Science- Plates Test

What type of plate boundaries is formed when 2 plates grind past each other? give an example of this plate.

A transform fault boundary is formed. Examples include the San Andreas Fault in California and many faults along ocean ridges.

what process occurs as the slab of oceanic lithosphere descends beneath the plate?

As the slab descends, water leaves it and travels into the warm mantle rock above, where partial melting occurs. When the magma reaches the surface, volcanic activity results. The volcanoes that form are called a continental volcanic arc.

How would the age of a rock sample obtained by drilling in the ocean floor near a mid-ocean ridge compare with the age of a rock sample from the ocean floor near a trench? explain.

Because of sea-floor spreading, the age of the rock sample from near a mid-ocean ridge would be much younger than the age of a sample from near a trench.

At sometime in the distant future, Earth's interior will cool to the point that plate movement will stop. Describe how earth would be different from that point onward.

Crystal deformation and volcanism will stop. Earthquakes, however, would still occur because of tidal stresses from the moon.

describe the process of sea floor spreading:

During sea-floor spreading, new oceanic lithosphere forms along mid-ocean ridges. It then cools and moves across ocean basins as a result of ridge push and slab pull. Finally, it sinks into the mantle through subduction beneath a trench.

Why is earth not getting larger if new lithosphere is being created to the oceanic ridges?

Earth is not getting larger because older portions of oceanic plates return to the mantle along convergent plate boundaries.

How are Earthquake Patterns used to provide evidence of sea floor spreading?

Earthquake patterns are used to show plate boundaries and to trace how the slabs descend into the mantle.

Why did the discovery of the mesosaurus in both south america and africa but no where else support the hypothesis of continental drift?

If mesosaurus were able to swim well enough to cross the Atlantic Ocean, its remains should be found over a wider area on other continents. Since its remains are not found, the two continents were together.

Form a hypothesis to explain what you think would happen if the direction of motion between india and aisa changed and india began to move in a southern direction.

If the motion of India changed to a southward direction, the boundary would change from a continental-continental convergent boundary to a divergent boundary. As India moved away from Asia, rifting would occur between them, and a new ocean might form.

At what location is lithosphere created? At what location is most lithosphere destroyed?

Lithosphere is created at divergent boundaries at ocean ridges. It is destroyed at convergent boundaries in subduction zones.

What are the three types of convergent plate boundaries?

Oceanic-oceanic, oceanic-continental, continental-continental

Explain how changes in polarity of earths magnetic field provided on type of evidence for the hypothesis of sea floor spreading.

Scientists mapped the magnetic polarity of ocean floor on both sides of the ridge. They found that the pattern of strips of rock with the same polarity matched on both sides of the ridge. This showed that the ocean floor moves away from mid-ocean ridges as new rock forms

At what type of plate boundaries do subduction zones form?

Subduction zones form at oceanic-oceanic convergent and oceanic-continental convergent boundaries.

What is the difference between the collision of an oceanic plate with a continental and the collision of two continental plates?

The collision of an oceanic plate with a continental plate produces a subduction zone and the formation of deep-ocean trench and a continental volcanic arc. No subduction zone, trench or volcanic arc is produced during the collision of two continental plates. Instead, the collision produces a major mountain range.

what pattern would the foci of the earthquake form if they were plotted in the diagram.

The earthquake foci would be shallow along and within the slab as it begins to descend beneath the continental plate. As the plate descends deeper, the earthquake foci will also be deeper within the slab.

describe the evidence that supported the hypothesis of continental drift.

The evidence that supported continental drift included the fact that the continents, especially South America and Africa, looked like they could fit together. Similar rock types and structures such as mountain ranges match up on different continents. Climate data supports continental drift because glacial deposits occur in areas that now have more tropical climates

Briefly explain the theory of plate tectonics.

The theory of plate tectonics states that Earth's rigid outer shell consists of rigid slabs called plates that are in continuous slow motion relative to each other. This interaction of plates causes volcanoes, mountains and earthquakes

How does the age of the ocean lithosphere and deepest sediment in an ocean basin change with increasing distance from the oceanic ridge?

The youngest oceanic crust is at the ridge crest and the oldest oceanic crust is at the continental margins.

Describe 2 events that occur on earth that you would not expect to find in mars because the lack of plate movement there?

Volcanoes, earthquakes

what is the weaker, hotter zone beneath the lithosphere that allows for motion of earths rigid outer shell?

asthenosphere

In the atlantic ocean basin, where is the oldest oceanic lithosphere found?

at continental margins

Most earthquakes, volcanos, and mountain building occur...

at plate boundaries

Support for Harry Hess's hypothesis of sea floor spreading did not include: A) magnetic strips in the ocean floor b) granitic rock in the ocean floor c) earthquake patterns in subduction zones d) the age of the ocean floor rock

b

Alfred Wegner is best known for what hypothesis?

continental drift

Complex mountain systems such as the Himalayas are a result of...

continental-continential convergence

Which of the following mountains ranges was not the result of continental-continential convergence? a) Himilayas b) alps c) appalachians d) andes

d

At what type of plate boundary do plates move apart, resulting in upwelling of material from the mantle to create new seafloor?

divergent

One of the main objections to Wegeners Hypothesis of continental drift was that he was unable to provide an acceptable.....

mechanism for continental drift

What is the type of plate boundary where two plates move together, causing one of the slabs of the lithosphere to descend into the mantle beneath an overriding plate?

oceanic-continental convergent

What is the name given by Wegener to the supercontinent he proposed existed before the current continents?

pangea

Most deep focus earthquakes occur near...

trenches