The giant iron ball at the centre of the Earth appears to be spinning a bit faster than the rest of the planet.
"Professor! I can't hold her much longer! She's gonna blow!"
"We'll have to evacuate!" |
 The solid core that measures about 2,400 kilometres in diameter is spinning about one-quarter to one-half degree faster, per year, than the rest of the world, scientists from Columbia University's Lamont-Doherty Earth Observatory and the University of Illinois at Urbana-Champaign report in the journal Science.
| It's probably Bush's fault... In fact, I'm sure of it. |
The spin of the Earth's core is an important part of the dynamo that created the planet's magnetic field, and researcher Xiaodong Song said he believes magnetic interaction is responsible for the different rates of spin. The faster spin of the core was proposed in 1996 by two of the current study's authors, Paul Richards of Lamont-Doherty and Song, now an associate professor at Illinois. The researchers studied the travel times of earthquake waves through the Earth, analysing what are called couplets. Those are earthquakes that originate within a 880 metres or so of one another but at different times. They analysed 30 quakes occurring in the South Atlantic and measured at 58 seismic stations in Alaska and found differences in the travel times and shape of the waves, indicating differences in the core as the waves passed through the centre of the Earth. Analysing those differences, they calculated that the core is spinning slightly faster than the rest of the planet and is a bit lumpy.
| It's the drilling in ANWR that did that... |
| ... or was it the melting of the Greenland glacier ... |
| You sure it wasn't the Halliburton Zionist Earthquake Machine Division? |
That solid inner core is surrounded by a fluid outer core about 6,760 kilometres across. Since the planet is divided into 360 degrees of longitude, a core spinning one-quarter to one-half degree faster than the outer surface could take between 700 and 1,400 years to get one full revolution ahead.
| And once that happens... Well, you can guess the rest... |
But Song said in a telephone interview that he expected that rate to vary over time and sometimes the core might be spinning slower than the rest of the planet. "What we see right now is a snapshot of a long time process between the magnetic field and the inner core," he said. "I do expect to see this rate change with time." |