Concepción Goes West and the Earth Slows Down

The factual news behind this sensational headline is a matter of scale and relativity. The massive 27th February earthquake off the Chilean coast has caused the tragic death of reportedly over 700 people and massive localised destruction.

Research scientists including some geophysicists, on the ground, were quick to analyse and produce measurements from the data gathered at the time. They report that the 8.8 magnitude earthquake (moment magnitude scale) lasted nearly four minutes. The tremor was so powerful that it moved the entire city of Concepción 3.04 m to the west, the capital Santiago 24 cm and even the Argentinean capital Buenos Aires (nearly 1300 km away) shifted 3.9 cm. The research team deduced the cities’ movement by comparing precise GPS locations known before the earthquake with those almost 10 days later. This change would definitely affect GPS positioning and large scale mapping.

Map from OSU Research News Website: Researchers Show How Far South American Cities Moved in Quake.

Richard Gross a US Jet Propulsion Laboratory research scientist has computed how the earth's rotation should have changed as a result of the quake. A preliminary calculation using a complex model predicted that the length of an earth day has been shortened by about 1.26 microseconds (1.26 millionths of a second). This change would have little effect on most people

For further information see:
Ohio State University (OSU) Research News Website: Researchers Show How Far South American Cities Moved in Quake.
NASA News: Chilean Quake May Have Shortened Earth Days