Blog
Apr 02

Iceberg ‘doodles’ trace climate history

It is as if a child has been doodling with large coloured crayons.

What you see are actually the great gouge marks left on the seafloor when the keel of a giant block of ice has dragged through the sediments.

The arcs and loops record the movement of the berg as it turns about, caught in the wind, currents and tides.

This “ice art” is from a stunning new collection of images that detail how glacial action has shaped the ocean floor in Earth’s polar regions.

The atlas is the work of more than 250 scientists from 20 countries and represents our most comprehensive view yet of what the seabed looks like at high latitudes.

“We now have a critical mass of high-resolution imagery, of the imprints left by the action of ice,” explained Dr Kelly Hogan, one the collection’s editors from the British Antarctic Survey (BAS).

“We can see where the ice has been and what it’s done, and this allows us to compare and contrast. Looking at what has happened in the past can help us understand what may happen in the future with modern ice sheets as they respond to climate change.”

.The book, published as a “memoir” of the Geological Society of London, has taken four years to put together.

It contains mostly images produced from ship echosounders, which pulse the ocean bed and then build depth maps from the resulting return signal (the “false colours” will usual denote different depths).

A first version of the book came out in 1997, but comprised really only low-resolution data.

The new tome, on the other hand, benefits from 20 years of multibeam swath technology, which is capable of creating spectacular perspectives of the ocean floor, often at sub-metre resolution.

Read the full story at BBC News