The 8.9 earthquake that hit Japan last week caused a lot of destruction, spawned many rumors of celebrity deaths, and now, it turns out, has actually shortened the length of the 24-hour day. According to Richard Gross, a geophysicist at NASA's Jet Propulsion Laboratory, the earthquake actually accelerated Earth's spin (by rearranging enough mass), which shortened the length of the day by 1.8 microseconds. To put that into perspective a bit, a microsecond is one millionth of a second, so we won't have to reinvent the clock anytime soon.
The initial data regarding the earthquake Friday suggests that on top of shortening the length of the 24-hour day, the earthquake also moved the island of Japan by about eight feet. This earthquake isn't one of the first to have a (relatively) noticeable impact on the length of the day, as an 8.8 earthquake in Chile last year shortened the day by around 1.26 microseconds, and a 9.1 earthquake that hit Sumatra in 2004 shortened the day by 6.8 microseconds.
(via The Manila Bulletin Newspaper Online)