The last best place

Ted writes:

Our move to the west side of the Peninsula renewed the challenges we have faced before in trying to get work done over the high, narrow Antarctic Peninsula ridge. The weather is rarely good on both sides at the same time, and communication can be more difficult. Iridium satellite phones or a powerful shortwave radio are needed. We have the Iridium system, which can be erratic when used across international Iridium numbers. And now, in early May, daylight lasts a mere seven hours.

The sea off the Antarctic Peninsula. Daylight is now down to seven hours in this part of the world. (Credit: Ted Scambos, NSIDC)

Sunset along the Antarctic Peninsula. (Credit: Ted Scambos, NSIDC)

A minke whale breaches near the R/V Araon. (Credit: Ted Scambos, NSIDC)

Days passed with more or less the same appearance outside: dimly lit low clouds, often with snow flurries. In the week ending April and opening May, we tried three times to high-jump over the icy wall of the Antarctic Peninsula, aiming to revisit the first site we had scouted last month, namely the rocky overlook near Crane Glacier—perfect for our instrumentation. But we succeeded only once, and even then the helicopters found the outcrop covered in deep snow, hiding the many large boulders covering the site and making it impossible to land. It was time to head north. It looked like we would get nothing installed.

But on our path to the South Korean research station (King Sejong Station, on King George Island) lay one more worthy target—Cayley Glacier  and the adjacent outcrop called Spring Point. Cayley Glacier is one of the largest west-flowing glaciers in the northern Antarctic Peninsula, and it has been thinning significantly in recent years. It represents a vantage point to observe the changes in western AP glaciers up close, and make some long-range measurements of changes driven mostly by the more recent and more dramatic changes on the eastern side. The ship sailed northward along the coast overnight, setting us up for a few hours at our last best place to measure climate change in the Antarctic Peninsula.

Next morning was snowy and gray, but still majestic with icy hills framing the large calving front of the Cayley. After some preparations, we boarded Zodiac watercraft (an inflatable landing craft fitted with outboard motors) and nine of us motored over to the Spring Point promontory. We loaded the Zodiac with a seismic monitoring station and an automated camera.

Erin Pettit, Ronald Ross, Suk Young Yun, and Won Sang Lee wait for a helicopter load at Spring Point. (Credit: Ted Scambos, NSIDC)

You Dong Cho directs the helicopter to a landing area near our Spring Point instrument installations. (Credit: Ted Scambos, NSIDC)

We could only man-haul some of the gear from the shoreline up the rocky hillside—the easy way to do it would be an airlift by the helicopters. But the weather was miserable—drizzle and snow, fog and low cloud. We were unsure if they could possibly manage it. From the hilltop we watched the back deck of the Araon, waiting to see if the cargo load would leave the deck by air (or we would have an arduous time with ropes and pulleys from the shore, requiring hours).

Despite the raw conditions, the pilots pushed on, doing three quick loads setting everything within 20 yards of our installation sites. A few hours of rock-bolting and assembling, and we had our site: three important instruments for monitoring change. The seismometer would record the fracturing and calving of the ice in the nearby glacier (about 2 miles away) as well as other glaciers up and down the Peninsula; the camera would witness the local calvings and the changes in the ice front; and a GPS system (installed earlier, but upgraded during our visit) would measure the rebound of the Earth as the great mass of ice slowly flowed off of the Antarctic continent.

Amy Leventer of Colgate College and Ronald Ross install an Extreme Ice Survey camera at Spring Point overlooking the Cayley Glacier calving front to the east, with the R/V Araon in the foreground. (Credit: Ted Scambos, NSIDC)

Ted, Amy, and Ronald make final camera adjustments as bergy bits float by in Brialmont Cove in Hughes Bay. (Credit: Erin Pettit, University of Alaska Fairbanks)

We finally got ‘er done. Even better, that night was the planned End-of-the-Cruise dinner party—a huge variety of good food, sweet rice wine, beers, and very good company. We are now heading north to King Sejong station.

East Side Story

Ted writes:

After returning from the day trip to the Crane Overlook site on April 17, we received satellite images that completely changed our plan. The images from both a NASA and a Canadian satellite showed that persistent westerly winds starting in early April had opened a large gap in the sea ice just to the east of the Larsen A, B, and C—a long highway of dark water that we could use to get to areas we have been trying to reach for four years. But the opened road on the eastern Peninsula came with a significant risk: at this point in the Antarctic season, such a path could freeze over or slam shut in a matter of days, making it difficult even for a powerful icebreaker like the Araon to escape.

The KOPRI (Korean Polar Research Institute) scientists were willing to take the risk, in part because the ship is fairly fast, capable of up to 14 knots, and because the science potential was high. The weather is much drier on the leeward eastern side of the Antarctic Peninsula, so we would be likely to fly more often. Communications and weather safety are better because one can see conditions approaching the ship or the field site from a long distance (without the blocking of the high Antarctic Peninsula ridge).

That evening, we took the ship as fast as possible over the northern tip of the Peninsula to the eastern side and sailed down into the gap less than two days later.

A tabular iceberg passed near Snow Hill Island as the Araon headed south toward the Larsen B region. (Credit: Ted Scambos, NSIDC)

A flock of emperor penguins, assembled on an ice floe near Snow Hill Island. (Credit: Ted Scambos, NSIDC)

 

The flock toboggans away from the sound of the passing ship.
(Credit: Ted Scambos, NSIDC)

And there we were: at the fast ice edge of the Larsen B Ice Shelf, ready to fly with helicopters to the three major glaciers of our study area, one of them already fast-moving and thinning as a result of global warming (Crane Glacier), and two others (Flask and Leppard glaciers) that were poised to change if the last remnant of the Larsen B, the Scar Inlet Ice Shelf, collapsed.

