Posts Tagged ‘field work’

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We’re back!

January 28, 2016

Ted Scambos writes:

The OTI research team has two projects for the 2016 season: a return to the Antarctic Peninsula where a large plate of ice is on the brink of collapse, and testing of a new instrument on a frozen Minnesota lake. The instrument (an ‘AMIGOS-II’, upgraded from the devices already operating in Antarctica) is designed to make combined measurements of weather, ice conditions, and ocean currents and temperature from atop an ice shelf or sea ice. The Antarctic field work is first, and then we’ll shift over to track the instrument expedition in February.

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Success

November 22, 2010

Ted writes:

Clear weather finally prevailed on the morning of November 18, and after one last check of satellite imagery, we bolted at noon in our 1970s-vintage DeHavilland Twin Otter (with brand-new instruments and engines) off the runway at Rothera, headed for the Larsen Ice Shelf. Aboard were myself, Martin, and Jenn, BAS pilot Doug Cochran, and a BAS staffer named Andy “Boat” Wilson – known as Boat because he is a diver and a boatman for the base, and a sturdy guy to have along.

A few puffs of grey cloud passed by on our way upward, but then gave way to one of the most glorious spectacles in glaciology: the Larsen Ice Shelves and the eastern coast of the Antarctic Peninsula. Spilling ice from the ridge, which sits in the southern storm track building snow, flows down like marshmallow cream through black, jagged peaks, and then spreads out to an impossibly flat, broad sheet of ice. Only the subtlest of rolls and ridges mark the history of the bending that the ice endured to reach the sea.

What we saw confirmed what we’ve learned from the data streaming in from the AMIGOS and other stations. While the west side of the Peninsula has experienced unusual snowfall, the east side, where our stations are, has been bone-dry and very warm all winter. Already there are melt ponds slowly filling, and the dry warm wind has scrubbed the surface down, exposing every crack and ridge.

Our first rendezvous was at the Scar Inlet AMIGOS site. Although the station is still functioning, two of the most important measuring devices have gone silent or intermittent over the winter: weather and ice motion. The camera is still working well for now. But as we circled the site, we realized that the landing last year was something of a miracle: the site is surrounded by dozens of narrow (2-foot wide)
cracks and slots. The pilot circled several times, determined to give us a landing if there was any chance; but the risk of bending a ski on the airplane was too great. We did manage to get several pictures of the site, and in some ways the news is good. The station is still standing, and with the anchors still firmly in place.

We then flew up the first major glacier feeding the Scar Inlet Shelf, Flask Glacier. A second AMIGOS there is working very well, but needed new software and a new snow reflectivity sensor. We use the snow reflectivity to gauge when melting occurs: the snow darkens quite a bit when it is wet. The landing went perfectly; right on the tracks from last year, and Doug pulled the plane right up to the station. The wind was brisk, but warm, right about at freezing. The station has about 70 centimeters of snow around it, but it is an oddity–everywhere around it is evidence of windswept snow surface.

While we were standing there, the camera came to life! It moved to the six set shots that Terry had programmed in months ago. I tried to remember the sequence, and started leaping around in the snow, trying to get in every picture. But the camera was too fast. So, in every one of those pictures, one second later, I’m standing right there smiling. Martin, Mr. Smarty-pants, let the camera come to him, by standing still, and Jenn just shrugged and kept working. Jenn and I opened the station and changed the software chip, while Martin removed the old snow sensor and installed the new one. A quick call to Terry confirmed it was all working again. We took off.

Martin’s main goal was to repair the GPS station on Leppard, and that was our next stop. Here again, the dryness and warmth of the winter and spring amazed us. There were crevasses and even melt ponds all over the glacier. We found the station, and as we had guessed, the solar panels had blown over during the winter. We had expected a major digging effort, but in fact the panels were just below the surface. It required about two hours to excavate them, stand them up again, and re-secure them. On the sat-phone again, the UNAVCO office confirmed we had a working station. Next!

