Icequakes: More than your regular frigid earthquakes

What comes to your mind when you think of Antarctica? This remote continent of the Southern Hemisphere with harsh climate conditions makes you think of icebergs, penguins, polar sunsets, whales and sunsets, isn’t it? But what we can’t imagine is an icequake while thinking of Antarctica. Well, these quakes that occur in the continent can be quite similar to the earthquakes that we face. Also, they are measured using seismographs like earthquakes. But they are not the same for sure. If you are thinking that icequakes are earthquakes that occur in icy regions, that isn’t really the case. Read on to know more about this geographical phenomenon.  

How are icequakes caused? 
Both earthquake and icequake make the ground shake. However, there’s a huge difference in their causes. As most of you know, earthquakes are caused when tectonic plates below the Earth’s crust are disturbed from their usual movements, collide with one another and often break or slip, releasing enormous bursts of energy causing the ground below us to shake. But icequakes have nothing to do with tectonic plates and more to do with ice itself. As it turns out, in frigid areas like the Arctic or the Antarctic, the water in the ground often freezes rapidly. And we all know what happens when water freezes, don’t we? Yes, that’s right, it expands. As it happens, at times it expands too much, breaking up the soil and rocks surrounding it. This in turn results in cracks on the ground, that scientists refer to as icequakes.  

But this isn’t the only cause behind icequakes. Turns out, at times large masses of ice breaks up due to massive rate of contraction. This too leads in a concussion of the ground. Interestingly, icequake also has two other nicknames, frost quakes and cryoseisms.  

Antarctica: The land of icequakes 
For those unaware, Antarctica is now deemed as the land of icequakes as it had experienced quite a few of them in the past few years. Okay, why is the coldest continent on earth having so many earthquakes? Is it because of the severely low temperatures? Turns out, it’s just the opposite. Thanks to global warming, the temperatures are now on the rise. This means that the ice is melting quicker than usual. Now, when this ice melts, it turns into slush. Before we go any further, here’s something else you should know: Most icequakes are recorded at night time.  

Now, let’s go back to where we were. At times, when temperatures drop more than the day at night, the top layer of the slush freezes too quickly. The water below this slushy surface needs more time to freeze, and when it does, it expands, as expected. You can guess what happens next, can’t you? Yes, it causes the slush to crack, triggering an icequake. Since temperature fluctuations are now more frequent than usual, Antarctica experiences more frequent icequakes. Interestingly, even though the ground shakes, it is often missed by humans. Instead, they realise it’s an icequake by hearing a loud pop or boom.  

In case you are wondering whether Antarctica is the only place where icequakes occur, no it isn’t. It occurs in most frigid regions, especially near glaciers, such as Greenland, Canada and even midwestern and north eastern parts of the USA.