Earth's mass distribution changes in the Japanese earthquake of 1.8 microseconds shorter day

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(Free-Press-Release.com) March 15, 2011 -- This image reflects the March 11 earthquake in Japan, the main shock (solid line largest red circle), and the subsequent location of a large number of aftershocks (virtual coils). 9, also before there was a strong 7.2 magnitude earthquake, followed by a large number of aftershocks is also accompanied by (the real figure in the small coil)

SAN FRANCISCO, March 16 News, March 11 earthquake in Japan caused by the length of a day on Earth changes, and changes in the Earth's overall mass distribution.

According to the latest data analysis, this magnitude 9.0 earthquake quickened Earth's rotation, thus shortening the length of day. According to NASA's Jet Propulsion Laboratory, a geophysicist Richard Gross (Richard Gross) estimate the magnitude of shortening is about 1.8 microseconds.

Taking into account the earthquake on the Earth's overall mass distribution within what effect, Gross calculated before the value is about 1.6 microseconds, but he was later carried out according to the latest revised data. 1 microsecond to 100 microsecond.

He said: "By changing the mass distribution within the Earth, Japan, earthquake in the Earth's rotation speed, thus shortening the length of day, by about 1.8 microseconds." Of course, with the summary of the updated data back further and perhaps an updated amendment.

This is figure skating athletes like to do to tighten his rotation action arms, thus speeding up the rotation speed. During the earthquake, the earth mass distribution more concentrated to the equatorial regions, the Earth would turn faster.

Earth day length of about 24 hours, or 86400 seconds. However, due to the seasonal occurrence of Earth's mass distribution changes, the length of the minor differences exist. In the year, its length there is about 1 millisecond, or 1000 microsecond differences. There are many reasons for this difference, such as the atmosphere in different seasons of the distribution of high-altitude jets are quite different, this will affect the Earth's mass distribution.

According to preliminary data analysis, the U.S. Geological Survey Kenneth Hoda special (Kenneth Hudnut) to calculate the shift Honshu Island in Japan earthquake of 8 feet (2.4 meters), and to shape the Earth axis (figure axis) changes in the past 17 cm.

The shape of the Earth axis and rotation axis are different concepts. Axis of rotation of Earth around its axis of rotation, while the axis of Earth's mass distribution is based on the reference axis, around the axis of the Earth showing symmetrical distribution of mass.

Gross said: "This change in shape of the shaft may cause the Earth's rotation occurred during the past not the same as shaking, but space does not change the Earth's rotation axis points. Alter the Earth's rotation axis points to only the external gravity, Therefore, only the sun, moon or other planets, these objects can do. "

This is not the first time a major earthquake because the day is often a result of changes in the earth. In the past, earthquakes have led to change the length of time a day. Last year in Chile, magnitude 8.8 earthquake accelerated the Earth's rotation, shortening the length of time the day of 1.26 microseconds, while the waters near the island of Sumatra in 2004 the 9.1 magnitude earthquake is the length of time a day shortened by 6.8 microseconds. In addition, the consequences of the earthquake in Japan will not end so soon. The aftershocks continue to occur may also be minor changes to the length of time a day.

According to the U.S. Geological Survey data, the 9.0-magnitude earthquake in Japan is the country's strongest earthquake in history, but also human beings since 1900 has the fourth largest earthquake ever recorded. Its epicenter was located 373 kilometers northeast of Tokyo, the ocean, about 130 km away from Sendai City. Strong earthquake triggered a tsunami that swept across the entire northeast coast. After the main shock has been recorded at least 20 times more than the strong 6.0 aftershock.

"In theory, any change in the Earth's mass distribution of the length of the day things will change," Gross said. "So despite the smaller magnitude, but these aftershocks same day the Earth will affect the length of time. However, these shocks is relatively small, its impact will be smaller.