Flashcards in Exam Deck (31):
What are convection currents?
Movements within the Earth’s mantle caused by the heat of the core. The heat rises up from the core to the crust where it cools down.
What happens on a destructive plate boundary?
Destructive plate boundaries occur when a continental and oceanic crust move together. The oceanic crust moves underneath the continental because it is much denser.
What happens on a conservative plate boundary?
When two continental plates move in the same direction at different speeds.
What happens on a collision zone?
Collision plate boundaries occur when two continental plates collide. Neither plate goes underneath the other, but are forced up and eventually form fold mountains.
What happens on a constructive plate boundary?
Constructive plate boundaries occur when two continental plates move away from each other. Then magma wells up to fill the gap, eventually new crust is formed.
What is a HIC?
A country that can afford technology to help to prevent natural disasters from damaging architecture, infrastructure etc.
What is a LIC?
A country that can not afford to buy technology to prevent natural disasters from destroying their country.
What are the four layers of the Earth?
Inner core, outer core, mantle and the crust.
What is the inner core made of?
The inner core is made mostly of iron and nickel.
What is the Richter scale?
A scale that measure the strength or magnitude of an earthquake. The Richter scale is numbered 0-10 (ten being the most destructive).
What is a seismometer?
A seismometer detects the vibrations caused by an earthquake.
What is the Asthenosphere?
The asthenosphere is the layer of the Earth that lies below the lithosphere. It is a layer of solid rock that has so much pressure and heat the rocks can flow like a liquid.
What is the Lithosphere?
Lithosphere, Rigid, rocky outer layer of the Earth, consisting of the crust and the solid outermost layer of the upper mantle.
What was Pangea?
When all the continents were together as a super continent.
What happens when tectonic plates break free?
They cause a volcanic eruption or an earthquake.
Which are the plates that are moving together?
Nazca and South America, Eurasian and Pacific
What are vents?
The openings through which lava flows from a volcano.
Molten rock from deep within the Earth.
What is lava?
Molten magma when it erupts at the surface.
The hollow at the mouth of the volcano
Hot avalanche of gas, ash, cinders and rocks that rush down the slopes of a volcano after an explosive eruption.
Define Lahar (mud flow):
Water mixed with volcanic ash.
What are the two types of volcanoes?
Composite and Shield volcanoes.
Give three descriptors of a composite volcano:
- Are very explosive.
- Have a narrow base.
- Contain sticky magma with lots of silica in it.
Give three descriptors of a shield volcano:
- Have a wide base.
- Contain more runny lava (with less silica in it).
- Erupt more gently.
How does lava shape composite volcanoes?
The sticky lava hardens and forms the steep-sided shape of a composite volcano.
How does lava shape shield volcanoes?
The runny lava spreads out and hardens to make the gentle slopes of a shield volcano.
Name three of the effects of the Icelandic volcano:
- Prospects of flooding.
- The wind took the ash south and east of Europe which led to flights being cancelled.
- Ash killed farmers’ crops.
How did Iceland respond to the volcano?
-They created a tourism industry.
- Created evacuation instructions.
- Built houses with much more solid materials.
Name three effects of the Icelandic volcano:
Tourism rapidly increased.
The ash made the soil much more fertile meaning farmers could produce higher quality crops.
Precious metals rose to the surface of the Earth, such as diamonds which people could mine and sell to earn money.