Tag: Antarctica

NASA spies the birth throes of a new iceberg

By Phil Plait | November 4, 2011 7:00 am

The Pine Island Glacier is a massive flowing river of ice on the western Antarctic ice shelf. And by massive, I mean massive: it’s 250 km (150+ miles) long, and has an area of 175,000 square kilometers — that’s bigger than the state of Iowa! Every year, a staggering 79 cubic kilometers (19 cubic miles) of ice drains from this glacier in the ocean, flowing via a tongue of ice floating in the water off the main land.

Flying over the glacier on October 14, scientists aboard a NASA DC-8 airplane as part of the IceBridge mission were startled to see a huge crack across the glacier. Flying back over it on October 26, they were able to photograph and measure this huge rift, and found it will almost certainly soon give birth to a huge iceberg. Check out this lovely picture of the ice crack:

[Click to enfloenate - and you really want to; it's amazingly beautiful.]

Brrrr. The scale of this crack is much larger than you might think: it’s 80 meters wide on average, and about 150 meters wide in the photo above, the size of a football stadium! It runs for 29 km (18 miles), and it’s pretty deep; a topographic map (shown here) indicated it’s 50-60 meters in depth.

Read More

CATEGORIZED UNDER: Cool stuff, NASA

Dramatic glacial retreat caught by NASA satellite

By Phil Plait | April 12, 2010 7:30 am

In January through April of 2002, the Larsen B ice shelf collapsed in the Antarctic.

This was a huge sheet of ice, about 3250 square kilometers (1250 square miles) in area, roughly equal to a square 57 km (34 miles) on a side. There had been a series of warm summers that weakened the shelf, and then the very warm summer of 2002 spelled doom for it.

The Landsat 7 satellite took many images of the collapse, but the Earth Observatory Image of the Day just released two dramatic shots of its impact:

craneglacierretreat
Read More

CATEGORIZED UNDER: Antiscience, Pretty pictures, Science

Sign of the apocalypse: blood waterfalls

By Phil Plait | March 2, 2010 7:00 am

Our planet is a weird place. I can imagine visiting Antactica, seeing nothing but white ice and gray rocks for days on end… but then, how would you react when you saw this?

bloodfalls

Yegads! That is a part of Taylor Glacier, specifically the Blood Falls, located in the dry valleys of Antarctica. Apparently, a lake was covered by the glacier about 2 million years ago, trapping the microbial life inside. They have evolved independently of outside life for all that time, and were discovered due to a few leaks from under the glacier.

The water coming out is red due to iron, and is incredibly salty with almost no oxygen in it. The microbes — 17 different kinds have been found there — must use sulfur as a catalyst instead of oxygen, which has never been seen before.

It’s always surprising when an entirely alien ecosystem is found on Earth. It makes me hopeful that when we start to explore other planets, we’ll find life in splendid and incredible varieties. Nature is clever, vast, and has had a long long time in the lab to experiment. If we can find things so alien in a place so familiar, what will happen when we explore a truly alien world?

Image credit: United States Antarctic Program Photo Library

CATEGORIZED UNDER: Cool stuff, Pretty pictures

Our ice is disappearing

By Phil Plait | January 21, 2010 10:49 am

If you are a normal person trying to figure out who is right and who is wrong on an issue, it can be pretty confusing. When it comes to things like global warming, there are folks out there who twist, distort, and spin the facts so grievously that it’s hard to tell the difference between what they are doing and outright lying. And when one of them does it, a slew of others pick it up, making the chorus of nonsense self-reinforcing, muddying the waters even more.

We saw this happen with the CRU emails that were hacked — a situation which was nowhere near as important as so many trumped them up to be — and of course we will see it again and again.

To help staunch that, there are two points about global warming I’ve recently come across that I want to make sure are very clear.

1) Some global warming denialists obfuscate what’s going on with Antarctica, saying the ice there is actually growing, not melting. That is patently false. Where it really matters, Antarctic ice is melting.

antarctic_iceloss

As you can see by this NASA graphic from the linked page, Antarctica loses over 100 billion tons of ice per year, the equivalent of about a hundred cubic kilometers (more than 20 cubic miles) of ice. That number is hard to grasp, but it’s the equivalent to the volume of a mountain about 14,000 feet high — or, if you prefer, it’s like saying that one Colorado Rocky Mountain’s worth of ice disappears every year. Just in Antarctica alone.

You may note that the line fitted to the points in that graph is changing its slope, getting steeper with time. I wouldn’t extrapolate that too much, but if true, it means the loss rate is accelerating.

2) The IPCC report in 2007 was a landmark analysis of the current GW situation. It has been attacked repeatedly by denialists, of course. As it happens, in one part of the report they said that Himalayan glaciers may melt away completely by 2035. This turns out to have been based on a report that was not peer-reviewed, and most likely incorrect.

However, this does not mean the entire report is wrong, and it certainly doesn’t even mean that Himalayan glaciers are fine! Quite the opposite, in fact. A new study of Himalayan ice using satellite data shows that the ice is disappearing, and from 2003 to 2009 shrank at a rate of 47 billion tons per year. I’ll be careful to note that the uncertainty in this measurement is about 25% (12 Gt/year) and has a short baseline in time, but even considering that, the loss of Himalayan ice is definitely large and almost certainly increasing — perhaps twice as rapidly now as it was in the past 40 years before the study.

This is supported by a ground-based study of over 600 glaciers being monitored by Chinese scientists, which showed that between 1980 and 1995, 90% of those glaciers were retreating, and in the period of 1995 – 2005, 95% retreated. In other words, the vast majority of the glaciers studied were losing ice, and in more recent years the number of glaciers losing ice increased.

This is all consistent with global loss rates of ice: it’s disappearing faster now than it was in previous decades.

himalayan_glacier

Get a good look at Himalayan glaciers while you still can.

Expect to hear the antiglobal warming crowd crowing over this, and the media misreporting this to sow more doubt about global warming. But the important point to remember is this: the Himalayan ice really is shrinking, and the same thing is happening in Antarctica.

Global warming is real. It’s also getting worse. You can shout, you can scream until you’re red in the face, and you can deny the facts all you want. But facts are pesky: they exist whether you believe in them or not.

My thanks to expert glaciologists Drs. Lonnie Thompson and C. K . Shum for taking time to explain the Himalayan studies to me and for providing me with the numbers from the ground studies.

Glacier image from mckaysavage’s Flickr stream licensed under creative comons.

CATEGORIZED UNDER: Antiscience, Debunking
NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »