Julian's Blog
October 30th 2006

The Dry Land



One thing that is very noticeable down here in the Antarctic is how dry the air is. It is in fact the driest continent on earth.

Windblown snow over the sea iceWarm air can carry a lot more moisture than cold air. This moisture is actually invisible vapour (gas). When you breathe out on a frosty day, the warm moist air from your lungs becomes chilled and forces the water to condense into tiny liquid drops which appear as a cloud. This phenomenon blizzard 2005once allowed me to appear as if I were smoking a cigarette at school (it was a plastic imitation) which successfully ‘wound up’ my teacher without leading to any painful consequences for myself or my lungs.

On Planet Earth – we could compare the hot and humid equator with our lungs breathing out. Due to the warmth Camping in gale, 2005there, the air expands, becomes less dense and rises. As it rises it expands further and cools, having to release its moisture as rain (hence the tropical rainforests) and then flowing away towards the North or South as high level dry air. After a somewhat involved journey which may include sinking to the surface and rising again, this air finally reaches one of the Poles eg Antarctica, where it is now very cold and sinks to the surface. It has nowhere to go but outwards, blowing away in all directions from the centre of the continent. The dome like profile of the ice sheets also encourages these dry cold winds to blow faster and faster towards the coastlines. So it is the windiest continent too.

 

Here at McMurdo, we are told to look out for banks of low cloud (which is the windblown surface snow) looming up from the South - a sure sign of bitter winds. I took the second and third photos last year - this year has been relatively quite so far...

 

So, if the air is so dry, and it therefore snows very little (a very few centimeters a year on most parts of the continent) how come there is about 4000 meters of snow and ice piled up over the landscape? - It has accumulated over many thousands of years and has never melted away due to the temperatures staying well below zero.

 

So this was all to tell you why we have to drink so much water continually through each day to avoid dehydration and a dry throat. I have just done a quick survey of 20 people working near by to me in the ANDRILL offices. Of the total, 17 of them had a bottle of water or drink beside them, and three did not. I was actually quite surprised at these three. On further enquiry I learned that each of them do regularly drink, but there mugs or bottles were just temporarily somewhere else.

 

Another related thing is that because of the dryness, static electricity builds up very quickly. Whenever I take my jacket off and hang it onto a metal hook there are usually crackling noises and an electric shock.  A great way to start the day!



The circling sun - October 29th

Things are changing slowly at McMurdo. The population has now reached just about maximum capacity with about 1200 people on Base. This is partly because the Summer  contingent  that are headed onwards to the South Pole Station are unable to travel due to exceptionally cold temperatures. They are still well below -50 degrees at the Pole- the threshold below which the Hercules aircraft are unable able to land safely.

Midnight Sun Another change is that the sun has climbed a bit higher in its path through the sky and no longer hides behind the horizon at night. It circulates through the sky, skimming the horizon to the south at midnight, and traveling up to a point about 23.5 degrees higher when it gets to the opposite (north) side of the sky at noon.

 

There is a convenient sundial on the base, which I can now use 24/7 to tell the time (if I want to go outside and look!). Look for the shadow to find what the time was when I took the photo of it last night.

Sundial 28th OctoberIf you look carefully at the picture there are a few interesting points to notice.

The shadow producing stick (gnomon) is leaning at an angle of 12 degrees towards the South. If we were at the South Pole itself it would be pointing straight up, as the sun would be traveling more or less horizontally around the sky from right to left. Because we are instead at latitude -78deg, we are 12 degrees north of the South Pole, and the axis of the suns daily path is tipped by that amount towards the South. So it’s simplest to tip a sundial in the same way to keep the gnomon lined up with the Polar Axis. That way the interval between each hour will stay simply 360 degrees/24 hours = 15 degrees

 

The letter GN and GW stand for Grid North and Grid West which represent the directions depicted on a map of the area. Doesn’t it seem a bit odd that Grid West should be pointing in almost the opposite direction to True West? I had to think about this for a minute or two. If you look at a map of Antarctica, the reason for it may become clear. Have a go and email me your ideas if you like!


28th October 2006 CORE BLIMEY!

An exciting day today!