Rifts near the calving front of Scar Inlet Ice Shelf could eventually form tabular icebergs. (Credit: Ted Scambos, NSIDC)

The next day (April 20) was clear and warm. The forecast suggested a gradual shift to cooler southern winds by late in the day. We loaded the helos according to a complex plan, trying to get as much done as possible. We would identify a second rock outcrop and install a seismic monitoring station, and begin work on a multi-instrument AMIGOS site on a small crevasse-free section of lower Leppard just a few miles away from the seismic site.

The flight to Leppard was spectacular and revealing. The remnant Scar Inlet shelf from the once-vast Larsen B is now completely fragmented, as cracked as a windshield after an accident, with huge deep rifts indicating fractures on the underside of the floating ice as well. It is clear that the next warm summer will be the last one for this shelf. We were eager to get to our site and get going.

Closely spaced crevasses on Scar Inlet Ice Shelf could fill with melt water during the next warm summer, leading to a possible disintegration event as happened to the main Larsen B in 2002. (Credit: Ted Scambos, NSIDC)

But there were problems. Our search on the mountain next to Leppard Glacier for a good seismic mounting site was hampered by bumpy winds around the peaks. Lower down, the rock sites were covered in gravel and loose talus, and were not suitable. So we decided to put the seismic station on the glacier at the AMIGOS site. Problems with the Iridium satellite phones arose. We could not contact the ship, except using the helicopter radios, and they had to be aloft to make a clear call.

Ted Scambos records some notes on Leppard Glacier. The field instrument next to Ted is a backpack-mounted, gas-powered steam drill.
(Credit: Jennifer Bohlander, NSIDC)

Rob Bauer (in black) and Erin Pettit (in orange) ready equipment prior to to a radar traverse of Leppard Glacier. (Credit: Ted Scambos, NSIDC)

Slowly things moved along despite these obstacles. We conducted a radar survey, skiing a few km across the glacier. The seismic crew began to build the station. A Korean geologist and I returned to the ship in early afternoon. On the flight back, I noticed low fog forming over the Scar, a very ominous sign. Fog had trapped a group of us for over a week in 2010, and that was in summery January, not April. When we landed I asked the pilots to hurry back and get the rest of the crew right away.

An approaching fog bank was the precursor to an intense snow squall that forced a retreat from Leppard Glacier by the remaining field team of seven scientists. (Credit: Ted Scambos, NSIDC)

But after the helos left, we realized that fog was only the beginning of the weather change. Far from being a gradual wind shift, a sudden abrupt blast of south wind hit the ship, and within minutes we were engulfed in cold blowing snow and mist. Temperatures plummeted. Our sunny day was going to end with a powerful snow squall, with seven scientists still at the Leppard site. Conditions remained beautiful there, 70 miles away.

The Araon, enshrouded in freezing mist and battling 40 knot winds at the Larsen B fast ice edge, awaits the final helicopter returning with a field party from Leppard Glacier. (Credit: Erin Pettit, University of Alaska Fairbanks)

We radioed the pilots and told them about the declining conditions at the ship, and they loaded the passengers and headed back. By the time they arrived at the ship, a gale of 40 knots was blowing, and visibility was only a mile or so. The pilots made two amazing landings in the blustery winds, with all passengers and gear safely returned.

By nightfall, winds had risen to 60 knots out of the south, with temperatures near zero degrees Fahrenheit. The scientists and ships crew realized that these were exactly the worst conditions for keeping the narrow lane of ocean clear of ice. Cold winds would freeze the open water, and the pack to the east of us (full of thick older ice) would start to shift westward and close us in. The Araon put on all speed and glided through the gathering slushy ice, a gale at its back, until we were north of Robertson Island (the most likely ‘pinch point’ for the drifting ice to close us in).

We were not done though—as the first gale subsided the next day, we returned south again, finding that the road was narrow but not completely shut. We traveled past the Larsen B into the Larsen C, almost touching the Antarctic Circle (in late April!) and collected a core from a key site of the Larsen C. On our way north again, we launched a quick mission to recover gear that had to be left behind when the squall hit. Then we left for good, as the oncoming Antarctic winter was rapidly freezing the sea around us.

We now are again on the west side, in a fjord called Flandres Bay, just opposite our main instrument sites, with one more week to get some stations installed.

Tomorrow looks like flyable weather.

The R/V Araon, ship of dreams

Ted writes:

After preparations in Punta Arenas, including shopping for comfort food (cheese, bread, peanuts, breakfast cereal) that we thought we might not see for a while, the LARISSA glaciology team boarded the Araon, South Korea’s new polar research vessel. The Araon is a large ship, and very clean—it was commissioned in 2010.  I noticed something right away walking through it—a new icebreaker smell, a bit like a new car. The labs and especially the cabins are quite spacious, and very comfortable.

The R/V Araon at the quay in Punta Arenas. (Credit: Ted Scambos, NSIDC)

The bridge of the Araon. (Credit: Ted Scambos, NSIDC)

A cabin on the Araon. (Credit: Ted Scambos, NSIDC)

With a late party on the night before departing (April 10), we boarded the Araon on the 11th and sailed out the Straits of Magellan, eastward, and then south. One of the first things we did was listen to a safety briefing video introducing us to the ship’s systems. At the end, the announcer told us that the Araon was “the ship of dreams for polar research,” and we had to agree. It was large, powerful, well-equipped, and new.

The food on board is indeed Korean, although on some occasions they have treated us to some western favorites: spaghetti, pan-grilled steak, eggs and bacon for breakfast. But in fact the best treats have been the Korean-style sushi and Korean barbecue: thawed fresh-frozen fish or grilled pork with lettuce leaves and rice and wasabi. And the soups have been very good; different, but very good. The chicken soup had a kind of dumpling made from rice paste, very soft and white and it had absorbed the taste of the stock very nicely. They allow a little beer or wine with dinner about every other night. Life is good; oriental, but good.

