2/7/2024 0 Comments High quality ice quake sound![]() Tidewater glaciers are full of pressurized air bubbles-which burst thousands of times per minute as the ice melts-raising underwater noise levels to as high as 120 decibels. Those bubbles are compressed to as much as 20 times the pressure of the Earth’s atmosphere. A cubic foot of glacial ice can hold over five million bubbles. ![]() They form as snow, accumulating over thousands of years, slowly compresses into ice under its own weight-squishing the air that was trapped between snowflakes into microscopic pores. Unlocking the anatomy of a melting glacierįew people realize it, but glaciers are full of tiny air bubbles. In addition to improving our understanding of climate change, her efforts could also explain sharp reductions in the abundance of seals in some Alaskan fjords. This new discovery stems from a 15-year effort by Pettit to understand an important but dangerous environment. The glaciers of Alaska, where Pettit’s team conducted the study, are currently losing over 70 billion tons of ice per year, a loss that causes seas to rise around the globe. The bubbles then rise buoyantly through the water-driving turbulent currents that also bring warm water into contact with the ice. That violent pop of air stirs up the cold layer of water that hugs the surface of the glacial ice-bringing warmer water, several inches away, into contact with it. In tidewater glaciers-large rivers of ice that pour into the sea-the steady melting of ice underwater causes billions of these bubbles to burst into the water “like little tiny gunshots,” says Erin Pettit, a glaciologist at Oregon State University in Corvallis, who is part of the team that made the discovery. They can be reported through email to the Maine Geological Survey at us to determine if there was a frost quake, we need human beings to tell us,” Berry said.Tiny, pressurized air bubbles, trapped in ice, are accelerating the decline of some of the world’s glaciers, scientists have recently discovered. “That means there is more moisture available for precipitation and that is, in part, fueling more rainfall.”īerry would love to see more people reporting any suspected cryoseismic activity, given that they do not register on the seismic monitoring equipment. “One of the factors is a warming ocean surface that increases evaporation and overall more moisture entering the atmosphere,” he said. While there are no hard data on what it means in terms of frost quakes, Birkel said scientific observations are showing these extreme events are creating conditions they need. “In winter this can mean patterns that bring extreme cold followed by extreme warmth.” “Maine winters are warming and as part of a changing climate, we are seeing a tendency for more extreme weather events,” according to Sean Birkel, Maine state climatologist at the University of Maine Climate Change Institute. Over time, the conditions needed for frost quakes in Maine are increasing with extreme weather events on the rise due to climate change. ![]() “A good analogy is when you step on your deck on a really cold morning and it cracks loudly.”Ĭurrent snow depth and meteorological conditions favor frost quakes near the coast, Dumont said. “You get that pressure release and it makes booms and cracks,” Dumont said. That creates a rapid freeze and expansion. Lack of snow cover means the saturated soil has little to insulate it when very cold, arctic air rushes into the area. “You need moisture in the soil and really cold, sub-zero temperatures.” “You need a shallow amount of snow,” Dumont said. Those conditions need to line up just right, according to Don Dumont, warning coordinator meteorologist with the National Weather Service office in Caribou.
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