It was getting late, now, the sun definitely lower as we rounded a cape on the ocean and approached the rusty-looking outcrop at Cape Framnes. Here Doug really had a challenge. None of us had seen this site before, and it was steep, icy, and loaded with narrow cracks. The outcrop was perfect for helicopters, deadly for an aircraft. We made three different low approaches, each one ending with some new Scottish swearing (Doug is from Glasgow), and a proper decision not to touch down. We eventually found a site 2.5 miles and 400 meters above our outcrop. Martin, Andy, and I hopped out, grabbed ice axes and the new satellite modem, and started hiking.

It was beautiful now, light winds, cool and refreshing, and we were walking downhill towards a stunning seascape. Walking and walking. The last 400 yards before the rock was a windswept blue ice surface, slick enough so that footing was tricky, but then we made it onto the rock.

The outcrop had a blasted appearance, shattered fragments covering a primeval surface of lakes, sand, gravel, boulders nestled between blue ocean, turquoise sunset sky, and pale blue ice. Truly: an end of the earth, and a spectacular place to be. The fix went quickly, and we paused to take in the surroundings before the hike back to the waiting plane.

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I want to take this opportunity to thank the people at Rothera and British Antarctic Survey. At every step they have been generous, helpful, responsible, and eager to see us get our work done. I especially want to thank Doug Cochran, who did an outstanding job of piloting, and made the right decision on every single landing and attempt (IMHO). He pushed for our success, but never lost sight of the far more important safety decision. Andy “Boat” was a ready, cheerful helper for whatever we had to do (and he practically dragged my lifeless body up the hill after Cape Framnes, after a very tiring, hugely successful day.) And, when we finally flew into to the Rothera hangar, at 20 minutes to midnight, both Clem Collins (a veritable institution at Rothera) and Andy Barker were there to help get the plane in and unload our gear. Thanks.

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Flask Glacier

November 18, 2010

Terry writes from Boulder, CO:

Ted, Jenn, Martin Truffer, and two BAS Twin Otter pilots traveled to Flask Glacier this morning to service AMIGOS-3. I got a call from Jenn at 9:55 this morning, and AMIGOS-3 took the attached images about 10 minutes later. They had made a pass over AMIGOS-2 at Scar Inlet on the remnant Larsen B ice shelf on the way in, but the pilots decided that the surface was unsafe for landing. The recent warm temperatures have exposed many previously snow-covered crevasses near AMIGOS-2.

I got call from Ted at 10:35. He finished the AMIGOS-3 repair and testing of the downward-looking albedometer sensor. I have also verified in the data we received in the last few minutes that the repair was successful. Next, the team is heading to Leppard Glacier to repair the GPS unit there.

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Barilari: A flight over the west coast

January 22, 2010

This map shows the location of Ted and Martin's goal near Barilari Bay.

Ted writes:

The LARISSA glaciology team flew again today. This time Martin Truffer and I looked at the possibility of a flight up over the ridge of the Peninsula to our target sites on the east side. Bad weather (clouds, and blowing snow at low levels) has hampered our attempts to get to any of the regions near the Larsen B embayment.

The Palmer has moved south, to a fjord called Barilari Bay, just across from the Site Beta ice core drilling location, which the LARISSA glaciology team surveyed in December. This is a very scenic area, even prettier to my eye because the bay is smaller and ringed by glaciers that flow down right into the water. It is clear that this area had a small ice shelf itself at some time in the fairly recent past, perhaps a few centuries ago. Our marine geology group will look into that possibility while we wait for good weather.

By the way, free bar of chocolate to the first one at NSIDC or in the reading public that can tell us all the correct pronunciation of Barilari. Right now, most of us are going with an Aussie inflection, rhyming with “Hillary,” but we also have a “Barry-Larry” dialect, and a rather odd quasi-euro version, “ba-rEE la-REE.”

We took off at 9:48 this morning, and headed north to peer into the glacier troughs for some kind of path with thinner clouds overhead and less mist and blowing snow below. En route, our pilot (Barry James) wisely steered around a magnificent spire of rock looming like our own Matterhorn over the bay.

“It doesn’t look at all like the Matterhorn,” mutters Martin Truffer. And with his Swiss accent, who can argue with him?

