Mobile version

Antarctica thinning seen by Envisat

Image of the Month - June 2012

Height variations from Envisat altimeter between September 2002 and October 2010. Most of the altitude variations are between -15 and +15 cm/year, often due to interannual meteorological variations. Closer to the coasts, however, some glaciers can loose up to several meters in altitude per year, especially in West Antarctica. (Black line : Pine Island Glacier area, see below) (Credits LEGOS)
Pine Island Glacier height variations from 2004 vs 2003, as measured by Envisat altimeter. Click to see the animation from 2004-2003 to 2010-2009 (Credits LEGOS)

 
Antarctica is the biggest fresh water reservoir on Earth, storing about 70% of it. It also plays an active role in the climate due to the strong feedback induced by its high albedo, and can significantly contribute to sea level rise by its melting.
Antarctica is completely iced, but not still: glaciers are flowing all over the continent. Moreover, those glaciers react differently depending on the geographical area.

Between September 2002 and October 2010, Envisat radar altimeter measured the elevation of the Antarctic ice sheet along a repetitive track. Each ground track was observed about 85 times during this time. This long and regular time series is processed using an along-track algorithm to depict in detail the spatial and temporal pattern of elevation change for the whole ice sheet. One advantage of the finer along-track spacing of measurements is that it reveals places of dynamic thinning in regions of rapid ice flow.  In West Antarctica, in the "Pacific" part, thos processing show that glaciers are thinning, losing up to several meters a year. Those that are reaching the Admunsen Sea even undergo an acceleration in their thinning which is measurable by altimetry. In East Antarctica, some glaciers are losing thickness, but without any observable acceleration.

Now that the Envisat mission has ended, other missions can measure up the poles: Cryosat, dedicated to these applications, and soon Saral, that will take over the Envisat's tracks.

See also:

References:

  • Flament, T. and F. Rémy (2012): Dynamic thinning of Antarctic glaciers from along-track repeat radar altimetry, Journal of Glaciology (accepted)
EnglishFrançais
Rss feedsContactPartnersFAQLexiconLegal noticePersonal Data Protection PolicyMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

This home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!