The Hawaiian Islands are formed by hotspot volcanism, while the Philippine islands belong to the Pacific Ring of Fire where volcanism is associated with subduction processes. A lava lake occupying the caldera floor of Kilauea was recorded from 1824 to 1923 before the magma drained back over an active hotspot. The Hawaiian Islands are examples of oceanic shields that have formed within-plate over an active hotspot. A plume may however occasionally break through this barrier to produce a surface hotspot with persistent volcanism, local high heat flow and high regional topography. The plumes that provide the source material for the hotspots are thought to remain fixed in position for long periods of time thus anchoring the hotspots to the mantle below the lithosphere.
Hotspots also provide information on plate motions.
The intraplate Hawaiian chain of islands has been created over 80 million years as the Pacific plate drifts at a rate of approximately 10 centimetres per year over a hotspot in a northwesterly direction. Active volcanism above the hotspot creates the shield volcanoes of Mauna Loa and Kilauea. Older, eroded extinct volcanic islands, originally created over the hotspot, form a chain northwestward, as the plate transports the islands away from the hotspot. This chain is known as the Emperor Seamount chain. A change in trend between the Hawaiian Ridge and Emperor Seamount chain suggests the speed and direction of movement of the Pacific plate changed approximately 43 Ma ago.