviously the main shock, therefore none have notable higher magnitudes than the other.

Earthquake storms

• A series of earthquakes occur in a sort of earthquake storm,

• Are Similar to aftershocks but on adjacent segments of fault.

• These storms occur over the course of years, and with some of the later earthquakes as damaging as the early ones.

Earthquake-proofing

• Some countries , such as Japan or parts of a country like California in the United States, have a lot of earthquakes.

• In these places it is a good practice to build houses and other buildings so they will not collapse when there is an earthquake.

• This is called seismic design or "earthquake-proofing"

India's high earthquake risk and vulnerability is evident from the fact.

Earthquake (Tsunami)

• The tsunami of fast waves in the ocean caused by powerful earthquakes. Is a very serious challenge for people´s safety and for earthquake engineering.

Tsunami 1.2.

• Those waves can inundate coastal areas destroy houses and even swipe away whole towns.

• Unfortunately, tsunami can not be prevented.

• However, there are warning systems which may warn the population before the big waves reach the land to let them enough time to rush and to safety.

The remolino formed after the tsunami of japan 2011.

Can we predict earthquakes?

• So far, earthquake prediction is highly contoversial as there is little or mutually acceptable evidence to link observable phenomena to subsequent seismicity. The frequent practice of publishing predictions after the fact. Scientists still a long way from

being able to predict when occur earthquakes.

The tectonic plates

• The tectonic plates is a scientific theory that describe the large-scale motions of earth´s lithosphere. The theory builds on the concepts of continental drift developed during the first decades of the 20th century.

Tectonic plates are composed of oceanic lithosphere and thicker continental lithosphere, each topped by its own kind of crust. Along convergent boundaries, subduction carries plates into the mantle; the material lost is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading.

Tectonic plates 1.2.• Tectonic plates are able to

move because the Earth's lithosphere has a higher strength and lower density than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Their movement is thought to be driven by a combination of the motion of seafloor away from the spreading ridge (due to variations in topography and density of the crust that result in differences in gravitational forces) and drag, downward suction, at the subduction zones.

Tectonic plates pushing together.

Types of tectonic plates

• These seven plates comprise the bulk of the seven continents and the Pacific Ocean. African Plate

• Antarctic Plate• Eurasian Plate• Indo-Australian Plate• North American Plate• Pacific Plate• South American Plate

Types of Plate Boundaries