Earth Science Test 2: Plate Tectonics

What are the 3 major layers of earth?

crust, mantle and core

who proposed the theory of plate tectonics?

Alfred Wegener

What was the last global supercontinent during the Paleozoic?

Pangaea

3 types of plate boundaries?

Covergent, divergent, transform

convergent boundary type of stress, what it creates?

compression stress, mountains, volcanoes, trenches

stress type of divergent plate boundaries, wha they create?

tension, ridges, new seafloor

how do divergent boudaries move?

2 plates move apart

How do convergent plate boundaries move?

plates collide

How do transform plate boundaries move?

plates slide past each other

type of stress for the transform boundary?

Shear stress.

What are the 2 types of plates and what are each made of?

continental: granite

oceanic: basalt

Hole in a plate that allows mantle material to escape is called?

hot spot

What is the average plate motion?

2-4cm/yr

what type of energy drives the mantle?

convection in the core

what are 5 evidences of plate tectonics?

hot spots, paleomagnetism and seafloor drilling, puzzle piece continents, fossils/rocks

Whats the difference btw lithosphere and asthenosphere?

the lithosphere- deals with upper ridge

asthenosphere-lower fluid, hotter and weaker then lithosphere, beneath lithosphere

Whats the continental drift hypothesis?

Pangea broke apart, continents drifted, continents broke through ocean crust forming new oceans

what is the lithosphere?

has many plates that are moving slowly

whats does the asthenosphere allow for?

the motion of the lithosphere

How do we measure plate motion?

hot spots space aging technology to show relative motion

VCBI-very long baseline interferometry

GPS- global postioning system

how does oceanic continental convergence work?

oceanic plate collides with a continental plate, causing the denser oceanic plate to subduct beneath the continental plate.

how does oceanic oceanic convergence work?

Occurs when two oceanic plates collide, 1 goes beneath the other

how does continental continental convergence work?

Occurs when two continental plates collide causing both plates to buckle

what are hot mantle plumes and what can they lead to?

long columns of hot mantle rock that rise from deep within the Earth, leading to volcanic activity as they reach the surface.

How do P waves move?

push pull motion

How to define an aftershock?

always orders of magnitude less then the actual event