Arctic Icepack Expedition May Have Found Mechanism Behind Unexpectedly Rapid Pack Ice Loss

[hatrack]

EDIT

Such data is usually obtained from ships. But during the spring, when melting is greatest, there's still too much sea ice for ships to make it through.

So the scientists walked from Borden Island to Ellef Ringnes Island and also from near the North Pole all the way down to the northern tip of Ellesmere Island, slogging about 10 kilometres a day in below-deep-freeze temperatures over rugged, uneven ice. What they found was a surprise — a layer of seawater about 200 metres below the surface that was actually colder than when it had been measured by previous expeditions.

"That's counterintuitive," said Boxall. "We would expect to see, with global warming, warming conditions generally." But when they realized that the colder water was also saltier than they expected, an explanation began to suggest itself.

Boxall points out that the older sea ice is, the less salt it contains. Ice that's two or three years old already contains very little salt. Year-old ice, however, remains fairly salty. And when it melts, it produces meltwater that's denser than the relatively fresh water from older ice.

As multi-year ice declines throughout the Arctic, more of the saltier meltwater from younger ice is mixing into the ocean. That colder, denser water sinks more quickly and forces less dense water from deeper in the ocean up to the surface. Because fresh meltwater is colder than seawater, that means relatively warm water is being forced upwards. And that, said Boxall, may be part of the reason that sea ice is melting so much faster than anyone thought it would.

EDIT

http://www.winnipegfreepress.com/arts-and-life/life/greenpage/124625789.html

[WhiteTara]

1. Well, that's some more depressing news.

We are such idiots and have such a death wish.

[patrice]

2. AND we are not permitted to say or think such things. If you do, you will be punished.

Recognition of our cthonic energy, a.k.a. the death wish, is particularly taboo, so it is projected upon others who respond in kind.

"Christianity" is a failure.

[fredamae]

3. Hydrothermal Venting produces a lot of hot water

from the bottom of the sea floor...could this be part of the cause?

http://www.ceoe.udel.edu/deepsea/level-2/geology/vents.html

[patrice]

4. How long has it been doing that & at what rate, on average? Why is it a factor now? nt

[NickB79]

5. Probably not. There are few rift zones or active volcanic areas in the Arctic

Hydrothermal vents are only found where the Earth's crust is actively being broken open to allow heat to well upwards from below. So far, only a very few have been found within the Arctic circle. Even if we found THOUSANDS of these vents, they produce so little heat in relation to the massive amount of ice found up there, their effects would be negligible. You have to understand that we're talking about MILLIONS of square kilometers of ice. It would be the equivalent of turning on and sinking a 100-watt lightbulb into a lake and expecting it to keep the lake ice-free in the dead of winter in Minnesota.

[fredamae]

6. Well, there are massive numbers of

underwater volcanoes/vents.....
http://www.iceagenow.com/Ocean_Warming.htm

I don't think we should discount their contributions/cumulative effects to the issue of ice melt, global warming and rising sea levels.

I am no scientist, thats for sure, but I cannot see how this could not be a contributing factor.

[NickB79]

7. The problem is that these volcanic eruptions have been going on for MILLENIA

Probably many tens of millenia, if not even longer than that. In all of that time, the Arctic ice sheet has remained. In fact, the Arctic ice sheet is estimated to be several MILLION years old. To try to blame that very same volcanic activity for the current melting trend makes no sense. Unless one can show that undersea volcanic activity has drastically increased in the past few centuries and explain why we haven't seen a similar increase in land-based volcanoes, OR explain why these volcanoes could be spewing heat and gases for hundreds of thousands of years with no effects until just now, the fact that there are X number of undersea volcanoes is irrelevant.

[NickB79]

8. Most of the volcanic vents and ridges are far from the Arctic

As your link points out. Indonesian or New Zealand volcanic vents have what to do with Arctic ice melting?

[XemaSab]

9. .