This causes tension and compression in the ice sheet, making the ice weaker and resulting in cracking. Dry cracks — as the name suggests; a crack with no water present. Pressure ridges or elastic compression areas — areas where compression forces push sheets of ice together.
Load-induced cracks — caused by a heavy weight applied to the surface of the ice e. Expansion cracks — caused by rapidly warming temperatures.
Contraction cracks — caused by rapidly cooling temperatures. Wind cracks — caused by effects of wind on wet cracks. Water level fluctuation cracks — caused by a rise or drop in water level. Dynamic wave cracks — caused by wave action underneath the ice.
For the most part, many of the cracks we encounter on Lake Windermere will not be dangerous to our safety as we skate, ride, or walk across them. If you notice a pressure ridge or other wide, wet crack while out on the ice, it might be better to avoid that area and go around it if you can. Along the shorelines, ice can sometimes become hollow if the water recedes beneath it — these areas may crack underfoot if the ice is not thick enough to support your weight; but generally, the area underneath the hollow ice will be just dry beach.
As you know, the thinner the ice is the more prone it is to crack under significant weight. Only go out on the ice if you can be sure it is thick enough to support several times your weight. Vehicles are involved in more than half of all ice-related fatalities. When driving a vehicle on the ice, your risks are compounded and the dangers of breaking through the ice, especially at a point where dangerous pressure ridges or circumferential cracks begin to form, increases. Whenever possible, only drive a vehicle on the ice if you absolutely must, and make sure you know the route you will be travelling.
See you next fall! Your email address will not be published. Save my name, email, and site URL in my browser for next time I post a comment. A freshly ploughed Whiteway skating trail, with a pressure crack visible crossing the trail In the last article, we learned how ice grows. Stress causes deformation All cracks in ice are caused by stress in the ice. Deformation causes cracking That tension and compression, when exerted long enough over the right density and thickness of ice, causes the ice to crack in certain ways.
The ice cracked so loudly and the crack veins just so happens to run right through the shack. Yeap, some water and mist came up and newbies were about to jump up and grab the shelter ceiling on that one. Now imagine being on the ice crack ridge. Cracks are ok as long as the ice is thick. On thin ice cracks can be dangerous, we found that out this past weekend. I don't know about you guys, but for me it doesn't matter how cold it is, or how much ice I am on God is great; beer is good, and people are crazy!
Cracking sounds can mean it is making ice, losing ice, or about to break under your feet. Listen to a lake on a cold night, it will be booming! Also on a warm day with the sun beating down on it. It means the ice is shifting, expanding, contracting. Think of it like earthquakes Be careful, especially on big water the cracks can heave and open up wide gaps of open water. Snowmobile launch ramps! Cracks on ice less then 5 inches in your Immediate vicinity are not good!
Crack are nothing compared to a below day when the lake booms like a thunderstorm and a spider web of cracks flash thru the ice under your feet!! That tends to make some Uninitiated go change their Undies!! I have been on ice that sounded like thunder. The more cracking the better. My wife had one crack run into her hole last year and pushed water out of it. Scared the heck out of her. I have a friend that had a crack 3" wide go through his hole while he had a fish on.
The fish found it's way to the crack and next thing he knew he was 20 ft from his hole trying to get the fish back to the hole.
Quote from: lefty on Nov 29, , AM. Time for a short physical chemistry lecture. In most cases this is a linear response unless there is a phase change eg. Water is one of very few substances where this behavior is NOT linear. Water is at its' greatest density at 39 degrees F. This is why the water at the bottom of a frozen lake is always at this temperature.
Water at below 39 degrees is less dense. Since it's less dense than liquid water at 32 degrees it has to expand when it makes the phase change to ice. The expansion creates stress which is relieved when the ice heaves upward, at the shoreline or at pressure cracks. If it's safe enough to be out there, loud ice is always good ice! Wish it would get that way around here!!!! Unexpected loud ice cracking booms, underfoot and all around. What a rush. It is the cracking of the ice surface that makes the interesting noises we have heard.
The sheet of ice on a lake is like a giant membrane that the sound travels across. This also explains why we have heard the most noise from the lake in the morning and evening, as the temperature rises or drops.
Have you ever heard ice making noise? What did it sound like? Dispersion of Sound Waves in Ice Sheets. Save my name, email, and website in this browser for the next time I comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. What is ice? How does ice form on lakes? Leave a Comment Cancel Reply Your email address will not be published. Type here..
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