Open your binder to the notes section. Prepare Open your binder to the notes section. Prepare to take notes. Head your notes and copy the to take notes. Head your notes and copy the

standard below.standard below.

S6E5e- Explain the effects of physical processes S6E5e- Explain the effects of physical processes (such as(such as plate tectonicsplate tectonics, erosion, deposition,, erosion, deposition,

volcanic eruptionsvolcanic eruptions, gravity) on geological features., gravity) on geological features.

Three Types of VolcanoesThree Types of Volcanoes• Shield Volcano

– Wide, gently sloping mountain– Layers of lava pour from the vent and harden on

top of a previous layer

• Cinder Cone Volcano– Steep (high), cone-shaped hill or small mountain

• Composite Volcano– Lava alternate with explosive eruptions of ash,

cinder, and bombs.– Tall, cone-shaped mountains in which layers of

lava alternate with layers of ash

3 Types of Volcanoes3 Types of Volcanoes• Shield Volcano

– Built out of layers of runny lava– Gently sloping sides

3 Types of Volcanoes3 Types of Volcanoes• Cinder Cone Volcano

– made of layers of pyroclastic material– Erode quickly

3 Types of Volcanoes3 Types of Volcanoes• Composite Volcano

– Sometimes called a stratovolcano– Forms from pyroclastic material and pouring lava– Steep sides

Below are cross-sections of each of the different kinds of volcanoes.

                                                   

cinder cone volcano

                                          

composite or stratovolcano

                                                                                                                                                                              

  shield volcano

EFFECTS OF VOLCANIC EFFECTS OF VOLCANIC ERUPTIONS ON THE EARTHERUPTIONS ON THE EARTH

VOLCANIC HAZARDS TO THE EARTH

                                                                                                                                                                       

GEOLOGICAL CHANGES TO THE EARTH

Craters and Calderas

                                                                                                         

When a volcano explodes, much of the rocks and debris are blown from the top of the volcano. This is called a crater. If a great deal is blown off and the magma chamber below the volcano empties itself of all its magma, then the top of the volcano caves in on itself and the earth all around the volcano sinks. This is how calderas are created.

LAVA PLATEAU

lava plateau is a geological landform that is created when large amounts of runny lava leak from large cracks in the earth called fissures. The lava may run and spread evenly over large areas of land to create a unique look. Two examples of lava plateaus in the United States are Lassen National Park in California, and the Columbia River Plateau in Washington.

VolcanoesVolcanoes• A volcano is a weak spot in the crust where

molten material, or magma, comes to the surface– The crust is fractured (broken), allowing magma to

reach the surface

• Magma is a molten mixture of gases and water from the mantle

• The Ring of Fire formed by volcanoes and earthquakes around the rim of the Pacific Ocean

• Most volcanoes are found along plate boundaries• A hot spot is an area material rises from deep

within the mantle and melts to form magma; volcanoes form above the hot spot

Ring of FireRing of Fire

Kinds of EruptionsKinds of Eruptions• There are two kinds of eruptions:

1. Explosive 2. NonexplosiveExplosive• Explosive eruptions break lava into fragments (pieces)• Gases and pressure build up until they explode• The magma has a high silica content (silica is made up

of silicon and oxygen)• Pyroclastic flow- explosive eruption throws hot gases,

ash, cinders and bombs

Nonexplosive• Volcano erupts quietly and oozes out• The magma has a low amount of silica

EruptionsEruptions

• Explosive– Pyroclastic material

• Nonexplosive– Flowing lava

Inside A VolcanoInside A Volcano• Magma chamber- magma collects

• Pipe- magma move up through this channel

• Vent- magma and gas move up through an opening

• Lava flow- area covered by lava as it pours out of a vent

• Crater- bowl-shaped area that may form at the top of a volcano around the central vent

• A caldera is a huge hole left by the collapse (fall) of a volcanic mountain– Pieces of the volcano fall inward

Cinder Cone & Volcanic BombsCinder Cone & Volcanic Bombs

Volcanic NeckVolcanic Neck

History• The first thing scientists do is determine a volcano's

eruption history. A volcano is classified as active, dormant or extinct based upon when it has last erupted.

• Active volcanoes are in the process of erupting or show signs of eruption in the very near future.

• Dormant volcanoes are "sleeping." This means they are not erupting at this time, but they have erupted in recorded history.

• An extinct volcano has not erupted in recorded history and probably will never erupt again.

• Tiltmeter• Scientists also have an instrument that they

attach to the side of volcanoes. It is called a tiltmeter. A tiltmeter will detect small changes in the slope of a volcano because as a volcano is about to erupt, the earth may bulge or swell up a bit.

• Gas Emissions • Another thing scientists look for is the amount

and types of gasses that are emitted from a volcano. When a volcano is close to erupting, the gasses become more pronounced. There is a slight problem with depending upon only gas emissions to predict eruptions, however. Sometimes lava will leak up through the top of a volcano and harden quickly.

Review QuestionsReview Questions

1. What is a volcano?

2. What is occurring at the Pacific Ring of Fire?

3. What is a hot spot?

4. What feature forms at a hot spot?

5. Explain the difference between an explosive and nonexplosive eruption.

Review QuestionsReview Questions1. What is a volcano?A volcano is a weak spot in the crust where molten (hot, melted)

material or magma comes to the surface.2. What is occurring at the Pacific Ring of Fire?Volcanoes, mountain ranges and earthquakes are forming along

plate boundaries.3. What feature forms at a hot spot?Volcanoes form above hot spots.4. What is a hot spot?A hot spot is an area where magma rises.5. Explain the difference between an explosive and

nonexplosive eruption.Gases and pressure cause lava to break into fragments and

pyroclastic material to be thrown from the volcano during an explosive eruption. Lava oozes out slowly and more quietly during a nonexplosive eruption.

• www.cuca.k12.ca.us/rcms/smith/volcano/erupt.htm

Review QuestionsReview Questions1. What is a volcano?A volcano is a weak spot in the crust where molten (hot,

melted) material or magma comes to the surface.2. Where are most volcanoes located?Most volcanoes are found along plate boundaries.3. What causes volcanoes to form at a divergent

boundary?The plates separate and magma pushes up to the

surface. The magma cools and hardens. Over time a volcano forms.

4. What is a hot spot?A hot spot is an area where magma rises.5. What feature forms at a hot spot?Volcanoes form above hot spots.

Energy Inside EarthEnergy Inside Earth1. In a hot spring, hot water and (rocks, gases)

escape from the ground.

2. In a geyser, the hot water and steam (shoot, flow) out of the ground.

3. Geothermal energy can be used to heat home and to produce (noise, electricity).

4. Hot springs are sources of (solar, geothermal) energy.