Ch.13 Geology 1401

What is the difference between a barrier reef and an atoll?

Barrier reefs surround an inactive volcano emerging above sea level, while atolls surround the previous location of a submerged volcano.

How is ocean depth calculated by sonar?

Ocean depth is calculated by the time it takes sound waves to travel from the ship to the seafloor and back to the ship again.

Satellites record slight variations on the sea surface using radar. What do these slight variations represent?

features on the seafloor

Land Hemisphere

Northern

Turbidity currents travel from the shelf through __________, creating deep sea fans.

canyons

What is a tablemount?

A seamount that grew above sea level, experienced wave erosion, and is now inactive.

What is a seamount?

An active volcano that occurs along the crest of the mid-ocean ridge.

Mountain ranges that are an example of continental arcs

Andes and Cascades

What is the relationship between coral reefs and seamounts?

Coral reefs at the ocean surface grow away from seamounts over time.

Which is the correct order of coral reef development near seamounts?

Fringing reef, barrier reef, atoll

Where do coral reefs exist with sea mounts?

In tropical latitudes

What is the main reason for the elevated position of the oceanic ridge system?

New, hot basalt is less dense here compared to the rest of the ocean basin.

Which of the world's oceans accounts for over half of the surface area of the planet?

Pacific

Why do coral reefs at the ocean surface grow away from seamounts over time?

Seamounts subside as tectonic plates move. Coral reefs grow away from the seamount in order to stay near the sunlight.

Water Hemisphere

Southern

What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?

The Earth would increase in volume.

What is the relationship between the crust and lithosphere?

The crust is part of the lithosphere

What is a volcanic arc?

a row of volcanoes that forms on the overriding plate near a subduction zone

The Pacific is an ______ margin

active

Where is the youngest ocean floor found?

along the crest of mid-ocean ridges

Which geologic features are associated with divergent boundaries?

mid-ocean ridges and continental rift valleys

What feature(s) are measured when studying the bathymetry of the ocean?

ocean depths and seafloor topography

Which geologic features are associated with convergent boundaries?

ocean trenches and volcanoes

The Atlantic is a _______ margin

passive

What type of ocean exploration technique is the best for determining potential oil and gas reservoirs?

seismic reflection survey

If the subduction angle is steep, the overriding plate may undergo __________.

subduction erosion

Continental shelf represents

the flooded portions of continents