 

We saw the first cores of the sea bed. These were retrieved by pushing a hollow core barrel out of the steel tube (which is called the sea riser). This riser has been dangling  940 meters all the way down from the surface to within a few inches of the sea floor. As it moved slowly from side to side with the tides, the drillers pushed the core barrel out under high pressure to grab some length of core from the upper layers of mud.

 

The very first of the cores were used for analyzing the chemistry of the water locked within the spaces between the particles. This process tells the scientists about the chemical processes happening near the surface, and how conditions are for living organisms. By analyzing the oxygen isotopes in the pore water, it will be possible to tell whether there was once a thick ice sheet that actually completely froze down to the sea bed (a higher proportion of relatively light isotopes will suggest a glacial rather than oceanic origin for the water). This would only happen if an ice sheet were big enough to push out all the sea water from the area. However this pore water analysis involves squashing the water out of the cores, and so the core is basically flattened in the process.

 

Ross Powell gets up close and personalThese six new cores we saw this morning were the first ones to be left intact.

Remember that the most recent part of the sediment has been laid at the top of the pile, so as you go down the core you are going further back in time.The cores were quite short – the longest about half a meter, but it is thought that that depth represents about 20 000 years of time – taking us right back into the peak of the last ice age!

 

Sediment Core from the top layer of the sea floorIn the cores we could see different layers. There were fine grained muddy layers, with quite a few larger pebbles lodged in them. These dropstones as they are called, are the boulders and pebbles that have been scraped off the land by the glaciers, and then taken out to sea before being dropped to the depths when the ice melted and released them. They are a classic deposit found below ice shelves or areas of ocean that contain icebergs.

 

There was also a turbidite layer – this is a layer of sediment deposited by a submarine avalanche flowing off a nearby underwater slope. By carefully studying the particles, the scientists will soon be able to tell where the avalanche came from. It is made of volcanic fragments, which can be analysed to find which nearby volcano they belong to. Fragilariopsis kerguelensis - Antarctic Diatom

 

The upper part of the cores contain a proportion of tiny fossil plants (diatoms) and parts of silica sponges, revealing the transition to more open water, where the sunlight was able to penetrate because the ice has retreated. One of these diatoms is called Fragilariopsis kerguelensis (Try saying that that ten times with your mouth full!) The amazing thing about this little plant is that it has been discovered in the North Atlantic having been transported by deep ocean currents moving from Antarctica via the Pacific and Indian oceans!

It was great to see the way that different information is already starting to build possible elements of a climate history...

 



Hut Point Ridge

The drilllers and scientists out there at the drill site are carefully setting up the initial extraction of samples of the soft surface sediments. This is a different and more complicated process from the hard rock drilling that will happen when the deeper layers are reached.  A maximum of three meters of the soft material can be extracted at a time - and the process is done in a different place for each additional three meters of depth to be sampled. At a certain point, when the sediment gets harder (probably within 9 meters depth) the drill bit will be changed to a rotary cutter and progress will speed up. This will be a big moment, and will jolt the whole machinery of the science analysis teams into action. There will be day and night shifts with most people working atleast 12 hours each day. It is absolutely fascinating to learn about the technical intricacies of how the technicians feel and test their way blindly into the sea floor one kilometer below them

So at the moment there is a relatively quiet waiting time, with everyone preparing in their own ways. Yesterday several of us went for a walk up the 5km (3 mile) Hut Point Ridge track. This is on the opposite side of McMurdo to Observation Hill. It was a windy day, so we were well wrapped up. To protect my face I had on my insulated face shield, neck gaiter, windproof fleece hat, ski goggles and ECW hood.



We set out first for Scott's Hut - a short walk out of the base. Then we started to climb the ridge above. The wind was very strong in places, and by the time we got to the flatter area at the top there was a steady gale blasting snow across the ground. Across the sea ice to the Transantarctic MountainsBehind us there were views across the sea ice, past the air runway to the Transantarctic Mountains. Ahead was the huge white dome of Mount Erebus, to the left we could see along the coastline of Ross Island, and to our right and below was McMurdo Station with Observation Hill and the distant Ice Shelf behind. Mount Erebus from Hut Point RidgeThe track veered around to the right, past the satellite receivers of Arrival Heights (a restricted area we had to stay clear of) and back down to the creature comforts of "town".

