The theory that explains why and how continents move is called
By what time period was there evidence supporting continental drift, which led to the development of plate tectonics?
What is "plastic" rock, and how does it move?
Asthenosphere it flows very slowly
Describe how continents and oceans are carried on tectonic plates.
They are on top of the plates and they move
How many major tectonic plates have scientists identified?
Why are the boundaries of the tectonic plates not always easy to identify?
Familiar outlines of the continents and oceans often do not match the outlines
How do scientists identify plate boundaries?
By studying data from earthquakes
A sudden movement along the boundary of a tectonic plate is a (n)
Frequent earthquakes in a given zone are evidence that
2 or more plates may meet in the area.
How do volcanoes help to identify the locations of plates boundaries?
Some form when plate motions generate magma that erupts on Earths surface
A zone of active volcanoes that encircles the Pacific Ocean is known as the
Pacific Ring of Fire
What do the characteristics of the Pacific Ring of Fire indicate?
That the pacific oceans is surrounding by plate boundaries
Name three areas where plate boundaries may be located
Middle of ocean basin edges of the continents within countries
What happens to magma at divergent boundaries?
it rises to the surface and cools to form new ocean lithosphere.
Describe the rock that forms when magma cools to form new oceanic lithosphere
Warm, light and sits higher than the surroundings sea floor because it is less dense
A narrow valley that forms where the plates separate at a divergent boundary is called a
Where are most divergent boundaries located?
Describe an example of a rift valley
The Red Sea
When oceanic lithosphere collides with continental lithosphere, the oceanic lithosphere is less dense than the continental lithosphere, so it sinks or
What deep-ocean feature forms at subduction zones?
As the oceanic plate subducts, it heats up and releases fluids into the mantle, causing magma to form and rise to the surface, forming
What happens when two plates made of continental lithosphere collide?
what happens is oceanic lithosphere is denser. it subducts, or sinks under the less dense continental lithosphere
What is an example of a large mountain range formed when two plates made of continental lithosphere collided?
What happens when two plates made of oceanic lithosphere collide
one plate subducts under the other plate and makes a deep ocean trench. Fluids are released from the subducted plate causes mantle rock to melt and form magma.
What is produced from magma formed from melted rock?
An example of a feature that formed when two plates made of oceanic lithosphere collided is
What causes earthquakes at transform boundaries?
Boundary at which two plates slide past each other horizontally
How are transform boundaries different from other types of boundaries?
They don't produce magma
An example of transform boundary is the
The San Andreas Fault is located between which two plates?
Between North America and the Pacific Plate
Transform boundaries that connect short segments of a mid-ocan ridge are called
What is an example of a convergent boundary?
South American and Nazca plates at the chilean trench along the west coast of South America
What is an example of a divergent boundary in the mid-Atlantic?
North America and Eurasian plates at the mid-Atlantic Ridge.
The movement of heated material due to differences in density is called
The cycle in which the cooler, denser water sinks and the warmer water rises to the surface to create a cycle is called
A convection cell
Earth's mantle is heated by energy generated by
Earth's core and radioactivity
What causes tectonic plate movement?
Hot material in the mantle sinks
What happens to newer, warmer rock at a mid-ocean ridge as it cools?
It is elevated above nearby rock
The force on the rest of the plate from the asthenosphere below cooling, sliding rock is called
What happens as a result of ridge push
Ridge push may help and drive plate motions. most scientist agree that ridge push is not the main driving force of plate motion.
Is Ridge push the main driving force of plate motion? along with ridge push, what did scientists study for clues about forces that drive plate motion?
No it is not the main driving force. scientists looked to convergent boundaries for other clues about forces that drive plate motion,
What happens to magma is places where plates pull away from each other at mid-ocean ridges?
Magma forms the asthenosphere rises to the surface.
The force exerted by a sinking plate caused by the subduction of lithosphere into the asthenosphere is called
Compared to the speed of plates that are not suducting plates that are subducting move
What three mechanisms of Earth's convecting system work together to cause plate motions?
The three mechanism are convection cell, ridge push and slab pull work together to cause plate motions.