We climbed the most promising trough in the ice, but as the ice rose towards the Antarctic Peninsula ridge-crest, the fog and clouds seemed to meet — no go for the east side today.  We turned to go back to the Palmer, and as we approached we had an excellent view of this ice-rimmed bay, and a look at just how tiny our floating village (the Palmer) is at the Antarctic scale.

Erin and Terry were there to greet us after our thirty-minute flight. Spirits are still high, and we expect a better break on the weather tomorrow.

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Mapping beneath the ice

December 21, 2009

The team has returned from the field, and sends this update (part one of two)

Ted writes:

We arrived at Rothera, a British base on an island just off  the southeast side of the Antarctic Peninsula, on Sunday, December 6. The camp is set in the most spectacular polar landscape you can imagine: mountains drenched in frosting ice. Some of it is windswept and blue, some of it shatters under the stress of flow over bedrock and scattered sea ice adrift in the wind. Almost surrealistic is the natural sculpture garden of icebergs, set out by some immortal art director in the bay just in front of the main dining and living building (New Bransfield House). It’s the kind of landscape reveals the hidden power of the forces at work in Antarctica: ice, ocean, weather, wind. It is a landscape of natural power. Orcas play in the open water between the bergs.

Rothera Base is built on either side of its two most valuable assets, a flat 3000-foot, perfectly smooth gravel airstrip, and an excellent deep-water wharf. The conjunction of these two things means that it’s a place where wheeled aircraft from the north, ships from anywhere, and ski aircraft of the deep icefield activities can mingle. Rothera stands at a rare logistical trifecta on the Antarctic coast. The base houses about 100 people, and has room for 150 (astonishing to find a base in Antarctica with room to spare). To a person, we met energetic cheerful people, starting with the base commander, John Withers, the science liason Tamsin Gray, the hanger staff (Clem, a veteran of four winters and countless summers), and the ‘Saints’, the team of staff from the island of St. Helena who run the kitchen, maintenance, cleaning, laundry, etc. We really enjoyed the people and personality of Rothera. It’s a gem, it’s successful, and it’s efficient.

By late that afternoon, we had our bunks set up, a large office (which we packed nearly full with our gear), and we were well on our way to finding everything that had been shipped down for us earlier: a snowmobile, sleds, generators, tents, food; all in all about 4000 pounds of gear to make our own outpost on the ice. We spent the next day (a spectacular day of sunshine) testing our radar gear at a nearby snowfield, ably assisted by Adam.  On Tuesday morning we were told the weather would be good enough for a put-in of our camp on the ridge crest of the Antarctic Peninsula.

The goal for the IPR study (Ice Penetrating Radar) is to find a good site for drilling the LARISSA ice core. With the ice core, we are hoping to retrieve a record of climate for the past several thousand years–the older the better. So the key is to find a spot that has smooth ice layers, and lots of them, from top to bottom. Earlier, the LARISSA team had pored over what data was available from aircraft and satellite, and selected a search area. It was our job to fill in the gaps in the search region with a ground survey, using ice radars, GPS, and all the previous data together. Basically, we had to put an X on the map, the best X we could find.  We had about 5 days.

The put-in by Twin Otter could not have gone better. The weather was clear, warm (about -8°C. That’s warm, isn’t it?), and best of all light winds. By the time I got there on the second flight, Erin and Rob already had the tents set up and the basic layout of the camp done. We looked it over, baking in the intense sunshine, the camp all neatly laid out and clean.  A smooth white plain stretched to the horizon, but in the distance there were mountain pinnacles and ridges, black like jet glass shards rising from the ice. I dared to be optimistic.

The next day proved to be more of a challenge. The wind picked up to 25 knots, and snow began to blow across the surface. We still managed to get the science gear mounted on the sleds, and by the end of the day we were comfortable with our plans to resurvey the airborne data and drive a grid pattern over the 8 by 8 km region we were mapping. In the next three days, we packed 70 km of snowmobile driving into that 8 by 8 box. Things could not be going better.

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