Plate Tectonics

What leads to creation of island arcs?

Collision of two oceanic plates

Is continental or oceanic crust thicker?

Continental

What type of crust is found under the continents?

Continental Crust

List one concept that is part of the theory of plate tectonics.

Continents are in slow constant motion

What are convection currents and what is the role of convection currents in plate tectonics?

Convection currents in the asthenosphere drive plate tectonics. The movement of hot, cold, dense, and not dense air causes the plates to shift and collide. Driving force of plate tectonics.

What kind of boundary is found at the meeting point of the Philippine and Pacific Plates?

Convergent Boundary

What is earths outermost layer?

Crust

What types of geologic features are created by convergent boundaries of continental and oceanic plates?

Deep Ocean Trenches- Where the ocean crust meets the continental crust the oceanic crust subducts and it leaves a trench between the rest of the oceanic and continental crusts. Volcanoes- Where trenches dig into the mantle and magma seeps up creating a volcano

How did sea floor spreading contribute to the theory of plate tectonics?

Early on, Harry Hess developed the theory of mid-ocean ridges and this led to the discovery that ocean floor was constantly being destroyed and rebuilt. After a while, the theory was proposed that there were plates covering the continents and these plates carried continents. These plates collided and rescaled our planet.

How are continental drift and plate tectonics related?

Continental drift said continents had drifted since early on in earths history. Plate tectonics proved the theory because it showed the force in which causes the continents to drift.

What geologic features are created by divergent boundaries of oceanic and oceanic plates?

Mid-Ocean Ridges are formed from this boundary. When the sea-floor spreads magma is able to come up and harden creating underwater mountains.

Name the 3 types of plate boundaries.

Convergent, Divergent, Transfrom

What type of boundary runs across Iceland?

Divergent boundary

What supporting evidence did Alfred Wegner have to support his theory of continental drift? What was he missing that ultimately rejected his theory?

Evidence: 1)Climate 2)Land Features 3)Fossils He was missing the supporting evidence of what made the continents move.

Who developed the theory of sea-floor spreading?

Harry Hess

What is NOT likely to happen at a divergent boundary?

Mountain formation

What types of geologic features are created by convergent boundaries of continental and continental plates?

Mountains are formed when two continental crusts collide and neither subducts and the crust will fold on itself, creating mountains

A device scientists use to Mao the ocean floor is...

Sonar

Mid-ocean ridges are places where tectonic plates are doing what?

Spreading Apart

Besides a transform boundary, what type of fault is the San Andreas Fault?

Strike-slip Fault

What is happening at the subduction zone of the Juan de Fuca and North American Plate?

One plate is being pulled under another

What is earths only liquid layer?

Outer core

List one real life example of transform boundary

San Andreas Fault

What is subduction? How does it creat volcanoes and trenches?

Subduction is the process where new sea-floor is constantly being created and destroyed. The process occurs when two plates collide. When the plates collide, the older more dense plate sinks under the younger less dense plate. The plate that is older taps into the mantle pulling up magma creating hardened volcanoes. Trenches are formed at the place where two plates overlap.

How do the lithosphere and the asthenosphere work together to contribute to the theory of plate tectonics?

The plates of the lithosphere move (or float) on the asthenosphere. Both these layers of Earth are constantly moving, causing plates to shift and collide. All of this is driven by convection currents in the asthenosphere.

What type of plate boundary is found where the North American and Carribean Plates meet?

Transform Boundary

What types of geologic features are created by convergent boundaries of oceanic and oceanic plates?

Volcanic Island Arcs- when two oceanic plates collide and one oceanic plate subducts under the other creating a dip into the mantle pulling magma creating volcanoes. Trenches- overlapping of plates

Explain Transform Plate Boundaries

When plates are sliding past each other

Explain Divergent Plate Boundaries

When two plates are moving away from each other

Explain Convergent Plate Boundaries

When two plates collide

Who developed the theory of continental drift?

Alfred Wegner

How long ago did Pangaea break up?

225 million years ago

When did the Himalayan mountain range begin to form?

40-50 million years ago

Rift Valley

A deep valley on land that forms along a divergent boundary.

Which of the geologic features can occur at a transform boundary? a) earthquake b)Mountains c)volcanoes

A) earthquakes

The tectonic plates float on which semiliquid layer?

Asthenosphere

List one real life example of convergent plate boundaries

Himalayas

List one real life example of divergent plate boundary

Iceland

What are magnetic reversals? Explain how they support sea floor spreading? What else supported sea floor spreading?

Magnetic reversals are reversals in the magnetic field surrounding our earth. During the magnetic reversal the plates switch. They support sea-floor spreading because reversals on the ocean floor are mirroring on each side of a mid ocean ridge.

How are magnetic reversals related to the material in the outer core?

Magnetic reversals happen when convection currents change change direction in the outer core.

This solid layer of earth is made up of mostly iron and nickel...

Inner Core

Who developed the theory of plate tectonics?

J Tuzo Wilson

Which of earths layers in broken into several large plates?

Lithosphere

What is the lithosphere and the asthenosphere?

Lithosphere- solid crust and upper mantle/ the plates Asthenosphere- semi-liquid molten layer/ contains convection currents

What type of geological features are created by divergent boundaries of continental and continental plates?

Rift Valleys are created at the boundary. These are created from the separation of two continental plates. The space between each of the plates is sometimes filled with water.