[Psycho_Bunny]

Actually, wouldn’t the greater amounts of ice increase the pressure of the magma and lead to bigger erruptions?

[muawiyah]

The greater part of the ice on top of Iceland disappeared for the most part about 13,000 years ago. The amount that's been there since has been a quite modest percentage.

[SpaceBar]

Actually, wouldn’t the greater amounts of ice increase the pressure of the magma and lead to bigger eruptions?

There is some truth to what they are saying but it is counterbalanced by factual inaccuracies in their claims. Here's why: overburden does in fact cap magma, specifically it keeps dissolved gasses in solution. Mount St. Helens is a prime example of an earthquake causing a landslide which relieved overburden which caused dissolved gasses to "boil out" resulting in a massive volcanic explosion. Problem is, icelandic vulcanism is from a mid-oceanic ridge and is therefore basaltic. Basaltic magmas are MUCH less viscous (e.g. more fluid) than the continental rhyolite/dacite composition of Mount St. Helens, which is more like gas charged toothpaste, and therefore exsolved gasses are not explosively released but rather gently vented. So they've jumbled some science in with some misconceptions and packaged it up as some sort of scientific mumbo-jumbo which in the final analysis ain't worth squat.