Post by Wes on Mar 2, 2010 22:23:11 GMT 10
Days 'shorter after Chilean earthquake'.
The earthquake that killed more than 700 people in Chile probably shifted the Earth's axis and shortened the day, Bloomberg reported.
The earthquake that struck Chile measured at an 8.8 magnitude, putting the entire Pacific on tsunami alert.
Scientists say earthquakes involve shifting hundreds of kilometres of rock by several metres, changing the distribution of mass on the planet which affects the Earth’s rotation.
NASA’s research reportedly shows the length of the day should have shortened by 1.26 microseconds.
"The axis about which the Earth’s mass is balanced should have moved by 2.7 milliarcseconds, which is about eight centimeters," Richard Gross, a geophysicist at NASA's Jet Propulsion Laboratory in California, explained.
"It’s what we call the ice-skater effect," David Kerridge, head of Earth hazards and systems at the British Geological Survey in Edinburgh reportedly told Bloomberg.
"As the ice skater puts when she’s going around in a circle, and she pulls her arms in, she gets faster and faster. It’s the same idea with the Earth going around if you change the distribution of mass, the rotation rate changes."
Some changes may be more obvious, and islands may have shifted, according to Andreas Rietbrock, a professor of Earth Sciences at Liverpool University in the UK.
"What definitely the earthquake has done is made the Earth ring like a bell," Rietbrock said to Bloomberg.
The last time a day was shortened was when the magnitude 9.1 Sumatran quake hit in 2004, triggering the Boxing Day tsunami.
The day was reduced by 6.8 microseconds and shifted the axis by about 2.3 milliarcseconds.
au.news.yahoo.com/queensland/a/-/newshome/6877960/days-shorter-after-quake
The earthquake that killed more than 700 people in Chile probably shifted the Earth's axis and shortened the day, Bloomberg reported.
The earthquake that struck Chile measured at an 8.8 magnitude, putting the entire Pacific on tsunami alert.
Scientists say earthquakes involve shifting hundreds of kilometres of rock by several metres, changing the distribution of mass on the planet which affects the Earth’s rotation.
NASA’s research reportedly shows the length of the day should have shortened by 1.26 microseconds.
"The axis about which the Earth’s mass is balanced should have moved by 2.7 milliarcseconds, which is about eight centimeters," Richard Gross, a geophysicist at NASA's Jet Propulsion Laboratory in California, explained.
"It’s what we call the ice-skater effect," David Kerridge, head of Earth hazards and systems at the British Geological Survey in Edinburgh reportedly told Bloomberg.
"As the ice skater puts when she’s going around in a circle, and she pulls her arms in, she gets faster and faster. It’s the same idea with the Earth going around if you change the distribution of mass, the rotation rate changes."
Some changes may be more obvious, and islands may have shifted, according to Andreas Rietbrock, a professor of Earth Sciences at Liverpool University in the UK.
"What definitely the earthquake has done is made the Earth ring like a bell," Rietbrock said to Bloomberg.
The last time a day was shortened was when the magnitude 9.1 Sumatran quake hit in 2004, triggering the Boxing Day tsunami.
The day was reduced by 6.8 microseconds and shifted the axis by about 2.3 milliarcseconds.
au.news.yahoo.com/queensland/a/-/newshome/6877960/days-shorter-after-quake