Sailing across the Drake Passage south of Cape Horn, we made very good speed, and the ocean was not very rough. We spent the time preparing the equipment: the K-AMIGOS systems (similar, but newer and upgraded versions of the AMIGOS systems we installed in previous years), and the “Balog Cameras” as we called them, for the project by James Balog known as The Extreme Ice Survey.

Jenn, Ronald, and Ted work on the Balog Camera. (Credit: Ted Scambos, NSIDC)

Ronald, Rob, and Ted work on the Balog Camera. (Credit: Ted Scambos NSIDC)

Ted and Erin Pettit, glaciologist at University of Alaska, Fairbanks, with a backdrop of the peaks and glaciers ringing Beascochea Bay. (Credit: Ted Scambos, NSIDC)

By the morning of the 15th we were off the western coast of the Antarctic Peninsula at 65 degrees South in Beascochea Bay, just above the Antarctic Circle. This was the best location for flights to our target locations for instruments, all on the eastern side of the Peninsula. But it meant flying over the ridge of the Peninsula, a tricky thing both for the weather and for the helicopters (lots of climbing and shifting winds).

Still, we’re set, with a huge and capable ship, instruments ready to go, and plenty of things to do while waiting for a good weather window in the fjords of the Antarctic Peninsula.

Terry wraps things up and heads back to Boulder

Terry writes:

Thu 12/20: Got on board the Dash-7 around 9:00 a.m. together with outgoing field operations manager Andy Barker, field assistant Roger Stilwell, scientists Beth Davies, Mike Hambrey, and Daniel Farinotti, and the flight crew of pilot Phillipe Leblanc and mechanic Chad Jones. We landed in Punta Arenas around four hours later. We were all staying at the Diego de Almagro hotel so we all piled into a van from the British Antarctic Survey (BAS) contractor AGUNSA. Later that afternoon, we all visited station support assistant Neil Malcolm who had injured his back skiing a couple of weeks earlier, and was making a fantastic recovery at a local hospital. Made a quick visit to the DAMCO warehouse to check on batteries. That evening I joined the other Dash-7 passengers for a fine dinner at La Marmita as they were all flying out of Punta Arenas early the next morning.

Fri 12/21: Went over to the DAMCO warehouse and, with the help of a couple of AGUNSA workers, located the two batteries in the AGUNSA warehouse that  I had tried to give Chris Hill of the Lake Ellsworth drilling project that he was unable to use. Added these two to the other six we had found in the DAMCO warehouse back in October. Arranged with Dave Morehouse to have these eight batteries sent to Tamsin Gray in Rothera on the next Gould cruise to back fill the five she had given me, plus to pay back Rothera for the other materials (poles, brackets, etc.) I had acquired during my stay.

Sat 12/22: Logged into AMIGOS-6 from the hotel, updated some program files, and downloaded the first two Sony images of the work crew. Posted the Sony images and sent an email to Ash Fusiarski pointing him to the images. Checked out of the hotel and walked over to the DAMCO warehouse. Met the DAMCO liason Marcella, loaded my gear into the DAMCO van, was driven to the airport, and was assisted by Marcella through the baggage check-in procedure including the payment of excess baggage charges. The flight to Santiago with a short stop in Puerto Montt was uneventful, as was the 4-hour layover in Santiago. I boarded my flight to Dallas at 10:30 p.m.

The first Sony camera images of the repair team (minus Terry) captured by AMIGOS-6. Left to right: Phil Harle, Jim Scott, Ash Fusiarski, Ian (Cheese) Rudkin, and Al Howland.

Sun 12/23:  The ten-hour flight from Santiago to Dallas was also uneventful. Made it through customs ok and even had time for some breakfast. Flew on to Denver arriving at 9:45 a.m., and just made it to the 10:25 a.m. bus to Boulder. My son Alex picked me up at the Table Mesa Park-n-Ride and, after a quick visit with my wife Sue at home, I dropped off my equipment at NSIDC. Ted was at work (of course) and he congratulated me on a successful field season.

Mon 12/24:  Sometime between 2012/12/23 2000 UTC and 2012/12/24 1200 UTC, a 1000-foot iceberg calved off the ice shelf about 2 miles from AMIGOS-6 on Cape Disappointment.

The right side of these AMIGOS-6 images show a 1000-foot iceberg calving off the ice shelf 2 miles southwest of the AMIGOS-6 tower. The event occurred between the time the second and third images were acquired. The earlier first image and later fourth image are included because they have better illumination.

A day of repairs

Terry writes:

Landsat-derived map of Larsen B showing field sites. Colors indicate ocean depths derived from sonar data: red for shallow areas and blue for deep areas. (Courtesy Eugene Domack and Caroline Lavoie, Hamilton College)

Zoomed-in version of a Landsat-derived map of LARISSA field sites on the Larsen B Ice Shelf. The map shows all the AMIGOS (blue asterisks) and cGPS (red circle and black square) sites visited by Terry Haran in November and December 2012. Cape Disappointment is shown but doesn’t have a blue asterisk, and AMIGOS-6 is located on the small black outcrop just below and to the left of the black circle. Colors indicate ocean depths derived from sonar data: red for shallow areas and blue for deep areas. For scale, Flask Glacier is about 4 miles across at the location of the AMIGOS-3 blue asterisk. (Courtesy Eugene Domack and Caroline Lavoie, Hamilton College)

Both the 0900 and 1100 UTC AMIGOS images from Flask Glacier and Scar Inlet showed good contrast at both sites, and satellite images looked good as well. We took off at 9:32 a.m with six people on board: pilot Al Howland, myself, field assistants Ian (Cheese) Rudkin and Ash Fusiarski (who spent the entire previous day with Daniel Farinotti man-hauling radar equipment on Flask Glacier), and builders Jim Scott and Phil Harle. Got lots of good pictures on the way to Cape Disappointment, particularly of the shear zone running along the northwestern side of Scar Inlet.

