# 12 - Small Update

Just wanted to let you all know that our project was featured in an article in the Antarctic Sun, the local Antarctic newspaper! Check it out!

http://antarcticsun.usap.gov/science/contentHandler.cfm?id=2987

Also, I do have a few remaining newsletters to publish. It's been rather busy around here with two jobs + grad school prep. In any case, I've been planning to take my previous newsletters and clean them up for a blog so they can be viewed for posterity. I'll be sure to let you all know when that goes online.

#11 - Salmon Valley

Salmon Valley: Hangin' out in the Royal Society Range, Seals and stuff!

Near the end of our seal sampling journey we made trips to the Royal Society valleys nearby and a trip to Marble/Gneiss point along the coast. All the seals sampled in my video included in the last email were from Salmon Valley. Since there isn't a whole lot to talk about about Salmon Valley (other than that we found no salmon,) I'll talk about the seal carcass weathering process and how we think it relates to age and environment. 

 

Left - A view of the ridge separating Garwood and Salmon Valleys from the air. The Ross Ice Sheet, Brown Peninsula, Black Island and White Island lie in the background.  Right - Salmon Valley Glacier

 

Left - Looking at the light snow left behind from a localized snow storm. Snow dropped in regional storms sublimates (instead of snow melting and then evaporating, ice goes straight from a solid phase to gas) and creates smaller localized storms inside individual valleys, often making weather very different between valleys that are even right next to each other. 

 

Left - Close to Salmon Glacier. The older, more experienced folk (Brenda and Paul) decided to skirt the edge of the glacier looking for seals, nobly putting themselves in dangers way instead of us kids. According to US Antarctic Program official Risk Assessment guidelines, this was rather risky. Many seals were found in the ice just beneath the glacier. Note how ice had recently broken off the face to the left of Paul and Brenda.  

Seal Carcass Weathering: How old are these things, anyway?

We developed the carcass weathering scale adapted from a paper that touches on the subject (Barwick & Balham 1967), and compiled by Laura Niven and I in the lab after some thought that this system could give us a good way of measuring seals in the field. Since we don't have the budget to measure the age of every sample we collected, we will be trying to use this weathering system to figure out a general age of the animals. After we fix radiocarbon ages to the mummies, we'll be able to extrapolate general ages to the state of the carcasses. Something to note is that this scale really only applies to mummies on the surface, buried mummies will undergo a different weathering process that is controlled by chemical microbial destruction, rather than the sun and wind, or mechanical action from glaciers grinding mummies. 

A - Complete. Fresh. Undamaged from wind erosion, no dessication. We didn't find really any seals that fit this definition; however, in Taylor Valley an unfortunate Leopard wandered in and died in December. While we couldn't and didn't want to sample such a fresh seal (we do not have a permit to collect anything that died after 1972 due to the Marine Mammal Protection Act), That seal would fall under that category.

B - Complete. Slightly weathered. Partial erosion of hair on exposed surfaces, cracks in skin exposing deeper tissues or bones in the flippers or cranium. We did find many seals in this condition. The seal below, for example, was found with most of its fur intact, however the wind was beginning to have an effect on the carcass. This seal was also close enough to the coast to have its eyes scavenged by Skuas. 

C-  Incomplete. Extensive erosion and exposure of bones of upward part of body (skull, ribs, limbs). Skeleton undamaged but soft tissues eroding between bony elements. The majority of seal mummies we found happened to be C or D. At this point mummies are often heavily wind abraded on one side with skin and fur preserved on the other as the exposed part breaks down more readily in the sun and wind.

D- Incomplete. Extensive erosion with regional destruction of bone and tissues. Vertebral column completely exposed and 40-50% tissue is destroyed. As you can see in the mummy below, the head is missing. This is a common occurrence in the world of vertebrate paleontology as heads are attached by relatively weak neck vertebrae and break off as soon as the soft tissue around it decays. 

