What causes flood ice?

[Geezle]

While checking out some of the potholes I noticed that some of them had spots that looked like they had been wet. Checked one of them out and there was a thin layer of ice, then slush underneath, then the 'good' () ice was under that.

Last year we had been out there in the end of December and there were still wet spots under the snow even though we were on close to a foot of ice.

So, is this caused by the ice cracking and allowing water to seep up? Spring under the ice? Something else?

Kinda gives a guy the heebie jeebies when you first step on to one of those spots

[CeeZee]

the weight of the snow pushes down on the ice and if a good enuf crack happens, water is forced through the hole on top if the ice. The more snow, the more flood water, the later in the season the more flood water can happen.

as far as i know that is lol

[walking buffalo]

A potential cause of flood water on frozen lakes is an incoming water sources; creek, springs.....

The additional water has to go somewhere.

Here is an explanation of how it can occur, and some safety concerns to watch out for.

http://redoubtreporter.wordpress.com...ion-thickness/

Lakes that have continued inflow of water after an ice cover has formed may have thinner ice cover in areas where groundwater seeps in or where stream water enters. Inflowing water will probably not be as cold as the lake water, so it will rise and possibly melt some of the overlaying ice. Even if the incoming water is colder than 40 C, it will stay on the top of the lake and may still cause some thinning of the overlaying ice. As careful ice skaters have known for a very long time, it is good to avoid those areas where water is still entering a lake.

As water enters and leaves a lake through normal input or drainage patterns, it can have an impact on the ice surface. Imagine a situation where water continues to enter the lake but the shallow outflow is blocked off with ice. The water level will rise imperceptibly and will push up on the ice. Since all lake ice covers have cracks, the rising pressure of extra water underneath can push liquid water through the cracks.

Water leaking through the fissures in the ice is referred to as overflow. When overflow occurs, unfrozen water sits on top of the ice. At times, overflow can be many inches deep. If there is no snow cover, the air will rapidly cool and freeze the newly exposed water. However, a thick snow cover acts as an efficient insulator and keeps the water from contact with the much colder air. Because of this insulating ability of snow cover, lake overflow may remain liquid for weeks at a time.

[CeeZee]

i disagree with that info, ice floats, if you add water the ice will still float, its the weight pushing down from the snow causes the water to come above the ice, why do you get flood water in a dug-out then? There are no creeks in most of them, just ground water from the high water table.

[KegRiver]

You are right CeeZee. The weight of snow is by far the most common cause of flooded ice on small rivers as well as on ponds and lakes, but not the only cause.

Inflow can cause flooding in some cases. Most often not due to pressure forcing water up through the ice but through pressure lifting free floating ice while shore ice remains anchored to the shoreline or when ice is anchored to submerged trees ext. In which case the ice is now below the new water level and thus is flooded. This is the most common type of ice flooding that happens along the lower reaches of the Peace River.
This type of flooding is very distinct as it always forms only where there are submerged objects close to the surface or along shorelines.
Flooding from snow load is also distinct in that it is always deepest in the middle of free floating ice pans. Therefore most common well out from shore.

[Gust]

Some non-fisher friends, wrapping up pipeline work down by McGregor, noticed the 1st ice get covered in snow and witnessed it causing breakage then the wickage of the snow (not sure if that's the word),, then that froze. However, water comes into most ponds and that water does have to go somewhere, seepage up and seepage down. I wish this cold snap was snowless, the ice would be more than perfect. Enviro Canada are calling for lows of zero and highs of 8 for Calgary starting Thursday, so add about 4 more for the Prairies and maybe we can get a snow melt happening that will allow for some good ice making, too much insulation right now. Nothing worse than heated arguements with the nonfishing gf about suitable ice,, 6 inches or better and I can head out.

[BBJTKLE&FISHINGADVENTURES]

ceezee is right , also with the melting and freezing of the snow . Or even with 3 feet of ice stick a group of guys together and its gonna flex that ice in that area causeing flood water . But the weight of the snow has a huge weight bareing on that ice .


On a side note . I cant beleave the amount of guys fishing on 3 inches of ice , makes me shake my head , but yet everyone will want a simpathy case if they end up going thru and drowning . IT hasnt been cold enough or long enough for good sturdy ice . Hell my rain barrel isnt even frozen the the way thru , the first foot the rest wasnt . Be careful out there folks . Invest in a set of ice picks and a long rope .

