Read an article on CNN.com today discussing a new report from Columbia University's Lamont-Doherty Earth Observatory and the University of Illinois at Urbana-Champaign report in Friday's issue of the journal Science (
here's the story). The study found that the Earth's solid core is spinning faster than the reast of the planet, and that that has some effect on gravity. But what interested me was a comment by Dr. Song; "..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."
Question 1: It has been shown that the planet's temperature has been cyclical. Could the swing in the core's spin rate affect the earth's temperature? Faster = warmer, Slower = cooler? Note that the study shows the core spinning faster now and we are going through a warming period.
Question 2: If the core spins faster than the crust at some times and slower at others, does that spin affect the length of a year? In other words, does the crust continue at the same rate regardless of the core's rate?
Question 3: What is it that causes the core to speed up and slow down? Magnetic effects? Friction?