FREE NEWSLETTER: Econintersect sends a nightly newsletter highlighting news events of the day, and providing a summary of new articles posted on the website. Econintersect will not sell or pass your email address to others per our privacy policy. You can cancel this subscription at any time by selecting the unsubscribing link in the footer of each email.

posted on 22 July 2016

What Lies Beneath Antarctica's Ice? Lakes, Life And The Grandest Of Canyons

from The Conversation

-- this post authored by Christine Dow, University of Waterloo; Felicity Graham and Sue Cook, University of Tasmania

There are few frontiers in the world that can still be said to be unexplored. One of these terra incognita is the land beneath Antarctica's ice sheets. Buried under kilometres of ice is a fascinating realm of canyons, waterways and lakes, which is only now being mapped in detail.

There are more than 400 known lakes in this harsh environment, and more are being discovered as technology advances. This water beneath the ice lubricates the interface between the ice sheet and its rocky bed, and thus controls the flow and behaviour of the ice itself.

Under such a large volume of ice, how is it possible for water to exist at all without freezing? The answer is pressure: when a large weight of ice is pushed onto water, it can stay liquid at temperatures well below the normal freezing point. What's more, the large body of ice actually insulates the bed and protects it from the very cold air temperatures above.

The liquid water is created by heat from the Earth's interior and from the friction generated as ice flows over the bedrock, which can melt the underside of the ice sheet. It is this water that flows into the subglacial lake basins and eventually into the ocean.

The network of lakes beneath Antarctica's ice. Zina Deretsky/US NSF/Wikimedia Commons

Huge water features

A tour around this subglacial landscape would take you first to the largest lake under the ice: Lake Vostok. At 12,500 square kilometres and with an average depth of 430 metres, Lake Vostok is the world's sixth-largest lake by volume, but as it lies beneath some 3.5km of ice, it's not easy to visit.

You can't see it, but it's there: Lake Vostok's location in East Antarctica. NASA

Using ice-penetrating radar and seismic techniques, scientists have mapped Lake Vostok to understand its origins. They have found that it may be up to 15 million years old. The lake has circulation patterns driven by freezing and thawing of the overlying ice, and even has small lunar tides.

Lake Vostok was discovered decades ago, but what is thought to be the second-largest lake under the ice sheet was first observed only this year. It is in Princess Elizabeth Land, East Antarctica, known as the "last pole of ignorance" because until recently it was virtually unmapped.

This region is also home to a huge canyon system, which extends all the way from the ice sheet interior to the coast. The system is as deep as the Grand Canyon but 100km longer.

Map of subglacial lake locations and ice thickness. NSIDC (Blakenship et al., 2009; Smith et al., 2012)

Dynamic environments

So far our tour has focused on the central regions of Antarctica, where ice and water are relatively stable. In contrast, at the ice sheet's dynamic edges near the coast we find fast-flowing regions called ice streams. Many of these have subglacial lakes in their catchments.

Tens to hundreds of kilometres in length, these lakes are short-lived, growing and draining over a period of just a few years. Evidence of this drainage process comes from satellite measurements of the height of the ice sheet. The surface can be seen to rise and fall, as the lake swells and then ebbs away again.

So far, at least 130 of these "active" lakes have been discovered. More are being found every year.

One example is Lake Whillans, in West Antarctica. Covering about 60 square km, it's small in comparison with the gigantic Lake Vostok, but is by no means insignificant. In January 2013, a US research expedition drilled into the lake, extracting clean samples that were later found to contain microbial life.

Such life thrives in this harsh environment without sunlight for photosynthesis. Instead, the microbes depend on the oxidation of methane and ammonia, derived from sediments that are hundreds of thousands of years old. This momentous discovery of life in such a harsh and unforgiving environment may provide scientists with critical information on the development of marine life cycles.

First view of the bottom of Antarctica's subglacial Lake Whillans. NASA/JPL-Caltech/Wikimedia Commons

Loose underpinnings

The water beneath the ice creates a mysterious and fascinating subglacial world, but it is also important because it lubricates the bed of the ice sheet and controls how fast the ice can flow. Where there is sediment under the ice, liquid water can make the ground unstable, while in other areas high pressure allows the ice to float on a pillow of liquid water. In both cases this reduces the friction at the base, allowing the ice to flow faster.