[walking buffalo]

Originally Posted by CeeZee

i disagree with that info, ice floats, if you add water the ice will still float, its the weight pushing down from the snow causes the water to come above the ice, why do you get flood water in a dug-out then? There are no creeks in most of them, just ground water from the high water table.

The info I posted IS correct.

Sure, flood water can come from snowmelt/runoff. Flood water can also come from underneath the ice, as explained in my earlier post.

Want to prove me wrong? Answer this: Where does flood water come from when it is -20 degrees, there is no runoff or snowmelt.


CZ,

Snow IS ice. Snow cannot increase the weight of the solid layer of H2O ( ice and snow) and push water on top of the ice. Your comment is like saying adding ice on top of ice will force the ice to sink.

The forces that push water on top of ice is Pressure or Compression.

Remember the unique quality of H2O, the ONLY compound that expands in volume in transition from a liquid to a solid. Increased volume in a confined space increases pressure.

Originally Posted by BIGBADJOHN

On a side note . I cant beleave the amount of guys fishing on 3 inches of ice , makes me shake my head , but yet everyone will want a simpathy case if they end up going thru and drowning. Be careful out there folks . Invest in a set of ice picks and a long rope .

BBJ Thanks for saying that. Be safe guys, the early fish is not worth the risk. A couple of the stories here today make me shake my head.

[CeeZee]

i dont know what to say to that, snow isnt ice, you dont see people driving a truck right on top of 3 feet of snow, 3 feet of ice yes. Ice is not a solid piece on a body of water, it cracks, and cracks ALOT! Plus people drill fishing holes, you drive your truck out on early ice, 12" or so and when you drill your whole and park a truck near it it begins to flood.
Snow is heavy, isnt it? Or is shoveling snow like shoveling feathers? It has quite a bit of weight IMO, Sorry if i dont got a fancy report or write up on it, I know enuf to know snow is not ice, and ice on a lake is not one solid peace.

So what is getting compressed?

[KegRiver]

walking buffalo;

I don't have to prove you or anyone else wrong. Ice will do what it does no matter what you or I think.
I know how to stay safe traveling on some of the most dangerous ice there is.
That's all that matters to me. What you think causes flood water makes no difference to me or to the ice.
I offer my knowledge acquired from over 45 years of dealing with flood water on ice, building trails across some of the most flood prone ice in the world and traveling on ice bridges/roads and trails across ice. If you think you more then me, good for you.

[walking buffalo]

Snow is not made of ice? lol..


Nothing heated in my tone here guys, we are talking about the cold stuff. Just trying to pass on some understanding about ice.

CZ, your last post regarding Ice sheets cracking and being formed from multiple pieces or layers is what my first post said.

"So what is getting compressed? " Both the ice and the water underneath.

Keg, nice one. While I would most likely trust your instincts, it doesn't make your explanation correct. Sorry, I don't play the rightous, I know it so there game.

If someone doesn't understand my explanation, that's cool. Safe fishing everyone.

[Gust]

I too worked on two seperate contracts dealing with the effects of ice on sub-sea structures and bridges. Snow does or is heavy, however it is only heavier than the ice when the ice is relatively thin. We built an ice structure on a simulator over 6 months in a very very very large tank, factoring in everything one could imagine ice to be,, I think there`s a Nova documentary on another crew. A physicist I worked alongside had been studying ice for 25 years plus and still had little grasp on immediate freeze and snow. We would frequently break the early ice with snow but at a certain point the ice was strong and the only thing that would break the ice was to add ice atop (this was the key to breaking ice around Beaufort platforms,,, if a sheet is broken away and forced from horizontal to vertical underneath ice it will break the horizontal ice). If you could take a chainsaw to the whole edge of the lake and cut it free, it would come up a bit,, ice is the surface of the lake not an addition to it.

Part of the safety training was to go through the ice and if you can keep this in mind if you are venturing out onto ice that you're unsure of, ,, if you go through, open your legs as quickly as possible, it will stop you from coming up under the ice. Wearing old school snow shoes distributes your weight better, just make sure you can kick them off. Another tip is to keep a good seal around your neck as once the jugular hits the water, you have essentially super primed yourself for hypothermia. Two friends have died going through the ice, one in a vehicle and the other stepping onto an unmarked area where fishermen chainsawed a hole big enough to go through. Be careful.

