terra firma plate interactions. earth’s interior crust under the oceans - basalt (more dense)...
TRANSCRIPT
TERRA FIRMA Plate interactions
EARTH’S INTERIOR
• crust under the oceans - basalt (more dense)
• crust under the continents - granite (less dense)
• mantle comprises 80% of the earth's volume
• outer core is liquid
• inner core is solid
• lithosphere - rigid blocks of the crust and upper portion of the upper mantle, also known as the plates, there are 10ish major plates
• asthenosphere - mixture of solid and molten (plastic-like) rock zone just below the lithosphere, allows the plates to slide
There are 3 types of plate boundaries: divergent, convergent and transform faults
divergent boundary- plates move away from each other and create new crustal material
this occurs in the oceans, exception is the Great Rift Valley in eastern Africa
rift zone is created as magma comes up from the mantle
magma creates volcanoes known as ridges, example mid-atlantic ridge
Earthquakes occur
Convergent boundary- plates collide,
3 possibilities due to the type of plate material
2 ocean plates (basalt) both plates will
descend into the mantle destroying
crustal material creating a subduction zone
subduction zones have trenches and as the plate is pushed into the mantle the plate melts and rises to create volcanoes
these volcanoes will form on the ocean floor and with time can extend to above sea level
these volcanic islands are referred to as an island arc
Examples- Japan, Mt Pinatubo
Earthquakes occcur
1 ocean plate (basalt) 1 continental
plate (granite) converge- the ocean
plate will descend into the mantle
destroying crustal material
creating a subduction zone
all subduction zones have trenches
and as the plate is pushed into
the mantle the plate melts and rises to create volcanoes
volcanoes will form on the edge of the continent these volcanic mountains are referred to as a volcanic arc
Examples- Andes, Mt St Helens
Earthquakes occur
2 continental plates (granite) converge- neither descends into the mantle
folded mountains
Examples- Himalayas, Alps
Earthquakes occur
transform faults- 2 plates slide past each other horizontally
Earthquakes occur, no mountains are created
example- San Andreas fault