Ice-capped Bildad Peak at an elevation of 2,600 feet rises some 1,300 feet above Flask Glacier and is visible in some AMIGOS-3 images. View is toward the northwest.

The northwest edge of Scar Inlet ice shelf, the last remnant of the Larsen B Ice Shelf, is being ripped open due to the increasingly large difference in velocity between slower moving ice northwest of the shear margin, and faster moving ice to the southeast emanating from Flask Glacier

Shear zone middle

Shear zone south

The collapsed AMIGOS-6 tower (middle, left) as seen during one of three passes made over Cape Disappointment just before landing.

After three passes around Cape Disappointment, including two touch-and-go landings, Al set us down at 11:14, about a mile northwest of the AMIGOS-6 site.

The team gathers materials and then rope up in anticipation of hiking out about a mile to the AMIGOS-6 site. (Courtesy Jim Scott, British Atlantic Survey)

Field assistant Cheese Rudkin at the toppled AMIGOS-6 tower on Cape Disappointment.

Seals (probably Weddell) resting on the banks of a sea ice lead extending south from Cape Disappointment. (Courtesy of Jim Scott, BAS)

We donned crampons and harnesses, roped up, split into two groups of three, led by Cheese and Ash each pulling a sled full of equipment, and left the plane at noon. Cheese, myself, and Al arrived at AMIGOS-6 at 12:50, followed closely by Ash, Phil, and Jim. Al, who used to work as a “rigger,” led the group raising the tower, installing the new three-pole outrigger arrangement, and securing the poles to the wire basket rock anchors.

Phil and Ash work on attaching the AMIGOS-6 electronics and high resolution camera enclosure to the now erect and pole-strengthened tower. (Courtesy Jim Scott, BAS)

The upwind anchor which had failed was rebuilt, and strengthened with an additional new wire basket rock anchor. The rock anchor surrounding the tower, which also had failed, was disassembled but not rebuilt. The consensus was that installation of the new poles and strapping the battery box to the tower were providing a sufficient tower anchor. Jim Scott rewired the solar power input and 12-volt output lines to the solar charger assembly, while I added a fourth battery to the battery box and tested the system.

Terry talks to Ted Scambos at NSIDC in Boulder to verify that at least some valid data are being received, so the Iridium cable and antenna seem to be working correctly. (Courtesy of Jim Scott, BAS)

I was dismayed that AMIGOS-6 wasn’t connecting to the internet through the NSIDC FTP server — until I remembered that I had seen an email a couple of days earlier indicating that the server and its associated disks would be down for maintenance all day on December 19. I called Ted who verified that, but who then suggested that he would ask the system administrators if FTP could be brought back up for my test. We started packing up, I called Ted back who said the FTP server was back up, and I then verified that AMIGOS-6 was connecting correctly. We were also able to verify that weather and GPS data were being received via email correctly, but we were unable to verify that images were being correctly received since the FTP disks were still down.

The repaired AMIGOS-6 tower stands ready to record and transmit weather and image data. (Courtesy Jim Scott, BAS)

But since all this had been working correctly in Rothera, albeit with a different Iridium cable and antenna, we felt that it the system was working okay. We started walking back to the plane at 4:30 p.m., arrived at 5:00 p.m., and took off for Leppard Glacier at 5:30 p.m.

After taking off from Cape Disappointment, a final view of the now repaired AMIGOS-6 tower.

After taking off from Cape Disappointment at 5:30 p.m., and before proceeding to Leppard Glacier, we made a slight diversion over Exasperation Inlet and part way up Crane Glacier. Ted Scambos wanted us to obtain some aerial photos of the lower part of the glacier which we did.

Composite image of Exasperation Inlet from Exasperation Point. Cape Fairweather is on the left. Crane Glacier enters the inlet far to the left and out of the frame. The foreground view is entirely sea ice, at most a few meters thick. There are a few icebergs in the foreground and many more as we approached the glaciers from which most of the visible icebergs have been calving. Prior to the disintegration event in February 2002, the entire foreground view of this image would have been of the Larsen B Ice Shelf which was several hundred meters thick.

The calving front of Mapple Glacier. Crane Glacier enters Exasperation Inlet
far to the right of this image.

The calving front of Crane Glacier is at the far left of the image and Exasperation Point is at the far right. The flat large tabular iceberg in the foreground has probably drifted into Exasperation Inlet from a glacier far to the south.

The 2.5-mile wide Crane Glacier calving front is heavily crevassed. The crevasses appear to extend to great depth causing virtually all icebergs that calve off to be very narrow relative to their total thickness. Such icebergs cannot float upright, and so either they immediately lay down on their side or they crumble into bergy bits. Thus most of the horizontal surfaces of the large flat icebergs in this image were originally the vertical surfaces of crevasses in the the glacier before calving.

Composite image of the northern side of the Crane Glacier calving front and the iceberg melange just downstream. The calving front is about 150 feet high and the largest icebergs are over 1,000 feet across. The Crane Glacier surface has lowered by several hundred feet since 2002. A small terrace of stranded glacial ice just above where the calving front meets the rock wall stands about 500 feet above the surface of the melange.

A side glacier about 2 miles across flows into Crane Glacier about 9 miles upstream of the calving front. A relatively uncrevassed area on the surface of Crane is visible in the lower left corner of the image and may suitable for some future instrument installation via Twin Otter.

About 20 minutes after taking off, Al announced it was time to exit Crane and head over to Leppard. We flew over the upper reaches of Mapple, Melville, Pequod, and Starbuck Glaciers, and crossed Flask Glacier just upstream of the AMIGOS-3 site where Ash and Daniel had been collecting radar data just the day before.

