Ice earthquakes will become increasingly common amid the climate crisis, which threatens to destroy homes and roads .
Ice earthquakes , like a string of earthquakes that struck 26 times in just 7 hours in a Finnish city, could become increasingly common if the climate crisis continues to cause extreme weather in cold regions. This strange and understudied weather phenomenon occurs as a result of water freezing in saturated soil or rock. The mechanism behind glacial earthquakes means they affect areas with a lot of moisture in the soil, often near water. Then, when the temperature drops suddenly, the water can freeze and expand rapidly, creating pressure inside the surrounding substrate.
The city of Oulu has recorded 26 glacial earthquakes in less than half a day. (Photo: New Scientist)
Ice earthquakes occur when the upper pressure is so great that cracks are created, causing the ground to shake . Like earthquakes, glacial earthquakes can be felt and heard, but not as severe on the classification scale. Many ice earthquakes occur unnoticed because they are so mild, while in some cases they sound like gunshots, and can even cause damage to tangible structures such as buildings.
By their very nature, glacial earthquakes are often associated with extreme weather, which has become more common due to the climate crisis in recent decades. Researchers are also interested in how climate change could affect the Arctic and subarctic regions, including ice earthquakes. A team led by Jarkko Okkonen from the Geological Survey of Finland announced the findings at the European Geoscientific Federation’s congress, IFL Science on May 15.
Recent reports from icy regions in Finland, Canada and the US show just how much damage earthquakes of this kind can do to infrastructure, so it’s a weather phenomenon worth looking into. if people want to be safe in increasingly unpredictable environmental conditions. To do so, the team built a model that allowed them to understand the relationship between thermal pressure and glacial earthquakes. The thermal stress created by any change in the temperature of a material causes it to expand and contract, like the effect of freezing water on saturated soil.
Okkonen and his colleagues used hydrological models to calculate snow depths, melting rates, and soil temperatures at different depths and explore what happens when temperatures suddenly change. This method reveals that rapidly dropping temperatures can cause thermal stress strong enough to rupture the ice-soil surface, leading to the cracks we see after glacial earthquakes.
In 2016, the city of Oulu in Finland experienced a series of glacial earthquakes. A total of 26 matches took place in the subarctic environment within 7 hours. The earthquakes broke the soil, destroying the foundations of many buildings and roads. Using the model, the researchers were able to calculate that this series of earthquakes was the result of a 17-degree Celsius drop in temperatures, which cracked frozen soil and curbs.
Understanding the tolerances of different substrates could allow researchers to predict which regions are vulnerable to glacial earthquakes, especially when temperatures fluctuate dramatically in the future.