Chilean quake was so strong, it shortened days: NASA

WASHINGTON - The massive 8.8-magnitude earthquake that struck Chile on Saturday was so strong that it may have shortened the length of a day, NASA scientists said.

Using a computer model, Richard Gross, a scientist at the space agency’s Jet Propulsion Laboratory in California, found the earthquake likely shifted the Earth’s figure axis by about 8 centimetres.

The shift of the axis on which the planet’s mass is balanced slightly changes the length of time it takes the Earth to make a complete rotation, meaning each day is now about 1.26 microseconds shorter.

The infinitesimal shift is slightly more than a similar change after the magnitude-9.1 quake that struck Sumatra in 2004, Gross said. Even though the magnitude of the Chilean quake was slightly less, its location and the angle of its fault lines made it more likely to shift the axis.

The quake and a resulting tsunami killed more than 700 people. It was felt over 1,600 kilometres across Chile.