Hawaii Plate Tectonics

What geological evidence supports movement of the Pacific Plate over time?

• Identical volcanic ages at every island
• Progressively older volcanoes along the Hawaiian chain
• A land bridge between Hawaii and Asia
• The complete absence of volcanic rock

How can a hotspot create a chain of volcanoes?

• The hotspot moves each island by ocean currents
• A moving plate carries older volcanoes away from the magma source
• Glaciers deposit each volcano at fixed intervals
• Earth’s surface remains fixed above the hotspot

Why do many Hawaiian shield volcanoes have gentle slopes?

• They are made entirely of ice
• Their relatively fluid lava can spread over wide areas
• Their lava never reaches the surface
• They form only from windblown sand

What does the Hawaiian Ridge–Emperor Seamount Chain include besides islands?

• A continental railway line
• Submerged extinct volcanic mountains
• A freshwater river delta
• An ice sheet extending from Alaska

Which geographic pattern fits the broad ages of the main Hawaiian islands?

• Older islands are all to the southeast
• All islands formed simultaneously
• Older islands generally lie northwest of younger islands
• Older islands occur only inside lagoons

How can an old volcanic island become lower and smaller over time?

• A steady rise in fresh lava everywhere
• Permanent growth without erosion
• Construction of coral reefs alone
• Erosion and subsidence

What typically happens after lava cools to form a new rock surface?

• The rock instantly becomes fertile soil
• Soil and vegetation can gradually develop
• The rock permanently prevents all plants
• The surface turns directly into seawater

Which statement is correct about Hawaiian volcanoes?

• Not every Hawaiian volcano is currently erupting
• Every island has a constantly erupting volcano
• Every Hawaiian mountain is an active volcano
• Hawaii has never had volcanic eruptions