Japan quake may have slightly shortened Earth days, moved axis, theoretical calculations suggest
Monday, March 14, 2011 - 21:30
in Earth & Climate
The magnitude 9.0 earthquake that struck Japan March 11, 2011 may have slightly shortened the length of each Earth day and shifted its axis. Using a U.S. Geological Survey estimate for how the fault responsible for the earthquake slipped, a NASA research scientist applied a complex model to perform a preliminary theoretical calculation of how the Japan earthquake -- the fifth largest since 1900 -- affected Earth's rotation. The calculations indicate that by changing the distribution of Earth's mass, the Japanese earthquake should have caused Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds.