Lobodon!: #8 - The Convoy Range

This'll be a mix of answering questions and describing the the Convoy Range, but might be a little shorter since we flew out of McMurdo yesterday and we've been busy traveling (Hooray!). I'm finishing this up in the Sydney airport waiting to board the plane. Two flights down, two to go!

Upper Wright Valley Addendum: Wind Blown Seals

Right and Left - Examples of seals that have been clearly been blown from they're original dying positions. Left - A seal that's tilited near vertical, showing the original normal wind-blown side. The other side of the seal is still covered in skin, which could only have been preserved by being covered on the ground. Right - A seal that has been wedged between rocks. While this could have been done by humans, this area isn't frequented by humans and generally experiences stronger winds that other areas due to a bottleneck leading me to believe that these strange positions were produced naturally.

A couple people asked if it's possible the seals were blown a good distance by those strong winds I mentioned, and in some cases that's true. However, the coastal wind isn't strong enough to blow seals up valley, the positions we find them at must be the minimum distance traveled inland (unless they've been picked up by humans, which is possible in places where Scott's expedition went or by huts that have been staffed since the mid 20th century when rules about touching seals weren't implemented). We usually can't identify how far they've traveled, though we have noticed more than few cases of related bones trailing downwind from the seals, sometimes up to 20-30 meters (~60-90 feet) away from the original carcasses. We know these downwind bones came from the same seal since their usually aren't any other mummies nearby, those bones are missing from the original carcass and they appear to have a similar weathering stage, size and shape to the original seal. If the mummies are whole, we'll sometimes notice they are in frost cracks, where they possibly could have rolled into. Other seals which are more weathered and shaped like sails could easily have traveled farther, and clumps of skin and bone that have assumed a rough ball shape farther still. Often carcasses will be found half buried, and once that happens they are much harder to move as the oils and fats that leak from the carcass cement the bodies to the soil.

I was also asked if I could describe the Antarctic Specially Protected Areas (ASPAs) a bit more. When the Antarctic Treaty was ratified in 1959, the signatory countries agreed to meet every two years to discuss amendments and changes in the ways they wanted things governed. One of these changes was the creation of ASPAs, which are areas of significant scientific or cultural value that can't be entered without special permits. Areas of cultural value include Scott's huts, Shackleton's hut, etc. from early habitation on the continent. The Dry Valleys were declared and ASPA for scientific reasons (I'll include the map again for reference), and the area on the map in the dotted red are no fly zones with more restricted access just to prevent helicopters from affecting the area. Another area like this is Explorer's Cove where there are bacterial mat grounds that are being studied so shouldn't be walked on. Hope that clears things up!

The Convoy Range: The Northern Extent

Our trip to the Convoy Range was rather special. Instead of being dropped off and left on our own to explore, we visited three smaller valleys (Towle, Greenville, and Barnacle) in one day with a larger B212 helicopter and crew spending the day with us at each stop. While we weren't expecting to find a large quantity of mummies at every stop, we did manage to find mummies in places we weren't expecting. The fact that mummies exist in these areas at all are important for the interpretation of our results, since the Convoy Range is much harder to access from the coast relative the Dry Valleys due to a massive ice sheet in the way, 65 km from the coastline.

Left - Our trusty pilot in 36 Julie navigating us through the Convoy Range. Right - A view of Battleship Promontory in the Convoy Range looking east with the East Antarctic Ice Sheet in the background.

Left - The East Antarctic Ice Sheet spilling onto the Towle Glacier from the North. Right - Heading back to the helo after looking around Towle Valley