E-  Very incomplete. > 50% of carcass is eroded. Vertebral column and cranium incomplete; limbs and rib cage becoming remnants. Difficult or impossible to identify species, sex, size. In the specimen below, you can see that the seal is a unrecognizable mess of tissue and bone. The best we can hope for is that an identifiable bone is present so we can try to figure out what species it is. While it might seem that a sample from a nearly destroyed carcass is useless, we can still use bone and tissue samples for DNA, radiocarbon, and stable isotope data, which will tell us the species, age, and diet of the animal. 

F- Fragments or isolated bones. We found many isolated bones, many of which are potentially very old and will be useful for identifying the long term population dynamics of different seal species over the past several thousand years. 

We have a similar system for measuring bone weathering, since isolated bones will also go through a similar weathering process where certain parts of bones will break apart faster than others. And that wraps it up for this email, thanks for reading!

# 10 - Cape Roberts

I realized I forgot to include my video from last time, so here it is: https://www.youtube.com/watch?v=TvkZFIRR-bc

Be sure to turn up the quality so you can get the full experience. It includes highlights from the entire trip. 

Cape Roberts: Life on the Coast 

While we focused on the coast during our field season last year, we decided to come back to spots we weren't able to visit during that season, Cape Roberts, Marble and Gneiss Points. Cape Roberts was full of all kinds of wildlife as an active Skua nesting ground with plenty of Weddell seals nearby on the sea ice. 

 

Left - A view of the sea ice with Taylor Valley and Explorer's Cove in the background, sites we covered in the 2012-2013 field season on the way to Cape Roberts. Right - Wilson Piedmont and Spike Cape, on the way to Cape Roberts. The Piedmont has been shrinking back over the past several decades, exposing mummies that had been long buried under ice.

 

Left - A Skua pair at Cape Roberts, claiming their territory and challenging anything that comes near it. Right - A Skua mother and chick, with the mother doing her thing, calling out to make us aware of her presence. 

For those unfamiliar with the term "Skua," I'll introduce them to you as fat devil birds. The South Polar Skuas (Skoo-uh) are highly territorial, aggressive, scavenging sea birds that nest on the Antarctic coast during the summer and migrate throughout the entire world during the winter. Skuas are territorial and aggressive for a good reason: these birds are cannibals. They'll eat each others young when given the opportunity. For example, in desperate times, a Skua will distract a mother away from her chick, and the other member of the hunting Skua pair will dive in and grab the chick while it's trying to hide under a rock. Skuas will also fight to the death over drinking water ponds, as evidenced by the clearly scavenged Skua bodies we found nearby. 

 

Left - A Weddell seal lying out on the sea ice near a big crack in the ice. The bottom of Mt. Erebus lies in the background just to the right of a large iceberg. Right - A recently deceased Weddell Seal is being scavenged by Skuas. 

The only other animals nearby are Weddell Seals, which typically lie out on the sea ice near accessible diving spots. Unlike other seals in Antarctica, Weddell's prefer to lay out on the ice all the time, whereas Crabeater seals will venture out into the open ocean during the summer, with Leopard Seals following (and hunting) the Crabeaters. Weddell seals will either take advantage of naturally formed cracks in the ice, or use their teeth to break through so they can go fishing below. Weddell's were one of the three main species of seals we were looking for. Judging by Weddell carcasses we found on the coast, Skuas had a hard time scavenging carcasses in areas other than the eyes or perhaps they just really like eyes. So if you fall asleep along the coast, you might want to be careful about your eyes. 

Southern Elephant Seals prefer north facing beaches and open water. In the project that inspired this one, Elephant Seals were the main focus since they have a complicated history on the Antarctic coast, and especially the Ross Sea. Several thousand years ago, when the Ross Sea had more open water, The largest known Elephant Seal colony existed in the Ross Sea. Around 1000 years ago, a regional cooling trend froze the Ross Sea, and the local Elephant Seal population collapsed, leaving behind only traces of fur that can be found on ancient beaches under rocks. Though we were searching for other species of seals in the main focus of the project, we were also looking for Elephant Seal fur that was left behind to find out more about ancient Elephant Seal populations as a small side project. Now that the Ross Sea is warming back up, we want to find out how other seal species will react to this climate change, and if the Elephant seals might return to these formerly populated beaches.

