Under these conditions, the mineral conducted electricity at high rates.
"This means that we have lots of electricity at the bottom of the mantle, which is coming from [Earth's] core," Hirose said.
Raymond Jeanloz, an Earth and planetary scientist at the University of California, Berkeley, was not part of the study.
"What this means is that the magnetic field in the core can grab onto, or lock into, the lowermost mantle," he said.
"And so one of the influences that this can have is in altering the length of day, or the rotation rate of the Earth, depending on when and where the core is grabbing onto the mantle."
Not So Minuscule
This interaction accounts for several milliseconds of increase in day length over the past 150 years, co-author Hirose said.
Such minuscule time periods might seem negligible, but they do matter, he added.
Quentin Williams, an Earth and planetary scientist at University of California, Santa Cruz, agreed.
"We do care about Earth's rotation, because you really want to know, at any given time, where a spot on the surface of the Earth is relative to its orbit," he said.
"That's why agencies like NASA have cared a lot about the Earth's rotation over the years."
|
SOURCES AND RELATED WEB SITES
|
