Supermoon" and Earthquakes: Is there a Correlation?
By Heather Buchman, Meteorologist
Mar 11, 2011; 3:02 PM ET
There has been much speculation about the upcoming "supermoon" on March 19, 2011 and what impacts it could have on the Earth.
Earthquakes and tsunamis, like the devastating ones that just hit Japan Friday, as well as volcanic eruptions and major storms, are included in the list of possibilities, according to some astrologers and conspiracy theorists.
There are scientists, however, who argue that "supermoons" do not play a role, and that natural disasters that have occurred around the time of a "supermoon" are just coincidence.
What Is a "Supermoon?"
A "supermoon" occurs when a new or full moon is at or near (within 90 percent of) its closest approach to Earth in a given orbit. This is the definition provided by Astrologer Richard Nolle, who gave this phenomenon its name in 1979.
This AP Photo by Dmitry Lovetsky captured the moon in St. Petersburg, Russia on Feb. 18, 2011. According to Nolle, the last "supermoon" was in effect at the time.
According an article written by Nolle, "supermoons" occur four to six times a year, and the "supermoon" on March 19, 2011 will be the second one this year.
AccuWeather.com Astronomy Blogger Mark Paquette discussed the topic of "supermoons" earlier this month. According to his research, an extreme "supermoon" occurs when the full or new moon is at 100 percent of its closest perigee to Earth, or the closest it can possibly get to Earth.
The "supermoon" on March 19, 2011 will be extreme.
Past "Supermoons" That Have Coincided with Natural Disasters
The last "supermoon" this year was in effect Feb. 12-21, Nolle said, just before the earthquake that left Christchurch, New Zealand in ruins on Feb. 22, 2011.
Nolle also stated that the last extreme "supermoon" occurred on Jan. 30, 2011, several weeks after the catastrophic earthquake that hit Haiti on Jan. 12, 2010.
Paquette also pointed out in his blog that the devastating earthquake and tsunami that hit Indonesia on Dec. 26, 2004 occurred about two weeks prior to a "supermoon" on Jan. 10, 2005.
More natural disasters, such as Hurricane Katrina, are mentioned in conjunction with "supermoons" in Nolle's article.
So What Effect Do "Supermoons" Actually Have on the Earth?
The moon does obviously have an influence on the Earth.
As Rich Briggs, research geologist with the U.S.G.S. stated, "The gravitational pull of the moon creates Earth tides and sea tides and causes portions of the Earth's surface to bulge."
In response to Friday's devastating earthquake offshore of Japan, however, Briggs said, "The moon does not need to be invoked to explain what caused this event. There are much simpler explanations."
He explained that the earthquake occurred along a major subduction zone, or convergent boundary.
"Along this subduction zone, the Pacific plate is colliding with the North America plate at a rate of 8 cm per year," Briggs said, "So that's the rate at which strain is accumulated. Over many decades and centuries, all that strain accumulates and eventually releases in one sudden rupture."
He added that slips along the fault when it ruptured Friday measured 18-20 meters, or about 60-65 feet.