Enormous 'mega-blob' under Hawaii is solid rock and iron, not gooey — and it may fuel a hotspot

Scenic view of sea against sky, Kaaawa, Hawaii, United States, USA.

A massive blob deep under Hawaii seems to be solid and iron-rich, new research finds.

This blob — scientifically known as a mega-ultralow velocity zone — may anchor the Hawaii hotspot, an area where hot material rises through the mantle and drives the volcanic activity that created the Hawaiian Islands.