Please
stand by.
>> Welcome to the LIMA Quest challenge.
Today we're going to listen to some scientists talk about the LIMA
project.
The purpose of this webcast is to learn more about the mystery
sites featured on the LIMA website and give you a chance to ask
some questions to these experts with LIMA imagery that's interesting
to you.
My name is Rebecca green.
I'm at the NASA Ames Research Center in northern California.
I'm here with Linda Conrad today.
Today Linda will be fielding your questions.
Tell us a little about yourself.
>> I've met most of the people already because I've sent
them little correspondence.
But I have the fun time of putting these kind of things together
for you.
And I will be looking forward to questions in the chatroom.
Please be very appropriate with them.
We have lots of people right now in the chatroom.
We would love to see questions about Antarctica and this imagery
that we're talking about and maybe some of the help you need to
get started on your projects.
I will be pulling questions out of chatroom.
I may interrupt occasionally but most of it will be handled in
a Q and A session near the end.
>> Let's begin by meeting some of our scientists.
Coming to us from various parts of the country through videoconference
and over the phone.
We'll learn a little bit about them and how the LIMA imagery is
helping them do their work.
We'll start with Robert Bindschadler the chief scientist in green
belt, Maryland.
Tell us a little about yourself, what led you to work with the
LIMA imagery and how it's helping you.
>> I sure will.
Thanks a lot, Rebecca.
I'm very pleased to be part of this panel of experts and part of
this Quest Challenge.
I'm a glacial olist.
I study ice.
I want to tell all the students that when I was their age I had
no idea I would end up being a glacial oh gist.
I love to climb mountains and hike in the mountains.
That led me to be interested in glaciers.
That led me to larger glaciers and now I have the privilege and
the joy of working on the biggest block of ice on the planet, Antarctica.
And I've been there 15 times with different field teams and what
I study down there is how fast the ice is moving.
The reason we're interested in that is that how fast the ice moves
determines the shape of the ice sheet and the size of the ice sheet.
As the size of the ice sheet changes, sea level goes up and down
and that affects people all around the world.
It really is a global issue that we deal with in Antarctica.
Certainly with warmer climates we know the ice sheets are sinking
and sea level the going up.
We're trying to answer how much, how fast.
That's really important.
A lot of the work we do in Antarctica, I think I have a slide here
that shows Antarctica.
And every time I go down there, I'm reminded of what a wonderful
place it is, what an interesting place and exciting place to work
but how small I am relative to how big Antarctica is.
I mean, Antarctica is huge.
It is larger than the United States.
And that's one reason this satellite data are so important for
our research.
It gives us the big picture.
Something like the land sat mosaic not only gives us the big picture
but allows us to zoom in and see fine detail that is so important
to giving us clues as to where the ice is going fast, where it's
safe to work and also other things that some of the other scientists
will be talking about that help us in our research.
But it also is part of our research because we can measure the
speed of the ice directly from satellite imagery.
The land sat imagery has a lot of uses for the time of research
I do.
And I can go on and on about that but I dare not.
I want to pass the video baton to my colleague at national science
foundation Tom Wagner.
>> Hi, everybody.
Welcome to the webcast.
I don't see my face on the screen but I assume you can all hear
me.
Is it going okay?
>> We're good.
We can see you.
>> I'm going to keep talking then.
So, you know, like Bob, when I was a kid I was into science.
Not so much the mountain climbing but I loved chemistry and physics
and all that stuff.
When I went to college I realized I wasn't to do science but I
wanted to get outside.
I started to get more interested in the Earth on how it works.
I settled on volcanoes eventually and I worked in new New Guinea
for a while.
Then I got a job where I worked today.
My job is hearing about the projects people want to do in Antarctica
and I help figure out which ones we're going to support.
The reason I got interested in LIMA was we realized scientists
needed a better way to see things in Antarctica to plan their work
and figure out where to go and what they were going to do there.
We worked with Bob and other scientists to get this mosaic together.
I'm looking forward to telling you some more about mystery mountains
and hearing about your proposals down the road.
I'll turn over now to Ted?
>> We're going to go to Ginny Catania who is a research
scientist at the University of Texas with Austin's institute of
geo physics.
Tell us a little about yourself, what led you to study Antarctica
and how the LIMA imagery is important to the work you development
>> Can everybody see me okay?
>> Yes, you're good.
>> I had a very similar background to Bob in that I was
really interested in being outside in the mountains and my first
trip was to Switzerland to study glaciers there and that's where
I got completely addicted by being in the field.
And I kept going into the field and studying Alpine glaciers and
eventually got really interested in Antarctica because the science
there is so important and it is so -- such a big scale.
And satellite imagery to me has really revolutionized our field
because in the last ten years we've had a lot more availability
of satellite imagery and a lot more frequent satellite images and
so we're able to see the rates of change of the ice sheets over
time.
And by seeing this, we're able to observe really fast rates of
change that we wouldn't have been able to observe other ways.
And so this has really changed our field and it has been exciting
to witness it from my perspective as a newcomer coming into this
field.
