Physical and Ecological ProcessesPhysical and Ecological Processes

Plate TectonicsPlate Tectonics

The surface of the earth is constantly changing due to plate tectonics and erosion and weathering.

The surface of the earth looks like one continuous piece but it is actually broken into several large pieces that fit together like a jigsaw puzzle. Each piece is called a plate and when two plates come into contact it is called a plate boundary.

The surface of the earth is constantly changing due to plate tectonics and erosion and weathering.

The surface of the earth looks like one continuous piece but it is actually broken into several large pieces that fit together like a jigsaw puzzle. Each piece is called a plate and when two plates come into contact it is called a plate boundary.

Plate TectonicsPlate Tectonics

Plates touch each other in four basic ways:A. Divergent BoundariesB. Convergent SubductionC. Convergent CollisionD. Transform

Plates touch each other in four basic ways:A. Divergent BoundariesB. Convergent SubductionC. Convergent CollisionD. Transform

Divergent BoundariesDivergent Boundaries

Divergent boundaries are often located at deep sea trenches such as the Mid-Atlantic Trench. The plates pull apart and as they pull apart magma comes to the surface and makes new crust.

Divergent boundaries are often located at deep sea trenches such as the Mid-Atlantic Trench. The plates pull apart and as they pull apart magma comes to the surface and makes new crust.

Convergent SubductionConvergent Subduction

Convergent subduction is when two plates crash together and one plate is forced under the other one. This happens most often when oceanic plates collide with continental plates.

Convergent subduction is when two plates crash together and one plate is forced under the other one. This happens most often when oceanic plates collide with continental plates.

Convergent CollisionConvergent Collision

Convergent collision is when two plates crash together and they both rise into the area. This type of boundary often creates mountain ranges.

Convergent collision is when two plates crash together and they both rise into the area. This type of boundary often creates mountain ranges.

TransformTransform

A transform boundary is when two plates slide past each other, causing a fault or fracture in the crust. One example of a transform boundary is the San Andreas Fault in California.

A transform boundary is when two plates slide past each other, causing a fault or fracture in the crust. One example of a transform boundary is the San Andreas Fault in California.

Volcanoes Volcanoes

Earthquakes and volcanoes can occur anywhere on the surface of the earth, including underwater, but they are more common at plate boundaries.

Earthquakes and volcanoes can occur anywhere on the surface of the earth, including underwater, but they are more common at plate boundaries.

VolcanoesVolcanoes

Sometimes volcanoes occur far from plate boundaries. These areas are called hot spots. A good example of a hot spot is the formation of the Hawaiian Islands in the middle of the Pacific. Magma burned through the crust under the ocean and formed a group of islands.

Sometimes volcanoes occur far from plate boundaries. These areas are called hot spots. A good example of a hot spot is the formation of the Hawaiian Islands in the middle of the Pacific. Magma burned through the crust under the ocean and formed a group of islands.

VolcanoesVolcanoes

There is an are around the Pacific Ocean where many plates come together known as The Ring of Fire. This area has many active and dormant volcanoes and volcanic eruptions are frequent.

There is an are around the Pacific Ocean where many plates come together known as The Ring of Fire. This area has many active and dormant volcanoes and volcanic eruptions are frequent.

VolcanoesVolcanoes

Scientists cannot predict when volcanoes will erupt. Unfortunately, people usually live near volcanoes because volcanic ash is extremely fertile and good for farming.

Scientists cannot predict when volcanoes will erupt. Unfortunately, people usually live near volcanoes because volcanic ash is extremely fertile and good for farming.

EarthquakesEarthquakes

Earthquakes are more common at plate boundaries.

The center of an earthquake on the surface of the earth is called the epicenter.

A seismograph is a device that detects if an earthquake has occurred.

The Richter Scale is a scale used for measuring the intensity of an earthquake.

Earthquakes are more common at plate boundaries.

The center of an earthquake on the surface of the earth is called the epicenter.

A seismograph is a device that detects if an earthquake has occurred.

The Richter Scale is a scale used for measuring the intensity of an earthquake.

TsunamiTsunami

Tsunamis are giant waves caused by earthquakes or volcanic explosions. Usually, tsunamis come in series of waves and they can travel hundreds of miles an hour.

Tsunamis can be detected with an early warning system but not all countries have the money to install them.

Tsunamis are giant waves caused by earthquakes or volcanic explosions. Usually, tsunamis come in series of waves and they can travel hundreds of miles an hour.

Tsunamis can be detected with an early warning system but not all countries have the money to install them.

An early warning system in the Pacific Ocean.

TsunamiTsunami

See a tsunami here:

http://www.youtube.com/watch?v=w9ygYqj4rVM

See a tsunami here:

http://www.youtube.com/watch?v=w9ygYqj4rVM

Humans and EarthquakesHumans and Earthquakes

Humans can’t predict earthquakes but they can build better buildings that will withstand the effects of an earthquake.

Humans can also build early warning systems that will detect tsunamis and warn people farther away from the epicenter of the wave.

Humans can’t predict earthquakes but they can build better buildings that will withstand the effects of an earthquake.

Humans can also build early warning systems that will detect tsunamis and warn people farther away from the epicenter of the wave.

Erosion and WeatheringErosion and Weathering

The surface of the earth is also being formed by erosion and weathering.

Weathering breaks rocks into smaller pieces.

Erosion moves pieces of rock or dirt.

The surface of the earth is also being formed by erosion and weathering.

Weathering breaks rocks into smaller pieces.

Erosion moves pieces of rock or dirt.

WeatheringWeathering

There are two types of weathering; mechanical and chemical.

Mechanical weathering is caused by ice and vegetation. When water freezes in cracks of rocks it will slowly break the rock apart. The roots of trees and plants will slowly break apart rocks also.

Chemical weathering is a chemical reaction between water and certain types of rock such as limestone that usually makes caves.

There are two types of weathering; mechanical and chemical.

Mechanical weathering is caused by ice and vegetation. When water freezes in cracks of rocks it will slowly break the rock apart. The roots of trees and plants will slowly break apart rocks also.

Chemical weathering is a chemical reaction between water and certain types of rock such as limestone that usually makes caves.

ErosionErosion

After rocks have been broken into smaller pieces the debris is moved by erosion. The agents of erosion are:

After rocks have been broken into smaller pieces the debris is moved by erosion. The agents of erosion are:

A. Wind

B. Water

C. Ice

D. Gravity

ErosionErosion

Erosion has natural causes and human causes.

People can take steps to prevent erosion by using nets, covering exposed earth with straw, and replanting vegetation.

Erosion has natural causes and human causes.

People can take steps to prevent erosion by using nets, covering exposed earth with straw, and replanting vegetation.

FloodsFloods

Floods happen when there is too much rain and rivers overflow their banks. Floods are natural but as human population grows there are more people that live in areas that are frequently flooded.

People can try to prevent floods by building embankments or levees.

Floods happen when there is too much rain and rivers overflow their banks. Floods are natural but as human population grows there are more people that live in areas that are frequently flooded.

People can try to prevent floods by building embankments or levees.

FloodsFloods

Typically, areas that are low in elevation and near rivers or the mouth of rivers experience floods. A few areas that have floods are:

A. Along the Mississippi River in the U.S.B. BangladeshC. Parts of Eastern China

Typically, areas that are low in elevation and near rivers or the mouth of rivers experience floods. A few areas that have floods are:

A. Along the Mississippi River in the U.S.B. BangladeshC. Parts of Eastern China