Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Giants joust in the cold


A new giant was born recently in the coastal waters of Antarctica. A series of images captured from May through the beginning of this month by ESA`s Envisat satellite shows the subsequent duel between the new iceberg and another as it breaks free of the Ross Ice Shelf and tries to move north.

Christened C-19 by the US National Ice Centre in Maryland, the new iceberg measured 200 x 32 km, and about 200 m thick.

As seen in the accompanying animation of images acquired by Envisat’s Advanced Synthetic Aperture Radar (ASAR) from 3 May through 7 October, C-19 jostles for position with an older iceberg, B-15a, resting aground in shallow water off Ross Island. C-19 scrapes along the side of B-15a and, failing to move its firmly anchored adversary, finally heads off into open sea and an eventual demise in warmer waters.

Iceberg "calving"

Several different processes are important in causing an iceberg to form, or "calve" as it is conventionally known, according to Dr David Vaughan, principal investigator of the physical sciences division of the British Antarctic Survey, based in Cambridge, UK.

"They can form as a result of the action of wind and waves, or simply because the ice shelf has grown too large to support part of itself," Vaughan explained. "Once in a while, an older iceberg collides into an ice shelf and breaks off a new iceberg."

The ASAR imagery also clearly outlines that the C-19 berg is not moving through open water. The white swirls captured in the image represent sea ice, offering more resistance to the movement of the iceberg, but winds and ocean currents finally prove too strong to overcome. Also evident in the radar image is the difference between Antarctic ice that is resting on land or water. The Ross Ice Shelf, for instance, is seen as a smooth surface. To the left-hand side of the images, however, the radar image shows the rougher terrain of Antarctic ice resting on land.

Part of the normal Antarctic ice cycle

Such iceberg calving like this one occurs in Antarctica each year and is part of the natural lifecycle of the ice sheet. Scientists are eager to understand if the mass of ice lost in such events is balanced by new snowfall accumulating on the continent. Any imbalance would imply a change in world sea level.

Since C-19 was already floating before it calved, however, it will not cause any rise in world sea level, according to the British ice expert. In addition, since this ice shelf has shown no progressive retreat in recent years, scientists are expected to view this event as part of the natural lifecycle of the Ross Ice Shelf.

“However, if similar events continue to occur then we may begin to believe that this is a result of climate change,” Vaughan cautioned. "For the moment, the jury is still out."

Envisat’s ASAR sensor has several key advantages over optical sensors: it can penetrate cloud cover, which is especially useful in studying polar regions, and can capture imagery at night. ASAR is the first permanent spaceborne radar to incorporate dual-polarisation capabilities - the instrument can transmit and receive signals in either horizontal or vertical polarisation. This Alternating Polarisation (AP) mode can improve the capability of a SAR instrument to classify different types of terrain. The sensor also can record imagery on-board the spacecraft and the images can be made available a few hours after acquisition.

Henri Laur | EurekAlert!
Further information:

More articles from Earth Sciences:

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

nachricht Enormous dome in central Andes driven by huge magma body beneath it
25.10.2016 | University of California - Santa Cruz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>