The results could help explain the evolution of these distant icy worlds.
Ice, the cold stuff you either love or hate, plays a fundamental role not only for ecosystems, but also for the global climate. The ice itself can act as a habitat for animals such as polar bears and penguins, and it also reflects a lot of sunlight back into space, keeping the planet cool. But what exactly is happening inside the ice as it responds to external forces, like a warming climate or even the environments on distant icy moons, is a little less known.
Now, a team of researchers at Lamont-Doherty Earth Observatory at Columbia University in Palisades, New York, has built a new apparatus called the “cryogenic deformation apparatus,” to get some insight into the behavior of ice.
The response to external forces, known as “deformational behaviors,” occur on Earth due to gravity. However, the icy moons of Jupiter and Saturn, for example, experience these as a response to tidal forces — the differences in the strength of gravity — from their host planet. The moons Europa and Enceladus are of huge interest to scientists because they might contain massive oceans hiding under their ice, which might even support life.
The new apparatus is similar to those used to study earthquake generation in rocks, but with one major addition. It now has a temperature control that allows scientists to measure the behaviors of ice, since ice conducts itself differently at varying temperatures, at conditions found on both Earth and frigid moon surfaces.
The device will examine three different ice processes.
First is friction. Glaciers are essentially rivers of ice that move, or slide, towards the oceans, which is a process that affects climate and water levels.
Second, the device will measure the anelastic behavior of the ice, which is essentially its ability to turn mechanical energy (the energy from its motion) into heat.
The third process is tidal dissipation, which has been a recent focus in planetary science as a potential heat source to create and maintain global oceans below icy surfaces.
“Our design allows for both glaciological and planetary applications over a range of deformational behaviors including friction, anelastic and viscous [properties]. That range of adaptability we hope will lead to new insights about ice deformation,” said Christine McCarthy, the study’s lead author, in a press release.
For now, the team will be testing ice at temperatures found on Earth, focusing on how the tides affect sliding rates and stability.
However, the next phase of the project will involve examining much colder temperatures, around -90 degrees Celsius (-130 degrees Fahrenheit), to study ice with small amounts of ammonia and sulfuric acid, which are found within the ice of Enceladus and Europa, respectively. The results could help explain the evolution of these icy worlds.
The paper has been published the journal Review of Scientific Instruments.
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