23 February 2008

Another reason to avoid beachfront property..

Some important glaciers in Antarctica are accelerating at an alarming rate.

So what?

We've heard about glaciers accelerating in Greenland, likely as a result of global climate change, but there's something else interesting in the works on the other side of the world, and what makes it somewhat scarier is two things.

The first is this part, which is just a set up really, for the knockdown which is to follow:

The reason does not seem to be warming in the surrounding air.

One possible culprit could be a deep ocean current that is channeled onto the continental shelf close to the mouth of the glacier. There is not much sea ice to protect it from the warm water, which seems to be undercutting the ice and lubricating its flow.

If you're like me, you knotted your forehead in confusion: surely the warm water can't be doing it all alone, even if that in itself is a factor from global climate change. So what else is there?

Julian Scott, however, thinks there may be other forces at work as well.

Much higher up the course of the glacier there is evidence of a volcano that erupted through the ice about 2,000 years ago and the whole region could be volcanically active, releasing geothermal heat to melt the base of the ice and help its slide towards the sea.

Oh snap! You mean we don't even need global warming to be true for this to be a problem?

Yep. Volcanism is a bitch.

You may already know about the appropriately named Mt. Erebus. (A volcano at the end of the world? It just has to be named after the realm of the dead in Hades in Greek mythology! Is there another Antarctic volcano we can name for the other half of Hades, where the Titans were imprisoned? Yes, we need a Mt. Tartarus!) Did I mention it has its own literal lake of LAVA? How cool it that!

Yeah, well it's not alone.

The entire western coast is literally peppered with volcanoes, and Erebus is only one of them. Check it out, the red triangles are identified volcanoes (from Global Volcanism Program):

Keep in mind that this only represents those volcanoes we've been able to identify. There may be more entombed beneath the ice like the one under the Pine Island Glacier. But so far that one is the only one we know of which might cause a catastrophic infusion of ice into the ocean.

How catastrophic? Well...

If the glacier does continue to surge and discharge most of it ice into the sea, say the researchers, the Pine Island Glacier alone could raise global sea level by 25cm.

That might take decades or a century, but neighbouring glaciers are accelerating too and if the entire region were to lose its ice, the sea would rise by 1.5m worldwide.

It's true that, in the last paragraph, he's only saying how bad it would be if, theoretically, it all were to melt at once, but the loss of just the Pine Island Glacier would be bad enough, That's almost ONE FOOT of water in increase.

To put that in perspective, look at this article about the Marshall Islands, an archipelago in the Pacific.

The scientists on the advisory panel said that, depending on several assumptions, ocean levels are likely to rise by a little over a foot during the next century, or perhaps by as much as three feet.

Taking the lower assumption, the study says, the population of the 29 atolls and 5 islands of the Marshall Islands would need to be rehoused in high-rise buildings near the highest points on the archipelago by 2022.

If ocean levels rise by the upper estimate of three feet a century, the study concludes, the entire population would be forced to abandon the islands, "the only realistic option.

OK, so if just the glacier goes, it'll make the Islanders head for high ground. Remember, the glacier is moving fast enough to already be a problem, but if the volcano that is suspected of being behind it actually erupts like it did 2,000 years ago, then who knows how quickly things could flood? Of courses I'm not suggesting a tsunami-like inundation, nothing that quick, but how long does it take a volcano to melt a glacier? (According to the team, in a separate news article, the volcano's last eruption was only slightly less powerful than that of Mt. St. Helens in 1980.)

And then there's the rest of the ice sheet, which is more than enough to make the Marshall Islands non-existent. And of course the Marshalls aren't alone. There are lots of islands around the world that are under similar threat. And let's not forget some prime coastline on the Gulf Coast...

Like I said, maybe that beach house wouldn't be the best place to live after all.

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