The Hawaiian hot spot

Part of Hall of Planet Earth.

The Hawaiian hot spot

A chain of 107 volcanoes – some islands, some submerged – extends from Hawaii to the northwest. This 6,000-kilometer-long chain begins with the still-submerged Loihi. Moving northwest, the volcanoes become progressively older. The chain forms as the Pacific plate creeps at 9 centimeters a year over a stationary hot spot in the mantle that has been providing magma for 80 million years.  The sharp bend records a shift in the plate’s direction of movement that took place 43 million years ago. 

Lavas of Hawaii

The Hawaiian lavas are mostly basalt. Basaltic rocks contain high proportions of calcium, magnesium, and iron relative to silicon. For this reason, the lavas are fluid, having the consistency of honey. Instead of erupting in great explosions as Mount St. Helens did, the lavas form slow-moving molten rivers.

Lavas of Hawaiian Map_ILL
Seamount Chain Map_ILL

In This Section

Exhibit Aa lava Aa (pronounced “ah-ah”) lava is more solidified and flows sluggishly compared to its more fluid counterpart, pahoehoe. Exhibit Pahoehoe lava Pahoehoe (“pah-hoy-hoy”) is a form of lava produced by hot, fluid magma. Exhibit Spatter Cone A spatter cone is created when blobs of lava are thrown into the air from a single event. Exhibit Lava Tree Lava may congeal around a tree to form a mold on the trunk and branches.