Since the weather window for Cape Adare has not yet opened, we set our sights on returning to Inexpressible Island, this time to sample fresh guano for calibration samples of modern isotopes and diet to compare to our paleo record. But Angelo, the meteorologist in Operations (actually this is a photo of Attilo and Fabio in Operations, but I figured you wouldn't know the difference), tells us that 30 knot winds are the conditions for the day on this southern island, so we reassess. We also needed fresh guano from Edmondson Point, to the north, and are interested in checking out small Kay Island nearby, where Baroni noted raised terraces and fossil snow petrel colonies on his geomorphology map. Bob is our pilot for the day, and will fly us where we need to go, and stay with us during our sampling. We flew out on the west side of Mt. Melbourne, up the Campbell Glacier, over a saddle, and across the Tinker Glacier Tongue, where this view of a spectacular peak on Cape Johnson came into view, replete with massive icefalls. Kay Island looked very intriguing to explore, but of no use to us for this project, as the terraces were wave-cut benches in solid rock. We grudgingly admitted that it wasn’t worth the stop, and flew on to Edmondson Point.
Our goal here was simple: shovel up 3 buckets worth of fresh guano from a recently occupied mound, carry these down to the shoreline and wash them down enough to make them bearable (weight- and odor-wise) to carry back to Terra Nova. It is a lovely job, and Ed and Steve tackled it with enthusiasm. We spent a bit more time observing the colony, then re-boarded the Squirrel for the flight home. We wanted to swing around Cape Washington to survey for potential beach terraces on our way home, and Bob readily agreed. This cape was a steep and spectacular crag, and although the sea ice below houses an Emperor Penguin colony earlier in the year, the potential for ancient Adelie sites was slim. Bob suggested we fly the ice edge back to Terra Nova, which sounded great to us. Sure enough, we soon spotted a disturbance in the water, and Bob dropped quickly to give us a good view of an orca pod patrolling the ice edge. He has their swimming speed and surfacing pattern down so well from flying the whale researchers that he can back along the ice from the point of last submergence to put us exactly alongside when they surface again. It was fantastic, and an experience I’m sure many would pay a large amount of money to have, and yet it is just part of our work day. Further along the ice edge, Bob dropped once again and swooped into a virtual ice canyon- a huge crevasse in the Campbell Ice Tongue that terminates in the sea. We flew up this amazing canyon for a half a kilometer or so, marveling at the 80 foot high ice cliffs and the flat floor. All too soon he zipped up over the rim, tracked past this frozen-in ice berg, and headed for Terra Nova. It was quite a ride.
We received permission to do an extended flight south to sample some important sites that Steve did not think he would get to this season. We wanted to visit Prior Island, a steep-sided, high island that Baroni has worked on, and re-visit Cape Hickey, the most northerly site we had visited from McMurdo in 2001. We had been unable to locate some important sites that Baroni found there with dates that suggest that Adelies occupied this site during the end of the Pleistocene (see Baroni and Orombelli, 1994). Dave was our pilot for the day, and again would stay with us until we were done. The flight down was gorgeous, and humbling with the amount of untrodden and untreadable ground we flew over. The winds were very high off the Reeves Glacier, although Dave told us we were flying in smoother air at 3000 m. We got a great view of Reeves as it constricts past the Hansen and Teall Nunataks, and beyond that the D'Urville Wall along the Larsen Glacier, almost 800 m high and dead vertical! But mostly we flew over the madly crevassed terrain of the Nansen Ice Sheet. Dave explained how in times of poor visibility it becomes impossible to make out detail from this uniformly white surface, making landing almost impossible. We had absolutely no desire to find out.
Prior Island came into view, and we set down on the south end near some exposed ledges leading down to the sea ice. With some survey, we quickly found some old-looking pebble mounds and began excavating. The site we found was very rich in eggshell and bone, but Steve felt that it looked relatively young regardless of its setting 150 m above sea level. We considered doing another site, but the weather was perfect without a breath of wind, so we decided to push on to Cape Hickey to make the best of our time and conditions. The last time we had stopped on the tiny bit of exposed land at Cape Hickey itself, and were baffled as to how Baroni could have found a 35 cm deep deposit in this rocky area. This time we asked Dave to fly us west to some slopes in the western distance. Even as we set down, we could see deep pebble mounds all around us. With the clock ticking, we had to decide fast where to work, and Steve chose a large mound near the helicopter. While they worked, I hiked up the adjoining ridges, and the size of the abandoned colony began to emerge. Every terrace, or flat spot between boulders, that I probed contained ornithogenic sediments. And much land was obviously still covered with snow. In addition, surface processes had obviously had more effect on these mounds than any we have seen before. Is this what a Pleistocene site would look like? We sampled another small but deep site on a boulder for good measure, but only the radiocarbon dates will answer the pressing age questions. We loaded the Squirrel, and took off for home.
On any lengthy trips such as this one, the helos can’t carry enough fuel on board, so they have established fuel depots at roughly 80 mile distances from Terra Nova along often-used routes. Dave refueled at Starr Nunatak, and I noted the excellent looking granite crag on its seaward side. We landed again at Prior Island to arrange a sling load for our samples, but Dave decided we could cram everything in for a single flight, rather than having to fly all the way back here to pick up the sling. He lifted off experimentally (as he put it: “Sometimes you just have to try it to see”), and we headed for home. There are a couple of new additions near our bunkhouse; a skua pair have hatched two eggs and have chicks. It will remain to be seen if one chick will succeed in committing ‘siblicide’ and having the nest all to himself. Our plans are to attempt to return to Inexpressible Island tomorrow if the Adare window doesn’t open.