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Infrasound Station at Windless Bight

Photos © 2002 Seth White

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About 25 years ago, an infrasound array was established at Windless Bight, about 15 miles NE of McMurdo. A new system was reconstructed at this site two years ago in conjunction with the Comprehensive Test Ban Treaty Organization, or CTBTO, which oversees a worldwide network of monitors for nuclear blasts. This photo is of one of the microphone stations, with Mount Erebus in the background. The CTBT program uses four technologies to detect blasts: infrasound, seismic, hydroacoustic, and radionuclide sampling. The infrasound array is a set of 8 microphones which are sensitive to very low frequency sound waves. These waves can travel thousands of miles, and are produced by a variety of sources. However, nuclear events have an identifiable signature which distinguishes them from other infrasound sources, such as storms, winds, icebergs calving off from the ice shelf, etc. These microphones are extremely sensitive, and the Windless Bight location was chosen since, as the name implies, it is not a windy place (at least as compared to the surrounding areas). The array is run by the Geophysical Institute at the University of Alaska, Fairbanks. A similar array exists at Fairbanks, and can detect the space shuttle launches from Cape Canaveral.

A closer picture of an infrasound installation.
The infrasound site is powered by a hybrid diesel/solar power supply. The system is housed in a big orange box, and is thus nicknamed BOB. Windless Bight is on the Ross Ice Shelf, and is a very flat place. So the first thing one sees approaching the site is this strange orange building sticking out of the uniform white plane. A bizarre sight.
A Pisten Bully, parked outside of BOB.
The winds tend to sculpt the snow around buildings.
Windless Bight receives about 5 feet of snow accumulation per year. Therefore each season the microphone vaults must be dug out and replaced on the top of the snow. Infrasound waves can penetrate a few feet of snow with little attenuation, so a year's worth of snow is not an issue for accuracy of measurement. But after a year or two it would become a problem. Also, the vaults must be accessible for calibration and repairs. So, out come the shovels.
Kay Lawson and Jay Helmericks (from UAF) digging out the vaults. This takes quite a while to do....and there are 8 microphones to reposition. As far as Antarctic field camps go, however, it's reasonably comfortable. Plus, if things get really bad you can always find all the heat and power you need inside BOB....
The vault itself. Inside is the microphone, some electronics, and a transmitter. Each vault transmits independently back to McMurdo. There are 4 ports to the vault, each of which branches off into 4 more lines. These 20 foot tubes connect directly to the microphone inside, have small holes drilled along their length. They help to reduce the effects of wind noise.
A Mattrack...a quicker and more comfortable way to travel than the Pisten Bully (but a less capable vehicle).
Mount Erebus, as seen from Windless Bight. Nice plume on this particular day.
Another pic of the neighborhood volcano.
And another.
To refuel BOB, a fuel sled is towed out using a Pisten Bully.
Another view of BOB. In addition to replacing the vaults on top of the snow, BOB must also be moved up each year. A crew from McMurdo comes out with a dozer, builds an elevated snow berm, then drags BOB up on top.
Me, on the infrasound antenna. In the background is a camp set up for the UAF group and the group from Northern Power, who do annual maintenance on BOB. Panoramic views of the Windless Bight installation are here.
University of Alaska sign. Another sign nearby wards off trespassers....which, believe it or not, can occasionally be an issue here.
Inside the vault. The microphone is in the lower left hand corner. (Photo by Laura Tudor)

This is Buck Wilson and Kay Lawson at the infrasound site. At the McMurdo store, you can get your name on an official-looking piece of paper that says something like "So and so has set foot on Ross Island, Antarctica, and by virtue of this fact, is an Old Antarctic Explorer (OAE)". Anyone at McMurdo can get this for about $5. Buck, on the other hand, is a real OAE. He wintered at Little America station during the IGY, and went on an overland traverse led by Bert Crary, after whom the McMurdo science building is named. He has stayed active in Antarctic reserach (and other areas), and was down here a couple years ago working on the installation of the new infrasound system. Kay Lawson is another legit OAE, having wintered here twice when the first generation infrasound system was running. They both work at the Geophysical Institute at UAF, and have great stories of Antarctica in the old days. (Photo by Laura Tudor)

