Quake moved Sumatra 20cm
2005-02-01 11:32
Copenhagen - The Indonesian islands of Sumatra moved only 20cm on average after last month's Asian earthquake and tsunami, and not dozens of metres as previously feared, media reported on Monday, quoting calculations by the Danish Space Centre.
The new numbers, reported on television channel TV2's website, vary greatly from reports in the days following the devastating December 26 earthquake that the tip of the Sumatra island may have moved by as much as 36m.
US Geological Survey scientist Ken Hudnut told AFP on December 27 that some of the smaller Sumatra islands may have moved about 20m while the northeastern tip of the Indonesian territory could have slid about 36m to the southwest after the quake, which measured 9.0 on the Richter scale.
Scientists Shfaqat Abbas Khan and Olafur Gudmundsson of the Danish Space Centre, who used a GPS satellite system to determine the extent of the plate movement following the earthquake, have however since found that the island did not move more than 20cm on average.
"For the Sumatra earthquake there were horizontal moves of about seven metres around the crack area. But that area is about 200 to 300km west of Sumatra, so Sumatra itself could only have moved about 20cm," Khan told TV2.
The two Danish scientists' findings also contradicts a report from the Malaysian navy published on Monday stating that the depth in certain stretches of the narrow Malacca Strait, one of the world's busiest shipping lanes, had changed by as much as two metres after the quake.