This is BS, based on how they phrase it. The moon’s not going to suddenly jump 20,000km closer next week. It’s gradually drawing closer over time due to the eccentricity of its orbit. The 19th is just the date of closest approach. It’s damn close to that perigee now, and a week is only going to make a difference of a few hundred kilometers, if that. Also, just because the moon’s tidal effect is greatest at new and full, doesn’t mean that its gravity well can’t affect the planet at other times. We still have tides when the moon isn’t full, or new, why is this any different?
Further, as noted above, just because it didn’t happen at closest approach, doesn’t mean that’s the only time it *could* happen. If the plates were right on the edge of slipping, any small input of energy could be the erg that broke the subduction zone’s back, so to speak.
All that said however, we’re talking about a 20,000km difference in an orbit that averages about 375,000km in radius. So right now, the moon’s about 356,000km away. Our moon’s pretty dense, but is it dense enough to affect the earth that much at such a distance?
When the Moon is full, the Earth is between the Sun and the Moon, so it's being pulled frm both sides like a tug of war. When the Moon is new, the Moon is between the Earth and the Sun so they pull together......
I wonder if anyone has correlated earthquakes with solar flares?
The square of the closest distance (now) is 1.25 times larger than the square of furthest distance between the Moon and the Earth. IOW, the tug of the Moon’s gravity is now 25% greater than it is, when the Moon is at apogee.
The gravitational constant is the proportionality constant used in Newton's Law of Universal Gravitation, and is commonly denoted by G. This is different from g, which denotes the acceleration due to gravity. In most texts, we see it expressed as:
G = 6.673x10-11 N m2 kg-2
It is typically used in the equation:
F = (G x m1 x m2) / r2 , wherein
F = force of gravity
G = gravitational constant
m1 = mass of the first object (lets assume it's of the massive one)
m2 = mass of the second object (lets assume it's of the smaller one)
r = the separation between the two masses