A research boat maps a shallow, gently sloping underwater area that begins at the coastline before the ocean floor drops steeply. What is this feature called?

A sonar map shows a steep underwater drop just beyond the shallow edge of a continent. What sea-floor feature is being described?

A deep-ocean map shows a broad, flat area covered with fine sediment far from the continents. What is the best name for that feature?

An ocean expedition finds a very deep, narrow valley in the sea floor. What feature has the expedition found?

A map labels an underwater mountain chain running through the middle of an ocean basin. What is this sea-floor feature called?

A fishing boat stays over shallow ocean water close to shore, where sunlight can reach the sea floor. What sea-floor area is it most likely above?

A submersible leaves a flat deep plain and approaches a long, steep-walled cut that reaches the greatest depths nearby. What feature is ahead?

At a beach, waves roll in one after another all afternoon. What is the main cause of most ocean surface waves?

A floating marker bobs up and down as a wave passes, then stays near the same spot. What moved across the water surface?

A model current turns when it reaches a coastline instead of moving straight ahead. What factor is steering the surface current?

A long-lasting wind blows from west to east across open ocean water. What ocean motion can that wind help drive?

A large current in the Northern Hemisphere slowly curves away from a straight path as it crosses the ocean. What helps cause this turning?

A high-latitude coastal city has milder winters than an inland city at the same latitude. What ocean condition is the most likely reason?

During a storm, stronger winds blow over the ocean for many hours. What change is most likely at the surface?

In a model, a student compares safe samples of ocean water and river water. They look the same, but they taste different. What does ocean water hold more of?

Ocean water is salty, even though the rivers that flow into it taste fresh. What process adds most of the salt materials to ocean water?

Near a river mouth, fresh river water mixes with ocean water. How should salinity there compare with the open ocean nearby?

A basin of seawater is left in sunlight, and some water evaporates while the salt stays behind. What happens to salinity in the basin?

A glacier melts and adds fresh water to a small coastal bay. What change in the bay water is most likely at first?

Students compare 1 liter of open-ocean water with 1 liter of water from a river. The ocean sample leaves salt crystals after evaporation. What does this show?

A survey ship travels straight out from a coastline and crosses, in order, a shallow gently sloping area, a steep drop, and then a broad flat deep area. Which list names those three features in that order?

Of the sea-floor features mapped in one ocean basin, which reaches the greatest depth?

A crew lowers a scoop onto the broad flat area of deep sea floor far from any continent and brings up a sample. What mostly covers that part of the sea floor?

Divers work over the sea floor close to shore where sunlight still reaches the bottom and the water stays shallow for many kilometers. Which feature are they above?

A ship maps the sea floor by sending a sound pulse down and timing its echo. Over one spot, the echo takes much longer to return than over the shelf. What does this show?

An underwater mountain stands alone, and its top never reaches the surface. Where are such mountains most likely to be found?

Scientists find that the youngest rock on the ocean floor lies along a mid-ocean ridge. What is happening there?

Wind blows across a bay for one hour and the waves stay small. The same wind then blows for six hours without stopping. What happens to the waves?

A gull sits on the water as waves pass beneath it. Each time a wave goes by, the gull is lifted to the highest point of the wave. What is that highest point called?

A tagged buoy released in a strong surface current is found hundreds of kilometers away weeks later. How does a surface current differ from a wave?

In a tank model, a fan blows steadily across the water and floating beads begin to travel in the same direction as the moving air. What is driving the beads?

A surface current flowing west meets the eastern edge of a large continent and turns to flow along the coast. What has changed the current's path?

Two beaches face the same open ocean. One has had light breezes all week and the other has had strong steady wind. Which beach most likely has the larger waves, and why?

A student says surface currents are called surface currents because they only move the top of the ocean. What makes that name accurate?

Most of the water on Earth is found in the ocean rather than in lakes, rivers or ice. About what share of Earth's water is salt water?

Of the small share of Earth's water that is fresh, where is most of it held?

A report states that one sample of seawater has a higher salinity than another. What is the report comparing?

Heavy rain falls for two days over one coastal bay while the open ocean nearby gets none. How should the salinity of the bay compare with the open ocean afterward?

Waves pound a rocky shore day after day, and the rocks slowly become smooth and rounded. What are the waves doing to the rocks?

A student says ocean water tastes salty because a layer of salt sits on the sea floor. What is wrong with that idea?