I have some pictures here, too, I don't know if you guys can see
them.
These are pictures of me getting dressed for the field to go to
Antarctica.
You need to have a lot of warm clothes because it gets pretty cold
there.
And this is another picture of the kind of work that I do.
I collect the ice penetrating radar data that you can see in the
lower right-hand side here.
It gives us a cross section of what the ice sheet looks like.
The way I collect it is going into the field we need to have satellite
images to tell us where to go in the field so we're safe in how
we drive around on the ice sheet but also to help us plan what
kind of features we're interested in looking at.
What areas show big rates of change and what kind of problems do
we want to really answer?
Satellite imagery helps to guide my work and I'm starting to get
more and more interested in satellite data because of the plethora
of data out there.
There is more data out there that is more easy to obtain than there
is field data.
It is harder to get funding to go into the field.
So I'm starting to get more and more interested in satellite data
and it has been a really enjoyable thing for me.
That's all I have.
>> Thank you, Ginny.
Do we have Ted Scambos on the phone?
He is a glaciologist.
He along with Ken Jezek a professor of Ohio State University are
also part of the LIMA project.
Ted will be joining us later on web khats or in the final webcast.
So let's check one more time.
Do we have Ted on the phone?
Okay.
Well, let's go ahead and talk about what this challenge is all
about.
As Earth scientists you and your group are going to study some
images that are provided through the LIMA project.
You're going to identify a specific ice feature that is of particular
interest to you and you're going to submit a proposal to these
scientists you're hearing from today.
In your proposal you'll do two things.
First you will talk about the geologic feature, why it's interesting
to you and why you would like to study it further.
And then second, you're going to give your opinions as to what
processes you think are happening to cause that feature.
We hope that you've already toured some of the LIMA website and
certainly there is an educator guide that we have available to
you to help guide you through the process and show you how to explore
that website.
We're particularly going to be looking at some of the mystery sites.
So let's take a look at that slide.
We have these mystery sites.
The scientists with us today, Tom and Ginny and Bob are going to
be talking about some of these sites that you see up on the screen.
As far as the submissions, we're looking for very interesting submissions
from you.
We want something that is unique and possibly that we haven't even
noticed ourselves.
If you select a site that is scientifically significant, then we
may actually add it to these group of mystery sites that you see
on the screen.
So that is certainly a goal that you can aim for.
So we know there is science in every piece of Antarctica and during
the challenge you'll be finding a spot on the continent that interests
you.
Today in this webcast we're going to help you understand the type
of submission that we're looking for and we're going to talk about
these mystery sites that have already been identified.
So let's start with Tom.
Tom, can you tell us about volcanoes and mountains on Antarctica
and why they intrigue you?
>> Yes, I can.
For a whole bunch of reasons.
Can you guys -- is my first slide up?
>> Yes.
>> It is, great.
If you look at this slide, there are all different kinds of mountains
in Antarctica and there are some mountains that are formed by
tectonic forces that push things up and others formed by glaciers
and some mountains are just volcanoes.
You can see all of them in this figure.
Let's go to the next one.
Sorry, this is the one here that shows you, this is a picture of
Antarctica with all the ice lifted off.
While you might have thought Antarctica is flat, it's not.
Those are mountains and volcanoes and valleys.
Let's go to the next slide.
Our mystery volcano was mount TAKAHI.
They're important to us for two reasons.
They tell us about -- because magma comes from great depth in the
Earth it tells us the characteristics of the deep Earth and it
is important to understand about the geologic history about Antarctica
and they help us understand global climate change.
Let's go to the next slide.
When a volcano erupts say like Mount St. Helens it throws a lot
of dust in the atmosphere and the dust falls down.
In Antarctica it puts a layer on the ice and it gets buried and
incorporated into the ice.
>> Can I interrupt you for a second here?
>> Sure.
>> I believe we need Ginny to mute her slides.
They are showing up in the corner.
Great.
>> A glaciologist trying to steel all the thunder.
>> Excellent, it's all fixed.
>> Okay.
Continue with your discussion.
>> Yeah, sure.
This is a cartoon that shows a volcano erupting in Antarctica and
how it develops a layer of volcanic ash all over the ice.
Let's go to the next slide.
And this is what it looks like if you go and chain saw out a block
of ice you can see a layer of volcanic ash in it.
This turns out to be really important to us.
Next slide.
One of the most important ways that we understand how the Earth's
climate has changed and how it was warmed and cooled in the past
and how it might warm and cool in the future is through ice course.
Every year in Antarctica a little bit of snow builds up.
Every year we get another layer and we drill through it and we
get a tube of ice.
We can go to the individual layers to figure out what the Earth
was like at the time that they formed.
In Antarctica now we've gone all the way back a million years.
How do we know it's a million years?
It's tough to do.
If you're only going back a few thousand years you can count the
layers you see in the ice core.
Sometimes they get cut off.
Maybe there was melting or something and this is where the volcanic
ash comes in.
