NASA Ames Research Center  + Visit the NASA portal Site Accessibility Notes
 LIMA banner
 Home
 

Welcome to the Webchat for the LIMA Challenge
Wednesday, April 23 with:

Quest_Moderator -- Welcome to the LIMA Quest web chat. Robert Bindschadler and Ted Scambos are online. Let's get started!    

Ted_Scambos -- Hello, all. A beautiful day in Colorado.

murphy01<Q>This question is for Ted Scambos--How are the megadunes that you talked about formed, and if these happened frequently how would this affect Antarctica.

Ted_Scambos <A>Hi Murphy - Megadunes are probably formed by a wave pattern in the wind that blows over Antarctica - this gets a bit complicated. Antarctica has a surface climate that is dominated by a cold layer of air near the surface; this air is dense, more dense than the air above it, and so it flows downhill. What happens in a megadunes area is that this layer of cold air (think of it as a layer of 'soft' water) begins to bounce over the surface, forming waves of air flow. The waves of flow in the air result in waves of snowfall, spaced with areas of no snowfall. Those are megadunes.

wisener<Q>My class is unable to join the live chat. We are interested in Academy Glacier. We would like to know its speed, whether it is shrinking or not, and to what degree its path debris has been studied. I am the teacher. We are at Caddo Hills School in Arkansas. Thank you for your time.

Robert_Bindschadler <A>Thanks for the question. Ted hosts a terrific web site at NSIDC where a lot of ice velocity data are available. He can give you the URL. LIMA will give you a true-color look at Academy Glacier. have you used it yet? For looking for changes, you want to check out the USGS Earth Explorer web site to look for other images collected at other times.

murphy04<Q>Dr. Bindschadler, i saw in your biography that you have been to Antarctica 14 times. How was the first trip different than the 14th one? I also would like to know how has your body adapted better to antarctica now compared to the first time?

Robert_Bindschadler <A>(Laugh). I'm getting older and I think less tolerant of the cold. But every trip is still and adventure. My research changes enough that I go different places in Antarctica. THe science progresses, too, so we have different questions to try and answer. Last season (Dec-Jan) was #15 and I'm still looking forward to more.

murphy01<Q>To all: If i wanted to become a scientist in your field what kind of education would i need?

Robert_Bindschadler <A>(oops, wrong button)... I was going to say that there are many other avenues that one can take--Antarctica has attracted many people to it that never thought they would end up studying the place. Get a sound foundation in physical science and math and you can folow your interests, wherever they lead.

 

Henggeler_Missouri_4th_grade<Q>What kind of clothing do you wear, and how much of it do you need in order to stay warm in Antarctica?

Robert_Bindschadler<A>Layers, layers, layers. Thermal underwear, shirt or vest, heavy parka, big heavy boots--my hands always get cold, so the biggest, warmest mittens I can find. Actually how cold I feel depends mostly on the wind, not the air temperature.

murphy02<Q>I know all types of science use some kind of math, but what level of math does your job require?

Robert_Bindschadler<A>Math can be very important and is the basis for lots of physical science, but a lot of the image anaylsis I do doesn't get to math-heavy.

murphy03<Q>This question is for Robert Bindschadler, have you seen a lot of changes in Antarctica over the 25 years you have studied it?

Robert_Bindschadler<A>Yes, I have seen changes, but because the continent is so big, satellites (aka "eyes in the sky" are the best way of watching such a big continent. That's why LIMA is so valuable. It's a snapshot of the entire continent at high resolution. One of the biggest changes anywhere in Antarctica is the sudden (like in a few weeks!) of large ice shelves on the Antarctic Peninsula. It got everyone's attention.

Henggeler_Missouri_4th_grade<Q>What the is the water temperature around Antarctica?

Ted_Scambos<A>The temperature of water near the coast of Antarctica is almost always right at the freezing point of seawater -- that is a bit below 32 F, becaue of the salt content of the ocean. The freezing point of seawater is about 28 F. It's pretty much always waaay too cold for a swim. But some people have done it anyway.

Henggeler_Missouri_4th_grade<Q>How deep is the deepest crevasse you have encountered and how do you go about studying it?

