Revise morning of Flashcards
What is the core
consists of iron and nickel
Temperature =6,200 degreed Celsius
Inner core is soldi 1,250 km thick
Outer core is semi molten , 2,200 km thick
What is the mantle
consists of silicate rocks, rich in magnesium, making up 84%
of earths volume
2,900km thick
temperatures of 1000 degrees c near crust, 4000 degrees c
near core
Semi Molten
What is the crust
Thin outer layer of the Earth consist of
- Oceanic crust, 6-10km thick, made of basaltic rock such as
silica and magnesium created into sima
- Continental crust, 70 km thick made of granite rock made up
of silica and alumni created into sail
What is the lithosphere
The lithosphere is the rigid outer layer of the Earth consisting of the crust and soil outer most layer of the upper mantle
What is the asthenosphere
A layer between the upper and mantle and the lithosphere
What are the different plate margins
Converging/diverging plate margins
diverging/constructive plate margins
conservative plate margins
What is the converging plate margin
Where plates move towards each other, for example off the west of South America
What is the diverging plate margin
Where plates move apart from each other, for example in Iceland
What are conservative plate margins
Where plates move alongside each other in opposite directions , or the same direction at different speeds, for example the San Andreas Fault in California
What is slab pull
At many convergent plate boundaries one plate is denser than the other this plate subducts beneath the other (less dense plate) The subducting plate is colder and heavier and therefore continuous to sink pulling the rest of the plate with it
What is ridge push
Where magma rising from the core can escape through weaknesses in the earths crust creating ridges or oceanic mounds to form
What are the negatives of measuring volcanic activity
it is still not possible to accurately predict when an eruption will occur or how long it will be
How can scientists measure to predict for volcanic eruptions
Its easier and more reliable to predict volcanoes compared to earthquakes because scientists can measure changes in gas emissions, ground deformation, hydrology, temperature changes and seismic activity
What is the seismic gap theory
Overtime all parts of a fault must average the same level of movement, a large seismic gap can indicate a earthquake is imminent, however there is still no definite proven way to predict earthquakes
Predicting tectonic hazards
If predicted wrong, people may ignore warnings
if predicted correctly loss can be minimised
