Post by Tulameen on Feb 15, 2005 12:06:36 GMT -5
Asia Quake, Tsunami Moved Islands, Shortened Days
Thu Feb 10, 2005 9:46 AM ET
By Jim Loney
JAKARTA (Reuters) - The massive earthquake that triggered the Asian tsunami wobbled the earth on its axis, forced cartographers back to the drawing board and changed time by a fraction, but there's no need to adjust your clocks.
Six weeks after the tsunami that may have killed 300,000 people on the shores of the Indian Ocean, scientists are discovering more about the changes wrought by the magnitude 9 quake, the fourth-largest in the last century.
It caused upheaval on the sea floor near its epicenter off the northwest coast of Indonesia's Sumatra island and moved several other islands, but scientists say any movement of land mass can be measured in inches rather than tens of yards.
Chen Ji, a seismologist at the California Institute of Technology, said he found movement along the fault line of about 33 feet laterally and 13-16 feet vertically.
But reports that the entire island of Sumatra -- 1,060 miles long and 250 miles wide -- 115 feet or more are wildly inaccurate, scientists say.
"We know we have movements of over a meter (yard), perhaps a couple of meters," said Ken Hudnut, a California-based geophysicist with the U.S. Geological Survey. "But the idea that Sumatra has moved 100 feet is just wrong."
Scientists are working on precise measurements by comparing geographic points whose locations were known before the quake with their new positions using the Global Positioning System, which reads exact locations by satellite.
High-tech British and U.S. ships are investigating changes to the sea bed and local authorities are measuring depths in critical shipping channels.
SHORTER DAY
Scientists at NASA, the U.S. space agency, said the Dec. 26 quake -- the largest to rattle Earth since 1964 in Alaska -- disrupted the planet's rotation and shaved 2.68 microseconds, or millionths of a second, from the length of a day.
NASA scientists B. F. Chao and Richard Gross calculated it shifted Earth's mean north pole about 1 inch and made the planet slightly less oblate, or flattened at the poles.
From Reuters.
Thu Feb 10, 2005 9:46 AM ET
By Jim Loney
JAKARTA (Reuters) - The massive earthquake that triggered the Asian tsunami wobbled the earth on its axis, forced cartographers back to the drawing board and changed time by a fraction, but there's no need to adjust your clocks.
Six weeks after the tsunami that may have killed 300,000 people on the shores of the Indian Ocean, scientists are discovering more about the changes wrought by the magnitude 9 quake, the fourth-largest in the last century.
It caused upheaval on the sea floor near its epicenter off the northwest coast of Indonesia's Sumatra island and moved several other islands, but scientists say any movement of land mass can be measured in inches rather than tens of yards.
Chen Ji, a seismologist at the California Institute of Technology, said he found movement along the fault line of about 33 feet laterally and 13-16 feet vertically.
But reports that the entire island of Sumatra -- 1,060 miles long and 250 miles wide -- 115 feet or more are wildly inaccurate, scientists say.
"We know we have movements of over a meter (yard), perhaps a couple of meters," said Ken Hudnut, a California-based geophysicist with the U.S. Geological Survey. "But the idea that Sumatra has moved 100 feet is just wrong."
Scientists are working on precise measurements by comparing geographic points whose locations were known before the quake with their new positions using the Global Positioning System, which reads exact locations by satellite.
High-tech British and U.S. ships are investigating changes to the sea bed and local authorities are measuring depths in critical shipping channels.
SHORTER DAY
Scientists at NASA, the U.S. space agency, said the Dec. 26 quake -- the largest to rattle Earth since 1964 in Alaska -- disrupted the planet's rotation and shaved 2.68 microseconds, or millionths of a second, from the length of a day.
NASA scientists B. F. Chao and Richard Gross calculated it shifted Earth's mean north pole about 1 inch and made the planet slightly less oblate, or flattened at the poles.
From Reuters.