Ted_Scambos<A>Some crevasses go for hundreds of meters (on big floating ice plates) right through the plate and down to the water. But for crevasses on land, they tend to close because of the pressure below about 50 meters -- that's 150 feet or so. Me, I tend not to go near crevasses. That's what satellite pictures are for!

Henggeler_Missouri_4th_grade<Q>What was your inspiration for going to Antarctica in the first place?

Robert_Bindschadler<A>Great question! In college I studied math and physics, then got interested in glaciers. In grad school I studied surging glaciers in Alaska. Then NASA hired me to make computer models of the big ice sheets. I realized we didn't really understand how they moved, so I had to start making measurements of the ice sheet so we could hope to put good computer models together. I'm still doing the field work, still trying to figure out how they work--it's kept me very busy, and excited, for nearly 30 years.

ioana.cnitv.ro<Q>upon what regions of Antarctica should we focus our attention?

Robert_Bindschadler <A>Oh, I have my favorites, but I'd like you to find your own! I'm an "ice guy", so I have 99% of the ice sheet to choose from. If you also like ice, go for one of the big outlet glaciers around the edge. If you like volcanoes, there are some dandies in West Antarctica or on Ross Island (RI is where McMurdo Station is).

Carla<Q>Can you tell us more about the collapse of the Wilkins ice shelf?

Ted_Scambos<A>Carla, that's a question with a long answer, and it's not entirely settled in the science debate yet. But the main reason, most agree, has to do with the warmer temperatures and higher amounts of melt in this part of Antarctica. The main idea I've been discussing and writing about is that if water is present in the upper part of a big plate of ice (like an ice shelf), then that is an unstable situation: water is denser than ice. So the water will seep into any cracks that are present on the upper surface of the ice shelf and push (the weight of the water will push) on the crack, forcing it downward. It is similar to what happens on many glaciers and ice sheets in melting areas; water on top wants to push to the bottom.

Radu_Cnitv_Romania_Stoica<Q>These questions are for both: Is the Earth going to encounter a new ice age in the following decades? Can you predict the moment?

Ted_Scambos          <A> I think you're talking about the idea that was shown in the movie, 'Day After Tomorrow'. Most oceanographers now think that the 'sudden ice age' idea, where melt from Greenland leads to a 'covering' of the warm water from the Gulf Stream in the far north near Europe, can't really happen anytime soon. I don't think 'ice ages' are going to be our problem

murphy05<Q>Dr. Bindschadler, have you done any studies, on your recent experiences to Antarctica, on the temperature changes in Antarctica?

Robert_Bindschadler <A>What's neat about ice is that the vertical profile of temperature records older and older temperatures the deeper you go. They get smeared out, which can make the analysis harder, but it's valuable information. The scientists who look carefully at this find that recent temperatures on the majority of the continent have not changed much over the past few decades--slight cooling, if anything. The Antarctic Peninsula, however is VERY different--2.5degrees Celcius warming in just 50 years--more than almost anywhere else on earth! Lots of ice is melting away there.

Davis123<Q> What new evidence has been found lately due to global warming?

Robert_Bindschadler <A>In Antarctica, the most direct consequence we can tie to warming is the sudden disintegration of floating ice shelves in the Antarctic Peninsula.  Any local place responds only to its local climate, but we know from weather station observations at a few stations on the Peninsula that it is warming at about 2.5 degrees Celcius in just the past 50 years.  That's many times the average for "global warming" (only about 1/2 degree in 50 years).  The regional warming of this ice causes lots of surface snow to melt during the summers.  We can see the vast meltponds of this water on the surface and then....suddenly the ice shelf seems to explode out into the ocean!!!  It doesn't really explode--we think the water works its way down into cracks in the ice and, because water is heavier than ice, the water drives these cracks all the way through the ice shelf. Once sliced up this way, the tall, thin ice sections fall over like dominoes and push the whole ice shelf away from the coast and into the open ocean.  It's very dramatic and with satellite imagery, like that used in LIMA, we've had a front row seat.

hill1515<Q>As Global warming is a bigger concern than ever, at what rate is the ice melting in Antartica?