If you find a layer of volcanic ash you can use chemical techniques
to date it.
This is a way for us to date the deep parts of the ice core.
Let's go to the next slide.
Also, too, as you might think, volcanoes can be pretty hot, right?
A lot of people are surprised that Antarctica is cold.
How can there be hot volcanoes?
We get liquid water underneath the ice.
This is what happens when you take off the ice.
There is water.
There are sub glacial lakes.
You can read more about them and you can use LIMA to show how it
flows underneath the ice sheet and modeling what the ice is going
to do in the future in a warming world.
Let's go to the next slide.
Those other mountains are really important.
They tell us two things.
They can tell us about Antarctica's geologic history and glacial
history.
Let's go to the next slide.
The mountains of Antarctica get shaped by the rivers of flowing
ice.
That's a big one.
To put that in scale some of those mountains are 14,000 feet tall.
You can even have a glacier scour in and dig up -- what we can
do is go out and use local topography to try to understand what
the glaciers were like in the past.
Like in this case you can see once upon a time the ice was probably
a lot higher and overrode all the mountains.
Now the ice is lower.
Also, too, you can see blue ice which hints that there has been
some melting.
Next slide.
Now in that mystery slide there was a black rock that looks like
this rock right here called basalt.
It tells us a lot about the geologic history of Antarctica.
Next slide.
Now, today all the plates are spread around the world, right?
Next slide.
200 million years ago all the continents were smashed together
and you can see Antarctica down in the lower right-hand corner.
What would happen was there was a super volcano that popped up
between Antarctica and Africa and literally broke them apart and
sent magma squirting throughout the rocks in Antarctica.
On the mystery slide that black rock in that image is the remnants
of that super volcano.
Next slide.
Going back 200 million years the other thing we had were dinosaurs.
I have my friend here to tell you about later.
Other things you can do with LIMA and the mountains we find fossils
but the surfaces are important themselves.
In this case here what we can see is there are glaciers that are
covered over with a soil layer and this is really important for
people trying to understand Mars because they want to know where
they might find life on Mars or where they might find ice.
A lot of times where we have ice we have a little water and we
can have life there.
People are using imagery like this and LIMA imagery to try to understand
and get -- I'll keep talking.
That last shot I showed you is from the dry valleys in Antarctica,
the largest ice-free area in Antarctica.
If you look on the web and if you look around the LIMA site you
can see this.
This area is important because it's got some of the most primitive
life on Earth but also lakes.
The next slide.
Here is a picture of one of those lakes called Don Juan pond.
This lake even in the middle of winter has never been seen to be
frozen over even at minus 50 degrees.
Next slide.
Just a couple of suggestions for you and we'll talk about this
more at the en.
In terms of using LIMA for your proposal.
Find your favorite feature.
Have fun with it and poke around LIMA and look around and see what
catches your interest but also read about that feature a little
bit, right?
See how can it -- what is the research question that you can ask
about that feature and how can LIMA help you study it?
There are plenty of great resources on the web.
The LIMA website and one that's not listed on here called CRESIS.
You'll find plenty of information.
I'll close and turn it back over to Rebecca.
>> Thank you, Tom.
That was very interesting.
We're going to now transition to Ginny and she a going to tell
us a little about glaciers and crevasses.
>> Okay.
The first picture I have if you guys can see it is one of the mystery
features that comes from the LIMA website.
This is a picture of a glacier in the dry valleys.
The dry valleys I'll turn to my map behind me.
It's down in here.
And Tom actually if you look behind Tom, there is a map, really
detailed map of the dry valleys on the wall behind his head.
But Taylor glacier occupies one of the valleys there.
You can see in the image that the ice wraps around and almost forms
a circular flow pattern.
This is a really interesting image to me because number one, I
think the scale is really interesting.
A lot of people think glaciers, you go to the mountains they may
not be very big.
This glacier is huge.
If you look on this image I've put on scale which is 500 meters
tall.
One of the tallest buildings in the world and I've scaled this
tower on the image to match what the image scale is.
It's actually pretty small.
If you stack all these towers across the ice it measures 2 1/2
kilometers wide.
This is a really big glacier.
It is not like something that you would see in the continental
U.S.
So the other interesting thing about this image is that you can
see these nice lines on the ice that kind of form and they go around
this block of rock right here.
And the cool thing to me is that you can actually tell what direction
the ice is flowing from this image and how these streaked lines
are formed.
If the ice was flowing in this direction around this bit of rock
in the middle, you wouldn't get the same pattern that you see over
here where these streak lines get deformed and pulled into the
ice flow.
What that implies is that the ice is flowing around it this way
and going down this valley.
That's also true because you can see as the ice comes up and over
this bit of rock you get all these crevasses that form as it tries
to get up there and fails.
This is a little bit of rock in the middle of the ice and it deforms
the ice around it because it's a pretty resistant piece of rock.
This is a really interesting image to me and I think it would be
neat to explore other ideas of what you might try to figure out
from this image.
