Volcanoes Flashcards
Why do volcanoes in general happen/form?
Tectonic plates in the Earths crust shift
What is the outer core?
A liquid layer of iron and nickel that’s extremely hot with temperatures similar to the inner core
What is the inner core?
The centre of the earth with the hottest part being solid. It’s made of iron and nickel with temperatures at 5500 degrees. It has immense heat energy and is the engine room of the earth
What is the continental crust?
The older and light crust that’s permanent and can’t sink. It carries the land made mainly of granite and is up to 70km thick
What is the oceanic crust?
The younger and heavier crust that can sink and is constantly being destroyed and replaced. It carries oceans and is mainly made of basalt rock. It’s between 6-10km thick with the deepest point at 1200 degrees
What is the mantle?
A semi-molten layer up to 2000 degrees being the thickest layer. It’s high temperature from the core makes convention currents which crust moves upon. It has silicate rocks which are rich in iron and magnesium
What is the crust?
The thin outer layer being 6-10km thick. There are 2 types; continental and oceanic and it’s solid rock on which we live made up of pieces called plates
Why does crust move?
Conventional currents cause semi-molten material to rise through the layers as it’s less dense and sink when it gets too far away from the heat source as it’s more dense. It pushes the plates out to the sides moving the crust and continents
What happens at constructive plate boundaries?
Plates separate from each other (diverge) and magma rises as a thin material. It smoothed over making a gentle volcano and can cause uncommon earthquakes. E.g mid Atlantic ridge
What happens at destructive plate boundaries?
Continental and oceanic plates converge together with the oceanic forces under as its denser melting due to friction. Friction can cause earthquakes/fold mountains at the subduction zone. Thick magma rises explosively because of pressure build up
What happens at conservative plate boundaries?
One plate moves faster than the other and friction causes them to slide together causing earthquakes. The epicentre causes shockwaves and the focus is where the release of pressure occurs. E.g San Andreas fault
How can monitoring prevent extra damage?
Remote sensing; satellites detect heat and changes to the volcano’s shape. Ground deformation; measure the volcano’s shape change with laser beams
Can you predict volcanic eruptions?
Yes
How can protection stop extra damage being caused?
Sloped roofs to prevent collapsing from ash buildup. Use explosives to re-direct the flow of lava away from civilisation