Robert_Bindschadler<A>That's a very important question a lot of people are working on. For the last 20 years, the loss of ice from Antarctica has only been enough to raise sea level about 0.1mm per year (about 5% of the total rise), but the contribution to sea level from Antarctica appears to be increasing. I believe it is due to glaciers at the edge flowing faster--and they can flow a lot faster, which could help sea level rise much faster. The best estimate is that sea level will be 3 feet higher by the year 2100, and Antarctica will probably contribute at least 1/3 to 1/4 of that.       

jim <Q>how long should the proposal which i submit be...?

Quest_Moderator<A>A description of what is needed in your proposal is posted on page 6 of the Educator Guide.

Henggeler_Missouri_4th_grade<Q>What is the population in Antarctica--human, not penguins!

Ted_Scambos          <A>That's a good one. Theres a big difference in the population in summer compared to winter -- very few stay on for the long dark polar night. In summer, over the whole continent, I'm going to estimate that it is about 4000 people; and probably 1500 of those are at the three main US bases, McMurdo, South Pole, and Palmer Station. In Winter, more like 1000 or so. Bob, any thoughts on this?

Mrs._Tomko<Q>I'm sorry if I'm repeating my question. I lost connection and am not sure if it went through. I'm a 4th/5th grade teacher, whose students are on spring break, so I may be the only one online today. My question: how are scientists integrating the use of data from the LIMA project with other data, like ice core samples?

Robert_Bindschadler <A>You are certainy not the only one on-line. I'm typing as fast as I can--lots of questions--and yours is a great one. LIMA is a good base layer to help the public and scientists in a lot of ways. Just after it was released, I was in Antarctica and saw other scientists use LIMA to get a look at the area they were about to travel to. Ice cores are usually taken at the summits of the ice sheet, so the layers won't be disturbed by ice flow. LIMA will help show whether there are flow features, and if so, from what direction the ice is flowing and wher it is flowing to.

jim<Q>how long should the proposal which i submit be...?

Robert_Bindschadler<A>I think we suggest just a few pages (like 4), but don't feel too confined by that recommendation. When I was in school, often the teacher responded by saying the paper should be long enough to cover the subject, but short enough to remain interesting--back then the simile referred to a woman's skirt, but nowadays that might be taken as too chauvinistic.

jim<Q>jim...is the melting due to underwater volcanic activity?

Ted_Scambos<A>No, not in general. A volcanic eruption would have a very localized effect, like a hot 'point' underneath the ice sheet or the ice shelf. You might melt a hole in the ice, or produce a big crater bowl of ice if the ice were very thick, but what we're seeing is spread too wide, and is too closely tied to regional ocean and air temperatures to be coming from volcanoes. Which is not to say that volcanoes have not been seen before, above the ice (Mt. Erebus is one, right near McMurdo Station,and it's spectacular), and below the ice in the middle of the continent. But they don't seem to be controlling the changes that we're seeing.

jim <Q>are there any oil reserves available in antarctica?

Robert_Bindschadler <A>Are you from Texas? Antarctica is a continent protected by international treaty for the scientific research and there are provisions of the treaty that prevent Antarctic resources from being exploited. Nevertheless, people have done some assessment of mineral resources. I've never heard about oil, but in the Earth's distant past, Antarctica had a tropical climate and fossil ferns have been discovered, so a big "maybe" on your oily question.

jim <Q>what about the volcanoes that we saw on the vidieo clip on the lima site?

Robert_Bindschadler<A>I'm glad you saw the video! Yes, there are many volcanoes in Antarctica. Most are in the western hemisphere-what we call West Antarctica. Mt. Takahe (in the video) is my favorite because it is so big and perfectly shaped. It can be seen from space and also in the LIMA image before you start to zoom in. Rough coordinates are 76S, 110W. Then there's Ross Island (McMurdo Station in on Ross Island) that is primarily made up of 3 volcanoes. Mt Erebus is the most famous of these. Some of the volcanoes are still smoking!

jim<Q>what is the possibility of the colonization of antarctica?

