Tag: Earthquake

Adjust your alarm clock!

A fascinating, perhaps even non-trivial, insight into that massive earthquake.

(Thanks to the website Mish’s Global Economic Trend Analysis for giving me a heads-up to this aspect of the ‘quake.)

MISH’s website pointed me to the website Space.com where there was this interesting reflection.

The massive earthquake that struck northeast Japan Friday (March 11) has shortened the length Earth’s day by a fraction and shifted how the planet’s mass is distributed.

A new analysis of the 8.9-magnitude earthquake in Japan has found that the intense temblor has accelerated Earth’s spin, shortening the length of the 24-hour day by 1.8 microseconds, according to geophysicist Richard Gross at NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

Gross refined his estimates of the Japan quake’s impact – which previously suggested a 1.6-microsecond shortening of the day – based on new data on how much the fault that triggered the earthquake slipped to redistribute the planet’s mass. A microsecond is a millionth of a second.

“By changing the distribution of the Earth’s mass, the Japanese earthquake should have caused the Earth to rotate a bit faster, shortening the length of the day by about 1.8 microseconds,” Gross told SPACE.com in an e-mail. More refinements are possible as new information on the earthquake comes to light, he added.

The scenario is similar to that of a figure skater drawing her arms inward during a spin to turn faster on the ice. The closer the mass shift during an earthquake is to the equator, the more it will speed up the spinning Earth.

I was also interested to read in that article more confirmation that the earthquake moved Japan! (I had mentioned it in an earlier post on Learning from Dogs.)

The initial data suggests Friday’s earthquake moved Japan’s main island about 8 feet, according to Kenneth Hudnut of the U.S. Geological Survey. The earthquake also shifted Earth’s figure axis by about 6 1/2 inches (17 centimeters), Gross added.

The Earth’s figure axis is not the same as its north-south axis in space, which it spins around once every day at a speed of about 1,000 mph (1,604 kph). The figure axis is the axis around which the Earth’s mass is balanced and the north-south axis by about 33 feet (10 meters).

“This shift in the position of the figure axis will cause the Earth to wobble a bit differently as it rotates, but will not cause a shift of the Earth’s axis in space – only external forces like the gravitational attraction of the sun, moon, and planets can do that,” Gross said.

So if you are the sort of person that likes to be precisely on time ….. take note!

The full moon – very full!

Brought forward as a result of the Japanese earthquake.

I had this item scheduled for publication on Friday 18th March, the day before this month’s full moon.  But recent events in Japan made me decide to bring it forward to today for reasons that will be clear when this Post is read further.

The world is set to experience the biggest full moon for almost two decades when the satellite reaches its closest point to Earth next weekend.

On 19 March, the full moon will appear unusually large in the night sky as it reaches a point in its cycle known as ‘lunar perigee’.

Stargazers will be treated to a spectacular view when the moon approaches Earth at a distance of 221,567 miles (356,577 km) in its elliptical orbit – the closest it will have passed to our planet since 1992.

The full moon could appear up to 14% bigger and 30% brighter in the sky, especially when it rises on the eastern horizon at sunset or is provided with the right atmospheric conditions.

Moon apogee and perigee

This phenomenon has reportedly heightened concerns about ‘supermoons’ being linked to extreme weather events – such as earthquakes, volcanoes and tsunamis. The last time the moon passed close to the Earth was on 10 January 2005, around the time of the Indonesian earthquake that measured 9.0 on the Richter scale.

Hurricane Katrina in 2005 was also associated with an unusually large full moon.

Previous supermoons occurred in 1955, 1974 and 1992 – each of these years experienced extreme weather events, killing thousands of people.

However, an expert speaking to Yahoo! News today believes that a larger moon causing weather chaos is a popular misconception.

Dr Tim O’Brien, a researcher at the Jodrell Bank Centre for Astrophysics at the University of Manchester, said: “The dangers are really overplayed. You do get a bit higher than average tides than usual along coastlines as a result of the moon’s gravitational pull, but nothing so significant that will cause a serious climatic disaster or anything for people to worry about.”

But according to Dr Victor Gostin, a Planetary and Environmental Geoscientist at Adelaide University, there may be a link between large-scale earthquakes in places around the equator and new and full moon situations.

He said: “This is because the Earth-tides (analogous to ocean tides) may be the final trigger that sets off the earthquake.”

UPDATE: This was noted in Naked Capitalism on Saturday.

Volcanoes have reportedly erupted in JapanIndonesia, and Kamchatka Russia today, presumably due to the massive Japanese earthquake. There have been no reports of damage from the eruptions.