 

Left - Skuas defending territory on the rocks at Cape Roberts. Right - A weather station at Cape Roberts. 

And that's about it for this email. I had a few questions since the last one, mostly about the timing of events and seal evolution. In terms of the sequence of Geologic events, Antarctica was not centered on the South Pole like it is today in the Mesozoic. At the time, Dinosaurs, trees and productive ecosystems existed with fossils of both in the sediments of the Royal Society Range (near Marshall Valley). The Ross Sea formed as a rift system, leading to volcanic activity that is still present with Mt. Erebus. As Antarctica centered over the South Pole in the Paleogene, the Southern Ocean formed a circular current which increased the cooling effect around the continent, which not only drove temperatures down around the continent, but around the entire world, killing off normal life in Antarctica. Significant amounts of ice and glacier penetrated into the valleys and receded repeatedly beginning in the Miocene until the Last Glacial Maximum in the Pleistocene. The first known seals are known from temperate environments, including California, in the Oligocene and Miocene. The three major groups of seals didn't separate until later on in the Pliocene. The five species of Antarctic seals are the Southern Elephant Seal (beach loving seals with colonies), Crabeater Seals (the most abundant seal, and possibly the most abundant large mammal after humans on Earth), Weddell Seals (sea ice lovers), and the rare and elusive Ross Seal (rare, elusive, deep divers out in the open ocean). 

 

That was a quick and dirty summary of the background. If something doesn't make any sense let me know!

#9 - Marshall Valley

Since I've recently made it back to Santa Cruz I thought I'd continue the newsletter!

Marshall Valley: The Royal Society Range, Life in the Valleys, and a Bonus Video

After visiting the Convoy Range in the far north, we moved our camp from Wright Valley to the valleys of the Royal Society range in the south, choosing Marshall Valley as our base camp since it had the most known seals (roughly 80). We spent several days hiking through Wright Valley finding almost every one, plus many more that hadn't ever been mapped. 

 

Left - One of many seals in Marshall Valley. The seals typically followed drainages or stream beds. Notice the moss to the left of the seal. Right - A seal on the flank of the south slope dipping into Marshall Valley. This seal happened to be lying above melting buried ice, the source of the drainage in the picture on the left. 

 

Left - An ice core pond in Marshall Valley. Ice core is a mix of ice and rock that was left behind by the Ross Ice sheet during the Last Glacial Maximum (~25,000 years ago). This mixture of ice and rock is unstable and creates these pothole ponds. Right - a seal nearby some ice core deposits.

 

Left - A closer look at the seal in the ice core photo above. There is a large quantity of moss growing behind the seal. Right - Bacteria/algae growing downstream of a seal near the bottom of Marshall Valley. The microbes here tend to range from orange/red to green. Lipid and cholesterol byproduct form bubbles on the surface of the pond.

Life inside the valleys is vastly different from what most people are familiar with, but it does exist even here. In some areas it is actually quite vibrant. The majority of life in the valleys are fairly isolated from the coast, the only organisms that venture in are the occasional seal, the rare penguin, and skua, a seagull-like scavenging bird. The ecosystems here are dominated by microbial life, generally, photosynthetic algaes, bacteria, and moss. These tend to grow in areas where there is a high nutrient supply which is phosphate limited. Luckily for many microbes, bones are an excellent source of phosphate, and seals are hypothesized to play a major role in supplying this nutrient. Other forms of life include red mites and springtails, arthropods and insects that are essentially living fossils. We sometimes found red mites and springtails on bones when digging bones out of highly productive soils. Red mites and springtails populations tend to be isolated and they differ genetically from valley to valley. Occasionally a lichen will be seen, however we didn't see any except for on the coast this year, and only one in Taylor Valley last year.  

