Tuesday, June 07, 2011

Does it seem like you can't get as much done as you used to? Maybe this is the reason. Our days are shorter than last year. Seems the massive earthquake that struck northeast Japan back on March 11 shortened the length the day by a bit.

I was reading that scientists using new more accurate data of the 8.9 magnitude quake found it was so intense that it actually accelerated Earth's spin, shortening the length of the 24-hour day by 1.8 microseconds. If you are wondering a microsecond is a millionth of a second.

Maybe that doesn't seem like much to you since each day is about 24 hours, or 86,400 seconds, long. BTW the speed which the earth turns actually changes several times during a year. It can vary by one millisecond ( 1,000 microseconds) due to seasonal variations in the planet's mass distribution such as the seasonal shift of the jet stream.

I was also interested to read that Japan is no longer located in the same place. The same data also showed Japan moved about 8 feet. Wonder how that will effect GPS landings ?

And if that was enough our seasons will change too. The earthquake also shifted Earth's figure axis by about 6 1/2 inches.

But don't worry. This is the first time this kind of thing has happened. Last year the 8.8 magnitude quake in Chile sped up our days by 1.26 microseconds. And the 2004 9.1 quake in
Sumatra shortened the day by 6.8 microseconds.

Well I'll sleep better now.

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