If you were to look at this, you know, what kind of questions would
you answer like besides which direction is the ice flowing, like
maybe how long has the ice been there, how would you try to figure
that out?
Which ice is flowing faster and how would you try to figure that
out?
Is it the ice that's flowing faster within this round valley or
is it the ice that's flowing over here that is faster?
How would you try to figure that out.
That's what I would encourage you to do with the LIMA website.
This is another picture of the same area from an airplane.
You can see the top of the airplane at the top of the image up
here to give you a sense of scale of what these big ice glaciers
look like when you're out in the dry valleys.
On the lower part of the image is a picture of beacon valley.
A beautiful area in the dry valley.
The next image I have is a set of crevasses that we see on the
ice sheet.
They are in a lot of places on the ice sheet.
These are located over here.
And this is a really fast-moving glacier that is forming and creating
the crevasses and the glacier is over on this side and there is
slow-moving ice on this side.
So you have this region where you have fast-moving ice next to
slow-moving ice and it causes the crevasses to form.
I have with me a little bit of silly putty which a lot of people
probably are familiar with.
It behaves a lot like ice does.
If you pull it quickly it breaks apart.
That's just what ice does.
If you pull ice quickly that's how you get the crevasses but you
can pull silly putty very slowly and it will stretch and that's
also like ice.
If you pull it really slowly it will tend to thin and it stays
coherent and doesn't crack if you pull it really slowly.
If you pull it quickly that's when you get the crevasses forming.
The interesting thing about this image is again if you take the
scale of this tower and put it on this image you can see the tower
here is tiny and could fit almost into the huge crevasses.
Number one, these are very big crevasses and you wouldn't want
to go anywhere near these except if you were maybe flying in an
airplane.
The other interesting thing is that you can see that the shape
of these crevasses are deformed.
That's because the ice is moving fast in this flow direction on
the side here and it tends to shear the crevasses on one side more
than the other and you get this shape to them.
The other thing that's really interesting is that on this side
the crevasses are not sheared as much so they tend to not be very
actively opening all the time.
So as the snow falls on the surface you can get a snow bridge.
You can end up closing the crevasse over time but you can also
have, as you can see these little pockets.
These little holes where the snow bridges have failed just kind
of randomly and so you want to be careful if you're planning to
go into the field to study this a little bit more detail that you
wouldn't want to go anywhere near these big crevasses.
Those are the two mystery images I've been really interested in.
So I would encourage you again, like Tom said, to go to the LIMA
website and check out all the things that are there.
There is a huge amount of data that's there to look at.
You could spend hours pouring over the imagery in great detail.
Then try to figure out what is that image and what kind of information
do you need to answer the question of what are you seeing in that
image?
I encourage you to think about what you would do to study it in
more detail.
Would you plan a field season.
What would that entail?
If you weren't going to plan a field season, would it be to look
at other imagery besides LIMA to help you understand the LIMA data
better or look at books to understand geology maybe or the books
to look at what ice looks like in other regions just to compare?
So I would encourage you to get online and check out the LIMA website
but the website Tom suggested and the other websites that have
lots of great photos of glaciers and ice sheets as well.
>> Thank you, Ginny.
We appreciate your input.
And Bob, we would like to transition over to you and learn a little
bit about some of the iceberg formations through the LIMA imagery.
>> All right, thank you very much, Rebecca.
I will share a secret that all these 17 mystery images that are
on the LIMA website right now I found.
And I found them in about half an hour of panic trying to put this
page together before I had to leave on a trip.
And I found it exactly the way that I hope a lot of the students
are going to be finding them which is just scrolling around this
huge dataset and looking for interesting things.
I thought I would just pick ten but I couldn't narrow it down to
just ten.
Almost every place I scrolled I saw something interesting so it's
really gratifying to hear so much science come out of each one
of these.
Such as Ginny and Tom described.
One of the favorites I picked is this image of what I call a puffy
marshmallow.
It was unusual to me and I've made some of these images seem unusual
by cropping them the way I did and removing some of the context
that can help explain what these are.
Just as one example, I think this serves as a good example.
If I go ahead and I just zoom out on this, to look at the region
around this particular region, you can see where the sub image
came from is still outlined in red.
We see in the upper right the coast of Antarctica.
That's the grounded ice sheet in the upper right and most of the
images actually frozen ocean with a thin covering of sea ice.
We also see from the upper -- the top middle something labeled
a land glacier.
This is a big glacier draining ice off the ice sheet into the ocean.
Ginny give a wonderful description about glaciers and ice flow.
This glacier is one of those that flows fast enough that it breaks.
The silly putty that is being stretched hard enough and quickly
enough that it breaks but it is still held together by the mountains
that it flows through and you can see those in the image as well.
Once it gets into the ocean and there is nothing holding it back,
the little pieces of the glacier just spread out like little chicklets.
If people know about that kind of gum, I'm not endorsing any product.
They're not really little.
But that glacier just falls apart.
And these icebergs in this mystery image are part of that collection
of icebergs.
The best photo I could find of what you might actually see if you
were in that area is this one.