Robert_Bindschadler<A>Are you vounteering? Chile has supported a village with cottage industries and even boast the first human conception and birth on the continent. More a political stunt, really. WIthout all the resources to support a human colony, I doubt there is much chance colonization will ever amount to much.      

gabriela<Q>why is the ozone layer getting thinner on top of antarctica?

Ted_Scambos          <A>The reason ozone is disappearing every year (in the southern early spring, the coldest time of year) is that a very unusual kind of cloud forms in the highest parts of our atmosphere when the temperature is REEEAAALLLLLY cold, like -120 F. This cloud, these tiny ice particles, atract certain molecules in the high atmosphere -- and unfortunately there are a few that we've put in the atmosphere that get attracted. Then, on the surface of the cloud particles, every time an ozone molecule bounces against, it breaks apart into oxygen. But the material on the cloud particle is still there. So it keeps on breaking apart ozone for many weeks, on and on. This process of helping a chemical reaction without being absorbed by the reaction is called 'catalysis' and the molecules in question are 'catalysts'. --- I skipped over the molecules; those are basically the gases used in air conditioners and refrigerators, the most common one is called 'freon'. Freon is like a gas form of Teflon.

Mrs._Tomko<Q>Thank you, Dr. Bindschadler -- I meant the only one online from my class,smile I think I understand why it's important for ice core samples to not be from a flow area -- so that you get a true chronological look at weather, etc. events, yes? But how do scientists know whether they have taken an unadulterated sample?

Robert_Bindschadler<A>It's impossible to tell how a single core's record might be corrupted by flow, so the best test is usually to compare one core's record with others. The major global climate cycles (ice ages and warm periods) have to appear in each core. In some cases, the layers have been seen to contain folds. That's asure sign the ice has been disturbed and the data are untrustworthy. Fortunately, that situation doesn't happen often.

catalin_cnitv.mrs_stoica<Q>It is suspected that the last inversion of the magnetic poles coincides with the disappearance of the dinosaurs. What will drastically change in our lifes if this occurs again?

Ted_Scambos<A>Hi catalin - Well, no, actually the magnetic poles have switched many times, before - during - and after the dinosaurs. Many people have looked for an effect on the past life forms, but as far as I know no one has proven that there's a big effect on the ecosystems. Still, it is fairly clear that there would be more radiation (which our magentic field protects us from) during the period of transition. But its all sort of a mystery. I don't want to worry anyone, but our magnetic pole is shifting very rapidly right now, especially in the north; it is moving out of northern Canada, towards Sibera, at a rate 10 times as fast as is was drifting 50 years ago (my numbers are approximate).

jim<Q>we are members of a class in astronomy at bristol community college in fall river, massachusetts...thanks for all of you good information...thanks for permitting us to participate.

Quest_Moderator<A>We're happy to have you! Thanks for joining us!

jim<Q>the volcanoes i am refering to were underwater and i think alvin the underwater search vehicle took the videoes.

Robert_Bindschadle<A>Ah, now we're getting to the heart of your interest! And farther from my expertise. Most of the ocean floor around Antarctica remains unexplored--so big, so few ships capable to explore. I have no doubt that with volcanoes seen on land (poking through the ice sheet), there are others on the sea floor. I've heard of some, but I don't know any in ANtarctica that Alvin has spotted--not to say it hasn't happened--I just can't add any information to your interest.

luca_mrs_stoica<Q>Is it true that Antarctica was originaly positioned in a tropical region?

Robert_Bindschadler<A>RIght you are! Fossil ferns have been discovered in the TransAntarctic Mountains. Tens of millions-maybe hundreds of millions of years old.

jim<Q>does the changing of the shape of earth due to the gravitational attraction of moon have any effect on the temperatures in Antartica?

Robert_Bindschadler<A>No. But the ocean tides have a surprisingly large effect on the flow of glaciers draining the ice sheet. They speed up (by as much as 50%) as the tide falls and slow down as the tide rises--how about that!! it surprised us.

Mrs._Tomko<Q>I've heard that, overall, the apparent melting on one side of Antarctica is offset by new ice formation on the other side, so that the continent as a whole is in equilibrium (I don't recall the source of info.). Is this something that is truly measurable at this point in your research/data collection?

