First 3D Map of Antarctic Sea Ice's Underside

Robot submarine uses sonar to map under-ice topography

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First 3D Map of Antarctic Sea Ice's Underside

Researchers have produced for the first time a three dimensional map of the underside of Antarctic sea ice, giving them a tool to measure the thickness of the ice in unprecedented detail. Accurate measurements of ice thickness are crucial for tracking the effects of climate change.

The team of scientists from eight countries sent an autonomous underwater vehicle (AUV)—basically, a submersible robot—under the ice. The AUV traveled in a lawnmower-like grid pattern 20 meters below the ocean's surface and mapped the inverted peaks and valleys of the ice using multi-beam sonar. AUVs have been used in the past to map the sea floor.

The scientists also measured the thickness of the snow and ice above the water using helicopters equipped with a scanning LiDAR (which uses light to image objects), high-resolution aerial photography, GPS, and a microwave radiometer. 

The combined data from above and below the ocean's surface allows researchers to produce an accurate measurement of the thickness of the ice—the holy grail of climate change tracking tools. The results also set a baseline to which researchers can compare changes in ice thickness over time, allowing them to better understand the effects of climate change. 

In the past, researchers have measured the thickness of Antarctic ice by taking drill line measurements or by observing the thickness of the ice while moving through it on a ship. Surface area is more easily measured, and has been for years using satellite images, but only offers limited clues to how much ice volume exists.

The inverted 3D map comes from a collaboration of 50 scientists from eight countries who are on a two-month voyage on Australia's research vessel Aurora Australis. The map is one project in a larger mission to investigate the relationship between sea ice environment and ocean ecosystems. The AUV, which launched from the Aurora, is operated in partnership with Woods Hole Oceanographic Institution based in Woods Hole, Massachusetts.

Photo: AUV team/Australian Antarctic Division

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This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

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