Restless Earth Flashcards
Explain what happens at a Destructive Plate Margin-Subduction ?
Convection currents in the mantle cause the plates to move towards each other. The denser Oceanic crust sinks under the continental this is knows as subduction. The oceanic crust melts through the immense pressure to form magma. The collision causes earthquakes as magma rises up it breaks through the crust forming Volcanoes.
Explain what happens at Constructive Plate Margins?
Oceanic plates pulls away from each other, cracks form and the magma forces it’s way up once reaching the surface it forms a volcano, often under the ocean.
What Happens at Conservative Plate Margins?
Two plates slide past each other both at different speeds, this does cause them to get stuck eventually all the pressure built up causes a sudden release as the parts separate causing a slight earthquake. As nothing is majorly being damaged volcanoes do not form.
What happens at Destructive Collision plate Margins?
Two CONTINENTAL plates move towards each other and collide at that point both push upwards forming mountains by the crumbling crust.
What are the features of Oceanic Crust?
. Newer most less than 200 million years old
.Denser
.Can sink
.Can be renewed and destroyed
What are the features of Continental Crusts?
.Older most over 1500 million years old
.Less dense
.Cannot sink
. Cannot be renewed or destroyed
Describe the structure of the earth?
At the top it’s the crust, then the mantle then the outer core and the deepest component is the inner core
Describe some equipment than can be used to predict and monitor Volcanoes?
You could use Tiltmeters which measure even the slightest tilt of the earths surface these are helpful as they can be used as a warning for a potential earthquake. GPs satellites can also be used to measure slight changes and measure the two pints in a volcano it can also pick up temperature difference meaning it can be used to predict a volcanic eruption as this would be present if heat temperatures were rising. These tools can be used to order emergency aid supplies and evacuation can occur to keep people away from area.
Describe the shape and size of a super Volcanos?
It is flat but on a large scale and must emit 1000km3 of material during an eruption it is also has a caldera which is a gap formed from the magma chamber in the volcano collapsing.
What is the focus of an earthquake ?
The point in the earths crust where the earthquake begins underground.
What is the epicentre of an earthquake ?
The point on the earths surface directly above the focus where the earthquake occurs on the surface.
How are Richter scales used to measure earthquakes?
It measures the magnitude which is the strength of the earthquake and is measured logarithmically so numbers jump by 10 each time
How is the Mercalli scale used to measure earthquakes
It measures the impact of an earthquake through stages theses are recorded in Roman numerals .