 

Left - A look at Ross Island (Mt. Erebus being the larger mountain on Ross Island) from Taylor Valley. Right - looking at a stream cut into ice core deposits. The white here is actually not ice, but salts that have been left behind. An abundance of Gypsum and Carbonates can be found in and around Marshall Valley, formed when large amounts of water were present as the ice sheet melted into lakes before draining out of the valley. 

 

Inside the Cook tent in Marshall Valley Camp, acting as our common living space were we read books, played cards, cooked and ate food, and hung up wet seal samples to dry (notice the bags hanging from the ceiling). 

And that's pretty much it for this newsletter. More to come later!

#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

  

Left -  the Towle glacial margin and the southeastern side of Towle Valley. Right - Spreading out in seal searching teams in Barnacle Valley.

 

Left- a view of the helo from up high in Barnacle Valley; despite searching, we found no seals here, and no barnacles either.  

That's it for this one! Time to go back to California! Questions are welcome as always!

#7 - Upper Wright Valley

Before I get started, I found a better labeled map that shows all the sites we visited in both our field seasons to give you a better idea of the places we visited. I'll be talking about our trip to a few of the smaller open spots in the northern Convoy Range in my next email, this email will focus on our trip up the Wright Valley where we were dropped on a helicopter day trip in the areas just east of the Labyrinth, around Lake Vanda and Prospect Mesa. Yesterday's email focused on the area between Lake Vida and Victoria Upper glacier, though the other two groups (as we were split into 3 groups of two) moved from Bull Pass to Lake Vida and the lower part of Victoria Valley near the Sand Dune Field. 

I was asked a few questions, though I'll just talk about one of them in this email. Though it doesn't look like it, the Dry Valleys are actually an ecologically active area, when I describe Marshall Valley I'll focus on the living things in these desolate and tough conditions. I was asked about precious minerals as well, and the answer is: there are none. At least no gold. There some strange rocks though, such a Kenyite, a mix of basalt and big anorthosite feldspar crystals that only form in certain divergent tectonic plate boundaries, so two places: Kenya in the Great Rift Valley, and Ross Island, but the Ross Ice sheet actively transported many basalts and kenyites from Ross Island and Brown Peninsula into some of the Dry Valleys, including Taylor, and the Royal Society Valleys, including Salmo, Garwood, Marshall and Miers Valleys.

Upper Wright Valley: Human Expeditions, Katabatic Winds, and Seal Traps

I was asked if there was much human history and impacts that can be seen in the Valleys. Turns out, if you pay attention, you can usually find signs of just about every time someone has ventured into the valleys. Last year we found seal mummies with their heads clearly chopped off with knives by Scott's crew (1910-1912) near Mummy Pond in Taylor Valley, a known site of the first expedition into the valleys. The valleys were essentially un-visited for another 30 years due to lack of funding and the world wars. Later on, as the US Navy and the NSF was scoping a spot for McMurdo Station in the late 1950s, the valleys were revisited and several sites were considered, including Marble Point along the coast (See map, I'll be talking about Marble Point in more detail in a later email). Though McMurdo was eventually placed on Ross Island, relics of old expeditions can be seen. As the Navy was exploring the valleys, they laid down survival caches and "dunny" (New Zealand speak for the bathroom) spots in various places. As we're looking for bones, we'll sometimes find toilet paper that is the roughly the same color from the 1950s until 1978 when the Antarctic Conservation Act designated the Dry Valleys as an Antarctic Specially Managed Area (ASPA). 

 

Left - A view of the Middle of Wright Valley. The Onyx River, the largest river in Antarctica, flows away from Lake Brownworth to Lake Vanda due to tectonic uplift creating a skewed topographical gradient resulting in a reversed flow direction; inland instead of to the ocean. Right - Tracks from a New Zealand tractor driven to Lake Vanda Station along the Onyx from the late 1950s. For a short period Lake Vanda station was staffed year round by New Zealand. Today Vanda Station remains staffed during the summer. Notice that the tracks look brand new despite being over 50 years old. 

