Plate Tectonics Study Guide

Which is the MOST LIKELY location of sea floor spreading?

B

____________________ helps explain why there are a large number of marsupial mammal species in Australia and South America, two continents that were once connected.

Continental drift

This event is generated by plate movement at both convergent and divergent boundaries. Dust and ash is thrown into the atmosphere affecting the climate for long periods of time. What is the event called that causes this type of physical damage?

Eruption

The Appalachian Mountains are approximately 480 million years old, making them the oldest mountains in North America. The Appalachian Mountains are folded mountains that were once as high as 20,000 feet. Now they reach to about 3,000 feet. How did these mountains form?

Folded mountains occur when two plates of the Earth's crust push against each other.

The most recent evidence supporting the theory of plate tectonics would include

GPS monitoring of plate speeds and movements

How is the crust DIFFERENT from the other layers of the Earth?

It is thinner

________ is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and gradually moves away from the ridge.

Spreading

This map shows the movement of the world's tectonic plates. Which plate moves in more than one direction?

The Pacific plate

Volcanoes are often formed at plate boundaries. This is a convergent plate boundary. From the choices listed, pick the correct description of what happens before the volcano forms.

The more dense oceanic plate subducts under the less dense continental plate. Subducted plate melts due to heat and friction. Melted plate, now magma, rises up to the surface.

Sedimentary rocks found high in the Himalayan Mountains contain fossils of clams, sea snails, and other ocean life forms. What does this tell us about the Himalayan Mountains?

The plates that formed these mountains were once under an ocean.

The image shows the Pacific Ring of Fire, a region of high tectonic activity. What evidence supports the theory that the tectonic activity of the region is due to the subduction of tectonic plates?

The region is bound by many oceanic trenches.

The surface of Earth is a thin, solid crust enclosing a molten core of lava. When the core moves, it disturbs the crust at specific locations, which causes earthquakes. How is an earthquake felt on the crust?

Up-down or sideways wave-like shaking motion

In the early 1900s German geophysicist Alfred Wegener began to question how the structures on the Earth formed over time. He proposed the Theory of Continental Drift to suggest that all continents were once connected and have "drifted" to their current location over time. What was the main reason that Wegener's theory received a lot of ridicule from the scientific community?

Wegener did not give a method on how the continents actually moved.

Where are earthquakes MOST LIKELY to occur?

along the boundaries of tectonic plates

A tsunami can lead to massive devastation on Earth, resulting in loss of life and property as well as the destruction of the natural habitats where it occurs. A tsunami is caused by

an earthquake on the ocean floor

The Earth's mantle is DIFFERENT from the outer core because the mantle is

closer to the surface of the Earth.

What geological theory explains how llamas and camels, close relatives, might be found on different sides of the world?

continental drift

What is the main method of heat transfer from the core to the crust of Earth?

convection

The movement of the tectonic plates is caused by

convection currents in Earth's mantle.

The 2004 Indian Ocean tsunami was caused by a shift in two plates that pushed one section of the sea floor under another section of the sea floor by 5 meters. What type of boundary is this?

convergent

Observe the plate boundary shown here. What type of plate boundary is this? Many geologic events occur at these boundaries. Some are shown, but one is missing. What geologic event would you predict would occur at this plate boundary?

convergent oceanic-continental plate boundary; earthquake

The movement of tectonic plates shown here is MOST LIKELY the cause of

earthquakes

The Himalaya Mountains were built when two plates in the earth's crust collided, millions of years ago. The place where two plates collide and build a new surface feature like these mountains is called a

fault

Different events on Earth are associated with different tectonic plate boundaries. Which events are associated with transform plate boundaries?

faults and earthquakes

Virginia's Blue Ridge Mountains were pushed up when the North American and African continents collided in a process known as

folding.

Aside from heat within the mantle generated by the decay of radioactive elements, the movement of the earth's tectonic plates is driven by

gravitational forces.

Humans must take action to minimize risk against natural disasters. Such minimization of risk is called _________.

hazard mitigation

Convection currents in the Earth's mantle cause plate movement which can cause all except

hurricanes

The movement of earth's plates directly cause all EXCEPT this type of catastrophic event:

ice age

Where is the youngest crust on earth is found?

in the ocean along the mid ocean ridges

Which layer of Earth is the warmest?

inner core

The volcano in the illustration is most likely a composite volcano, which is also called a stratovolcano. A composite volcano eruption differs from other volcanoes such as a shield volcano. A composite volcano has magma that

is thick and slow moving.

Weather forecasters and emergency personnel keep a close eye on tropical storms. These storms can develop into hurricanes. All BUT one of the effects listed here might be the result of a hurricane. Which is it?

lower gas prices

An earthquake is a vibration of the Earth produced by a rapid release of energy. This vibration usually begins when there is a build-up of stress in the Earth's crust resulting in

plate movement at fault lines

The volcanoes (red dots) in this map are MOST LIKELY caused by

subduction.

Most earthquakes occur along fractures in the Earth's crust called faults. Most faults occur along the edges of

tectonic plates.

California has been plagued with earthquakes over the centuries; earthquakes that are a severe danger to life and land. Earthquakes are prevalent because in California

the Pacific plate is moving northwest, scraping horizontally past North American plate.

What is the action force responsible for seafloor spreading?

the intrusive of magma forced up toward the ocean ridge

The core (C), beneath the mantle (B), is the deepest and hottest layer of the Earth. It is made almost entirely of metal. The core is made of two layers: the outer core, which borders the mantle, and the inner core. The inner core is shaped like a ball. Iron and nickel in the outer core form an alloy, or a mixture of metallic elements. The outer core is approximately 2,300 kilometers thick and very hot, between 4,000 and 5,000 degrees Celsius. The inner core is made mostly of iron. It is about 1,200 kilometers thick. The iron core is extremely hot—between 5,000 and 7,000 degrees Celsius and

the pressure there is so great that it cannot melt and it is solid.

Where would an explosive volcano MOST LIKELY occur?

where large plates of earth are colliding