The diagram shows mantle rock rising beneath a ridge, spreading sideways under the plates, cooling, and sinking again. Which process does this show?

The diagram shows mantle rock rising beneath a ridge. Where does the cooled mantle rock typically sink back down?

In the diagram, why does the mantle rock sink after it cools?

The convection cell in the diagram lies in the mantle. Which rigid outer layer sits above it and gets dragged along as the mantle flows?

Above the rising limb of a mantle convection cell, like the one in the diagram, which type of plate boundary typically forms?

Above the sinking limb of a mantle convection cell, like the one in the diagram, which type of plate boundary typically forms?

A cold, dense slab bends downward at the boundary shown and sinks into the mantle, dragging the rest of its plate along behind it. Which driving force is this?

In the diagram, molten rock rises at the ridge crest and the new lithosphere pushes outward on both sides as it cools and thickens away from the ridge. Which driving force is this?

Two volcanoes along the same hot spot track lie 120 kilometers apart. Rock at the older one formed 3 million years before rock at the younger one. Using 1 kilometer = 100,000 centimeters, find the plate's average speed.

In the diagram, why does the descending slab sink rather than float on the mantle beneath it?

As lithosphere formed at the ridge in the diagram moves away and cools, what happens to its density, and how does this drive plate motion?

Using the island ages on the map, what does the pattern of ages along the chain show?

Using the ages on the map, which island is the oldest?

Using the ages on the map, which island is still actively erupting today?

Order Oahu, Molokai, and Maui on the map from oldest to youngest.

The map shows Kauai at 5.0 million years old and Hawaii at 0.4 million years old. Why is Kauai more eroded than Hawaii?

On the map, why is Hawaii the only island still producing new lava?

The map shows island age increasing steadily with distance from Hawaii. What does this steady increase indicate about the hot spot's location over time?

In the diagram, a column of hot rock rises from deep in the mantle to feed a volcano far from any plate boundary. What is this rising column called?

What term names a fixed source of unusually hot mantle rock that rises and melts to feed volcanoes far from any plate boundary?

The Hawaiian Islands sit thousands of kilometers from the nearest plate boundary yet have hosted active volcanoes for millions of years. What feeds this activity?

Kilauea, on the island of Hawaii, erupts because of a stationary mantle plume rather than a converging or diverging boundary. What process instead feeds most Ring of Fire volcanoes?

Two volcanoes along the same hot spot track lie 200 kilometers apart. Rock at the older one formed 2 million years before rock at the younger one. Using 1 kilometer = 100,000 centimeters, find the plate's average speed.

Two volcanoes along the same hot spot track lie 90 kilometers apart. Rock at the older one formed 1 million years before rock at the younger one. Using 1 kilometer = 100,000 centimeters, find the plate's average speed.

Two volcanoes along the same hot spot track lie 350 kilometers apart. Rock at the older one formed 5 million years before rock at the younger one. Using 1 kilometer = 100,000 centimeters, find the plate's average speed.