megaplume

plural megaplumes

1. A very large plume or column of water.

   As well as these small continuous sources there exist much larger-scale episodes, which give rise to the so-called ‘megaplumes’.

   1997, John E. Simpson, Gravity Currents in the Environment and the Laboratory, Cambridge University Press, →ISBN, page 138

   4 more examples

   A megaplume is a supermass of extremely hot rocks that moves very slowly under the surface of the earth and influences the breakup of tectonic plates.

   1990, Richard Moran, Magill's Survey of Science: Earth Science Series Supplement, Salem Press, pages 4-5

   The rise height of a buoyant plume increases with the discharge rate of its source fluid, and all previously observed hydrothermal plumes had been found no more than a few hundred meters above their sources. The megaplume reached a stunning 1,000 meters above the ridge axis depth of 2,300 meters.

   1991, Woods Hole Oceanographic Institution, Oceanus, Volume 34, Number 4 Winter, Woods Hole Oceanographic Institution, page 85

   Taken together, the two pieces of evidence could mean only one thing: the North Atlantic volcanoes were sitting atop a titanic, previously unknown hot spot, a megaplume of superheated magma rising from far down in the earth's mantle.

   1995, Richard Moran, The Empire of Ice, TOR, →ISBN, pages 4-5

   "That's what I mean," Use said. "What if we emit an active sonar beam, one that's directionally very tight, at minimum power? Wave it back and forth and grab the micro-echoes off the precipitation particles? That would give a picture of water motion in the megaplume."

   2000, Joe Buff, Deep Sound Channel, Bantam Books, →ISBN, pages 311-312