[Cal]

Originally Posted by walking buffalo

Snow is not made of ice? lol..


Nothing heated in my tone here guys, we are talking about the cold stuff. Just trying to pass on some understanding about ice.

CZ, your last post regarding Ice sheets cracking and being formed from multiple pieces or layers is what my first post said.

"So what is getting compressed? " Both the ice and the water underneath.

Keg, nice one. While I would most likely trust your instincts, it doesn't make your explanation correct. Sorry, I don't play the rightous, I know it so there game.

If someone doesn't understand my explanation, that's cool. Safe fishing everyone.

Snow is responsible for far more ice flooding than creeks flowing in. I'm not sure if I completely understand all your posts but if you are trying to say that snow does not cause flooding you are wrong. If you think that snow needs to melt to cause flooding you are wrong. If you think that creeks flowing in can cause flooding you are probably right but I've hardly ever seen any major ice flooding that was caused by this. Not saying it couldnt happen but I have seen alot of ice flooding in my life and nothing major that I would blame on inflow other than in the late season from runoff. The flooding happens because the weight of the snow pushes the ice below the surface of the water, like ceezee says the water then finds its way on top of the ice through cracks and holes.

[CeeZee]

Originally Posted by Cal

Snow is responsible for far more ice flooding than creeks flowing in. I'm not sure if I completely understand all your posts but if you are trying to say that snow does not cause flooding you are wrong. If you think that snow needs to melt to cause flooding you are wrong. If you think that creeks flowing in can cause flooding you are probably right but I've hardly ever seen any major ice flooding that was caused by this. Not saying it couldnt happen but I have seen alot of ice flooding in my life and nothing major that I would blame on inflow other than in the late season from runoff. The flooding happens because the weight of the snow pushes the ice below the surface of the water, like ceezee says the water then finds its way on top of the ice through cracks and holes.

EXACTLY! Thanks CAL!

[nicemustang]

x3 to ceezee and cal. It's the snow.

[beetlebailey]

Everyone should just have a drink and put some flood ice in it.

[Sundancefisher]

Originally Posted by walking buffalo

The info I posted IS correct.

Sure, flood water can come from snowmelt/runoff. Flood water can also come from underneath the ice, as explained in my earlier post.

Want to prove me wrong? Answer this: Where does flood water come from when it is -20 degrees, there is no runoff or snowmelt.


CZ,

Snow IS ice. Snow cannot increase the weight of the solid layer of H2O ( ice and snow) and push water on top of the ice. Your comment is like saying adding ice on top of ice will force the ice to sink.

The forces that push water on top of ice is Pressure or Compression.

Remember the unique quality of H2O, the ONLY compound that expands in volume in transition from a liquid to a solid. Increased volume in a confined space increases pressure.

.

Ummm... Sorry to say but you are wrong. I see it first hand all the time. Water gets forced to the surface through cracks in the ice from the additional weight of snow on the surface. I have seen first hand that areas with drifting snow...has water on surface... Areas without snow...no water. Even on Lake Sundance this is a pretty clear cut fact. Mass is mass...whether it is a 200 lb fisherman or 200 lbs of snow. Snow as a mass is not affected by bouyancy principles when it is not in water. It is like you say 500 feet of snow on a lake floats on the surface of the ice and does not compress the ice down under it's weight. If you think about it...it just does not compute. Are you just teasing us? Regardless... water only forms on the surface of lakes and ponds under the following principles:

1. Melt...melted snow and ice will pool on the surface until finding a way down through the ice, evaporating or refreezing.

2. Surface runoff and creeks. These can be deflected to the surface of the ice. Generally they refreeze or work their way to a crack.

3. Cracking and water expulsion to the surface under compressive weight. If you sink the ice below the depth of the lake...lake water will flood to reach equilibrium. I have seen this happen with snow, people, and vehicles. Sometimes you can even see that the water after you drill a hole floods over the top. Tip...when really cold...don't park your car there or set up a tent with flaps in the water...ops!

4. Urination and beaverage dumping. Excessive urinating will melt snow and ice and create a puddle.

5. Fires. Fires on the ice will melt snow and ice and create a puddle.

Cheers

Sun

[The Elkster]

Consider this...

100 meters * 100 meters * 0.3 meters deep * 100 kg/m3 (average density of new snow) and you will find that.

