If dealing with temperatures plummeting to minus 32C overnight wasn’t bad enough, the frozen residents of Chicago received a shock when the city was afflicted by a “frost quake”.
A series of loud booms across the US’ third largest city, which led some people to think their houses were falling apart, has been put down to the frost quake phenomena — more scientifically known as cryoseism.
The ground beneath people’s feet was quite literally ripping apart.
Tourists, unused to the cold, have spoken of how it felt like their eyeballs were freezing, while police have pleaded with criminals to take a break from committing crimes.
Transport chaos has seen trains, planes and a fair few automobiles come to a standstill with railway tracks set on fire to stop them cracking in the cold.
The deaths of 12 people have now been linked to the huge lick of Arctic air that has swept into southern Canada, the Midwestern and north eastern United States.
The bitter cold has been caused by a displacement of the polar vortex, a stream of air that normally spins around the stratosphere over the North Pole but whose current has been disrupted and is now pushing south.
Some people have perished when becoming trapped outside for relatively short periods of time. In Illinois, an 82-year-old man died from cold exposure when he slipped just outside his front door. A 38-year-old woman who died in her apartment may have had a malfunctioning thermostat.
A mum in Kansas was arrested when she allegedly left her two toddlers in a car with no heat. Temperatures in the area plummeted to -21C.
Previously, authorities said it was dangerous to leave shelter and if people were out they shouldn’t breathe too deeply for fear of frozen air reaching their lungs.
The town of Mount Carroll, 200 kilometres west of Chicago, recorded an unofficial overnight low of -39C on Thursday.
On Thursday morning at 8am the commute in Minneapolis was a bracing -31C.
The polar vortex is not done yet. It’s Thursday across the states and icy blasts are still on the cards.
This could lead to more of the “frost quakes” that have been plaguing Chicago and worrying residents.
“Heard two loud booms last night, thought my house was falling apart,” said Melissa Eckhardt on the Facebook page of WGN-TV.
“I thought I was crazy!” said Chastity Clark Baker. “I was up all night because I kept hearing it. I was scared and thought it was the furnace. I had everyone’s jackets on the table in case we had to run out of here.”
Others thought birds were attacking roofs or that thieves were breaking in.
In fact, what people heard was a seismic event called cryoseism caused by the expansion of frozen soil and rock.
Heavy snow and rain can saturate the ground. When that’s accompanied by a sudden drop in temperature the moisture freezes which leads it to expand and suddenly crack and break causing the booms and even earthquake-like shaking.
Talking to USA Today, Ball State University meteorologist Dave Call said to think of a bottle of liquid in a freezer, expanding and exploding.
“It’s more of a noise phenomenon, like a balloon popping, than a physical danger,” he said.
However, because frost quakes are so localised and relatively small in nature they are not picked up by seismographs so there is no record of them having occurred.
TRAVEL PLANS ON ICE
More than 8000 flights have been cancelled so far as the brutally cold weather disrupts airport operations, with Chicago’s Midway and O’Hare airports bearing the brunt of the cancellations.
Among the many problems brought by the extreme weather is planes and runways icing over and water sources on planes freezing up, as well as the difficulty of carrying out repairs.
Rail operator Amtrak has cancelled all its trains through the Midwest corridor, making long-distance travel almost impossible in vortex-struck areas.
In an incredible move, Chicago’s train system Metra started lighting the tracks on fire to keep them warm enough for trains to operate.
Snow and ice can clog the points used to keep the train rolling, so the gas-fuelled flames — which technically run alongside the tracks — keep the switch points warm so they don’t get clogged. It’s actually not uncommon for Metra to resort to the practice when the mercury drops below zero.
And while Americans are struggling with the historically low temperatures brought by the Arctic vortex, many visitors to the US have no idea what they’ve walked into.
Irish expat Louise Barry, who is in Chicago, told the Irish Times the weather was so cold it “felt like my eyeballs were freezing”.
“This weather is on a whole other level,” she said. “It’s eerily quiet as everything shut down on Wednesday as the temperatures plummeted. It hit -47C degrees in the morning!
“The cold is unbearable; walking home from work on Tuesday night as the temperatures hit -30C, the only part of my body exposed to the elements was my eyes. I’ve never experienced my eyeballs freezing but that’s exactly what it felt like was happening with the freezing wind.
“The winter weather can be deceptive as we have gorgeous bright blue skies, you wouldn’t think it was as cold. No one will be outside today as frostbite will occur after five minutes on any exposed skin.”
PLEA FOR CRIMS TO STAY HOME
Police have even taken to social media to plead with criminals to take a break during the cold weather.
On Facebook, police in Maryland asked: “Those thinking about doing some crime tonight, It’s really super cold outside and only getting colder.”
Instead, the force suggested crims stay home and binge watch Netflix, read a book with some hot chocolate, or “watch old re-runs of COPS”.
Others have taken to social media to post images and videos of the weird effects the deep freeze is causing.
This includes pasta frozen so solid it can support the weight of a fork, T-shirts becoming petrified in gravity defying positions and hot water instantly turning into frozen smoke the second it hits hot air.
But the polar vortex’s days may be numbered with Thursday expected to be the last day of extreme cold. Temperatures should edge up from Friday. By Monday, Chicago could be on a balmy 10C — almost beach weather.
Atlanta, where the Super Bowl is due to be held, will go from temperatures in the single digits this week to mid-teens next week.
But while eyeballs will unfreeze and criminals will resume normal business, the cost of the polar vortex could be substantial.
Weather website AccuWeather has totted up the final bill of business, schools and museums forced to lose, insurance claims, flooding damage and increased heating costs at almost $AU7 billion.