Daniel Osborne, the PI for the infrasound project, and another member of the Geophysical Institute group. Dan was the first person to take real-color images of sprites and jets (weird above-cloud lightning displays), and has also worked on the Aurora Color Television Project, which showed the Aurora in real color by using an ultra-sensitive camera. (Photo by Laura Tudor)
This is MTRS-2, a NASA installation near T-Site above McMurdo. This place has a good view of Windless Bight, so the infrasound project uses it as a relay station to McMurdo. The antennas are on the legs of the platform while the radios and line drivers are inside the hut below.
Late in the season, Dan Osborne asked me to visit the field site to inspect BOB. Each year they will build a 5' berm and drag BOB on top of it. This place gets about 5' of accumulation per year, so this is done to avoid having to dig it out every year. Last year, they saw significant melting and shifting of this berm, and were worried about the same thing happening this year. So I drove out one morning with Huck Auen, Susan Stalfort, Suzanne Bopp, and Laura Bradford. There wasn't a lot of work to be done (just looking around and reporting back), so it essentially was a boondoggle for all of us. We brought pack lunches and had a picnic on the Ross Ice Shelf. Here is a clip of us starting out. The trail from earlier in the season was covered in a few feet of snow, so we were driving into virgin snow the whole way out, following the flagged route. The flags along the route kept getting shorter and shorter as we got closer, due to the increased accumulation at Windless Bight compared to McMurdo. This is a little video clip of us crusing in the Mattrack with some retarded commentary from yours truly.
Along the way, we saw this horizontal line extending across the trail. There are not supposed to be any crevasses in this area, but the Mattracks can only safely clear a 12" gap. So we stopped and probed up to it using flagpoles from the back of the truck. Up to and across the 'crack', the snow was just as solid as behind us, so it must have been something else. Maybe an animal track? Well, none of us were experienced enough to positively identify it, but we certainly knew enough to check it out before driving across. So here is me, walking back from probing along the 'crack'. Looking very heroic and weathered, but in reality, quite the amateur. (Photo by Susan Stalfort)
After you probe the snow with a pole, these pretty holes are left that descend into darker and darker blue.
Here's Huck and I standing by the Mattrack while we stopped for some pictures. (Photo by Susan Stalfort) Today was a nice sunny day, so I took another panorama of Windless Bight, which is here.
Susan brought along this little stuffed squirrel, which belongs to her nephew. It's been to various places around here (including the South Pole), so she brought it along today.
Huck, meet BOB. BOB, meet Huck.
BOB, with Hut Point Peninsula in the background, with the Royal Society Range behind it.
Me and my old friend BOB.
Along the way, the snow got deeper and deeper. Deep enough for one to lay down in the vehicle track. But, the Mattrack kept chugging along just fine. (Photo by Susan Stalfort)
On top of Bob, here is the view of White and Black Islands.
And the view of the mountains, from the same vantage point.
Susan again, after having made the acquiantance of BOB.
Suzanne, Huck, Laura, and Susan doing you-know-what.
Anyway, back to the whole reason for the journey. This is how we found BOB - very well seated on its berm and drifted up with snow. Last year was a much warmer and quiter year, and they had significantly more melting. This year, no such problems.
We also took a look at a couple of the microphone sites. All of them had already been covered in snow - at least 4'. This is good as far as temperature stability goes (the snow covering will insulate the microphone vaults), but it means much more work next year for the Alaska crew to dig these things out!
Tracks on our return. (Photo by Susan Stalfort)
So that was the boondoggle trip. On our return, Scott Base radio started coming in. So here's a short video clip of us cruising along, tuned in to 97.0 FM. If Scott, Shackleton, et. al. could have ever envisioned modern Antarcticans traveling along this ice shelf at 20 mph in a heated truck listening to the local radio station, after driving out for a picnic, they would have soiled themselves....
The road up to MTRS2 is often buried in significant drifts. No worries, because there are usually Mattracks to be had, and the Mechanical Equipment Center (MEC) has been great about letting me use them when required. So, off you go up the hill, plowing through drifts and floating across the snow with the Mattrack. I actually like the Mattracks better than the Pisten Bullies, since they are a bit faster, more comfortable, and they have 4 points of contact with the snow unlike the two treads of the PB's. Thus, you don't thrash backward and forward as you pivot over high points in the snow.
Later on in the season, a problem developed with one of the microphones. Its signal started dropping out, the problem got worse, and then it died all together. It was nothing we could fix remotely from McMurdo, so I had to go out and fix the problem. I went out with Matt Shoop, Alia Sorensen, and Olivia the other scitech. Here is our Pisten Bully parked along side the misbehaving microphone station.
