Connor Schloffman

Aj Mcoy

Brandon John Charles

Unit 3

How do earthquakes affect the earth?

An earthquake is defined as a vibration of the earth’s surface that occurs after a release of energy in the earth’s crust.

Crust described as the top layer of the earth made up of continental and oceanic crust

The epicenter is the point directly above the focus or source of the earthquake

What is an earthquake??

When earthquakes appear they are recorded with a special l machine called a seismograph

A seismograph is an instrument that plots the intensity of earthquake waves on a roll of specially marked graph paper.

How earthquakes are recorded??

The Richter magnitude scale (often shortened to Richter scale) was developed to assign a single number to quantify the energy that is released during an earthquake.

The scale is a base-10 logarithmic scale. The magnitude is defined as the logarithm of the ratio of the amplitude of waves measured by a seismograph to an arbitrary small amplitude. An earthquake that measures 5.0 on the Richter scale has a shaking amplitude 10 times larger than one that measures 4.0, and corresponds to a 31.6 times larger release of energy

How earthquakes are recorded cont..

Charles Richter

http://www.youtube.com/watch?v=1qbg7orb1lc

Video

Earthquakes are know for their destructive power and damaging effects. They can destroy buildings and roads as well as cause a lot of problems wherever they appear

Earthquake range from intensity from a seismograph.

The highest recorded earthquake was a 9.5 in chile on may 22 1960

The indonesian earthquake of dec 26 slightly changed the earth’s shape and quicked earth’s rotation

Impact of earthquakes

How Can Plate Tectonics Depict The Future Of Mankind?

Plate Tectonics is the theory used to explain the structure of the Earth’s crust or “Sima”and many of the associated phenomena.. The rigid lithosphere is split into 7 major ‘plates’ that slowly move on top of the underlying asthenosphere (mantle). This branch of geology studies the faulting and folding of the crust along the various boundaries; convergent, divergent, subduction, and conservative.

Mankind has long dreamed of a way to predict earthquakes and escape their terrible power. Scientists and amateurs alike have tried to link quakes to phenomena as diverse as animal behavior, tides, weather, the movements of the planets, the rise and fall of water in wells, even to psychic visions. Unfortunately, none of these factors can be linked consistently enough with earthquakes to provide a useful forecasting tool.

For now, the most reliable clues to future quakes are the patterns of past earth movements. These allow geologists to suggest where earthquakes are most likely to strike. Areas most at risk of earthquakes can develop and implement strategies to minimize harm to people and property when the inevitable occurs. Geologists are still seeking a way to predict exactly when a quake will happen, so that people can be evacuated and valuable or dangerous substances can be secured.

The concept of Plate Tectonics was first coined by the German geophysicist Alfred Wegener back in 1915, but several ideas of continental drift date back many years before. Today we almost take for granted our knowledge of how the Earth’s crust shifts and regenerates on a continual cycle; but the theory of plate tectonics wasn’t widely accepted until the 1960s.

Even though there has not yet been a way to predict when exactly a earthquake will happen, humans have made houses and buildings with new technology that almost makes them indestructible.

http://www.sciencechannel.com/tv-shows/strip-the-city/videos/tectonic-time-bomb.htm

Video

How were the Oceans formed????

The surface of the earth developed 4,600 million years ago

When earths crust solidified oceans were able to form for the first time

As we know today the earth is mostly covered by the oceans

Early earth

So where did all the water come from?Scientist believe that water came from one of

two sourcesFirst source was steam and other gases

vented out from the earths mantel over millions of years

Second source is believed to be extraterrestrial, its said that 5 to 30 icy comets vaporizing in the atmosphere adding water

Early Ocean

When two plates meet at a convergent boundary one plate is subducted under another and creates trenches

The area that these collisions occur are called subduction zones these areas are at a greater risk for volcanoes and earthquakes

Some subduction zones can create a chain of islands created by under sea volcanoes

Shifting Surface

Hotspots are under sea volcanoes, that form when a powerful plume of magma pushes up through the mantel and breaks through the crust

This is how some island chains are formed such as the Hawaiian Islands

Hydrothermal vents are springs of super heated mineral rich found in ocean ridges

Hot Spots

Earths surface is made up of plates moved by forces deep within earths core

German meteorologist Alfred Wegener suggested in 1912 that plates just slowly moved over time

This was further explained further by American geophysicist Harry Hess

Hess said magma boils inside the earth comes out of the mid ocean ridges

Spreading Seas

The magma cools and is pushed down by more magma and the accumulation of the cooled magma created the ocean floor

The ocean floor moved continents and widened the ocean basins

When a ocean plate and a continental plate meet usually the ocean plate subducts under continental plate and creates volcanoes, earthquakes and trenches

Spreading Seas cont.

http://www.youtube.com/watch?v=hwVU0-2Qnso

Video

THANKS FOR LISTENING