Geological Features and Processes

The video explains that the tallest mountains, deepest valleys, and flattest plains are found in the ocean. It covers the continental shelf and slope, seafloor changes due to currents and plate movements, and the formation of trenches and mid-ocean ridges. Volcanic activity along these ridges creates new crust, while seamounts can form volcanic islands like Hawaii.

What is the continental shelf?

• A type of underwater volcano

• A flat area on the ocean floor

• The edge of a continent that extends underwater

• A deep ocean trench

What feature marks the end of a continent underwater?

• Continental slope

• Mid-ocean ridge

• Abyssal plain

• Sea mount

How do currents affect the seafloor?

• By causing earthquakes

• By forming volcanic islands

• By depositing sediment that fills valleys

• By creating new oceanic trenches

What happens when Earth's plates converge?

• A mid-ocean ridge is created

• A new crust forms

• A trench is formed

• A sea mount emerges

What geological activity is likely in oceanic trenches?

• Formation of new islands

• Volcanic eruptions and earthquakes

• Creation of mid-ocean ridges

• Sediment deposition

Where is volcanic activity commonly found underwater?

• On abyssal plains

• Along continental shelves

• In oceanic trenches

• Along mid-ocean ridges

What is the result of volcanic eruptions along mid-ocean ridges?

• Destruction of the seafloor

• Formation of new crust

• Creation of deep valleys

• Emergence of new islands

What is the cycle involving crust at mid-ocean ridges and trenches?

• Crust remains unchanged

• Crust is destroyed at trenches and formed at ridges

• Crust is only formed at sea mounts

• Crust is formed at trenches and destroyed at ridges

What are sea mounts?

• Underwater volcanic cones

• Deep ocean trenches

• Edges of continents

• Flat areas on the ocean floor

How do volcanic islands like Hawaii form?

• Due to the erosion of continental shelves

• When sea mounts grow large enough to reach the surface

• By the accumulation of sediment

• Through the convergence of tectonic plates