Let's Talk with Jane Ferrigno about Using GPS in Antarctica

AMNH: What's so important about your field of study in Antarctica?

Jane: We didn't really know our planet that well until the last thirty years or so, when satellite imagery developed. With satellite imagery, we could begin to learn what's really there. With remote sensing, it's possible to get a bird's eye view of what's happening over any large region of the world. That gives us a picture of what might affect the world as a whole. This is very useful for studying climate change, or sea-level change, or changes in the West Antarctic Ice Sheet.

AMNH: The Ice Sheet is really important, huh?

Jane: Yes! If that breaks up or melts, sea level will rise all over the globe.

AMNH: Is that what you do in Antarctica?

Jane: The research group with which I work studies glaciers worldwide, but we've gradually focused on Antarctica because most of the world's glacial ice is there. Our tools are especially useful for looking at Antarctic ice. As I said, the extent of that ice affects the temperature of the globe, and water systems all over the Earth. If those ice sheets weren't there, or were smaller or larger, our planet would look very different. I also work with other researchers to monitor a number of short-term effects of changes in Alaskan glaciers. When icebergs break off and get into shipping channels, you have to worry about oil tankers running into them; that can lead to a major disaster. We also try to figure out what glaciers are doing in the Canadian Northwest. We need to know if they are getting larger or smaller because hydropower is a huge industry and the icebergs can be used for water supply when they melt. Hydropower concerns are a practical application of remote sensing in glaciology. Remote sensing is also used to monitor glaciers that might advance, damming up rivers or causing floods downstream. We also monitor glaciers that sit on top of volcanoes in places like Iceland and Peru. Not many years ago, one of the volcanoes became active, melting a large part of a glacier, and releasing a huge amount of water. A similar event happened in Peru that was even more disastrous–the heat from the volcano quickly melted the glacier and caused mudflows and floods

AMNH: Remote sensing is a pretty new field. Have you seen alot of changes since you began?

Jane: Basically, satellites that are in orbit around the Earth take photographs of the Earth's surface from several hundred miles up. The photographs are digital images, and they can be pieced together to look at large areas or to examine an area over time by comparing images taken at different times. This has become a powerful new scientific tool. We can use remote sensing to study all kinds of phenomena–the movement of tectonic plates, ocean currents, the growth of sea ice, or the retreat of sea ice. In Antarctica, the sea ice doubles each fall and winter! We can also look at the movement of icebergs breaking off of ice shelves in polar regions.

AMNH: Can you give a simple definition of Remote Sensing?

Jane: Basically, satellites that are in orbit around the Earth take photographs of the Earth's surface from several hundred miles up. The photographs are digital images, and they can be pieced together to look at large areas or to examine an area over time by comparing images taken at different times. This has become a powerful new scientific tool. We can use remote sensing to study all kinds of phenomena–the movement of tectonic plates, ocean currents, the growth of sea ice, or the retreat of sea ice. In Antarctica, the sea ice doubles each fall and winter! We can also look at the movement of icebergs breaking off of ice shelves in polar regions.

AMNH: How detailed are the images?

Jane: I just heard about a satellite that views the Earth at one meter resolution. That means that you could almost see the cover on a trash can in your backyard–from outer space. That level of detail is such a change from thirty years ago.

AMNH: Your team works on creating map that use these images. How hard is it to put Antarctica on a flat map?

Jane: One problem is that Antarctica often has a lot of cloud cover. We need to piece together a whole bunch of satellite images in order to make one big picture of Antarctica, and it can be hard to find enough imagery to cover the whole continent and still not include cloud cover. That's why the upcoming satellite mosaic is going to be fascinating. It is so difficult to get the coverage you want without sacrificing the detail. I prefer to use a kind of imagery called LANDSAT imagery. This is a good compromise between being able to cover a big area and being able to see a lot of detail. You see, some maps let us see a big area but don't give us a lot of detail; others give a lot of detail but only for a very small area. The LANDSAT image lets us have some of each type.

AMNH: You and your team created the new USGS satellite map. How did you do it?

Jane: We had created an earlier map of Antarctica using mosaics produced by some British researchers. We used their data, edited it a little bit and added a latitude-longitude grid. Our new map adds on to this earlier map. We added more AVHRR scenes so that there was less cloud cover, and we also added a lot of labels. Our first AVHRR map did not have many names associated with it; it was mainly just the image. That's harder for people to follow. We ended up adding hundreds of names so that the forms relate to names of places in Antarctica. In short, we improved the imagery and added names to create the new map.

AMNH: Why were you drawn to map making?

Jane: actually enjoy mapping for mapping's sake, just to know what's there, and where. I also love being able to look at imagery that offers a bird's eye view of the world. The experience is like looking down from a cloud at the world's forms–rivers, mountains, features like that. You see large sections of Earth, you get an idea of what's happening. It's like taking the pulse of Earth's forms.

AMNH: Can it get tedious to make maps?

Jane: Sometimes things become very routine. When I take a measurement or determination for the first time, it's very exciting. I'm finding out something new. But then I have to present my ideas in a paper, and I need to make many calculations. I also have to read over the paper twenty or thirty times; I admit that after the twentieth time, I get tired and a little bored. It's also hard sometimes because this subject means a lot to me, but it isn't even known to many people. They don't know much about glaciers–"out of sight, out of mind"–and they don't realize why it's important to study them. People get caught up in their own smaller worlds; they don't have a feeling for what's going on in the natural world, even though it affects all of us. I'm glad that my job gives me chance to spread the word