Types of Boundaries

The movement of the tectonic plates is caused by

• the rotation of the Earth.

• convection currents in the Asthenosphere

• the gravity of the iron-nickel core.

• the Moho discontinuity.

In some areas of the world, like California and Japan, earthquakes are a common occurrence. How can this best be explained?

• The strong ocean currents are undermining both areas causing earthquakes.

• Both areas are located near the edge of the Pacific Ocean, the unstable sand causes earthquakes.

• Both areas are subjected to strong ocean wind and waves that causes earthquakes.

• Both areas are on the boundary of active plates, the motion of the plates causes earthquakes.

Observe this diagram of a plate boundary. One statement BEST describes what is happening. It is that

• the oceanic crust is melting.

• the denser ceanic crust is subducting under the less dense oceanic crust

• volcanic islands are forming.

• the tectonic plates are moving away from each other.

What geological forces might be responsible for this range of mountains?

• diverging tectonic plates
• erosion of the land by the ocean
• converging tectonic plates
• deposition of sediments by the ocean
  

Earthquake epicenters (center of where the earthquakes started) were mapped for a 35 year period in the diagram above. The black dots indicate these epicenters. The black dots appear along what feature on Earth?

• hot spots

• plate boundaries

• rift zones

• sea floor spreading

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?

• divergent

• convergent

• transform

• metamorphic

What is the source of energy that drives plate movement?

• the subducton of the sea floor

• the different densities of the oceanic and crustal plates

• convection currents in the asthenosphere

• the friction force between the plates that move past each other

A plate boundary where two plates move away from each other is called

• Divergent Boundary
• Convergent Boundary
• Transform Boundary
• Subduction

Which of the following is where one plate slides under another plate?

• submarine zone
• divergence zone
• subduction zone
• lower zone

Below is a picture of sea-floor spreading. How are the ocean crusts moving?

• Converging

• Diverging

• Sliding

• No movement