The state of the sea ice.

A lot of people have been writing me, or people I know, asking about how the penguins are doing and what's going on with this enormous iceberg parked out side our back door. For those of you who haven't seen the article, it's on the CNN site: http://www.cnn.com/2004/WORLD/asiapcf/12/14/nz.penguins.ap/index.html

What's happening is that the Ross Ice Shelf is in the middle of a calving event. Huge chunks of this enormous glacier (the size of Texas) are breaking off and floating around in the Ross Sea. These events seem to occur about every 50 years or so. This in interesting because McMurdo Station is only about 50 years old. So this is the first time in the station's history that it has had to deal with the Ross Sea becoming littered with enormous icebergs. By enormous, I mean really, really, really big. Like the iceberg takes up the entire horizon. The largest iceberg, B15A, is close to the size of Ross Island, where McMurdo Station is located, and has been described has the largest floating thing on the planet right now. Not only is it a huge obstacle, but it also creates another very significant problem: persistent sea ice. The surface of the water in the Ross Sea freezes in the winter. But as summer approaches the rise in temperature and the energy of late winter/early spring storms causes most of the frozen sea ice to break apart, thus allowing ships access to McMurdo in the summer (an icebreaker is sent down every year to break a channel through what little ice remains between the open ocean and McMurdo). These ships provide vital equipment and supplies needed for the town. These huge icebergs cause the sea ice, also called fast ice (cause it doesn't move, it's held fast) to stay around. The reason for this is rooted in some complex oceanography, but the upshot is that the icebergs create a stable structure that the sea ice adheres to and, more importantly, the icebergs block warmer ocean waters that would usually circulate around the sea ice. This keeps the water around the sea ice much colder and therefore stops the usual progression of the break up of sea ice during the summer months.

This creates problems for both the humans and the wildlife. The sea ice around McMurdo is very old, having not been thawed or blown away for some 5 to 6 years. This has allowed the ice to thicken to about 16 to 18 feet! Very tough work for an icebreaker. Luckily, not all of McMurdo Sound is that thick, since the sea ice has blown out in other areas in more recent years. Still, the iceberg has caused the ice edge (where the sea ice ends and the open ocean begins) to be about 100 miles further north than it usually is. This means that the icebreaker (provided by the US Coast Guard) has that much more work to do.

Two years ago the ice was very hard to clear out for the same reasons. It took 2 icebreakers to clear a channel for the resupply vessel. Even then it was very delicate work because the channel was full of ice chunks that were up to 14 feet thick. The resupply vessel has a reinforced hull, but it is not an icebreaker. Pieces of ice that big could easily rip the hull open. In fact, that year the fuel resupply ship did not even enter the channel for fear of the ship busting open and spilling fuel all over the pristine Antarctic waters. Instead, fuel lines were laid down over the sea ice and the fuel was transferred that way.

This year though, more icebergs have moved into the area and caused the ice edge to be even further away, making the above option a much more difficult one to carry out. Also, there will only be one icebreaker this year (the National Science Foundation tried to get a second, but it never worked out). So as mentioned in the CNN article, this iceberg has created very large logistical problems concerning how to resupply the station. There are stores emergency foods and fuel, to be sure, but no one wants to eat 10-year-old frozen hot dogs for breakfast, lunch, and dinner. It will be very interesting to see how this problem gets solved, especially in the long-term. Hopefully the icebreaker will be able to clear the channel all by itself, but to some people supposedly in the know, they don't think it's likely. Some rare, late season storms would help out as well, so that more ice might blow away. Truly vital supplies (food and fuel) can be flown it, but not without an enormous cost that the NSF would probably like to avoid.

The other side of this iceberg situation is its influence on the biology of McMurdo Sound. The most notable problem is that the penguin rookeries in Ross Island face a very grim outlook (as discussed in the CNN article). This is because the parents rear their children at established rookeries on Ross Island. They take turns going on foraging missions where they walk to the sea ice, swim and get food, return to the rookery and regurgitate the food up for the chicks to eat. Only problem is what used to be a short walk to the sea ice (the rookeries were seemingly established during better times when the sea ice blew out) for the parents has now turned into a Homerian Odyssey of hundreds of miles. By the time they return to the rookery, if they return at all, they've used up all the food just to make the journey. This results in the penguin chicks dying of starvation. The closest penguin rookery to McMurdo (at Cape Royds, an Adelie penguin rookery) is likely to lose all their chicks this year. Zero survival. Very grim. This too could happen at a couple of more rookeries. These giant icebergs have already worked over the Emperor penguin rookeries at Caper Crozier. The rookeries there were smashed to bits and pieces when these island-sized icebergs initially fell off the Ross Ice Shelf and rammed into the frozen sea ice where the Emperors established their breeding grounds. It's very difficult imagining something 100 miles long smashing into your house.

The sea ice is also experiencing another problem. The last 4 to 6 weeks have been extremely warm here. Well above freezing (the high temperature today was 39F). The sea ice around the station and where the sea ice runway is located is very thick and its structural integrity is not about to compromised anytime soon. The problem is that with the warm temperatures we've had it's caused the 16 feet thick ice to turn into 14 feet thick ice that is now covered in 2 feet worth of slush. The road that goes from the hard ground of Ross Island to the frozen sea ice of McMurdo Sound (called 'the transition') has suffered the worst. This road is covered now with huge puddles of standing water, some up to 3 feet deep. The road to the ice runway is filled with these puddles as well (the constant driving of vehicles on the roads has dramatically increased their degradation in these warm conditions). This has resulted in the sea ice now being closed to just about everyone. The sea ice runway is closed as well. This means that planes bringing personnel and supplies to Antarctica from New Zealand can no longer land on wheels, but need to be equipped with skis (the runway on the permanent Ross Ice Shelf is different from the hard surface provided by the frozen sea ice and thus only ski equipped planes can use it). This change in landing gear severely limits the amount of cargo the planes can carry. So the good life of fresh food and mail packages being delivered in a timely fashion that was experienced during the days of the big C-17 and C-141 jets are now over. With the ski equipped planes handling the cargo, fresh food and mail fall very low on the priority of cargo to be shipped. People (myself included) don't know if Christmas packages sent by friends and family will arrive in time for Christmas. But this is not a huge problem, its just means the easier days of fresh food and mail aren't as frequent anymore (harsh continent indeed!).

So that's the state of the sea ice. Wow, that was a long post. You may not hear from me for the next 2 or 3 weeks. I've also put a photo in that shows Ross Island and these huge icebergs floating around the Ross Sea wreaking havoc on our little Antarctic operation (and the poor penguins too!).