NASA Scientist Explains Science Behind 'Supermoon' Phenomenon
The tragic earthquake and tsunami in Japan Friday (March 11) set the Internet abuzz with the idea that the moon, which will be at its fullest of the year on March 19, played a role in the devastating natural disaster.
The seed for the idea was planted by an astrologer, who contended that this large full moon – a so-called "supermoon"– would touch off natural disasters like the Japan earthquake since the moon would make its closest approach to Earth in 18 years. Scientists, however, dismissed the notion entirely and now a top NASA scientist is weighing in.
In a statement released Friday, noted NASA scientist Jim Garvin explains the mechanics behind the moon's phases and the causes of the supermoon. Garvin is the chief scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.< class="fullpost">
"'Supermoon' is a situation when the moon is slightly closer to Earth in its orbit than on average, and this effect is most noticeable when it occurs at the same time as a full moon," Garvin wrote in the NASA statement. "So, the moon may seem bigger although the difference in its distance from Earth is only a few percent at such times."
The full moon of March will occur next Saturday on March 19, when the moon will be about 221,567 miles (356,577 kilometers) away from Earth. The average distance between the Earth and the moon is about 238.000 miles (382.900 km).
"It is called a supermoon because this is a very noticeable alignment that at first glance would seem to have an effect," Garvin explained. "The 'super' in supermoon is really just the appearance of being closer, but unless we were measuring the Earth-Moon distance by laser rangefinders (as we do to track the LRO [Lunar Reconnaissance Orbiter] spacecraft in low lunar orbit and to watch the Earth-Moon distance over years), there is really no difference."
It was astrologer Richard Nolle who linked the full moon of March 19 to natural disasters. He claimed that this "supermoon" would trigger massive earthquakes, volcanoes and powerful storms when it arrived. But scientists assure that this is not the case.
Garvin, for example, said the moon's effects on Earth have been the subject of extensive studies.
"The effects on Earth from a supermoon are minor, and according to the most detailed studies by terrestrial seismologists and volcanologists, the combination of the moon being at its closest to Earth in its orbit, and being in its 'full moon' configuration (relative to the Earth and sun), should not affect the internal energy balance of the Earth since there are lunar tides every day," Garvin wrote.
But while the moon helps drive Earth's tides, it is not capable of triggering devastating earthquakes.
"The Earth has stored a tremendous amount of internal energy within its thin outer shell or crust, and the small differences in the tidal forces exerted by the moon (and sun) are not enough to fundamentally overcome the much larger forces within the planet due to convection (and other aspects of the internal energy balance that drives plate tectonics)," Garvin explained.
The 'Supermoon' Did Not Cause the Japanese Earthquake and Tsunami
The devastating earthquake and tsunami that struck Japan early today (March 11) were "completely unrelated" to the approaching "supermoon," despite a news report that tied the earthquake to the upcoming lunar event, according to U.S. Geological Survey geophysicist John Bellini.
The supermoon will occur on March 19, when the moon is at or near its point of closest orbit — lunar perigee — and is also full. As we explained in our previous coverage of the upcoming supermoon, seismologists have found no evidence to believe that lunar perigees heighten seismic activity.
The best evidence that this earthquake was not caused by a supermoon is that it happened now — exactly a week away from the date the moon will be full, and almost a week after it was new, the two times that the moon exerts its greatest pull on the planet.
A very small correlation exists between full or new moons and seismic activity, because the stronger-than-usual tidal forces caused by the alignment of the sun and moon puts added stress on tectonic plates. [Photos: Our Changing Moon]
But this quake happened with the sun and moon askew — the time when tidal forces are weakest. Putting aside the fact that the moon doesn't trigger massive earthquakes, blaming this quake on the supermoon is like trying to pin a house fire on an arsonist who is out of town at the time of the crime.
The Japanese earthquake thus points to the fact that astrology — an astrologer was the first to suggest the supermoon could be a threat — isn't a science. That this earthquake occurred a week before an astronomical event is mere coincidence. The vast majority of earthquakes, tsunamis, volcanic eruptions and natural disasters do not follow the lunar cycle or tides. "This is something that builds up over hundreds of years," Bellini told Life's Little Mysteries.
source: space.com
No 'Supermoon'-earthquake connection: Scientists
The phrase 'Supermoon' is believed to have been coined by an astrologer, Richard Nolle, on his website, and spread to astronomers online. -- PHOTO: AP
THE mega earthquake that hit Japan on Friday had no connection to the 'Supermoon', scientists said, referring to an event on March 19 when the moon will be at its closest to Earth in 18 years.
Dr Paul Walker, a senior meteorologist for AccuWeather Inc, told ABC News that 'there is no connection between the moon's position' and the 8.9-magnitude earthquake, which is feared to have killed over 1,000 people. 'I don't think you can attribute it to being a full moon... These moon events can cause the tides to run higher than normal, but I've not heard of any correlation between them and extreme weather events,' Dr Walker added.
The phrase 'Supermoon' is believed to have been coined by an astrologer, Richard Nolle, on his website, and spread to astronomers online.
Mr Nolle had written that the last 'Supermoon' this year was just before the earthquake that hit Christchurch, New Zealand, in February. Other disasters occurring near a 'Supermoon' included Hurricane Katrina and the 8.8 Chile earthquake, Mr Nolle said in his post.
However, Nasa astronomer Dave Williams agreed with Dr Walker's view that the moon had no connection to the Japan quake, ABC News reported.
In an e-mail to ABCNews.com, Mr Williams said that at the time of the earthquake in Japan, the moon was actually closer to its furthest point in orbit from Earth than it was to its closest point (on March 19), 'so the gravitational effect of the moon was, in fact, less than average at that time'.
SOURCE: www.straitstimes.com
Did a supermoon cause the March 11 earthquake in Japan?
The moon’s farthest point from Earth for this month – was March 6. Perigee – the moon’s closest point to Earth for this month – will be March 19. On March 11, the moon was about halfway between its closest and farthest point to Earth.
So, on March 11, neither condition for a supermoon existed. The moon was not particularly close to Earth, and the Earth, sun and moon were not aligned. In fact – both in the sense of its distance from Earth, and also in the sense of an Earth/moon/sun alignment – the moon was far from the condition of “supermoon.” And yet there was this massive earthquake. What is the connection?
One more thing. My colleague at EarthSky – Bruce McClure, who writes most of our Tonight pages – passed along this link. You can see from the chart of perigee full moons on this page that these sorts of full moons – full moons coinciding with the moon’s closest point to Earth – happen about every 1 year 1 month and 18 days. You can also see from the chart that full moon distances do vary, but the variation in lunar distance is small in contrast to the moon’s overall distance.
For example, the last perigee full moon – on January 30, 2010 – was only 30 kilometers (20 miles) farther than the March 19, 2011 full moon will be. That’s in contrast to the moon’s mean distance of 384,400 kilometers (about 239,000 miles – or nearly a quarter million miles).
Supermoon conditions were not in effect during the March 11 8.9-magnitude earthquake in Japan. If a connection between supermoons and earthquakes exists, it should be easy to spot and track over time. Scientists will notice it and incorporate it into their efforts to predict earthquakes and save lives. Until then, the idea of a supermoon has not been supported by science.
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Source: earthsky.org
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