This picture is a little out of sequence, actually. Before we could do anything, I had to locate the right microphone. The 8 microphones are in a pentagon (1 km on a side) with a smaller triangle inside. The malfunctioning one was one of the outer micropohnes, so a look at the map was required to figure out which of the antenna towers we should drive toward. This is easy when there's light, but in the winter GPS is very helpful.
So we dug up the microphone vault and looked inside. Here's me thinking about what the problem might be.
It seemed the radio was the problem, so here's me again, looking in the Pisten Bully for the spare set of radios that I brought along.
So I put the spare radio inside the vault and headed toward BOB, were I could hook up the second radio and see if the system was now transmitting. To aid in this, I climbed the antenna mast and pointed the antenna from McMurdo towards Bob. And this is the gratuitous picture of me doing that.
Here are Alia and Matt inside Bob. Alia is a DA (dining assistant) and Matt is the Crary lab facilities engineer. They are two very cool people who came along for the ride.
We hooked up the laptop computer and mating spare radio inside Bob and were able to receive the signal from the microphone vault. That signal can be seen on the laptop screen. And this is the signal of triumph at a task completed!
Here is a picture of Bob with its nearby mast which holds the official CTBT meteorological instruments.
I asked Olivia if she wanted to drive back. She said sure, and so off we went. Or sort of. Remember how these Pisten Bullies can spin in place? Well she did that on, as it turned out, an unstable piece of snow. And we augered in like a drill bit. So this is what a Pisten Bully being stuck in the middle of Antarctica looks like! We crawled out of the thing at various weird angles and got the shovels. And we dug. Then dug some more. Finally, we got the thing out and drove home.
Here are a few pics from another trip to Windless Bight. I had to go out later to check on a generator problem inside Bob, and as usual a bunch of people from station came along for the ride. The trip was pretty uneventful, but we did get a great view of this beautiful moon rising over the Ross Ice Shelf. This and the next two pictures show it coming up. The temperature fluctuations in the still air caused it to look very irregular as it rose. Very cool. Photo by Robin Krumm.
Photo by Robin Krumm.
Photo by Robin Krumm.
Here's one of my hand with the moon inside. Photo by Robin Krumm.
And another one. Photo by Robin Krumm.
In May, I had to go out again to take care of another misbehaving microphone station. All told, I have now driven out there 8 times. But I got the problem fixed and the people who came along had a good time, so all in all not a bad way to spend the day. Here is Bob in the distance, illuminated by our lights.
Another picture of Bob in the darkness. This structure looks particularly neat when you see it in the middle of winter with just the headlights shining on it.
This is the group with Bob. From left to right, Madison Iler, Chad Carpenter, Molly Frazier, Deb Woods, and Elise Welterlin.
Here's me in the Pisten Bully, broken hand and all. I set up the laptop inside here and connected to the microphone vault with a super-long cable. This is because the computer does not like to function outside in the cold. I'm talking to Olivia back at McMurdo to see if I have fixed the problem. It was the sort of problem where it is much easier to see if you're back at the point where the data arrives at McMurdo, so this worked out well. It would have been a pain to set something up out here to see if the problem was fixed. I then gave a call to Fairbanks via the Iridium (satellite) phone system that I brought. It's amazing, actually...they can see the computers at McMurdo over the internet as though they were sitting on their desks at Fairbanks. And I can call them via a satellite phone as they watch what I'm doing change things on the computer screen! And all the while I'm on the radio doing real-time work with someone back at McMurdo at the computer room.
This is me with Erebus in the darkness. We did 4-second exposures with my camera, each person standing still while another person "painted" the subject with a flashlight. These pics turned out pretty OK.
This particular day, some large solar flares had reached the earth and there was a strong possibility of good auroras. On the drive back, it started to clear up. As we got near McMurdo (at Cosray), they started up and we stopped to take pictures. This was the best display I've seen so far. But my camera limitations didn't allow me to take great pictures. These are the best I got.
More auroras. We get green ones here almost exclusively. They look much fuzzier in the pictures than they are. I have to use a very long exposure to get them to show up well (15 seconds). But these things change shape and can move pretty quickly across the sky. So the image blurs during the long exposure. But the color is right on...very nice green.
The next day I saw that my magnetometers and auroral photometers at Arrival Heights had gone nuts right about this time. I usually see this after good aurora days, but this was the first time I had actually seen the auroras themselves. Most of the time I'm either indoors whe the best ones happen or I just forget to look up! And when I do go outside of town to watch them, they are very faint. But today there were some good ones.