And it shows a number of icebergs just floating in the ocean and
they are thicker.
They're higher because it's thick ice.
And around these icebergs is much thinner sea ice that's frozen
ocean nowhere near as thick.
Only a few feet thick for the sea highs.
Hundreds of meters think for the icebergs.
The big difference there if you were to be in that area and see
it.
What you don't get from either the image that I showed or this
picture is an idea of the scale.
This is something that Ginny spoke about and I want to emphasize
it, too.
I go back to one of my opening remarks.
Antarctica is just so big.
It's hard to really appreciate that.
Here is another a fairly small iceberg but at least this photograph
includes an airplane for scale so you can get some idea of how
big a small iceberg is.
But let me keep emphasizing that point by going back to this larger
image and now what I've shown included on this slide is part --
a map of Washington, D.C.
Washington, D.C. is this small yellow dot in the middle but around
Washington, D.C. is this major highway we call the capitol beltway.
It's 25 miles from side to side.
What I'm going to do is circle that with this blue circle and then
put the -- circle the same size on the land glacier.
What that says is the land glacier is big enough that if it were
in Washington, D.C. it would not only cover the City of Washington,
D.C., it would cover the whole area from one side of the beltway
to the other.
To help people get a sense of how big these features are in Antarctica.
And just to come back to that mystery image, I go back to that
mystery image on the right here and what I've done is taken another
popular, familiar, geographic feature, the lower half of Manhattan
island.
Same scale, these two images and what I want to emphasize here
is again how big these little icebergs are.
Most of them would clog up the east river on the right side of
Manhattan island there.
If you look at the Brooklyn bridge there, most of those icebergs
wouldn't even fit underneath the Brooklyn bridge.
So again Antarctica is bigger than you can ever imagine.
And that's one thing that actually makes it interesting.
One final comment about icebergs, you have to remember that although
you see something that's quite big, you are looking at literally
the tip of the iceberg, which is only 10% of the full size of these
icebergs.
90% of the features that are included in this particular image
are contained underneath the surface of the ocean.
Antarctica is big.
That's the message.
And I think hopefully Linda has been flooded now with a lot of
questions and we've piqued your appetite.
I hope the students led by their teachers will do what I did in
that afternoon, scroll around Antarctica, poke through these websites.
Find interesting features.
There is a science story to tell about each one of those.
But those 17 are offlimits.
You have to find your own.
>> Well, thank you, Bob.
I want to thank Tom and Ginny and Bob for the explanations of the
mystery sites, the images have been great in your comparisons
to features here on our continent and to things like silly putty
have been enlightening.
We're going to turn now to our audience and do some of the Q and
A.
We're going to start with a few of the questions that we've received
so far.
Linda, what do you have?
>> I did want to mention that we will put the Power Point
slides that we've been playing up online so that you can have a
look at them a little closer later after the show.
And this will also be archived for those of you who are having
trouble connecting to the video.
However, you can still post your questions in the chatroom.
We just got one from -- let me see if I can pronounce this -- middle
science from New York.
And they ask, we're looking for the area where the lake is located
under the ice.
Is that one of the areas we could study?
>> The largest sub glacial lake is called VASTAFF.
I don't remember the coordinates right now.
>> It's in LIMA, yes.
>> Okay.
It's -- you know the coordinates.
>> I can show you on a map.
>> You don't need to do that.
You can go to the LIMA website and there is a link called find
a feature and you go there and you type in lake VOSTOK.
And you query on that.
You'll get a description of the lake and then there is another
link there, click on that and you'll be brought straight into LIMA
centered on the lake and that will set you up as that is your starting
point and you can zoom in and out and scroll around.
So the LIMA website allows you, if you know the name of the feature
to go and see it.
>> Okay.
>> Can I throw something else out there for that one?
>> Sure.
>> Another thing to think about there are a couple of these
other lakes.
They're is sub glacial lakes but other lakes around the land areas
of the coast.
Can you use LIMA to answer any questions about those?
Their size, shapes, locations.
Find one that hasn't been found yet.
Things like that.
>> Speaking of one that hasn't been found yet, who is your
friend?
>> This is Elvis.
Elvis wanted to make a couple of points.
Elvis likes ice but Elvis is also saying you know, climate change
is one of the things that wiped out me and a lot of my friends
over the year, right?
And he says look, you guys can spend a lot of time studying ice
but I was found in Antarctica on a mountaintop that was unexposed.
I wonder, is it possible for you to use LIMA to look for things
like me again?
>> That would be fun, actually.
Okay.
We have another question from Idaho kid who says, how can you tell
how deep and iceberg really goes?
>> A great question.
One of the best ways to do that is with imagery.
Landsat imagery is taken of a Sun lit surface so we know where
the satellite is and what time it collects the image so we know
where the Sun -- what the elevation of the Sun is.
And often we can measure the length of the shadow and that will
tell us how much of the height of the ice above the water and then
we multiply it times nine and we know how thick the ice is.
