Volcanic landforms introduction Flashcards
Define volcanology
Volcanology is a term used to describe “all the processes by which solid, liquid or gaseous materials are forced into the earth’s crust or ejected onto the surface.” (An Integrated approach)
Why are there so many different outcomes?
There are numerous different variations of the characteristics of these processes which consequently means there are numerous different outcomes in terms of very much contrastingly landscapes produced.
Why is magma semi solid?
Material in the mantle has a high temperature, however it is kept in a semi solid state because of the enormous pressure exerted on it.
How does magma reach the surface?
If this pressure is released by plate boundary movement, some of the semi solid material becomes molten and rises, forcing its way into weakness in the crust, or onto the surface where it cools crystallises and solidifies.
Magma vs lava?
Molten rock is called magma below the surface and lava above the surface.
Extrusive
Extrusive formed from magma which has solidified on the earth’s surface e.g. the Giant’s Causeway in N. Ireland
Intrusive
Intrusive produced when magma solidifies within the earth’s crust i.e underground, e.g. the Sill at Drumadoon, Arran. (you can seen them on the surface but they were formed underground).
Both intrusive and extrusive produces…?
Hard, igneous rock.