- Created by: ellieheritage
- Created on: 17-05-15 18:48
Can you explain the layered structure of the earth?
Crust- Oceanic and continental crust. They are both solid. Continental has a granite composition and the oceanic has a basalt composition. They have a temperature of up to 900 degrees cecius.
Mantle- This includes the astennosphere and the mantle. The mantle is made up of periodites. The astenosphere is partially molten and the mantle is solid. The mantle is made u of silica based materials. and the astenosphere goes from 900-1600 degrees celicus and the mantle goes from 1600-4000 dgrees celicus.
Core- The inner and outer core. The outer core is liquid and the inner core is solid. They are made up of an iron/nickel composition and are between 4000-5000 degrees celcius.
What are the differences between the oceanic and continental crust?
The continetnal crust is between 25-80km thick whereas the oceanic is only 6-8km thick. However, the oceanic is denser. With a density of 3.3 and the continental plate with a density of 2.7.
Can you explain how the earths core generates heat through radioactive decay and convection currents?
Radioactive decay- the core of the earth has unstable atoms and as a result relases heat. This heat released warms up the surrounding magma and as it is warmed up it becomes more dense. More dense materials rise up to less dense areas. As they rise the magma plumes and cools as it is now in a less dense area. However, wants to then fall back down to the more dense area but falls to the sides as more magma is rising in the middle. This is a recurring cycle and continues to heat the centre of the earth.
Can you explain how the earth creates a magnetic field?
What is a tectonic plate?
Can you name and draw a conservative plate boundary, destructive plate boundary, a collision plate boundary and a constructive plate boundary?
A conservative plate bounary is where two plates rub against eachother. This creates friction and as a result; earthquales occur here. No volcanoes as no material has been melted or broken through any cracks. For example; St Andreas Fault, California.
A destructive plate boundary is when the oceanic plate subducts under the cotinental plate as it is denser. This melts materials in the upper mantle and magma escapes through the cracks creates from the force of subbduction. As a result, volcanoes, earthquakes and new islands can form. For example; The Andes mounatins.
A collision plate boundary is when two plates crumple against eachother. This causes eathquakes and occasinaly a volcano. For example; Himalayan mountains.
A constructive plate boundary is when two plates are forced apart due to new balastic material rising to the surface as magma is rising and pluimg between them as the convection currents is causing the magma to heat and…