Chilean earthquake changed the planet's rotation, shortened the length of days

The massive 8.8 earthquake that hit Chile, the seventh strongest in recorded history, may have changed the entire Earth’s rotation, shortening the length of days on the planet, a scientist at NASA’s Jet Propulsion Laboratory said. According a computer model conducted by scientist Richard Gross, the quake shifted Earth’s axis by about eight centimeters, and shortened the length of an Earth day by 1.26 microseconds (millionths of a second).

Other strong earthquakes have altered Earth’s days and axis in the past, such as the 9.1 quake registered in Sumatra in late 2004. It shortened Earth's days by 6.8 microseconds and shifted its axis by about 7 centimeters. The Chilean one was smaller than the Sumatran earthquake but had a larger effect on Earth’s figure axis due to its location, in the mid-latitudes rather than near the Equator.