21 January 2023 Store in a cool dry place

Store in a cool dry place

An amazing thing about Antarctica is the different systems and rules the natural world plays by. All the laws of science are the same, it's just the combination of the variables. When talking about being a PolarTREC teacher with 2018 PolarTREC alum, Kevin "K-Dawg" Dickerson, he relayed a story which perfectly summed up the change in perspective: He told me that one evening in the Dry Valleys he was eating a sandwich. He couldn't finish it (which is very rare) but didn't want it to go to waste. When he asked a veteran what to do they said just leave it there and get it the following day. Anywhere else in the world there are thousands of reasons not to set your food out overnight; Temperature, precipitation, bacteria, scavengers, etc. but here conditions prevent almost all the mechanisms of food spoilage (except for UV radiation).

These different rules affect more than just where you can leave your sandwich unattended. Because things don't decompose, seals who have become lost or disoriented and died in the Dry Valleys are still here, hundreds of years later. It isn't worth the time for soil bacteria to stake out a place in the soil, waiting for that type of meal. Even if bacteria were there, laying in wait for millennia for a lost seal to come along, the conditions would soon dry and freeze the meal, making it indigestible. Human food that is stored in the camp huts may have expired 10 years ago is usually perfectly fine to eat. Many meals well past the "best by:" dates have been shared and enjoyed by Antarctic researchers.

These cold, dry conditions require other considerations for visitors to Antarctica. A mandatory piece of equipment before heading out to the valleys it the P bottle. The P doesn't stand for Phosphorus. Any human waste from humans - biological or otherwise - must be removed - either in bucket, bag or bottle. Nothing is allowed to enter the Antarctic ecosystems. The addition of chemicals and nutrients could have significant effects on the soils and waterways. In a place where so much long-term research is taking place, human waste could invalidate results and alter ecosystems. Imagine also, in a place without decomposition, that waste will sit there for years.

Being stored in a cool, dry place also allows animals and plants that call Antarctica home to live a really long time. It may be a really slow life. Microscopic nematodes that would have a few months or weeks long lifespan in temperate climates can live many years in Antarctica. One feature of animals adapted to the Dry Valleys is that they can go into a state of anhydrobiosis. In this state, animals remove the water in their cells (or replace with other chemicals) and stop their metabolic activity (breathing, burning energy, moving). This lets these creatures sit out the most inhospitable seasons/years/decades?/millennia?, saving their game until later. Some animals in the right conditions in the Dry Valleys may technically be thousands or even millions of years old. They spent most of their lives in a state of suspended animation, only to become rejuvenated with the presence of liquid water and the right temperature.

In the photo, Meredith is chopping out an ice skirt from the front of a glacier. Our hope is to extract sediment and soil from below the glacier where anhydrobionts have been waiting for warmer, wetter conditions. Lots of interesting questions are flying around about whether or not this is going to work, but that is what scientists do. Could there be million year old tardigrades in our sample, just waiting for the glacier to recede so it can finish up its life or have some baby tardigrades? This tardigrade from a plot near Lake Hoare could have been born when the Great Pyramids were being built.

Boulders and water have different relationship here

In most parts of the world - like the midwest and border of the Ozark mountains where I normally spend my time, rocks and water work together in a predictable way. But that I mean, in a way most people are used to expecting. Rock is broken apart by water freezing and thawing. The rocks fall into water. Rocks sink in water. Rocks are carried down stream by water.

The weird thing you might see here is a boulder sitting on top of water, being carried away over the course of thousands of years. Rocks are still slowly broken down by freezing and thawing but can get transported on the top of the ice, far from where they started as part of a mountain. Notice the pattern of time? Go slow.

You can imagine how, as a sheet of ice slowly flows through a valley, boulders may fall onto the surface or get picked up from the valley floor. As the glacier flows, the rocks towards the top could melt out. Glaciers are full of sediments that fall on top and get incorporated into the layers of ice. It's still pretty weird to think about how long and how far that rock has just being riding that ice. New rocks or sediments that are deposited on top of the glacier can find their way into the ice sheet as they melt their way down from the increased heat (see previous post).

Out on the lakes you will also see boulders. Huge rocks just sitting on the top or embedded into the ice. Looking around, you won't see a nearby source from which these boulders may have fallen. Unlike glaciers, these ice sheets are permanently in place, only moving up and down on occasion with changes in lake level. Check out my video on these weird boulders and how they may have gotten on top of the ice. Be sure to comment if you have any other ideas about how the boulders got there.