Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Transcript of Volcanoes
A volcano is a weak spot in the crust where magma has to come to the surface.
What is a volcano?
Where are they located?
Hot spot volcanoes often lie in the middle of continental or oceanic plates far from any plate boundaries. They form almost like regular volcanoes but do not result from subduction.
How does magma begin?
Volcanoes are located at many different places but most volcanoes occur along plate boundaries. The most famous example is the Ring of Fire.
Another location where volcanoes take place is called a Hot Spot
A hot spot is an area where magma from deep within the mantle melts through the crust above it
Volcanoes occur at diverging plate boundaries where lava pours out of the cracks onto the ocean floor
Hot spot volcanoes
Many volcanoes form near the plate boundaries where oceanic crust returns to the mantle. Many volcanoes often occur on islands. The resulting volcanoes that create a string of islands is an island arc.
Volcanoes at converging
Inside a volcano
Lava begins as magma in the mantle. There magma forms in the asthenosphere which lies beneath the lithosphere under great pressure.
There are different type of eruptions, one of them is called a quiet eruption. Some quiet eruptions usually take place in places such as Mount Kilauea and have up built over hundreds of thousands of years ago.
A vent is the point on the surface where magma leaves the volcano's pipe.
Types of volcanic eruptions
A pipe is a narrow,almost vertical crack in the crust through which magma rises to the surface
Magma is extremely hot, molten material that contains dissolved gases including water vapor
Sometimes magma forces its way out of a volcano through a side vent.
As magma rises toward the surface, it forms a large underground pocket called a magma chamber
When magma pours out onto the earth's surface its then often called lava
Another type of eruption is called an explosive eruption. A explosive eruption has thick and sticky magma and erupts explosively.
Stages of a volcano
Most volcanoes do not erupt once they have already erupted. There are different names for volcanoes once they have erupted.
One of the names for a volcano is dormant. A dormant volcano is like a sleeping bear, not active. It is assumed to erupt again but not for a long time.
Another name for a volcano is an active volcano. An active volcano is one that shows signs that it will erupt in the near future.
Last but not least, the extinct volcano. An extinct volcano is a volcano that is unlikely to erupt again.
Volcanoes usually give short warnings before it erupts. Scientist use tilt meters and laser-ranging devices that detect the changes of elevation and tilt caused by magma moving underneath the ground.
Even though quiet eruptions and explosive eruptions cause different volcano hazards, they both cause lots of damage far from the craters rim. During a quiet eruption, lava pours from the volcano's vent setting fire and burying everything in it's path. With an explosive eruption the volcano can belch out hot burning clouds of volcanic gases causing people to have Asthma.
Soils from Lava and Ash
Over time lava breaks down into soil. As soil is formed, plants grow. People settle next to volcanoes because of the fertile soil.
Landforms from lava and ash
Volcanic Necks, Dikes, and Sills
Rocks and other materials from from lava create a variety of landforms including shield volcanoes, composite volcanoes, cinder cone volcanoes, lava plateaus, and calderas.
Shield volcanoes occur at some places on earth's surface with thin layers of lava pouring out of a vent and hardening on top of previous layers
Cinder Cone volcanoes
A volcanic neck forms when magma hardens in the volcano's pipe. The softer rock wears away then over time exposing harder rock. Magma forces itself across layers of rock that hardens into a dike when magma squeezes between layers of rock that forms a sill.
A cinder cone volcano is a steep, cone-shaped volcano or mountain. A cinder cone's lava is thick and stiff.
Sometimes lava flows alternate with explosive eruptions such as ash, cinder, and bombs. This is called a composite volcano.
A batholith is formed when a big piece of magma cools inside the crust. Over time rocks above batholiths wear away.
Some small bodies of magma can create dome mountains.Tthe magma forces layers of rock to form into a dome shape. Over time the rock above the dome mountain wears away, leaving it exposed.
Landforms from Magma
Sometimes magma reaches the surface, then cools and hardens into rock.
Some eruptions of lava form high. This is called Lava Plateaus.
A caldera is a huge hole left by the collapse of a volcanic mountain. The hole is filled with the pieces of the volcano that have fallen inward, as well as lava and ash.
When you look at a moon through a telescope you see that the moon is pockmarked with lighter color craters. The craters mark where meteorites have smashed into the moon over billions of years. The smooth areas are where lava flowed onto the moon's surface more than three billion years ago.
Volcanoes on Venus
One of the lava flows on Venus is 6,800 kilometers long. The largest volcano on Venus is called Theia Mons. Scientist are trying to find evidence to prove that volcanoes on Venus are still active.
Volcanoes on Mars
Volcanoes on Distant moons.
Volcanoes on space
On earth nitrogen is a gas, but Triton is so cold that most of the nitrogen is frozen solid. the heat from the sun melts the gas and they become so hot that it erupts through the icy crust.
Mars has a long history of volcanic activity. Although mars has fewer volcanoes then Venus and are only found in only a few regions of mars' surface, it has a variety of volcanic features. Mars' has large shield volcanoes similar to those on Venus and earth as well as cone-shaped volcanoes and lava flows. Mars' largest volcano is a shield volcano called olympics Mons.
Volcanic ash falling in Japan
Thanks for watching!!!!!
- Anastasia and Alexis <3