With Mauna Loa’s Eruption, a Rare Glimpse Into the Earth
In 1963, a geophysicist named John Tuzo Wilson proposed that the islands, that are lined with layers of volcanic stone, sit above a magma plume, which varieties when rock from the deep mantle bubbles up and swimming pools under the crust. This “hot spot” regularly pushes towards the floor, generally bursting via the tectonic plate, melting and deforming the encircling rock because it goes. The plate shifts over thousands and thousands of years whereas the magma plume stays comparatively nonetheless, creating new volcanoes atop the plate and leaving inactive ones of their wake. The outcomes are archipelagoes just like the Hawaiian-Emperor seamount chain and elements of the Iceland Plateau.
The scorching spot principle gained broad consensus within the subsequent many years. “There is no other theory that is able to reconcile so many observations,” stated Helge Gonnermann, a volcanologist at Rice University.
Some confirming observations got here comparatively just lately, within the 2000s, after scientists started putting seismometers, which measure terrestrial power waves, on the ocean ground. John Orcutt, a geophysicist on the University of California, San Diego, who helped lead that analysis, stated that the seismometers had supplied an X-ray of the magma plume rising beneath Hawaii. The devices had been in a position to precisely learn the course and pace of the magma’s stream; the outcomes pointed resoundingly towards the presence of a scorching spot.
This scorching spot has in all probability been fomenting volcanic exercise for tens of thousands and thousands of years, though it arrived in its present place below Mauna Loa solely about 600,000 years in the past. And so long as it stays there, Dr. Orcutt stated, it would reliably produce volcanic exercise. “Few things on Earth are so predictable,” he added.
Closer to the floor, predicting when, the place and the way intense these eruptions can be turns into harder, regardless of the profusion of seismometers and satellite tv for pc sensors. “The deeper you go, the more smooth the behavior gets,” Dr. Orcutt stated. “By the time you get this interface between rock and molten rock and the ocean, the magma tends to come out sporadically.”
Under the hood of the volcano
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