Days are shorter, literally
Permalink | August 28th, 2005
This is really, really old news, but it was brought up in a recent conversation and I thought it was rather interesting. Following the Indonesian earthquake last December (has it been that long?), scientists have determined that the massive tsunami which was generated actually changed the rotation of the Earth and shortened the day. As reported by NASA,
They also found the earthquake decreased the length of day by 2.68 microseconds. Physically this is like a spinning skater drawing arms closer to the body resulting in a faster spin.
…
The researchers concluded the Sumatra earthquake caused a length of day change too small to detect, but it can be calculated. It also caused an oblateness change barely detectable, and a pole shift large enough to be possibly identified. They hope to detect the length of day signal and pole shift when Earth rotation data from ground based and space-borne position sensors are reviewed.
In more recent news, according to Wired, scientist have determined that the Earth’s core is spinning faster than the crust.
The giant iron ball at the center of the Earth appears to be spinning a bit faster than the rest of the planet.
The solid core that measures about 1,500 miles 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 Friday’s issue of the journal Science.
[thanks Paul]
