Great, just when we thought we at least had a handle on how bad things could get…

Surely when the moon is new the Tidal force = Moon force – Sun force, so will result in lower than normal tidal ranges?

No.

How it works is along these lines:

Every tidal force arises as the result of the gravitational force from one object (let’s call it A) declining with distance. If another object (let’s call it B) nearby is large enough, the difference in gravitational attraction caused by A from the proximal side to the distal side of B means that B gets stretched by the gradient in A’s gravity. Thus, if Earthly tides were caused by the moon only, we’d always have tides the same height, and there’d always be a high tide on the side of Earth facing the moon, and a high tide on the side of Earth opposite the moon, with low tides in regions that are facing 90° away from the Earth-Moon line.

With the sun’s gravity in the mix too, we have tides from both the moon and the sun at the same time. This means that, when the moon and sun are at right angles in the sky from our perspective (i.e. waxing or waning quarter moon), we have smaller tides. These are Neap tides. When the sun and moon fall on the same line through the Earth, whether it is new or full moon, we get larger tides as the tidal forces add up. These are called Spring tides, and they occur roughly twice each month, around the time of both full and new moon.

To add to the effect of waves and tides, hurricanes tend also to generate a large storm surge – an upward bulge of water caused by the reduced pressure of the air at the centre of the storm. It was a combination of strong winds (and thus large waves), Spring tides and a massive storm surge that caused so much flooding around the North Sea (mainly the Netherlands and East Anglia) in 1953. There’s even a wikipedia entry about it.

Edited to add – D’oh, I just saw your post #20, so you don’t need all this stuff now.

One nice thing about quakes is that they’re one of the few natural disasters that (as far as we know so far) can’t be exacerbated or made more common by climate change.

You know, it’s funny you should mention it, but I recall reading somewhere that as land-based ice sheets melt, earthquakes will become more common in the vicinity as the earth that was previously beneath the ice “rebounds”, having had several million tons of ice removed from on top of it.

After a stew . . . I googled nasa hurricane weather report … ( I know right, of all things ) and in the National Hurricane Center Rainfall Expectations section are the expectations.

http://www.nasa.gov/mission_pages/hurricanes/archives/2012/h2012_Sandy.html

So if I have this right last night there was a mega storm brewing off Florida a 7.7 struck just above our heads here in Washington and a tsunami was headed for Hawaii. I wonder if that’s just a typical night for the Earth.