Tuesday, December 6, 2011

Antarctic Answers!





1. How has Antarctica changed over the years?
This is a great question, and one I’ll answer first.  To understand Antarctica, you have think very long term.  Continents are all found on massive plates that move over the mantle of the Earth.  The US and Europe are moving away from each other at about a ½ inch a year, as the mid-atlantic ridge grows.  On the other side, the Pacific is slowly subducting, and in a few million years, trips to Japan will be a little shorter than they are now. Antarctica used to be connected to other landmasses in a supercontinent called Gondwana.  About 50 million years ago, Australia and Antarctica split apart and Antarctica drifted south.  All plants and animals left on Antarctica eventually died, but we still find fossil records of plants that existed millions of years ago.
As Antarctica moved south, ice began to develop as ocean waters cooled, and the continent started to resemble what it is today. By 15 million years ago, Antarctica was covered in ice and snow.  So much in fact, that it weighs down and depresses the entire continent by as much as half a mile!


Much more recently, humans have had some small impacts on the area, the largest is McMurdo where I live.  There are roughly 1500 people on station in a recent season, but the military had as many as 4000-5000 here in the 1940’s and 1950s doing exercises and building the station originally. The impact from humans is small compared to the rest of the world, but still we do find evidence of pollution.  One notable problem – in the 1950s, they just pushed all their trash right on to the sea ice. When it melted in summer, the trash sunk to the bottom of the sound.  Obviously it wasn’t going anywhere, so that trash still sits there today and includes things like trucks, housing materials, food trash, sewage, and more.


2. What is the range of temperatures in Antarctica? How is the weather during the summer?
Because it is summer here right now in the southern hemisphere it is relatively warm for Antarctica.  I looked up the current temperature here and it is 30F with 6mph winds, so not worse than an average January day in NYC really. South Pole station, because it is much farther from the ocean, further south still, and at a much higher altitude, is much colder however. It is currently -17F, -27F with wind chill there, and that is almost as warm as it gets there. For the most part the summers are relatively mild on the coast where we are, much like a New England winter.  The interior of the continent is much colder in general.  And in the winter, when it’s dark 24 hours a day, everything is cold.  The coldest temperature ever recorded on earth was at Vostok Station (a Russian station) was −128.6 °F on July 21, 1983. Brrrrrrr. 

You can see average temperatures at a few Antarctic stations, as well as New York, 
London, and Sydney.  Notice how New York and London seasonal changes are 
reversed from Antarctica and Sydney.

3. Does the ice ever crack near you? And why does it crack?
Oh yes, all the time.  By ice though, I’m talking about sea ice.  There is, of course, many millions of kilometers of land ice out here, but that stuff is far more stable.  The sea ice, on the other hand, actually breaks, floats away, melts, and reforms in large sections every year. When we drive our vehicles over the ice, we have to always be on the lookout for ice cracks. Under snow, it can look very small, but a crack could be several feet wide at the base, and you don’t want to drive right into the water!  It is always a bit weird to remember that I’m not on land when we drive to our field sites, I’m over hundreds of feet or more of seawater.  The cracking occurs every year in the summer months due to a couple of factors. First and most importantly is temperature - as the ice warms it melts a little bit.  This causes a weak spot to form.  And because it is made from seawater, the ice isn’t as strong as land ice, due to the salt. Another factor is the influence of tidal shifts.  As the ocean underneath flows back and forth, it creates pressure against the ice.  If the ice has been weakened by melting, it may crack.  This crack may continue to grow, or if it gets colder “heal up” and reform with new ice. 

What you are seeing here is a pressure ridge, caused by the transition of sea ice to land ice right where the land meets the sound.  They are beautiful formations, but they can be very dangerous to try to cross with vehicles.


4. What types of animals have you seen up close?
I have gotten to see a lot of marine invertebrates – including the sea urchins we work on, and the super cool sea spiders! Also, I have gotten to hang out with some fish with antifreeze proteins in their blood.  They have this because they live in seawater that is below the freezing temp for fresh water, and if they didn’t have antifreeze, their blood could freeze inside them! And as for larger animals, I’ve seen a number of Weddell Seals near sea ice cracks, as well as in our research ice holes, and of course my favorite, Emperor Penguins!  They are really amazing animals!
Seal, hanging out by a sea ice crack


This penguin knows how good it looks.  Show off.



5. Do you hear the seals calling under the ice? How do the seals survive in that kind of weather?
Unfortunately, I haven’t had a chance to hear any of them, since I haven’t been out on the ice with recording equipment on a quiet day.  I know the scene from the movie you are referring to, and it is an amazing sound.  If I get a chance, I will ask one of the divers here if they’ve experienced the Weddell Seal sounds underwater, and get back to you. As for how they survive out here in this weather, that's a great question - in fact it's a question that scientists are currently studying right now! They are using infrared heat sensing cameras to understand how a seal maintains it's internal body temperature when the outside temperature is downright bitter cold. What we know is that they have a huge layer of blubber - fat - that helps insulate them in the very chilly water and sometimes even colder air. They have evolved to be as round as possible, because the less of their body that is exposed to the cold, the warmer their core can be. Also, they can keep blood from flowing to their extremities when they're diving, conserving as much heat as possible in their chest and body.

That is a fat and happy Weddell seal.  We named him Rusty.



