Unit 3: Earth

StructuresBy Table 4

How old is the Earth? Scientists believe the Earth is about 4,600

million years old because that’s the age of the oldest rocks ever to be found

There’s also some layers with a crystalline core. The crystalline core is a called a kraton

They look a lot like geodes

How are the layers of the Earth formed?

Layers of rocks are formed when sediment is laid down on top of each other

Then gravitational compression, the energy of impacting bodies, and radiation will partially melt them together

When this happens, the densest material will sink toward Earth's center, while the less dense stuff will rise up to the top

*Sediment is rock formed from consolidated clay

Another way… A change in tectonic plate (A scientific

theory that describes the large-scale motions of Earth's lithosphere) motion can cause those sedimentary layers to be brought up so we can see them today

FUN FACT

This isn’t photoshopped. These are the Rainbow Mountains

In China's Danxia Landform

Don’t believe me? Google it

ONE MORE WAY! When volcanoes erupt, the lava that

comes out can spread across broad areas, forming a layer of igneous rock

within the sedimentary layers. The mantle is the layer that lies directly

under the crust. It’s the thickest layer and it’s super hot

FUN FACT

Did you know that the Earth’s core temperature is about 7000 degrees Celsius?

Video http://youtube.com/watch?

v=Q9j1xGaxYzY

Speaking of Volcanoes… What is it exactly?

A volcano is a mountain or hill, typically conical, having a crater or vent through which lava, rock fragments, hot vapor, and gas are being or have been erupted from the earth's crust. There are 3 types of volcanos; Shield, Cinder, and Composite.

Types of Volcanoes

Where can you find a volcano?

Volcanoes are on just about every continent. The area with the most concentration of volcanoes is know as the Ring of Fire. The ring of fire is the border of the Pacific plate (pacific ocean)

How does a volcano work? Active volcanoes are volcanoes that are

erupting or showing signs of activity. When pressure builds up, eruptions occur. Gases and rock shoot up through the opening and spill over or fill the air with lava fragments. Lava is molten rock or magma that is on the earths surface.

Largest Volcanoes 1. Mount Mazama/Crater Lake, Oregon-Over

6,000 ago Mount Mazama erupted. Before the explosion the mountain was 12,000 feet high.

2. Mount Etna, Sicily-Although Mount Etna the highest active volcano in Europe

3. Mount Vesuvius, Italy-Vesuvius' eruption in 79 A.D Vesuvius covered the cities of Pompeii and Herculaneum, preserving them for generations to come.

In what ways do volcanoes reconstruct the environment?

Volcanoes change the environment a lot. The lava can add land to earth. If

the eruption is explosive it can destroy the land. The gasses add the green

house gasses which contribute to global warming.

A video about Volcanoes http://www.youtube.com/watch?v=BcFtp

WjZwlE

Erosion can also reconstruct the Earth’s surface

What is erosion? Erosion is the wearing away of the land by

forces such as water, wind, and ice. Erosion has helped to form many interesting features of the Earth's surface including mountain peaks, valleys, and coastlines.

What causes erosion? There are many different forces in nature

that cause erosion. Depending on the type of force, erosion can happen quickly or take thousands of years. The three main forces that cause erosion are water, wind, and ice.

Erosion by Water Water is the main

cause of erosion on Earth. Although water may not seem powerful at first, it is one of the most powerful forces on the planet.

Here are some of the ways that water causes erosion

• Rainfall - Rainfall can cause erosion both when the rain hits the surface of the Earth, called splash erosion, and when raindrops accumulate and flow like small streams

• Rivers - Rivers can create a significant amount of erosion over time. They break up particles along the river bottom and carry them downstream. One example of river erosion is the Grand Canyon which was formed by the Colorado River.

• Waves – Ocean waves can cause the coastline to erode. The shear energy and force of the waves causes pieces of rock and coastline to break off changing the coastline over time.

• Floods - Large floods can cause erosion to happen very quickly acting like powerful rivers.

Erosion by wind and glaciers

Wind

Wind is a major type of erosion, especially in dry areas. Wind can erode by picking up and carrying loose particles and dust away (called deflation). It can also erode when these flying particles strike the land and break off more particles (called abrasion).

Glaciers

Glaciers are giant rivers of ice that slowly move carving out valleys and shaping mountains.

Random Facts about Erosion The word erosion comes from

the Latin word "erosionem" which means "a gnawing away."

Scientists estimate that the Colorado River has been eroding the Grand Canyon for many millions of years.

Wind erosion can cause huge dust storms.

The fastest glacier ever moved over seven miles in three months.

Fossils in sedimentary rock are often uncovered by erosion.

Video http://www.youtube.com/watch?

v=R48zYr-S7v0

That’s all great but what would happen if the Earth equilibrium messed up?

First we need to know what equilibrium is…

Equilibrium is the state of which systems are in balance.

Planetary Equilibrium Temperature

Planetary equilibrium- Theoretical temperature that the planet would be at when considered simply as if it were a black body being heated only by its parent star.

The presence or absence of an atmosphere (and therefore any greenhouse effect) is not considered, and one treats the theoretical black body temperature as if it came from an idealized surface of the planet

Hydrostatic Equilibrium A fluid is said to be in hydrostatic

equilibrium when it is at rest, or when the flow velocity at each point is constant over time.

This occurs when external forces such as gravity are balanced by a pressure gradient force. For instance, the pressure gradient force prevents gravity from collapsing the Earth's atmosphere into a thin, dense shell, while gravity prevents the pressure gradient force from diffusing the atmosphere into space.

Radiative Equilibrium The condition where a steady state system

is in dynamic equilibrium, with equal incoming and outgoing radiative heat flux and negligible heat transfer by conduction and convection

The net change in the tropopause after temperatures readjust to radiative equilibrium in the stratosphere, is used to determine the radiative forcing, as part of an assessment of natural and anthropogenic climate change

What is the atmosphere composed of?

The common name given to the atmospheric gases used in breathing and photosynthesis is air. By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other trace gases.

How do large bodies of water form?

Large bodies can form in many ways

They can form during earthquakes, rainfall, melting ice, condensation, evaporation man-made structures and volcanoes

Large bodies of water formed by earthquakes

A river can be formed when an earthquake splits the tectonic plates in a subduction zone the resulting gap was filled with water

Large bodies of water formed by rainfall Craters made by volcanoes or

meteorites could be filled over time with massive amounts of rain

Large body of water formed by ice

The great lakes were carved out of the earth by ice during the last ice age and has since then filled up either from melting ice or rainfall

Large bodies of water formed by evaporation/condensation Hurricanes get there strength from

heated ocean water that evaporates it then drops all of the water

Large bodies of water that are man-made

Lake Powell is the second largest man-made body of water

Large bodies of water formed by Volcanoes

Volcanoes can form large bodies of water either by exploding and leaving a caldera or by erupting and cutting off a river, thereby creating a lake or an island with a lake or river