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!
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