After dinner, I did the walk again, this time in the opposite direction, the wind was calmer and the views impressively expansive.

As you can see from the photos the landscape is mainly black or white - well at first sight anyway.  Perhaps strangely, the absence of colours actually makes you more sensitive to what you see. I find myself noticing subtle shades of white, grey, yellow, orange. It is as if your eyes become hungry for differences in texture and colour that would normally not stand out at all. I have quickly and happily realised that the views never look the same twice.

Julian





Observation Hill

This morning I set out for the short walk up observation hill just above McMurdo Station. It is one of the few walks for which it is unnecessary to sign out from the base. Observation Hill from McMurdoI wrapped up very warmly, with several layers and my big ECW (extreme cold weather) jacket over the top, ski goggles and a face mask that protected me completely from the wind. At the entrance to the main building I strapped on some attachable studs to give my feet extra grip, and off I went.

There was quite a strong breeze blowing as I left Mactown behind me and clambered up patches of snow lying in areas of gravel and volcanic boulders. Up higher the ridge became more distinct, and the cross wind was blowing snow sideways. I soon found out that to the right of the ridge the drifting snow was much harder to climb than the crest itself which was swept clear and had a layer of good hard snow for my studs to push in to.



McMurdo Station from Observation HillSoon I was at the top, with a view across to Scott Base, the Ross Ice Shelf with the ANDRILL drill site visible in the distance. Behind me was a great view of Mactown and the sea ice airfield.



This small peak has a sad history as it is the place from which Captain Scott's men looked out for him to return from the Pole, only to be disappointed as the days and weeks passed and he never returned. The wooden memorial cross was set up the summer following, in 1913.



On the way down I spotted some smooth snow slopes leading off to the road between McMurdo and Scott Base. Initially tempted, I quickly found that the snow was very hard , and I realised that a slip would send me at high speed onto steep rocks at the base. So the normal path offered a quick and simple return...



Base in Antarctica!

 

Well at last we are here. It has been a very busy and exciting time, and there is a lot I could describe.

We flew from Christchurch in a C17 which is a huge US military plane. Very spacious and faster than the Hercules I traveled in last year. In only 5 hours we landed on the frozen sea ice that is used as an airport for McMurdo Station and the smaller New Zealand Station, Scott Base

McMurdo station has over 900 people staying at the moment. It is a strange ugly settlement. Mt Discovery from McMurdo StationLooking across the central area you see large concrete and metal buildings, linked by telegraph wires. When the noise of the freezing wind stops for a while, you hear the sound of humming from every building, - and large trucks and four wheel drive vehicles cruise slowly passed or stand waiting with their engines endlessly running. People are few to be seen outdoors - they pace purposefully from one building to another. There are over 100 buildings; each has a number, but nothing to indicate its use from the outside. Everything from a sea water distillation plant, a chapel, hydroponics greenhouse, a shop, machine storage sheds and workshops, and 11 accommodation blocks.

We are settled into our accommodation units and have been briefed about everything from outdoor safety, environmental care, helicopter travel, recreation possibilities, tents, lighting stoves, and water conservation.

Night Sky from McMurdo 1 am on October 21 2006Last night I went for a walk at 1am. The sun actually sets at this time of year at about midnight, and rises again at 3am. It wasn’t dark at 1am though, more like a colourful sunset, which quietly and unnoticeably turned into sunrise without a dark time in between. Before breakfast this morning I went for a short run from the accommodation block to Hut Point – about 1km away... The temperature was about – 25˚C and with a strong breeze the wind-chill made it about -40˚C. It was good to get a feeling for how cold that is! Especially when running into the wind. Parts of my face that were not covered by my neck gaiter, 2 hats, jacket hood and ski goggles were instantly in pain. These conditions are by no means described as “bad”. They are “weather condition 3” (i.e. normal) as opposed to condition 2 or 1 which become progressively harsher. No-one is allowed to move outside in condition 1, which means that you are stuck in whatever building you are in, for as many hours or days that the storm lasts! Thankfully that doesn’t happen too often, but I do think i might get a stash of food into my room...







Snow caving in New Zealand, 3rd October 2006



Snow caving in New ZealandHere in New Zealand we are having a day of cold southerly winds and rain. This blasts straight off the Southern Ocean - the only thing between us and Antarctica. It makes me think of that cold white wilderness where these winds must ultimately come from...