Ted_Scambos<A>I"m not sure if you're talking about sea ice or the continent's ice sheet; for sea ice, what you're saying is more or less the case; we're seeing less ice near the Peninsula (where it's getting warmer) and slightly more in other regions, although there is a lot of year-to-year variations. For the ice sheet, what you're saying is something that was thought would be the case 10 years ago; and there is some of this 'offsetting snowfall' happening in the uppermost parts of Greenland. But no one has been able to prove that there is truly an increase in snowfall in the central or eastern hemisphere Antarctic. There are studies showing no change, based on 'being there' and measuring the snow; and studies from space that suggest some growth. Hard to say.

luca_mrs_stoica<Q>why is antarctica a good area for finding meteorites?

Robert_Bindschadler<A>I was hoping someone would ask about this! Meteorites fall all over the earth, but when they land on Antarctica, the ice carries them along with the flowing ice. Many places the ice flow encounters a mountain range, forcing the ice to flow upward. Wind and sun erode the ice, but not the meteorite, so as the ice continues to flow into the areas with their meteorites, the ice is continually removed. The meteorites are left to pile up as they collect. Pretty cool, huh?

Mrs._Tomko -- Thank you so much for your time today, gentlemen!

Henggeler_Missouri_4th_grade<Q>Ted, when you leave Colorado how long does it take for you to get to Antarctica, and what route do you take to get there?

Ted_Scambos<A>It takes about 4 days; we go from Denver International Airport to Christchurch New Zealand (that takes about 20 hours of traveling). Then we try to stay away until evening, collapse, then the next day we get our polar clothing issued to us -- NSF provides us with basics, from long johns to parkas. Then we go through some saftey and 'how-to' briefings.

Then we hop aboard a C-130 and fly for about8 hours, due south. About the 6th hour we can see ice floating on the ocean, and about the 7th hour we can see the mountain ranges. Then we land, on frozen ocean usually, and they come out to get us in these gigantic monster-truck buses. It takes about 30 minutes of slow crawling to get to the base.

Mrs._Tomko<Q>What, in your estimation, is the most important data that is currently being gathered and analyzed, and why?

Robert_Bindschadler<A>Climate data that help us determine how the very, very complex climate works. Scientists are working very hard to be able to predict not just globally averaged conditions (that's actually pretty easy), but how it varies on the state-by-state level and even town-by-town level. That's really hard. In my field of Antarctica, job#1 is learning how the ice sheet is responding to climate, so we can offer accurate predictions on how much ice is going to be lost (we know there will be less ice in a warmer world) and how fast.

Quest_Moderator-- As you reach the end of the hour, I'd like to thank Drs. Bindschadler and Scambos for their time answering our questions. Also thank you for joining us and good luck in your continued preparation for the LIMA Quest Challenge!

hill1515 -- Thank you, very informative!!!!

Mrs._Tomko<Q>What role do you think volcanoes play in the "big picture" of Antarctica?

Robert_Bindschadler<A>Volcanoes often spew enough fine particles into the atmosphere that the earth cools--but only for 3 years (give or take a year), before the particle settle out. Antarctic volcanoes can disrupt the local ice sheet more, but subsequent snowfall covers things up pretty fast, so the influence locally is pretty minor (in my humble opinion).

Robert_Bindschadler -- Sorry everyone, but I've got to go to another (less interesting :(() meeting. I had a GREAT time, and I hope to hear from you again at a later date. Go explore LIMA!!!

Quest_Moderator          We will have an archive of this chat online by day's end and will handle last minute questions until our remaining expert need to leave us.

ioana -- On behalf of our class and Mrs. Stoica teacher we would like to thank you very much for the information you gave us.

ioana -- We consider this has been a great opportunity to learn about Antarctica, and we are looking forward for similar activities.

Ted_Scambos -- Bye, this was very interesting -- big questions from every corner. Thanks.

 

 
 FirstGov  NASA

NASA Official: Liza Coe
Last Updated: May 2005
+ Contact Us