#mysteryboom — Public Fediverse posts

Rapid deep freeze can lead to frost quakes

It’s been awfully cold in many parts of the US this week. As I tried to ignore the wicked wind outside, I thought, hmm, this is frost quake season. Sure enough, the Chicago area, hit hard by an Arctic air blast, reported frost quakes this week.

Frost quakes cause localized noise and shaking

Most people have never heard of frost quakes (sometimes called cryoseisms, although this normally refers to cracking of lake and sea ice). New scientific observations suggest that populations in regions prone to frigid winter temperatures will experience them more often. So, now is the time to get up to speed on this icy topic of spooky geology.

Frost quakes are one cause for mysterious booms and shaking heard by northern residents who are not used to earthquakes. They are not uncommon in the upper Midwest and New England, from January to March. Caused by the rapid expansion of water (thermal stress) as it freezes underground, the energy from the expansion releases suddenly, creating a cracking or booming sound, breaking rock layers, fracturing roads, and ripping tree roots.

Frost quakes are more likely to occur where the ground is saturated (after heavy rains or having a high groundwater table) and when rapid freezing occurs – when the temperatures drop to far below freezing over 8 hours.

Frost quakes are not deadly

Frost quake events are very localized and short-lived, however, if the explosive expansion happens near homes or structures, there is the chance that the shaking can cause moderate damage similar to small earthquakes. Frost quakes cannot create shaking and damage to the extent that a geologic quake can, but ground fractures and heaves can damage foundations, land surfaces, and roads. Frost tremors, which have more irregular waveforms, are less violent expressions of the stress release.

Lessons from Finland

Finland seems to be particularly susceptible to frost quakes. In January 2023, the Finnish town of Talvikangas experienced 26 frost quakes in 7 hrs, the greatest number recorded so far. A recent study from Finland will soon be published showing that wetlands, swamps, and irrigated areas, will more likely experience frost quakes.

• Frost quakes are a growing problem in Finland and other sub-Arctic countries
• Frost Quakes Shake Up Finland’s Wetlands

Frost quakes are typically associated with lack of snow cover. Snow provides some insulation against the rapid freezing that creates the stress leading to the sudden release. Climate change suggests that greater rainfall and less snow will be the trend in northern areas. The reduction in Arctic ice creates a destabilization of the Jetstream that allows frigid air masses to dip south, resulting in the cold zap like we got this month.

As the Finnish study showed, we would be wise to take frost quakes more seriously, as their occurrences may be increasing. Certain structures (utility lines, roads, water towers, power generating facilities, bridges, etc.) should be evaluated for risk from frost quakes even though they are outside typical fault-related seismic risk zones.

More: History of mystery booms

#arctic #coldWeather #cryoseism #earthquake #frostQuake #mysteryBoom #MysteryBooms #seismic #SpookyGeology #winter

https://sharonahill.com/?p=8376

Mystery boom from December 2023, Council Bluffs, Iowa

An unexplained mystery boom rattled a neighborhood in Council Bluffs, Iowa around 5:20 PM on the night of December 20. The interesting characteristic of this incident is a reflection in a vehicle window. I have a guess at what it was.

If you are a regular reader of my content, you’ll know that I have a fascination for mystery sounds and lights. I published a comprehensive look at Mystery Booms in 2021 on my Spooky Geology site and republished it here. Last year, I took a look at a collection of booms in the news for 2022 and came to some general conclusions about what caused them.

Today, I was curious about this event in Iowa. The explosion occurred in the very early evening, just about when it was getting dark. It made a very big noise. Police were called to investigate and didn’t find anything. There were also no signs of this being a meteor explosion or an electrical line explosion. So what was it?

Home video surveillance cameras have been a huge benefit to attempting to explain these mystery booms because they reveal flashes of light and direction as well as pinpointing the time. Sometimes, multiple recordings can allow triangulation or, at least, identify a general area.

While this latest Council Bluffs incident did not have a camera pointing in the direction of the boom, a big clue was still found in the video as a vehicle was parked facing the explosion, and you can see a rising fireball in the windshield reflection. See the entire video in this news report.

The light very much appears to be an explosion from the ground upward. One witness noted that it sort of looked like a firework but wasn’t.

The road where the camera was located and on which the witness was travelling is a fairly steep hill. There are some wooded areas around and people have decently-sized backyards. Someone blew something up.

From the evidence available, I’m going to guess that this was a directed tannerite explosion that took place on an area at a slightly higher elevation from where the camera and vehicle were located. The exact address of the camera was not given but locals familiar with the neighborhood should be able to get a good idea of where this came from estimating the line of sight from the vehicle location. There might be a good chance whoever did this will try it again.

There are videos all over YouTube about how to create dramatic tannerite explosions by using household products and containers (like a thick-sided wooden box) to direct the flame upwards instead of blowing out at the bottom. I’m going to guess someone was doing this experiment at dusk this Wednesday evening. The explosion would not leave a visible trace unless you inspected the property.

There is no doubt that people are setting off tannerite explosions all over the U.S. You can readily buy the stuff, mix it yourself, and have a blast, so to speak. While this kind of explosion in a residential neighborhood is dangerous and probably against local ordinances, unless your neighbor reports you, anyone playing around with tannerite is likely to get away with it.

If anyone has additional information, please feel free to get in touch.

#CouncilBluffs #explosion #mysteryBoom #tannerite

https://sharonahill.com/?p=7874