A panorama taken where we exited Crane Glacier fjord en route to Leppard Glacier. A pressure ridge marks the confluence of the left (southwest) and right (west) branches of Crane Glacier. Another side glacier can be seen entering the fjord from the right (northwest).

Bildad Peak and Flask Glacier, this time looking southeast. AMIGOS-3, though not visible here, is located near the right edge of the image.

Panorama of Flask Glacier from Spermwhale Ridge on the left to Pip Cliffs on the right.

Due west view looking up Flask Glacier which is almost 3 miles wide at
this point.

Another five minutes brought us within sight of the LPRD cGPS on Leppard Glacier. We made a touch-and-go landing, and then a final landing at 6:15 p.m.

Images of the Leppard Glacier continuous GPS system before and after
a touch-and-go landing

The goal at this site was to simply raise the solar panels. This required first re-excavating the hole dug during our previous visit three weeks earlier. Then more snow and ice covering the two solar panel poles below the floor of the hole needed to be chipped away so that the overlapped section of pole extension installed two years earlier could be fully exposed. Then the now useless guy wires extending to the deadman snow anchors needed to be cut, the clamps binding the extension needed to be loosened, the extension slid up about three feet, and the clamps re-tightened.

Images of the Leppard Glacier continuous GPS system before and after
being raised about 3 feet.

Image of the Leppard Glacier continuous GPS system’s GPS antenna located
2.12 meters (about 7 feet) above the snow surface.

All this was done as planned, but unfortunately the cable to the weather station was accidentally damaged in the process. However Ash Fusiarski was able to repair the damaged cable, and Seth White of UNAVCO in Boulder was able to verify that the system was posting good GPS data, although confirmation from Seth of the posting of good weather data had to wait until the next day.

Ash Fusiarski repairing the damaged weather station cable after the solar panels had been raised.

We finished the repairs and took off for Rothera at 8:15 p.m. arriving at 9:30 p.m. After scarfing down the dinners that had been saved for us, I bought a round of beer in the bar for the entire crew. I didn’t go to bed that night since I had to unpack all our gear, separate out the BAS gear that needed to stay in Rothera, and then repack all my gear for the Dash-7 flight in the morning.

Seals seize bridge

Terry writes:

Tue 12/11: After the event yesterday, I decided to replace the ten AMIGOS3 (Flask Glacier) and ten AMIGOS4 (Scar Inlet) images acquired at both sites at 17:00 UTC (14:00 Rothera) with ten images acquired at 11:00 UTC (08:00 Rothera). Although these 11:00 UTC images wouldn’t show up in Rothera until after the pilot’s weather briefing at 07:45, they would still be useful as a verification of any previously reached decision whether to fly or not to fly to the Larsen B region.

Thu 12/13: Daniel Farinotti and Ash Fusiarski returned last night from their camp at Starbuck Glacier after a two week stay. They collected almost 200 km of radar data. Meanwhile I’m still waiting for a weather window for another return to Cape Disappointment and/or Leppard Glacier.

An elephant seal has parked himself on a short bridge over a utility coduit between Admiral House and New Bransfield.

The seal’s presence forces gators to make a detour.

Builder Jim Scott confronts the seal, which wasn’t intimidated enough to allow passage.

Sun 12/16: Cloudy weather over the Larsen B region has prevented any flights since Daniel and Ash returned last Wednesday. I spent the day preparing a set of AMIGOS-6 and LPRT cGPS installation instructions for Tamsin Gray and Chris Buckley, who have graciously offered to perform the the work in case I am unable to get a flight before I have to leave on Thursday.

Mon 12/17: Not flying today due to cloud layer over Scar Inlet creating a low contrast surface. AMIGOS images showed evidence of clearing to the northwest, but satellite images showed the band of clear skies closing rapidly. Will try again Tue and Wed. AMIGOS-6/LPRD training session for Tamsin and Chris scheduled for Tuesday (if I don’t fly). Still scheduled to leave Rothera for Punta Arenas on Thursday.

An attempt to keep elephant seals off the bridge by parking an empty trailer on it has failed. Now instead of a single seal, the bridge is claimed by as many as three or four at a time.

Tue 12/18: Unable to fly today due to a layer of cloud at 10,000 feet over Scar Inlet thick enough to reduce surface contrast just enough to make it not flyable to Cape Disappointment. But Daniel and Ash flew to Flask Glacier (for which AMIGOS-3 showed better contrast than AMIGOS-4 on Scar Inlet) to do their final radar work. Trained Tamsin and Chris today on AMIGOS-6 and LPRD work, and am confident they can probably do a better job than me due to their extensive experience maintaining BAS automatic weather stations. Decent chance of flying tomorrow to Cape Disappointment and possibly on to Leppard Glacier.

Skunked

Terry writes:

Fri 12/07: Called my son Jeff and talked to my grandsons Jack and Jude. Wished Jack a happy birthday.

Terry talks to his grandson Jack on Jack’s birthday from Memorial Hill.

Sat 12/08: Warm and no wind, so ran 8 laps (9 miles) on the runway. Neil Malcolm hurt his back skiing over the cornice coming out of Stork Bowl. He had to be taken back to the station via Snowcat, then airlifted to Punta Arenas on the Dash-7.

Sun 12/09: Stretching video on the Old Bransfield porch with about 6 others. Roger and Sharon Duggan returned from the field this evening, so Roger will go back to being my field assistant for the Cape Disappointment trip. Forecast for tomorrow is for good weather over the Larsen B region. Early morning AMIGOS-3 and AMIGOS-4 images showed lots of fog over Flask Glacier and Scar Inlet, but then later images showed clearing.