It's using the imagery and knowledge about the Sun location to
determine the height of the ice above the water.
So some simple geometry there but it can be done and has been done.
Oftentimes we want to know exactly that.
>> Okay.
We have a couple of questions on the logistics of when, which seasons
you go to Antarctica and how you get there.
>> We knew there would be some questions about that.
Because Ginny had that wonderful slide of her getting dressed we'll
let her answer that.
We don't want to answer too many questions about the field work.
We want to sort of help people get their questions answered so
they can satisfy this challenge that has been put to them.
Ginny.
>> Yeah.
Well, we go to Antarctica in the summer that happens in the northern
hemisphere wintertime.
So typically you leave sometime in October and you can be there
until February.
But the beauty of satellite imagery is that you can see Antarctica
all the time as long as it's sunny and you're looking at visible
imagery you can see Antarctica from your desk all the time and
so it's actually -- you can go to Antarctica right now if you wanted
to.
You have the luxury of doing that now.
In some way I think satellite imagery allows everybody to go there
and allows us to go there a lot more frequently than we can physically
do it.
>> Okay.
I think you folks are having to see us more often than they should.
We aren't being able to switch to Ginny.
I apologize for that.
Hopefully we'll get that settled here soon.
Another question here, do you find the most interesting features
of Antarctica to be located in the interior or along the coast?
>> There are interesting features of Antarctica throughout
the continent.
And I think if somebody goes to the LIMA website and starts scrolling
around, you could answer that question yourself.
I think you will find that there are interesting things to see
throughout the continent.
So I'll put that challenge back to you.
Go look and I bet you'll find interesting features all over the
place.
>> Also don't forget to look at the peninsula that extends
up toward South America.
>> Speaking of how to get there.
Okay.
You try to get images from different times of year or only during
the Sun lit months?
>> Ginny, did you want to answer that one?
I don't want to hog all the questions.
>> I mostly use visible satellite imagery so I do try to
get data from just the summer times.
And I really like to look at change of the ice sheet.
So I want to have repeat images of the same area.
It is important to make sure there are no clouds in the image so
you can actually see the ice or the rock below you.
So I want to get repeat images of the same area at different times
during the year or different years and at different -- the same
date but every year for maybe five years or so.
One of the things you could look at are seasonal changes.
Are there changes over the summertime?
Are there changes over many years due to global warming or due
to natural variability?
And to me it's really important to be able to see changes in the
ice sheet.
That's the kind of thing I'm very motivated by.
So I love to see repeat images.
That's like the best thing for me.
>> I'll just add to that that on the wall behind Ginny.
She's already used it a couple of times, is another map of Antarctica
not collected with optical imagery but with a radar sensor that
actually transmits a radar beam and records the scattered energy
that it receives back.
And it is a totally different view of Antarctica.
On the LIMA website we've been able to combine different maps of
Antarctica.
LIMA is one of them.
Once you have an interesting feature in your sites, you can click
to this radar sat is the name of the satellite imagery of that
same feature and even another optical sensor and you can get different
views of that feature looked at in different parts of the electromagnetic
spectrum.
It will look different.
There is interesting science to do with comparing and contrasting
with different views of the same feature.
>> We have a question here from wren middle.
How can water flow under the ice that is frozen?
>> You want me to handle that one?
>> Sure, Tom.
>> What happens.
At the base of the ice even though it's really, really cold, in
some places it's warm enough you still have liquid water and
this is something that is pretty exciting because it's only been
figured out in the last -- even in the time I started with the
program five years ago, you know, we've realized there is much
more water than anybody thought of and part of it has to do with
the geo thermal heat flux from the Earth and -- some of the exciteings
things is that there are lakes around Antarctica and also underneath
big thick parts of the ice.
We're talking about two different kinds of lakes.
I hope everybody understands that.
In the ice-free parts of Antarctica, less than 5% of Antarctica,
there are small ponder around or small lakes.
These are things that might be 50 to 100 feet deep.
Some of them are ice covered and a couple of them are open water
in the summer at least.
Then there is that one lake I showed you that stays open water
all winter.
Then under the thicker parts of the ice sheet, places where the
ice is literally miles thick, there are great big lakes like lake
VOSTOK that is miles long and kilometers deep.
There is evidence that some lakes have popped a seal on the side
and drained downhill into another lake.
Geologic evidence in the past that there were massive ice sheet
lakes that broke out and created their own valleys at a place called
the lab -- labyrinth in the dry valleys.
>> As people who study the ice like Ginny and I the recognition
that there is so much water underneath the Antarctica ice sheet
is an absolute revelation and entirely new field in our discipline
because there is so much water it's moving around so much, that
it has to have an important influence on how fast the ice is going.
So it's one of the -- one of the real frontiers in our science
right now.
I'll just use that as an opportunity to tell people out there,
because often students think that all the neat questions are happening
right now.
All the neat science is going on right now.
But the neat thing about science is the questions never do stop.
This is just a perfect example of that.
We're not going to get all the questions answered.
We can't even anticipate what some of the questions are.
