# Japan Quake May Have Shortened Earth Days, Moved Axis

The March 11, magnitude 9.0 earthquake in Japan may have shortened the length of each Earth day and shifted its axis. But don’t worry—you won’t notice the difference.

Using a United States Geological Survey estimate for how the fault responsible for the earthquake slipped, research scientist Richard Gross of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., applied a complex model to perform a preliminary theoretical calculation of how the Japan earthquake—the fifth largest since 1900—affected Earth’s rotation. His calculations indicate that by changing the distribution of Earth’s mass, the Japanese earthquake should have caused Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds (a microsecond is one millionth of a second).

The calculations also show the Japan quake should have shifted the position of Earth’s figure axis (the axis about which Earth’s mass is balanced) by about 17 centimeters (6.5 inches), towards 133 degrees east longitude. Earth’s figure axis should not be confused with its north-south axis; they are offset by about 10 meters (about 33 feet). This shift in Earth’s figure axis will cause Earth to wobble a bit differently as it rotates, but it will not cause a shift of Earth’s axis in space—only external forces such as the gravitational attraction of the sun, moon and planets can do that.

View NASA images of the earthquake area at https://www.nasa.gov/topics/earth/features/japanquake/index.html

## 6 thoughts on “Japan Quake May Have Shortened Earth Days, Moved Axis”

1. Mandar Kolhe says:

Regard this

2. KIERON says:

how long as it been shortened by

3. karthik says:

Great analysis….hope japan will recover soon…

4. jcgeny says:

the NASA people should hurry up to build some robots that could refresh the reactors .
that should be the top priority to create machine that can prevent reactors to explode . if that happen the region west of usa will be contaminated : intel / hollywood … will die of it

Well,

it’s good to know we’re not gonna see any of those sci-fi world armaggedon scenarios 🙂

Thanks for the info.

Regarding the comment one of the others readers wrote, I’m not sure if Japan is going to be recovering very soon from this. There are some estimates that the total damages is over 100 Billion Dollars and that this generation of Japanes won’t see Japan rebuilt so fast.