It is pure unadulterated nonsense. The isostatic rebound causing volcanoes is even pretty idiotic just from the common sense point of view. From a scientific point of view it is beyond stupid.
The actual amount of change that 500 meters of ice would make, which is the max amount in Iceland, not how much it melted would amount to a change in the level of the magma by about 20 meters. It would make it about 20 meters deeper not shallower. That isn't what causes the volcanoes though.
The movement of the crust might even help trigger one a little bit earlier but it was going to go off anyway. It is part of the mid Atlantic ridge. Logic would dictate that loss of ice would make it less likely to erupt.
Earthquakes probably would be more frequent from the crust rebounding but again, it doesn't cause them. It might be a factor in triggering them. It probably doesn't even apply in this case.
The volcano erupted under the glacier. They are trying to scare people with nonsensical scenarios that are a complete fantasy in the real world but what is new. http://wattsupwiththat.com/2010/04/16/re...
What Prof Weisman is referring to is something called Isostatic Rebound (or glacial rebound). When the mass of glacial ice pushing down on a part of the Earth is decreased the ‘springiness’ of the Earth’s surface allows the ground to bounce back. It’s a very slow process and is something that happens over many thousands of years.
Today sea-levels are rising by 3.2mm a year, most of this is down to glacial run off and thermal expansion but a part of it is the result of isostatic rebound continuing after the last glacial retreat c10,000 years ago. If Weisman were correct then we should have seen a massive (and I mean MASSIVE) increase in volcanic activity coinciding with the end of the last ice age. More ice melted during this episode than exists on the whole of the planet today (~45 quintillion tons melted, ~30 quintillion tons remain).
Further, if he were correct then there should be a correlation between the tectonic plates most affected by recent ice-melt and volcanic activity, there isn’t. Iceland is on the Eurasian Plate, the greatest ice-melt is occurring above the North American Plate, the next greatest above the Antarctica Plate. Statistical analysis comparing the locations of earthquakes and volcanic activity with the tectonic plates most directly affected by isostatic rebound would appear to indicate that the incidence of such geological activity is actually below the statistical mean.
It may also be worth taking into account the magnitude of ice-melt. As mentioned, there is ~30 quintillion tons of ice on the planet, this is melting at ~700 billion tons per year. To put it another way, each year about one 40,000th of the total volume of ice is melting.
From the limited evidence it would appear that Weisman’s supposition is in diametric contradiction to the observed events. Of course, the sample size and my five minutes looking at a map of tectonic plates hardly constitutes a scientific study and no conclusions of any kind should be inferred. - - - - - - - - - - - - - - On a slightly separate note.
You commented “Or is this simply alarmism, bred by the current climate of hysteria over global warming?”. Yes, this is alarmism but if you’re going to level this kind of accusation then you need to look at the skeptics and deniers camp as well. Weisman is a journalist not a scientist, journalists have written all manner of garbage concerning climate change and together with bloggers are the primary source of arguments used by the skeptics and deniers.
If you’re going to dismiss Weisman then I have to assume that in the interests of fairness and impartiality that you will also be dismissing other journalists as well. The scientific process and debate does not allow for selectivity.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.