posted on Oct, 18 2011 @ 06:20 AM
reply to post by Curling1
There is no reputable irrefutable evidence that tidal forces causes volcanic activity or an increase in earthquakes.
But lets examine how we arrive at that conclusion, but first let me remind you that the moon and sun exert over 98% of the tidal forces on earth in
the solar system, and by comparison if all of the planets could be in alignment directly opposite the earth and sun the combined tidal force would be
around 1.7% of what the moon exerts, and a comet is a millionth the mass of the moon, so that's why it's stated your Volkswagen exerts more tidal
force on the earth as you drive than any comet millions of miles away.
Lets also point out the greatest tidal forces the earth undergoes and put it into perspective, about once every 14 days the moon and sun are aligned
with earth, either a full or new moon, creating the highest tides or force on earth, hence they are called the "fortnightly" tides. This also
creates a bulge in the earth but is this bulge enough to move tectonic plates or make volcanos more likely to erupt?
The USGS has measured this and offer a nice illustration on how much of a bulge this is. The earth's surface tilts up to 0.03 microradians in
response to the apparent passage of the moon overhead. A tilt of one microradian is the tilt of a solid bar one kilometer long with one end raised by
the thickness of a dime.The idea is that if a volcano is full of magma, the squeezing at the fortnightly tidal maximum might be just enough to
overcome the resistance of the crust, push magma out, and get an eruption going. This is ludicrous! Not good enough?
More than 25 years ago, a pair of earth scientists compared the records for 680 eruptions that occurred since 1900 and found that "the probability of
an eruption is greatest at fortnightly. A specific look at 52 Hawaiian eruptions since January 1832 shows the same sort of pattern. Nearly twice as
many eruptions have occurred nearer fortnightly tidal maximum than tidal minimum.
Although this is a fascinating correlation, there are just too many tidal maximums and too many volcanoes to base predictions on tidal cycle alone. In
the Hawai'i example of 52 eruptions since January 1832, there have been nearly 3,900 tidal maximums, of which roughly 3,850 of them went by without
causing an eruption. Statistically, this is about one percent!