Blog authored by AccuWeather Astronomy expert on Facebook, Daniel Vogler.
On May 6, 2012 we will have the closest lunar perigee of the year to coincide with a full moon, known as an Extreme Super Moon. What is a Super Moon you ask? It’s when the moon gets to its closest point to Earth coinciding with a syzygy within 90% or greater of its mean perigee. To calculate this, we need some numbers. We can either use this years numbers or an easier route would to use average mean perigee and apogee distances. But why do that?
Using the Lunar Perigee and Apogee Calculator website, we see that the closest perigee of 2012 is May 6 @ 356,953 km. The farthest apogee is 13 days later on May 19th @ 406,450 km. Subtracting the distance gives you 49,497 km. So 90% of that would be 44,547 km. Any syzygy that’s closer than 406,450 - 44,547 or 361,903 km would be by definition a Super Moon, in accordance to Richard Nolle, the astrologer gets credit for coining the phrase.
At 100% (its closest approach of the year) it is known as an Extreme Super Moon. The “Extreme” has been misguided throughout the internet, where people think it only happens every 17 years, which is not true. It happens every year on the closest Super Moon of the year, only the distances vary from year to year. (For example: last years Extreme Super Moon was 400 km closer than this years).
What makes this event stand out is not the distance that it gets, rather the timing.
At 3:34 UTC, the Moon will be at full moon syzygy. Then only TWO minutes later, at 3:36 UTC, the Moon will be at its closest point, a perigee at roughly 356,900 km. I looked back at other Super Moon data and cannot find any closer than that timing-wise, remarkable!
So lets talk about what this will bring us. As you all know, the tide is controlled by the gravitational pull of the Moon and its distance and position determines how much the tide rises and falls.
What we have on May 6th is what we call a perigean spring tide. A spring tide isn’t named because of the season, it literally means spring, jump out. Spring tides occur around New and Full moons and tend to have higher “high-tides” and lower “low-tides”. So you can imagine when this coincides with an Extreme Super Moon, giving you the perigean spring tide. On average, the tide increases 25% during these times. That’s a lot of water displacement over the course of the day! Not only will we have to watch for coastal flooding if there happens to be a storm brewing nearby, as what happened back in 1962, “...a catastrophic perigean spring tide struck from the sea in the darkness of predawn, and for the following 65 hours inundated the entire Atlantic coastline of the United States from the Carolinas to Cape Cod". This disastrous event resulted in a loss of 40 lives and over $0.5 billion in property damage. As other representative examples, severe tidal flooding of similar origin occurred in regions of the Atlantic coast on Dec. 30, 1959, March 4-5, 1931, and April 10-12, 1918 and at points along the Pacific coast on March 6, 1970, Feb. 3-4, 1958, and Jan. 3-5, 1939. Still further flooding was experienced simultaneously on both coastlines on Dec. 11, 1973, March 26, 1971, and Jan. 6, 1931. All of these instances of coastal flooding were caused by a special combination and reinforcement of the gravitational forces of the Sun and Moon producing unusually high tides-which were concurrently lifted onto the land by strong, persistent onshore winds. Such exceptionally high tides and their accelerated ocean currents coupled with intense sea-surface winds-accompanied the total destruction of an offshore Air Force radar tower on Feb. 12, 1963.”
Please see the link here to see the quote above in its entirety.
What I want to concentrate on though, is the higher risk for major earthquakes. Yes, the March 11th Japan quake did happen a week before the 2011 Extreme Super Moon but that wasn’t the tipping point, as Richard Nolle points out in a reply to the debunkers. “During the March 19 Super Moon window: 66 at last count, not quite halfway through the cycle. However much of this shaking consists of aftershocks from the magnitude 9.0 mega-quake that struck Japan on March 11 (midway between the February and March Super Moons and within the customary plus or minus 30-hour window of the March 12 north lunar declination peak, the same combination of lunar extremes present when the Dec. 26, 2004 mega-quake and tsunami struck). There has been a surfeit of moderate-to-severe (magnitude 5+) seismic activity.” (Quoted on March 22nd 2011)
Again, please see the link here to see where the above quote came from.
The window for major earthquakes will be from May, 3rd-9th in UTC time, as the tide shifts millions of tons of water on the ocean floor. Watch for coastal flooding and an increase in major quakes. As far as pinpointing the whereabouts, I have yet to figure out astro-locality maps, being that's an astrology tool, I won't use it in this blog, but going by patterns, I would say somewhere near the Australia/New Zealand region.
You can leave your comments, as well as be part of a community where discussions on any astronomy subject such as light pollution when you join AccuWeather's Astronomy facebook fanpage by clicking here.
We are now well over 3,200 likes. Tell your friends about this site and blog and have them weigh in on some exciting issues. We encourage open discussion and will never criticize any idea, and no negative conversation will be allowed.
My experts will keep you up-to-date on any astronomy related subject. Please feel free to share your opinions.
And please keep the astronomy pictures coming. They have been simply amazing. Ask questions, share comments, share anything.
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
Stargazers are in for a treat on Monday night as Jupiter rises in tandem with the full moon.