Scientists Say Earthquake Caused Shift in Earth's Axis

Vanessa Evans – Sun Mar 13, 5:44 pm ET

It appears the 8.9 earthquake that shook Japan on Friday as well as causing massive damage and loss of life in that nation, also had some global implications as well. Multiple scientific reports started surfacing in the aftermath of the quake that estimate that the actual rotation of the Earth may have been affected, as well as Japan's physical position and other global phenomena.
The scientific community takes an intense interest in natural disasters like the Japanese earthquake because monitoring the action both during and after the event can provide huge clues as to how the Earth itself is constructed and moves.
There have been several developments in scientific understanding of the Japanese earthquake in the last couple of days.
* Although the largest earthquake recorded on Friday was the massive 8.9 quake that caused the vast majority of the damage, there have been hundreds of aftershocks, some of which reached magnitude 6 strength, according to the U.S. Geological Survey.
* Any number of those aftershocks were as large as the earthquake that shook Christchurch, New Zealand, late last month.
* Geophysicist Richard Gross of NASA's Jet Propulsion Laboratory in California, has estimated that the Japanese earthquake shortened the Earth's day by 1.8 microseconds. Gross also said that the axis of the Earth probably shifted about 6.5 inches, which affects how it rotates, but not its position or movement in space.
* The Japanese Meteorological Agency has actually upgraded the earthquake to a magnitude of 9.0, although other global agencies have yet to follow suit. The U.S. Geological Survey's Susan Hough maintained that great quakes are harder to measure and that a difference of .1 magnitude in initial strength estimates is not unusual.
* The U.S. Geological Survey initially estimated that Japan as a whole has physically moved by approximately 8 feet, but other scientists around the globe have estimated that some parts of the country may actually have moved as much as 12 feet closer to North America. In addition, parts of the country's terrain are not permanently under sea level, which will make it difficult for the flooding caused by the tsunami to drain.
* The tsunami that followed the earthquake was caused when the Pacific Plate shifted, actually moving under Japan at the Japan Trench. This caused additional tremors and the devastating wave that crashed into the nation's east coast.
* The loss of 1.8 microseconds as a result of the shift in the Earth's axis is unlikely to cause more than minute changes, but among those changes will actually be differences in the passing of the seasons. This will only be observable using satellite navigation systems with very precise monitoring equipment.
* The shift of the Earth's axis and loss of time is similar to that experienced after the Chilean earthquake last year, which sped up the Earth's rotation and resulted in the loss of 1.26 microseconds.

Reference: http://news.yahoo.com/