Hotspots - Hawaii

Why does Hawaii have shield volcanoes?

Low-viscosity basaltic magma produces fluid, effusive lava flows, creating broad, gently sloping shield volcanoes.

How large are Hawaiian shield volcanoes?

Mauna Loa and Mauna Kea rise 9km above the ocean floor, demonstrating the scale possible from long-term hotspot volcanism.

Why is Hawaii evidence of intraplate volcanism?

It is located within the Pacific Plate, away from a plate boundary, showing volcanism can occur at hotspots.

How does a mantle plume produce magma?

Hot mantle upwells - pressure decreases - decompression melting - basaltic magma forms.

How does the Hawaiian hotspot create a volcanic island chain?

As the plate moves, new volcanoes form above the hotspot while older volcanoes become inactive, erode and subside.

How does Hawaii help evaluate the mantle plume theory?

Hawaii supports it, but the exact origin and movement of mantle plumes remains debated.