So students out there that are interested in science, there is
going to be some absolutely fascinating stuff to do.
And so that's just serves as a reminder to students out there that
science is fun.
It actually is very much like acting like Sherlock Holmes day in
and day out and getting paid for it.
It's great.
>> Okay.
We have a question from O.L.M.G.
Samantha.
Could anything exist in the sub glacier lakes?
>> You want me to -- Ginny, do you want that one?
>> I'll give that one to you.
I'm not much of a biologist.
>> That's the million dollar question, Samantha!
One of the big things.
Chances are there are probably not fish.
But there probably is microbeall life and we have so good evidence
to that.
Right now nobody has ever drilled into a sub glacial lake but there
is discussion of drilling into lake VOSTOK.
There is a report online that tries to assess what might be in
the lake and how we might safely drill into it without contaminating
it.
The people that study it right now, what they've done is sampled
the ice around the lake and there is evidence that part of lake
VOSTOK as the massive ice sheet flows over the surface, on one
side of the lake it melts a little bit and on the other side of
the lake it crystallizes and forms more ice and the ice is lake
water which we've drilled into.
There are some microbes in there.
It's sketchy or the science is really just beginning to happen
but it looks like these things are like an Alpine lake that you
might find in other cold parts of the world.
Mostly microbial life.
This lake has probably been isolated from the surface for many
millions of years.
7 to 15 million years.
So potentially the life that's down there has evolved a little
bit.
One of the other questions is what is their food source?
How could they live?
There is a theory that maybe there is a little bit of like a hydrothermal
system that you might find at a mid ocean rings and black smokers
on the sea floor.
Hot rocks that are causing water to percolate through it or maybe
there is enough background heat to keep that lake alive and going.
This is probably one of the most exciting areas for future research
and the next few years you're going to see a lot more coming out
about it.
>> I can't let that one go, either.
NASA, we look for life all over the place in the solar system and
beyond.
And it's a big, big question for us.
And Antarctica is the perfect test bed for many of the experiments
that we are designing ultimately to be launched to other planets.
And so there -- the extreme environment in Antarctica is tremendously
unique place on this planet that we have much easier access to
and whether it's the sub glacial environment that you were asking
about or some of the hyper saline environments with Don Juan pond
and why it never freezes because it has so much salt in it.
You can find portions of LIMA that are related to these questions
in biology and life in extreme environments.
You'll look at the dry valley area because that's where scientists
are focusing their attention in the extreme environment experiments
and investigation.
Go for it.
That's a great line of questioning to follow.
>> Okay.
Want to follow up with a question that is not totally LIMA directed
but has anyone sent a sub to see under there, Amanda wants to
know?
>> Let me take that.
She's probably talking about the sub glacial lake environment that's
totally enclosed with ice and you have to drill through the ice
to get to it.
And nobody has entered the sub glacial lake yet.
During the International Polar Year there are countries expressing
serious intent to do that.
But because she mentioned submarines, I will mention one of my
favorite topics, which are the floating ice shelves around the
fringe of Antarctica.
Certainly you can see these with LIMA.
This is where the activity is really taking place on the ice sheet
changes.
We have a project underway right now to study one of these major
ice shelves that's called the pine island glacier ice shelf.
I was there and we had the first landing on the ice shelf this
past summer during the field season.
But this next field season what is going to happen is that a research
vessel, the U.S. research vessel is going the get as close as it
can to this ice shelf and they're going to release an automatic
submarine.
Automatic undersea vehicle and its mission is to go underneath
the ice shelf and sample that water for the very first time.
There are biological questions there and physical questions about
how the water that gets underneath that ice shelf interacts with
the ice.
How much ice does it melt?
We have indications from satellite imagery that it melts a huge
amount of ice.
Tens of meters and hundreds of meters of ice every year.
We've never been able to sample it and submarines will give us
the first view.
Ultimately we want to drill through the ice shelf and put other
instruments into the water that can stay a long time.
A submarine goes in and comes back out.
Hopefully comes back out and gives us a glimpse.
That's again one of the frontiers of science.
These are great questions because they're really taking us to the
most exciting science that's being done right now.
>> Okay.
Jasmine asks, can I study the core of the ice and ash?
That's Amanda's question.
>> Yeah, you can.
There is actually a big--
>> Sure.
>> There is actually a big ice core drilling project that
is happening right now for the next couple of years.
I don't know if you guys can see me but the drill is being -- the
core is being taken from a place right here.
And the reason that it is being taken from there is it it acouple
later a lot of snow in that area.
You get a lot of snow that dumps on the ice sheet there and that
means every year you have a big annual layer of snow and over time
that gets compressed by more and more snow so you get really thick
layers of annual layers in that area.
And the other thing that Bob and Ted touched on earlier is you
have melting at the base of the ice.
This is one of those places.
It is thick ice here.
You have melting at the bottom of the ice sheet here.
Not only do you have a lot of ice coming on the top of the ice
sheet, a lot of snow on the top of the ice sheet but you have some
removed from the bottom.