6. Is Frosty Boy good?
I had Frosty Boy yesterday!  And yes, it’s delicious.  It is the best soft-serve ice cream I’ve had. I’ve tried vanilla, butterscotch, mocha, cinnamon, and mint tea.  I do NOT recommend mint tea – it tastes like a mouthful of frozen tooth paste.  However, the rest are all delicious, and they go great with the other wonderful deserts found here occasionally – like chocolate chip cookies or pumpkin pie.  Also, for the ladies, the South Pole Station has a machine they’ve called Frosty Girl. 



That’s it for now – Jan-Hendrik I’ll get to your questions soon, and more pictures on the way!

Sunday, December 4, 2011

Taking Your Questions




Hey reeders - especially to those in Ms. Mahl's class in NYC!

If you have a question about anything Antarctica or Ocean Acidification related, please put them in the comment section to this post entry, and I will do my best to answer them in this post, with pictures if possible.

I'll answer the two questions I get the most, right now.

No, I haven't seen any Polar Bears. They live at the North Pole. But yes, I have seen penguins!

No, you can't see the Aurora (southern lights) when it's sunny. You can only see them in winter, which i will not be here for. I do have a cool holographic postcard of them, and they are awesome!


Other than that, ask away!!

GET TO DA CHOPPA!!


Oh yeah.



I've been saving this one for a special post, but i've got a treat to share, reeders. A field trip to the Dry Valleys!

For this post, we're talking ..... first steps on the actual continent ... first (and second) Helicopter Trips ... aerial photography .... Hiking .... Divetending for equipment ... and mummified seals! yes, you heerd right reeders, mumified seal.

So, we've been putting instruments down in a number of places to get longer-term enviromental monitoring. We had sensors close to base at Fish Hut 9 (where rusty the seal hangs out) and a bit farther at Cape Evans, but we also had a sensor at New Harbor which is in the Dry Valleys. The dry valleys are an incredible habitat, a desert so harsh that NASA uses it as the Mars Proving Grounds, testing equipment to be sent to another planet. It receives less than a couple centimeters of precipitation per year, and the winds are powerful strong. Glaciers flow down between each peak, and there are corpses of seals that are hundreds and in some cases thousands of years old - well preserved because of the cold, dry environment. We flew out to the base right at the edge of the sea ice to meet divers there who retrieved our equipment that had been down about 3 weeks, and then pack it all up to go back with us to McMurdo. The whole trip took about 6 hours, of which we did about 3 hours of work, had some lunch, and had a little time to hike up a couple hills and see a seal mummy. Well, it might have been a daddy - I wasn't sure, and I considered it impolite to ask. Also it had been dead for centuries and was a seal, so communication would have proven difficult.

And if you'd like more detailed information the dry valleys and lots of maps and GORGEOUS pictures go here:
http://www.mcmurdodryvalleys.aq/home

And now for my pictures!

Let's take the bird up for a spin...



It was a bit cozy with 6 people and all of our gear, but I didn't mind at all. It's hard to worry about that...

..when your view out the window is this! Mt. Erebus from about 1000 feet up on the ride out. The whole trip was about 40 minutes each way


We actually flew over the seal group who were skidooing (and riding sleds) to find one of there satellite tagged animals.

My first site of the dry valleys. They are on the main continent, as opposed to McMurdo which is on Ross Island. We had to cross the McMurdo Sound which is of course frozen entirely right now, which you can see in the foreground.


This is the little New Harbor camp that the divers have spent the last 8 weeks at. They were really awesome and the camp was very cozy and fun. The shed Evan is entering is actually the outhouse. You pee in a funnel (or for the ladies a tin can that you have to empty into the funnel), and you poop in a bucket. When the bucket is full you have to put the lid on and pack it for shipping back to McMurdo. There is no leaving human waste on the continent because of the environmental impacts. However, do not envy the job of lidding and carrying the poop buckets...

Divers preparing to retrieve our sensors - They're from UCSC! Go Banana Slugs!

Danni testing the strength of our rope to make sure it would support hauling up our 115 pound instruments and weights. It held me doing pull ups just after that, so it was all good.

What's in the hole? SURPRISE SEAL!!!! no, just kidding this time, but you can see the extra scuba tank they tie off down there. Pretty clear water.

After successful sensor recovery and packing, it was time to take a little walk on the most remote desert on earth.


Even in the desert, there is water. A little bit of ice melt leads to small streams. We have to make sure not to touch the water with our boots because microbes grow in the water, and we don't want to introduce any foreign species into it. Here Pauline is doing a running jump to clear the stream.

No words can capture the stark beauty of this place

Here she is. One side of her is bone, stripped by the prevailing winds for centuries, and the other side still has fur! Sad and beautiful all at once.

I think Georgia O'Keefe would have loved to paint this.


This is a glacier spilling into the valley- albeit fairly slowly. Also, want a novel idea for a drink? Try 100,000 year old ice in your next glass of soda or whiskey. I enjoyed some glacial ice in my cup last night, and the thought of this ice being formed 20,000 years before Homo sapiens even left Africa was pretty amusing to think about.

A view over the Taylor Valley with a suspiciously well stacked pile of rocks we found. I sensed a little human involvement in the creation of that particular formation.

Thank you Dry Valleys, and thank you Antarctica! My time here is brief, but the memories are indelible.

PS- i lost that hat the next week. have you seen it? email me if you find it - thanks.