Mon 12/10: Both AMIGOS-3 and AMIGOS-4 showed clear skies in their respective 6 am images, which, together with a favorable forecast, meant we were flying. Pilot Doug Pearson and field assistant Ian Hey took off at 8:50 to take Daniel and Ash to their Scar Inlet GPS site. We followed them at 9:00 with pilot Al Howland, Roger, Jim, Phil and me. As we got over the divide, we could see low clouds over the Larsen C ice shelf, and at 9:40, Al told us that Doug and Ian had turned around. Our target was a few hundred feet above the ice shelf, so we kept going. As we crossed Leppard Glacier at about 10:00, we could see that the location of LPRD cGPS was very close to the edge of the clouds. As we approached Cape Disappointment, we could see that the clouds were thickening appreciably. We made three passes over the cape, and with each pass there were fewer breaks in the clouds, so Al abandoned the search for a safe landing site at about 10:45 and we headed back to Leppard Glacier. As we crossed Flask Glacier, I could see that the AMIGOS3 view of Bildad Peak would be completely fogged out, when it had been completely clear just a few hours before. By the time we got to Leppard at 11:05, it was worse than Cape Disappointment. We didn’t even circle, we just headed back to Rothera. As a consolation, Al went a bit west of the shortest route back which took us through The Gullet. It’s a narrow channel between Adelaide Island and the mainland that is used for ship passage when the sea ice conditions are favorable (they aren’t at the moment). We flew through the Gullet below the level of the peaks that line the sides. Quite a spectacular ride. Got back at 12:20, just in time for lunch, copied some photos, wrote this report, and then got to take a boat cruise in the evening. We’re still on the list for another possible attempt on Cape Disappointment, but the forecast for tomorrow is poor.

A relatively clear view of Bildad Peak is seen at 6 a.m.

A fogged out view of Bildad Peak is seen at noon, six hours later.

Terry snaps a cloudy view of Flask Glacier taken about an hour
before the previous noontime image of Bildad Peak.

A relatively clear view of Cape
Disappointment at 6 a.m.

Cape Disappointment intermittently
peeking out of the clouds at noon, six hours later.

AMIGOS-6 site somewhat cloud obscured just
before landing attempt called off at 10:45 a.m.

Glacier covered peaks on the eastern side of the
Gullet.

Arched iceberg seen during evening boat cruise.

Testing AMIGOS-6 in Rothera

Terry writes:

Thu 11/29: Spent the last two days sorting through email, pictures from  the field and writing the daily reports since my last posting on  11/19.

Sat 12/01: Spent the last two days moving equipment from the hangar to the Old Bransfield lab and preparing to bench test AMIGOS-6. Noticed that a bolt and washer assembly that fastens the camera assembly to the enclosure had come undone, probably during transport. Was able to retrieve all the loose parts from inside the enclosure. Performed as Terry and the Disappointments with me on electric guitar and vocals, Roger on bass, Adam on sax, Chris Buckley on electric piano, and Rob Green on drums. We ran through three numbers as the opening act. We were okay. Not great, but okay.

Sun 12/02: Powered up AMIGOS-6 using the Compact Flash (CF) chip I had  created in Boulder just before leaving. Quickly realized I was missing  some files, so reverted to the original CF created last year. Copied  all data and program files from the original CF to my 8 GB thumb  drive. Made slight modification to one program file to all allow the  camera to operate when no light sensor is present. Successfully  acquired some photos in the lab using the small 12 volt gel cell  battery I use for standalone Iridium field communications.

Tue 12/04: Finished testing AMIGOS-6 including running it overnight and uploading backup files to NSIDC. Tore down the test setup after taking some photos of it. Brainstormed with Tamsin as to how to strengthen the tower with components available in Rothera. Plan is to retain the existing rock basket guy wire anchor concept that has guy wires extending from each of the 3 triangular tower vertices. We will rebuild the central basket that failed, replace the upwind basket with a new wire box basket, and add three additional wire boxes each anchoring one of three 10-foot outrigger poles that will extend along the ground and along each of the 3 sides of the tower’s triangular base. We will use six identical brackets, two for each tower base strut. Each bracket has a 1.25-inch coupling that fits over each 1 inch tower strut, and a 2.125-inch coupling that fits over each 2-inch outrigger, with each smaller coupling rotated 90 degrees to the larger coupling. The plan is to first disassemble the current tower basket anchor and replace the failed upwind circular anchor with a new box anchor. Before raising the tower, we will fit two brackets over the bottom of each tower strut. Then we raise the tower, and adjust the guy wires to hold the tower vertical. Then we will fit the outriggers through the larger couplings in each bracket with the other end of each outrigger extending through a new box basket. We’ll remove the three broken connectors (two solar, one power) from the battery box, and simply feed the corresponding 3 wires directly into the box and the charge controller, using tie-wraps for strain relief.

AMIGOS-6 test system on the Old Bransfield porch.

High-resolution Nikon thumbnail image taken by AMIGOS-6 test system and succesfully transmitted to NSIDC. High peaks are the 7300-foot Mount Liotard on the left and 7600 -oot Mount Gaudry on the right, the two highest peaks on Adelaide Island.

Outriggers assembled on Old Bransfield porch. Short upward protruding pieces represent the ends of the vertical tower struts.

One of four new baskets that fold flat for transport, and are then assembled and filled with rocks on site. Three will serve as outrigger anchors and a fourth will replace the failed upwind guy wire anchor.

Wed 12/05:  Copied AMIGOS-4 data and program files from the CF to my 8 GB  thumb drive. Moved equipment to the hangar. Found out that the GA for  Cape Disappointment will be Ian Hey who just returned from four weeks in  Ablation Valley with Mike Hambrey and Bethan Davies. Tamsin won’t be  able to go with us, but instead we will be accompanied by Builders Jim  Scott and Phil Harle.