As scientists, we want to predict how the ice sheet will react to a warming climate. To do that, it is essential to pin down the role of water in the current flow rates of Antarctic ice. These fascinating lake and canyon features are therefore not only intriguing, but also play a crucial part in the future of the icy continent.

The ConversationChristine Dow, Assistant Professor of Glaciology, University of Waterloo; Felicity Graham, Ice Sheet Modeller, Antarctic Gateway Partnership, University of Tasmania, and Sue Cook, Ice Shelf Glaciologist, Antarctic Climate & Ecosystems CRC, University of Tasmania

This article was originally published on The Conversation. Read the original article.

>>>>> Scroll down to view and make comments <<<<<<

Click here for Historical News Post Listing

Make a Comment

Econintersect wants your comments, data and opinion on the articles posted.  As the internet is a "war zone" of trolls, hackers and spammers - Econintersect must balance its defences against ease of commenting.  We have joined with Livefyre to manage our comment streams.

To comment, using Livefyre just click the "Sign In" button at the top-left corner of the comment box below. You can create a commenting account using your favorite social network such as Twitter, Facebook, Google+, LinkedIn or Open ID - or open a Livefyre account using your email address.

You can also comment using Facebook directly using he comment block below.

Econintersect Contributors


Print this page or create a PDF file of this page
Print Friendly and PDF

The growing use of ad blocking software is creating a shortfall in covering our fixed expenses. Please consider a donation to Econintersect to allow continuing output of quality and balanced financial and economic news and analysis.

Take a look at what is going on inside of
Main Home
Analysis Blog
Run A High Pressure Economy? Janet Yellen Does Not Understand the Problem
A Short Note on a Connection Between Marginalist Economics and Folk Medicine
News Blog
Why Amazon Gives So Many Perks To Prime Members
Where Workplace Trust Is Strongest
How A Lack Of Sleep Affects Your Brain - And Personality
How Accurate Are Final US Election Polls
What We Read Today 27 October 2016
A Pony And His Beloved Teddy Bear Reunite After Being Apart For 3 Years
October 2016 Kansas City Fed Manufacturing Remains In Expansion
September 2016 Median Household Income Not Statistically Different Than The Previous Month
September 2016 Pending Home Sales Index Improves
22 October 2016 Initial Unemployment Claims: Rolling Averages Marginally Worsen
Durable Goods New Orders Marginally Declined in September 2016
Infographic Of The Day: 41 Interesting Facts About Tesla Motors
Early Headlines: Asia Stocks Down, Oil Lower, Great Lakes Wind Power, Chinese Moving Mfg To US, Tesla Reports Profit, Dems Forecast To Take Senate, China's Debt And More
Investing Blog
Gold That Pays Dividends
Galaxy Note Disaster Wipes Out Samsung's Mobile Profits
Opinion Blog
Global Debt Investors: The Silence Of The Lambs
A Hard Brexit And Reduced Migration Won't Benefit UK Workers
Precious Metals Blog
Inflation Surging As Platinum Signals Stock Market Decline
Live Markets
27Oct2016 Market Close: Wall Street Closes Fractionally Lower, Interest-Rate Stocks Outweighed Gains In Healthcare, Market Indicators Bearish
Amazon Books & More

.... and keep up with economic news using our dynamic economic newspapers with the largest international coverage on the internet
Asia / Pacific
Middle East / Africa
USA Government

Crowdfunding ....



Analysis Blog
News Blog
Investing Blog
Opinion Blog
Precious Metals Blog
Markets Blog
Video of the Day


Asia / Pacific
Middle East / Africa
USA Government

RSS Feeds / Social Media

Combined Econintersect Feed

Free Newsletter

Marketplace - Books & More

Economic Forecast

Content Contribution



  Top Economics Site Contributor TalkMarkets Contributor Finance Blogs Free PageRank Checker Active Search Results Google+

This Web Page by Steven Hansen ---- Copyright 2010 - 2016 Econintersect LLC - all rights reserved