We've heard of animals driven mad by the swarming insects of the Arctic, bedeviled by thousands of biting critters from which there's no escape. There are increasing examples, though, of different ways by which unwelcome guests can drive an animal mad.
Ah, good old terra firma! Or maybe not, considering the Pacific Rim of Fire, where the earth regularly shakes and shimmies. Nevertheless, except for these minor lapses, we all know that the good old earth is a mostly a nice solid piece of work. Except, of course, for the molten rock that occasionally squirts out in the form of lava.
What may come as news to some of you, though, is that the planet's
solid core is separated from the outer, solid parts by a thick layer of molten metal.
Even worse for those who become queasy easily, the solid surface layers, the molten
layer, and the iron core don't seem to be all that firmly connected. In the 1960s,
we learned that the continents drift around in relation to one another. Now we've
evidence that seems to nail down a phenomenon that we've suspected for some time:
that central, solid ball of iron is actually turning a little bit faster than the rest
of the planet! Looks like Earth just can't pull itself together.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Kerr, R. A. 2005. Earth's inner core is running a tad faster than the rest of the planet. Science 309:1313.