Meet Earth"s Martians! | YouTube Nation | Tuesday

At Not Just The News, the privacy of our visitors is of extreme importance to us (See this article to learn more about Privacy Policies.). This privacy policy document outlines the types of personal information is received and collected by Not Just The News and how it is used.

Log Files

Like many other Web sites, Not Just The News makes use of log files. The information inside the log files includes internet protocol (IP) addresses, type of browser, Internet Service Provider (ISP), date/time stamp, referring/exit pages, and number of clicks to analyze trends, administer the site, track user"s movement around the site, and gather demographic information. IP addresses, and other such information are not linked to any information that is personally identifiable.

Cookies and Web Beacons

Not Just The News does use cookies to store information about visitors preferences, record user-specific information on which pages the user access or visit, customize Web page content based on visitors browser type or other information that the visitor sends via their browser.

DoubleClick DART Cookie

• Google, as a third party vendor, uses cookies to serve ads on Not Just The News.


• Google"s use of the DART cookie enables it to serve ads to users based on their visit to Not Just The News and other sites on the Internet.


• Users may opt out of the use of the DART cookie by visiting the Google ad and content network privacy policy at the following URL - http://www.google.com/privacy_ads.html.

These third-party ad servers or ad networks use technology to the advertisements and links that appear on Not Just The News send directly to your browsers. They automatically receive your IP address when this occurs. Other technologies ( such as cookies, JavaScript, or Web Beacons ) may also be used by the third-party ad networks to measure the effectiveness of their advertisements and / or to personalize the advertising content that you see.

Not Just The News has no access to or control over these cookies that are used by third-party advertisers.

You should consult the respective privacy policies of these third-party ad servers for more detailed information on their practices as well as for instructions about how to opt-out of certain practices. Not Just The News"s privacy policy does not apply to, and we cannot control the activities of, such other advertisers or web sites.

If you wish to disable cookies, you may do so through your individual browser options. More detailed information about cookie management with specific web browsers can be found at the browser"s respective websites.

Meet Earth"s Martians! | YouTube Nation | Tuesday

We’ve got a few billion years left until Earth’s too hot to live on

AP Photo/Eduardo Verdugo

Twin hurricanes in Mexico

People stand on the edge of a collapsed bridge, background, as they wait to ferry their goods via a boat across the Papagayos River, south of Acapulco, near Lomas de Chapultepec, Mexico, Wednesday, Sept. 18, 2013. Mexico was hit by the one-two punch of twin storms over the weekend, and the storm that soaked Acapulco on Sunday – Manuel -re-formed into a tropical storm Wednesday, threatening to bring more flooding to the country’s northern coast. With roads blocked by landslides, rockslides, floods and collapsed bridges, Acapulco was cut off from road transport.

Salon.com

We’ve got a few billion years left until Earth’s too hot to live on

Earth’s Inner Heat Melts Greenland Ice

Earth’s Inner Heat Melts Greenland Ice

Email    Print    Share

Posted on Aug 18, 2013

LeonWP (CC BY-SA 2.0)

By Tim Radford, Climate News Network

This piece first appeared at Climate News Network.

LONDON—Greenland is the largest single reservoir of ice in the northern hemisphere and, with Antarctica, a big contributor to sea level rise. The island sheds 227 billion tonnes of ice every year, and this alone lifts the mean ocean levels by 0.7mm (the seas are rising by 3mm each year in total). Alexey Petrunin and Irina Rogozhina of the GFZ German Research Centre in Potsdam report in Nature Geoscience on a new approach to the great Greenland riddle: what is happening to the ice?

They coupled an ice/climate model that should simulate what happens as temperatures shift, and linked it to a thermo-mechanical model of the planet’s crust and upper mantle far below the island.

Geophysicists call this region the lithosphere: temperatures below the surface increase steadily with depth, and it is the heat from the mantle that powers sea-floor spreading and sends continents drifting across the globe on tectonic plates. Heat from the lithosphere is also the driver, around the world, for boiling mud pools, hot springs, geysers, volcanic discharges and unexpectedly wet, slippery rocks at the base of glaciers.

But there is a catch for scientists who try to model the processes in the lithosphere, especially in heavily glaciated regions. The colossal weight of ice presses down on the rocky crust, and deforms it. The mountains of Scandinavia, once covered by thick glaciers during the ice age, are still rebounding as the depressed lithosphere springs back into shape. What the Potsdam scientists had to do was adjust the model to square with temperature differences observed at separate boreholes and variations in seismic and magnetic data.

Thin rocks and thick ice

At the bottom, Greenland’s subglacial rocks can be warm in one place, cold in another – and very thin, for a 2 billion year old slab of crust, “anomalously thin” say the Potsdam team. This lithosphere heat would be of no great consequence if Greenland were exposed rock, but because it bears a permanently insulating sheet of thick ice, the heat flow from deep in the Earth becomes an important part of the pattern of change.

They ran their model to cover a simulated three million-year span, and settled the argument: the dynamics of the Greenland ice sheet are affected by the heat flow from the planet’s interior. “Our model calculations are in good agreement with the measurements,” said Dr Petrunin. “Both the thickness of the ice sheet as well as the temperature at its base are depicted very accurately.”

Now researchers know a bit more about the dynamics of the ice sheet, they can start to calculate the rate of melting in the decades ahead, and in the Proceedings of the National Academy of Sciences, a large group of international scientists, led by Sarah Shannon of the University of Bristol in the United Kingdom, has been trying to make sense of the flow of surface and subterranean meltwater from the Greenland ice sheet.

The concern is that the melting at the base could lubricate the movement of the glaciers and possibly accelerate the loss of ice as great blocks of the stuff hit the coast and calve as icebergs. They conclude that it could, but there’s no evidence to say that it is doing so right now.  For the moment, on the evidence of simulations based on climate models, and on observations so far, they calculate that Greenland’s contribution to sea level rise from basal melting will be small: no more than 5%.

Get truth delivered to
your inbox every week.

Previous item: Climate Change Boosts Disease Spread

New and Improved Comments

If you have trouble leaving a comment, review this help page. Still having problems? Let us know. If you find yourself moderated, take a moment to review our comment policy.

Truthdig: Drilling Beneath the Headlines

Earth’s Inner Heat Melts Greenland Ice