Tectonic Plates Flashcards
(31 cards)
When two tectonic plates are moving away from eachpther what plate boundry is that? e.g <———->
Divergent plate boundry
What is the crust?
Thinnest layer, 5-70Km, thinner under ocean than land, coldest layer, solid rock brockwn up into peices called tectonic plates
What is the mantle?
Thickest layer, moves in slow big circles caused by convectional currents, aprrox 1000°C near crust and 3700°C near core, semi molten
What is the outer core?
Semi liquid iron, temp between 3700° and 5000°C
What is inner core?
Most inner part of earth, aprrox 1250km, hottest part of earth- temp over 5000°C, material very dense, rock solid
What is Wegners theory?
Continents fit togther like a puzzle, believed continents used to be connected and called PANGAE, 200million years ago. Shifted away because of continental drfit
What is the plate tectonic theory about convection currents?
Movements of volcanic rock in mantle rises to crust and sinks. As repeats scientists believe powerful enough to move earths plates
When one tectonic plate slips under another one what is this called and what type of plate boundry is it?
This is called convergent plate boundry. The less dense continental plate moves towards denser oceanic plate and forced below this is called subduction. Subduction zone where earthquakes occur
What is a conservative plate boundry?
Plates slide past eachother. Plates rub rock breakes causing earthquakes
What is epicentre?
Point on ground above where an earthquake happens
What is the fault line?
Line on earths surface that traces a geological fault
What is stress and release?
Pressure builds up between two plateson fault line. Too much pressure is released
What is primary shockwave?
Travel fowards, backwards and move quickly
What are secondary shockwaves?
Slower and move sideways and up and down
What is the richter scale?
Measures magnitude
What is the mercalli scale?
Measures intenisy, visually
What is richter scale measures in?
1-10
What is the mercalli scale measured in?
1-12 in roman numerals
How are volcanous and earthquakes formed?
By tectonic plates making large amount of pressure and it being released causing an earthquake. Volcanous are formed by lava seeping through cracks in earths surface
what are convection currents and why are they important?
In mantle, lava/magma rises and it is able to go through the crust and find an entrance through the crust and make a volcano and an eruption.
What happens at convergent boundries?
At Convergent boundries the curst is destroyed as one plate lives under another
What happens at divergent boundries?
Where new crust is generated as the plates pull away from eachother?
What happens at conservative plate boundries?
The crust is neither produced nor destroyed as the plates slide horizontally past eachother
Primary impacts from Haiti earthquakes?
220,000 people killed, 2million Haitians left without food and water, Hospitals and goverment buildings destroyed,100,000 houses destroyed, 4,000 inmates escaped prison1.3mill homeless