Enigmatic volcanic hot spots around the world might be pulsating
together — like a great planetary heartbeat — at the rates of
five and 10 million years, say researchers from Norway, Hawaii
and Australia. The discovery suggests that hot spots are
responding to regular fluctuations that come from way down in
the Earth's core. It's from the core that pulses of heat are
thought to be launched through the mantle, which rise and melt
rocks nearer the surface to create hot spot eruptions. Among the
most famous hot spots are Hawaii, Yellowstone and Iceland. All
of these sites have a long history of eruptive pulses that have
burned through the slowly moving crust above like a cutting
torch — leaving a long, telltale wake of dead volcanoes made of
progressively older rocks. This is in contrast to other sorts of
volcanoes, which are caused by shallower things, like one
tectonic plate being shoved under another then melting. "Hot
spots... remain some of the greatest enigmas in earth science,"
commented geologist Mike Co