The powerful earthquake that killed hundreds of people in Chile on Saturday probably shifted the Earth's axis and made days slightly shorter, a Nasa scientist has said. Richard Gross, a research scientist at Nasa's Jet Propulsion Laboratory in California, calculated how much the axis may have changed in position following the the disaster. More than 700 people died and two million are estimated to have been affected by the 8.8-magnitude tremor and subsequent tsunamis. The quake, the most powerful to hit the nation in 50 years, sent shockwaves out from the epicentre 70 miles from Chile's second city, Concepcion. Buildings and roads collapsed and 500,000 homes have been left severely damaged. If the planet's axis did shift by 8cm during the quake, days would have shortened by 1.26 microseconds, Mr Gross calculated. A microsecond is one-millionth of a second. Earth days are 24 hours long because that is the amount of time it takes the planet to make one full rotation on its axis, so shifting the axis would affect rotation.