January 28 Mountains, deserts, rivers and lakes - Antarctica above and below the ice

Typical map of the Antarctic continent - brown bits 'exposed' mountains, grey bits ice shelves over sea

Wright Valley in the Transantarctic Mountains - I remember the first time I saw this range - awesome!

And for a slightly different view of this frozen continent, this most southern desert - Antarctica!  It’s not all snow and ice. My learning curve did another steep ascent! Dry valleys exist in the Transantarctic Mountains. These valleys are some of the driest places on Earth and have not seen rain in two million years - does it rain in Antarctica? Unlikely but I think they are referring to precipitation. The valley floors are covered with loose gravel. One of those places is Wright Valley. At its western end lies Don Juan Pond one of the saltiest bodies of water on earth and unsurprisingly it almost never freezes. A few Kms east of this ‘pond’ is Lake Vanda, a frozen lake. The ice can be 3-4m thick and it is quite clear. Beneath that is liquid water fed by the Onyx river, the longest river in Antarctica.  I want to go there and I believe you can hike in - mais hélas pas possible, pour moi. Learning about this opens up this massive continent as vast and staggeringly, surprising, excitingly diverse to me – almost unbelievable. Antarctica really got to me.

The ice sheet is on average 2Km thick but can be almost 5km thick in some places

The Antarctic ice sheet across its vast extent is about 2 Km thick on average, but in some places this huge polar ice cap is almost 5 km thick. Lift the deep ice layer off (zingingly, mindboggling satellite and other astonishing technology) and voila the continent has a vast system of rivers and lakes. 

Lake Vostok is the largest of Antarctica's almost 400 known subglacial lakes. Bear with me as I sneak images from the internet and lectures but some of this is so incredible.

Location Lake Vostok - roughly, perhaps

Staggering - it's worth zooming in and checking out this schematic!

Lake Vostok is located at the southern ‘Pole of Cold’, beneath Russia's Vostok Station under the surface of the central East Antarctic Ice Sheet; it sounds horrendous. Southern ‘Pole of Cold’? In 1983 it recorded a temperature of −89.2°C, the lowest naturally occurring temperature ever recorded on Earth at that time. An interesting little titbit I learnt is that when the air is colder than freezing, molecules of ice and snow skip the liquid form and go straight from their solid state to gas – this is called sublimation. I love this word and this whole notion. The things you learn when you’re not in school!  (Exploring and journeying is not just about, is rarely about the food!) In the schematic image above it shows that in an ice core drilled almost 4km through the ice, they found pollen, bacteria, marine diatoms (plankton) and totally unknown 'things'.  Exciting to contemplate the history of our home planet. 

Scientists believe that Lake Vostok's sole source of water is melted ice from the ice sheet that hides the lake as it seems that there are no subterranean or sub-glacial rivers feeding it. For me that raises the question of what is melting that ice? At almost 4km below the surface of the ice?  Earth's core temperatures perhaps? There's also no way for its water to escape, making Vostok a breeding ground for underwater life.  The science and exploration behind all this is perhaps a little beyond me but .... Wow! Imagine what life forms we are yet to discover.

But here's the thing, where water flows ice flows. Obviously the ice as it accumulates, like water, is always on the move flowing to a lower point, to sea level - basic 'something' but I am no glaciologist and haven't got my head around that yet. However .. ice streams form where water is under the ice and we've just seen that there are rivers under the ice. Here's an interesting image from what we might think as a solid-state, ice-engulfed continent - climate change notwithstanding. The colours show ice movement! Thank you Dr Sue Currie.

Talk to me about glaciers!

From the depths to the peaks - but still sub-glacial! 

Mountains under the ice?! You may have contemplated this, I had not really but it stands to reason of course. The Gamburtsev Mountain Range, which is believed to have started forming around a billion years ago, is a subglacial mountain range located in Eastern/Greater Antarctica, just underneath what is referred to as the Southern Pole of Inaccessibility. Pole of Inaccessibility? Such names and concepts are logical but rarely do we think about them. Why would we?  but I can’t pass them by when they leap out at me. Just briefly the ‘Pole of Inaccessibility’, as the name suggests, is the point on the Antarctic continent that is farthest, in all directions, from the surrounding seas; it is located on the Polar Plateau in a vast territory claimed by Australia. The site almost 4000m above sea level, is occupied by a meteorological research station set up by the Soviet Union during the International Geophysical Year (1957–58). Obviously all continents have these points but it’s a concept that I only first heard about when we were traveling in Australia in 2021. In Australia, the continental pole of inaccessibility is located approximately 160 km west-northwest of Alice Springs – we got fairly close but couldn’t get to the spot with our rig – it’s inaccessible! All these concepts, facts, roll around in my head tantalising me, daring me to go to the next bit of information and  and  and .....

Not brilliant images - they were captured from lectures that had me rivetted to the screen (again thanks to Dr Sue Currie.)

The Gamburtsev Range is about the same size as the European Alps evidently and was discovered by the Soviet Antarctic Expedition in 1958 – how? I have absolutely no idea, I haven’t had time to investigate that yet. It is named for Soviet geophysicist Grigory Gamburtsev. The Range is approximately 1,200 km long, almost 3 km high and is completely covered by up to 1 km of ice and snow.   Current thinking is that glaciers began sliding down the Gamburtsev Range around 40-50 million years ago and merged to form the East Antarctic Ice Sheet, burying the entire range in the process. 

I leave you to contemplate the unknown places on our amazing planet.