The Changing Earth🌏🌍🌎 Flashcards
What is an igneous rock and how is it formed? Give an example.
Rocks formed from cooling magma/lava.
Eg: Basalt, Obsidian, granite
What is a metamorphic rock? Give an example.
A sedimentary or igneous rock gone through additional heat/pressure.
Eg: Quartzite, marble, slate.
What is the Inner Core made out of? And what is the temperature?
Iron and nickel. It is a solid due to the immense pressure. It is roughly 7000C. It is 2400km thick.
What is the Outer Core made out of and how hot is it? What is its thickness?
It is made out of molten iron and nickel, it is mostly liquid and is roughly 4000-6000C. It is 2300km thick.
What is the mantle made up of? What is the temperature and what is the thickness?
Molten rock, 500-2000C is in a liquid state and s 2900km thick.
What is the Crust made out of and how thick is it?
It is made out of rocky material and is 40+km thick. It is a solid.
How do scientists know the different layers of the Earth and what state they are in?
Scientists use earthquakes which cause a seismic wave, these waves travel through the earth and get refracted or bent when it hits a new layer. We know the density because the speed of the waves change the denser the layer gets.
Name the three seismic waves.
- Primary (P wave)
- Secondary (S wave)
- Surface Waves
Name the characteristics of each seismic wave.
- P waves: Fast moving compression wave like a sound wave in air.
- S waves: Ripple like lateral movement of the ground, relative to the direction of travel. Slower than p waves
- Surface waves: while other waves go through the earth, surface waves do not.
What is an epicentre of an earthquake.
The start point of an earthquake.
Describe weathering.
Breaking up of rocks.
What is physical weathering
Tree roots, ice, wind, water, rain
Chemical weathering
Acid
Describe erosion.
Removal of weathered material.
What is an agent?
What causes rocks to be weathered and eroded
What is the difference between intrusive rocks and extrusive rocks?
Intrusive rocks formed under the earths crust
Extrusive rocks formed on top of the earths crust
How does this affect crystal sizes in rocks?
Intrusive rocks have larger crystals because the rock cools slower and giving more time for crystals to form.
Extrusive rocks cool quickly so crystals have less time to cool.
Give examples of intrusive and extrusive rocks
Intrusive: granite, diorite, slate
Extrusive: Basalt, obsidian, porphry
Why is coal and limestone named an organic rock?
Coal and limestone are made from living lifeforms.
What is a sedimentary rock and how is it formed? Give an example.
Rocks formed from sediments deposited by water, wind or ice. The sediments are cemented together in layers, under pressure.
Eg: Conglomerate, sandstone, siltstone
Describe lustre
How it reflects light from its cut surface. Might be described as dull,metallic, pearlescent or glassy.
Describe streak.
Is the colour and texture of the mark that the mineral leaves behind when its scratched across over a hard white surface.
What is the lithosphere?
Rigid outer part of the crust, consisting of the crust and upper mantle