 My snow caving expedition was a success. Thirteen of us slept under the snow. It took about three hours to dig the snow cave, but amazingly, we had plenty of room. It even felt rather warm! On the next day we climbed up the steep slopes to In snow cavethe top of Ruapehu and had a great view of the crater lake and clouds far below us.

 Well that was a few days ago. Tomorrow I intend to travel back up there again. This time to do some skiing with my youngest daughter. It is to be our treat before my absence Ruapehu Crater Lake, New Zealandfrom home for two months. I’m hoping that the weather will improve and that there will be a pile

of fresh snow for us, as well as perfect calm and sunshine!



After I return from the mountain again I will have to get more serious about packing and other final preparations. I will fly to Christchurch and meet the rest of the team on 17th October, ready for our scheduled flight to the ice on the 19th.

Thank you to all of you who have sent messages to me so far. I will be away fro a few days, and can be back in touch on Monday.



cheers!



Julian



September 22, 2006

It may seem quiet right now in terms of activity on this site - but behind the scenes the pace is hotting up. With one month to go before we are due to hit the ice, there are literally dozens of people - scientists, drillers and support staff, all checking out plans and organising themselves so that the whole Antarctic geological drilling project will run smoothly.

It’s quite something to be part of all this. But spending hours in front of a computer screen seems a long way away from that bleak, wild, cold place that is the reality of Antarctica.



So for now I am putting information together, spreading the word and planning a cold night in a snow cave with some of my students this weekend. We will be digging ourselves in above one of the ski fields on Ruapehu - our snow covered volcano in the centre of the North Island. That should be a nice precursor to a visit to the coldest place on earth...



So, if you are reading this - do feel free to send me a message, introduce yourself and ask any questions that you may have about Antarctica and the ANDRILL project. I will be updating this blog more as the journey south begins...



Cheers for now



Julian





Learning every day 3rd November 2006

Since the soft sediment cores were retrieved, there has been a lull in core extraction while the drillers have been repositioning the sea riser (steel tube down which the drill is operated). It is presently being pushed into the sea floor and is at about 17 meters depth. When the drillers are satisfied that it is well enough embedded they will pour a special cement down the riser which will flow out of the end and make a water tight seal  to allow the continuous rock drilling to start. So we still expect to be waiting for a couple of days before we start to get into the routine of dealing with a daily batch of core for analysis.

 

In the meantime there has been plenty to do – people on the day shift usually come into the lab and office area between 7 and 8 am. For me the day usually includes lots of emailing, writing, organising audio interviews with scientists, and a whole variety of other activities including meeting and talking with a lot of people.

Each morning at 9.30 we have a science update meeting in which the latest news from the drill rig is described, and individuals give presentations about their work which is invariably fascinating

View from Crary Lab windowIt is, for example, wonderful to be told in detail by Lionel Carter of Victoria University in New Zealand, how the Ross Ice Shelf visible right outside the Crary Lab window, is one of the main physical drivers of the world’s ocean circulation! It is hard to grasp that this is the largest ice shelf in the world – about the size of Spain, and 800 km across. Huge quantities of sea water circulate underneath it and become cooled by about half a degree C before recirculating out to the open sea. Then, during the winter months, an area of the surrounding Southern Ocean the size of the Antarctic continent itself, freezes into sea ice about 1 – 2 meters thick. Sinking waterAs the water freezes it leaves it’s salt behind – so the water just below the ice is now very dense – due to its cold temperature as well as it’s very high salt content. In addition there are areas of open water, called polynyas, caused by the freezing winds blowing off the continent and pushing the sea ice away. These open water areas are chilled further by the winds (down to about -2˚C – the salt content allows the water to stay liquid below O˚C). As the surface water rolls down into the depths due to the increased density, it is replaced by an upwelling current in a continuing process. All of this super cold dense water eventually reaches the bottom of the Southern Ocean, and slowly slides northwards, past New Zealand and into the central Pacific. From there it goes on its world tour through the Indian and Atlantic Oceans, gaining and releasing its heat, rising and sinking, until it  finally returns to Antarctica again, after perhaps 1000 years.   Great Ocean Conveyor

 



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