Thu 12/06: Ran 9 miles and wrote this report. Logged onto AMIGOS-4 and  removed file /mnt/gpio/NEED_ETH needed for on-site debugging, and  whose removal should reduce the average current load on the system and  hence increase average battery voltage (this just in: the average  current appears to have dropped from about 0.22 amps to about 0.11  amps due to this change). We are now waiting on weather on a  day-to-day basis for going to Cape Disappointment where weather has been bad since our visit a week ago. A visit to Leppard Glacier to  raise the solar panels on LPRD cGPS will probably be done in  conjunction with the pull-out of Daniel and Ash from nearby Starbuck Glacier next week.

Rothera to Cape Framnes cGPS

Terry writes:

Got the go ahead for deployment to Cape Framnes and Leppard Glacier cGPS sites. Will also support Daniel Farinotti’s deployment by carrying a half load of the required 2.5 plane loads of equipment and supplies to his Starbuck Glacier camp. We again had Ian Potten as our pilot and Roger Stilwell as GA, but substituted communications manager Adam Bradley for GA Ash Fusiarski since Ash is Daniel’s GA. We took off from Rothera at 9:10 a.m. and headed for Cape Framnes at the eastern tip of the Jason Peninsula which divides the Larsen B region, including the last remnant of the Larsen B Ice Shelf in Scar Inlet, from the still intact Larsen C Ice Shelf. The CAPF cGPS system needed a replacement of its GPS receiver.

Aerial view of the Cape Framnes continuous GPS system
perched on a rocky outcrop with sea ice in the background. Photo
courtesy of Roger Stilwell, used with permission.

We arrived at the cape at about 10:35 a.m. and quickly spotted the solar panels powering the system perched on a rocky ledge. Ian made a couple more circling passes to try to see if a small snow patch very close to the instrument would be usable as a landing site as opposed to the more obvious site about a mile away up a blue ice slope to a much larger flat, snowy plain. During one of the circles, Ian spotted a dark circular spot down just above the sea ice a few miles southwest of the instrument. He suspected it could have been a penguin colony, and as we approached it became clear that it was a breeding emperor penguin colony containing a few hundred adults and chicks.

Hundreds of emperor penguins, including large dark
adults and smaller lighter chicks, just a few miles southwest of the
Cape Framnes cGPS.

Ian stayed a suitable distance and height above the colony to avoid stressing the birds, but close enough that we could obtain some photos that could be used to count the number of individual penguins. After a couple more passes, we finally landed at 11:15 a.m. at the more distant but safer site about a mile from the instrument. We donned ice axes and crampons and were able to cram all the necessary equipment and tools into our rucksacks and proceeded downhill toward the instrument. At first we tried staying on some sastrugi to the left of the shortest path to the instrument in order to minimize our passage over blue ice. But after I stepped through a couple of thin snow bridges over some unseen slots, Roger decided to take us back to the more direct blue ice path where we could more easily avoid the obvious narrow slots. Our crampons held us well on the sloping ice and we arrived at the instrument about an hour after leaving the plane. We took some quick photos and noted that the receiver appeared to be logging data. We swapped out the defective receiver for the replacement, and then ran some tests, one of which, namely the ethernet test, was failing.

At that point we called Seth White of UNAVCO who suggested we put back the original receiver. I started removing connectors, but noticed that I had apparently bent a pin on the new receiver when attaching the multi-pin ethernet connector to the receiver. I was able to bend the pin back, re-attach all the cables and rerun the tests. This time the ethernet test passed, so we closed up the box and called Seth again. He said everything now looked good, so we packed up and headed back to the plane, this time taking the more direct route staying on the blue ice all the way. After arriving in about half an hour, Ian informed us that Andy Barker had relayed him a message from Seth that he had erroneously told us that everything was working and that the receiver was not tracking satellites most likely due to the GPS antenna either not attached or not attached correctly. Turns out he had been looking at data logged before I had discovered the bent pin, and that I must have incorrectly seated the GPS antenna cable the second time. So after a quick snack we started back to the receiver. Upon opening the case we could see that the satellite tracking LED was not lit, so we must not have checked it after fixing the bent pin. I removed the GPS antenna cable from the receiver and carefully reattached it, noting that this time it seemed to take up more threads than when I removed it, so I must have had it cross-threaded. After powering up the receiver we noted that it was now tracking satellites, so we again closed up the box and called Seth. He said he was sure he was now looking at new data and that everything looked good. We climbed back up the ice hill, noting that a new lead had opened in the sea ice to our right since our previous ascent. We got back to the plane, packed up, and took off for Starbuck Glacier at 8:00 p.m. after just under nine hours on the ground. We landed at Daniel and Ash’s scenic Kilo camp on Starbuck at 8:35 pm, unloaded their final equipment, took a few photos, and were back in the air at 9:05 pm headed this time for the Leppard Glacier cGPS.

Roger Stilwell and Adam Bradley next to the newly repaired CAPF continuous GPS system.

Kilo camp on Starbuck Glacier installed earlier in the day by Daniel Farinotti and Ash Fusiarski.

Daniel Farinotti, the scientist on the Kilo project, and my office mate since arriving with me in Rothera at the end of October. He’s happy to have finally gotten into the field, and received the last of his equipment so that he can begin his ice penetrating radar survey and automated GPS maintenance work.

Our next stop at 9:40 pm was at Leppard Glacier, the site of another continuous GPS instrument. Ian was able to land just a few meters from the solar panels and antenna, so Roger and Adam were able to hop out of the plane and immediately started digging behind the panels. The goal was to uncover the box enclosing the electronics in order to copy some new firmware and a configuration file to the GPS receiver.

Adam and Roger begin digging in an attempt to uncover the lid of the continuous GPS electronics enclosure. Note that the snow surface is just touching the bottom of the bottom panel indicating an acculation of over 6 feet of snow since its installation in January 2010.

