Earthquakes
WHat is an Earthquake?
The shaking and trembling that results from the movement of rock beneath the Earth's surface
What was wegener's theory about the continents?
They were once all together as one supercontinent called Pangea
What are the Tectonic plates?
A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of continental and oceanic crust.
What is a Fault?
Breaks in Earth's crust where rocks have slipped past each other.
What is a Volcano?
Mountain that forms in Earth's crust when molten material, or magma reaches the surface.
What are seismic waves?
Vibration similar to sound waves. They travel through Earth carrying energy released by an earthquake.
WHat are the 3 types of faults?
Normal, Reverse and Strike slip
What happens in reverse faults?
In reverse faults is the same structure as the normal but the blocks move in reverse direction
What happens in Strike-slip faults?
In Strike-slip The rocks on eaither side of the rock slip past each other sideways, with little up and down motion.
WHat are the parts inside a Volcano?
Magma chamber, pipe, vent, lava flow and crater
Explain the 3 types of waves?
P waves(Compress and expand the ground), S waves (vibrate from side to side) and Surface waves (slower that P and S waves but they can cause severe damage)
Explain what happens when Tension occur (stress)
Two plates pull apart
Explain when does compression happen?
When two plates come together
Explain what happens when Shearing occur (stress)
plates slip past each other
Explain the three ways in whick a Volcano can form:
By converging and diverging boundries and by hotspots
What does the mercalli scale measures?
rates the amount of shaking from an Earthquake
What happens in divergent boundries:
plates move apart
What happens in convergent boundries:
Plates come together
What happens in tranfrom boundries:
Plates slip-past each other
What happens in a volcaninc eruption?
The force of the expanding gases pushes magma chanmber throught the pipe until it flows or explodes out of the vent.
What does the Richter scale measures?
The magnitude of Earthquakes
What is sea- floor spreading?
the formation of new areas of oceanic crust
How do Mid-Ocean Ridges form?
formation of long chains of mountains that rise up from the ocean floor
What does the Theory of Plate Tectonics state
Earth's plates are in slow, constant motion, driven by convection currents in the mantle.
Explain the two types of volcaninc eruptions?
In quiet eruption magma is hot and low in silica and in an Explosive magma is high in silica