As the ice layers go down through the ice columns, they don't get
compressed as much because you have removal of ice at the bottom.
You get nice thick layers really deep in this one particular area
and it allows a great high resolution of data within each annual
layer and it is going to be a very unique dataset, I think.
There have been a number of ice course drilled both in Greenland
and Antarctica and many glaciers all over the world.
This will add a lot of new information about more recent temperature
changes and changes in the atmosphere over the last 100,000 years
or so.
It will be a great addition to the set of data that's out there
already.
>> Okay.
A couple more before we wrap up here.
How often are the LIMA images updated?
>> Good question.
For LIMA what we did, we wanted a snapshot of Antarctica so we
tried to make the time window as narrow as possible because of
the fact that clouds get in the way and we needed cloud-free
images.
LIMA spans a time period of about four years and it is what we
call a benchmark.
A snapshot and reference point and we hope that every five or ten
years we'll update it.
We'll do a new mosaic so we can look for changes on the continental
scale but images taken at other times, landsat imagery started
as early as 1973 and continues now with landsat seven.
New images are being collected all the time.
We hope there will be lots of time comparisons with individual
images but very often I think LIMA is going to be a reference point
we compare those changes to.
For right now, LIMA is that snapshot.
Because we've done it and we've been able to describe how we did
it, I think it makes it easier to do it again and again and again
on into the future.
So my hope is in the ten years' time we'll have another activity
to produce another mosaic.
>> It would help to turn my Mike on.
One last question here.
Does the LIMA imagery provide data on temperature or depth?
>> Well, no, not directly.
However, the landsat data that are collected includes a number
of bands.
We used three spectral bands to produce a true color image.
What you see is what you get.
This is the very best representation of what you would see if you
were in Antarctica is by going to the LIMA website.
And that, as Ginny said, it is one way of us allowing you to bring
Antarctica to you.
There are other bands collected by the lansat sensor.
One of those is a band so it actually does measure the surface
temperature.
It is just we have not included that dataset in the LIMA imagery
that is most easy to use through the website.
But the scientific data are there for scientists.
About ice thickness, again, no, we don't.
Only if that ice is floating and we have a shadow and through the
techniques that I described earlier can we get an idea of how thick
the ice is.
We really need to measure the elevation of the ice and with other
sensors called ice penetrating radars we can actually measure the
thickness.
Those are important datasets in their own right but when we combine
those datasets with LIMA, we just have that much more to work with
and it adds value to all the data.
It doesn't measure everything, but it gives us a lot of good information
that helps us understand other data that are collected.
>> I don't know if you want to add anything to that, Ginny
or Tom.
>> I learned something new.
I didn't know there was another band that was sensitive to temperature.
>> Okay, great.
That only proves we can all learn something at these webcasts.
Thank you for your questions.
>> That concludes our question and answer period for today's
webcast.
I do want to give our scientists a chance to say any last words
that they want to share with you before we sign off.
So let's start with Tom.
Tom, do you have any last words or thoughts to share?
>> Yeah.
I just want to say you should have a lot of fun with this project
and again, as we -- all of us pointed out, the way to go about
it is look at LIMA or find a feature or if there is something
you know about Antarctica or learned somewhere else, see if you
can use LIMA to help you understand that.
Dream your big dream as a scientist and you're starting out your
career now and we're all looking forward to reading your proposals.
>> Ginny, do you have any final thoughts you would like
to share?
>> I would echo Tom's words.
It's an exciting time to be interested in science because we have
so much data available right now.
So I would just encourage you to browse on the website and check
out all the things you're interested in and zoom in deeply to see
what scales you can resolve and zoom out to try to figure out what
you're looking at.
It will be a really fun project.
I encourage you to explore and have fun with it.
>> Thank you.
And Bob, how about yourself?
Would you like to share any last thoughts.
>> Both Tom and Ginny said the magic three letter word.
We hope by making this dataset the view of Antarctica as it looks
so easy to look at that you will have fun.
Science is fun.
And you can be scientists.
You can just poke around, explore the continent and see what interests
you.
That's what starts a lot of science projects is exactly that.
It's that sort of interest and intrigue and scratching your head
saying what is that?
That's why we've come back to that as the central objective of
this challenge is what is that?
Go explore Antarctica and see what you find and learn a little
bit about it and you're doing science and hopefully having fun
while you do it.
>> Well, thank you.
I want to thank Tom and Ginny and Bob for their enthusiasm and
their expertise that they've shared with us today.
And to our audience, we look forward to receiving your proposals.
Just a reminder they are due -- the preliminary proposals are due
on November 5 and you can send those.
You'll send those to Linda.
And then our scientists will be reviewing them and we'll have a
closing webcast at the end of our challenge.
So go out there, do exactly like Bob, Tom and Ginny said.
Look at what sinting and explore it and enjoy it.
Send us something that is interesting and something that will even
surprise us that will spark our interest as well.
So thank you all for joining us for listening to us today.
For sending in your questions.
And good luck. |