The box is almost identical to the one at Flask Glacier that we had visited three weeks earlier. The difference was that the box at Flask was buried under a couple of feet of loosely consolidated snow, whereas the box here at Leppard was under at least six feet of more firmly compacted snow (aka firn). After almost two hours of digging by Roger and Adam, they were down about 5.5 feet below the snow surface and still hadn’t reached the top of the box, let alone uncover its entire lid which would allow us to open it.

Roger poses at bottom of the 5.5 foot hole he and Adam have dug without reaching the top of the box.

We also hadn’t yet exposed the bottom of the splices in the solar panel legs and associated cables, both covered in ice, that would allow us to raise the solar panels another couple of feet or about a year’s worth of accumulation at this apparently snowy site. So we decided to call it a day and head back to Rothera. We took off at 11:40 p.m. and arrived in Rothera at 1:00 a.m.

Closeup of one of the spliced solar panel legs and associated power and Iridium cables encased in ice near the bottom of the hole.

Rothera to Scar Inlet AMIGOS to Cape Disappointment AMIGOS

Terry writes:

After a Mexican Night dinner and party, including dancing until 3:30 am, I somehow made it to the usual weather briefing at 7:45 am. Clear but windy forecast for Scar Inlet, so probably not flying. But the Scar AMIGOS showed diminishing winds all morning, so I received the word from Andy Barker we’d be flying after lunch with pilot Ian Potten, GA Roger Stilwell, with GA Ash Fusiarski serving as co-pilot. We took off at 3:47 p.m. and arrived at Scar Inlet AMIGOS at 5:24 pm. Ian landed somewhat farther from the AMIGOS this time at about 300 meters, so after putting on harnesses, we had a 15-minute hike with Ash checking for crevasses, followed by me, and then Roger pulling a sledge carrying AMIGOS-4, our tools, and a pallet to place under the new battery box.

New battery box on its wooden pallet platform, and suspended by ratchet straps and rope and lashed to the tower.

Once at the tower, Ash and Roger quickly replaced AMIGOS-1 with AMIGOS-4, which I then verified was working properly. Then Roger attacked the snow and ice covering the old battery box while Ash and I used a couple of ratchet straps to suspend the new box above the snow surface. We then excavated a space under the box into which we slid the forklift pallet. In doing so, we uncovered another narrow crevasse just a meter from the new box but running parallel to it. Meanwhile, Roger succeeded in lifting the lid of the old box without damaging it, revealing ice filling the box and encasing its four lead-acid batteries, its charge controller, and a data logger once used to collect a temperature profile down to about ten meters below the snow surface. Roger closed the old box, we lashed the pallet to the tower, closed up AMIGOS-4, and hiked back to the plane and Ian. We then took off for Cape Disappointment at about 7:35 pm.

The old battery box with its opened lid showing it full of ice and fully encasing its contents.

A narrow crevasse unconvered by Ash while removing snow from underneath the suspended new battery box.

First image taken by newly fixed Scar Inlet AMIGOS4 showing Ash, Terry, and Roger walking back to the Twin Otter to be flown by Ian to Cape Disappointment.

We circled Cape Disappointment a couple of times, and spotted the tower. It clearly had been blown over. Ian found a landing site about a mile or so to the northwest. After the usual skis-down touch-and-go pass, Ian landed us at 7:55 pm. We decided we would attempt a repair, so we loaded most of the equipment and tools we had brought, including a spare 70-pound, 12-volt battery onto three sleds. We still had our harnesses on. Roger and I donned crampons and Ash wore skis. Roger towed the largest of the three sledges which left Ash with a train of the two smaller sledges. We headed off to the toppled tower about an hour after we had landed.

The rock cage at the base of the tower next to the damaged battery box and the top of the upwind rock cage anchor that had beed dragged toward the tower.

The three foil wrapped cable connectors that had been ripped from the battery box.

At first the tower was visible, but it soon dropped below our immediate horizon as we climbed a small hill. Most of our route was over moderately sculpted sastrugi. The tower soon became visible again near the top of the first hill. We then hit a flat spot for a while, but soon started climbing again. The last few hundred meters was over blue ice, so Ash traded his skis for crampons. The sledges were a bit hard to control over the ice, but we eventually made it to the scree patch surrounding the tower about an hour and 10 minutes after we had left the plane. We took a few photos, noting that all three plastic connectors on the battery box (the two solar cable connectors and the AMIGOS power connector) had been damaged when the tower blew over. The upwind wire cage had been ripped open by its guy wire attached to the tower. We measured about 12.5 volts on the batteries, but zero volts on the load output of the charge controller whose top light was solid red. We tried hot-wiring a battery directly to the power input on the AMIGOS enclosure and did succeed in getting the computer to boot up. I was able to reset the date/time using the ethernet interface since I couldn’t get any output from the serial port.

Opposite side of base cage.

Downwind side of tower showing apparently undamaged weather sensor, albedometer, cameras, and solar panels.

By now it was near midnight local time and the sun had dipped slightly below the horizon. We decided to disconnect the charge controller and the entire AMIGOS enclosure, which we then loaded onto the sledeges, leaving the 12-volt battery we had brought. On the way back I relieved Ash of the smaller of the two sledges he had towed which simplified the trip across the blue ice. The trip back was down hill a bit, so we made slightly better time. We loaded up the plane, Ian took off at 01:05 am, and we made it back to Rothera at 2:25 am. Several people had to stay on the job until we landed, including Karen, Adam, and Rosie doing communication and weather observations in the tower, with Clem and Brian in the hangar helping us unload our gear and park the Twin Otter. I got to bed at about 3:30 am, roughly five minutes or so earlier than the previous night.

Terry and Ash returning from Cape Disappointment AMIGOS6, which can be seen at the leftmost tip of the outcrop just above Ash.