Getting back to our research mission, we found that seals are generally distributed fairly evenly throughout the Valleys, except for several specific types of areas: bottlenecks, generally edges of glaciers that they have trouble climbing up and over or cliffs and closed off areas, such as the area directly beneath the Labyrinth. 

 

Left- Cliffs where Wright Valley thins out just below the Labyrinth. We found over 10 seal carcasses and scattered bones in this area. Right - Looking down toward the middle of Wright Valley. Many of the boulders in here would appear to be tough for seals to maneuver, yet they trudged not only through here but a few have sighted up and over the edge into the Labyrinth. 

 

Left - traveling down valley from the cliffs, we found we needed to climb over a Rock Glacier, often found only on Mars. Rock glaciers are a roughly 50-50 mix of rock and ice that flow very slowly and are formed when snow patches and glacial ice becomes buried under sediments. We found several seal carcasses on the rock glacier, many of them fairly early in stage of decomposition. Right - The "naptime while waiting for a helicopter pickup" photo with Lake Vanda in the background and the famous "bunny boots" in the foreground. However, katabatic winds were blowing pretty strongly to the point where we weren't certain of a pickup. Luckily the winds didn't prevent the helicopter from reaching us at the end of the day.

Winds are a major component of the environment in the Dry Valleys. Typically there are two sources of wind, cold constant and moist winds from the coast that blow in from the Ross Sea at around 5-20 knots and warm, dry and strong katabatic winds that blow in from the continent at anywhere from 5-30 knots, with gusts higher than 60 at times. For reference, the "shovel test," in which the winds can keep a shovel from falling over, occurs at around 40 knots. For those in Southern California, you may recognize katabatic winds as the Santa Anas. Katabatic winds are essentially gravity driven currents of strong winds that blow from high areas to low and expand as they descend, becoming drier and even stronger. During the winter katabatic winds here will blow as strongly as 200 mph, which often send seal carcasses flying and generally sandblast mummies. 

We experienced a 3 day katabatic windstorm, which started when we noticed the constant daily coastal wind stopped for about 15 minutes, then the wind direction began to pick up in the opposite direction. Unlike the coastal winds which would typically stop during the the night, the katabatic winds blew throughout the night, reaching a crescendo on the third day when the winds were reaching a constant 20-30 knots. At that point we had to give up on seal sampling, which was getting difficult anyway just because we had to put rocks on our notebooks and sample bags to keep them from blowing away, and go make sure our tents were tied down securely so they wouldn't blow over. Luckily our yellow Scott tents can withstand extreme winds up to 250 mph. 

In a storm on the ice sheet a few years ago, the members of a research team needed to huddle in a single Scott tent since the winds had torn apart and destroyed the other tents. When they left the tent by the time the storm had dissipated, a snowmobile had been blown away. According to Brenda, our 25 season veteran, she had been in a katabatic wind storm where they could hardly breathe inside because the tent was flapping so much. As a result, they couldn't light a match for the stove since the wind was too strong even inside the tent and had to resort to drinking juice packs for three days while huddled in their sleeping bags. Luckily the wind was never that fierce for us. While walking across the rock glacier photographed above, however, we were experiencing coastal winds when out of nowhere a katabatic wind blast nearly knocked us to the ground, and after that strong winds made us worry about our helicopter not being able to get us. Curiously, our other teammates farther down valley on the other side of Lake Vanda were still experiencing coastal winds, which made for some confusion as the helicopter pilots were feeling strong katabatic winds at altitude. 

That's a lot more than I was expecting to talk about winds. I'll try to get some pictures of wind blown seals to show you all in the next email. Still to come: The Convoy Range with Carcass/Bone weathering, Marshall Valley and wildlife in the inland valleys, Cape Roberts and wildlife on the Ross Sea Coast, Glacial reaction to Climate Change in Salmon Valley, Marble Point/Gneiss Point and the Antarctic Conservation Act, all of these with fun seal mummy action, and perhaps a conclusion with the future of the project and some penguins back at McMurdo Station.

As always feel free to ask questions and I'll try to cover them later on.