A 100 meter square area with a foot of snow cover creates a downward force of 300000 kgs! Thats equivalent to about 100 minivans. If snow is the same depth but compacted or water soaked, as is often the case later in the season, this number could easily triple.

[Sundancefisher]

Originally Posted by The Elkster

Consider this...

100 meters * 100 meters * 0.3 meters deep * 100 kg/m3 (average density of new snow) and you will find that.

A 100 meter square area with a foot of snow cover creates a downward force of 300000 kgs! Thats equivalent to about 100 minivans. If snow is the same depth but compacted or water soaked, as is often the case later in the season, this number could easily triple.

I know how much snow weighs...cause I have shoveled enough of it this winter....

[Geezle]

Wow, lots of good info here, and a nice healthy (no mudslinging) debate. Thanks guys

[Kim473]

Its the weight of the snow and people, thats one reason you never drive real close to shore buy weed banks. The snow drifts in there and more weight and insulation to keep the water not frozen.

[Kim473]

Ice it self also, the water will freeze then try to sink somewhat. An ice burg, you only see 1/3 above the water. The water will freeze then sink some and displace the water under itself thus forcing water up above it self. Like in a glass when you drop a ice cube in, the water level goes up.

[walking buffalo]

Originally Posted by Kim473

Ice it self also, the water will freeze then try to sink somewhat. An ice burg, you only see 1/3 above the water. The water will freeze then sink some and displace the water under itself thus forcing water up above it self. Like in a glass when you drop a ice cube in, the water level goes up.

Ta Daaaa!!!


Compression and dispalcement.

[Sundancefisher]

Originally Posted by Kim473

Ice it self also, the water will freeze then try to sink somewhat. An ice burg, you only see 1/3 above the water. The water will freeze then sink some and displace the water under itself thus forcing water up above it self. Like in a glass when you drop a ice cube in, the water level goes up.

Not sure what you are trying to articulate and argue. Talking icebergs versus lake ice in the context of surface water is not clear.

Ice forms within the surface of the water column. If there is displacement...ice will be pushed up under constant bouyance forces causing cracking but no water to surface. No one is disputing that if you dropped 1000 square feet of iceberg in a lake that the volume displaced would not elevate the lake level. However your ice growth displacement theory causing surface water expulsion is not so clear cut. Firstly...lake surface ice is not fixed and immovable. Secondly, even on a pothole lake you get ice heaves and cracking versus an immobile shield repressing water movement.

If your theory held true regarding the uniform nature of ice compressing water upwards...then the hypothesis is proved wrong when you walk out on a lake with open ice in one area and snow drifts in another and see that only the holes drilled in amongst the drifts shows water upwelling to surface...versus nearby holes with no surface snow demonstrates water levels below the top of the ice. The fact is you get varying water levels in ice fishing holes based upon how much surface snow their is. In your hypothesis...you require uniformity. That does not happen...therefore your hypothesis is proved false.

Sorry :-( Still makes for an interesting though topic.

Cheers

Sun

[freeones]

Wow, this thread is a head scratcher. I'm not sure how something so simple and obvious can turn into a 20+ post thread lol.

[The Fisherman Guy]

My contribution to this thread is this.

When the temperature of water dips below zero degrees Celsius, it changes states from a liquid to a solid.

Snow is ice. With assistance from air resistance the water takes on a solid state with each it's own individual shape, as we know it - snow.

Before you throw hail at this; Hail is caused by updrafts which, if strong enough will continue to cycle the hail up and down within a storm cell. With each rise and fall, and dependant on the ambient moisture, the hail grows in size before it overcomes the force of the updrafts and falls to Earth.

Now.

What weighs more? A 10lb bag of feathers, or a 10lb bag of hammers?

Water in a solid state floats. That would include snow, as it is solid water because water in a solid state is less dense than when it is a liquid.

SO! It does not matter how much solid water accumulations there are above the liquid water level, it will continue to float above the liquid level.

"pressure lifting free floating ice while shore ice remains anchored to the shoreline or when ice is anchored to submerged trees"

This is as close to a simple accurate answer as you are likely to get. Without bringing in the unmitigated opinion of a topic that is brimming with intelligence.

I didn't realize a degree in biology also entitled some to the belief that they are absolutely correct in what they believe based on a case study of a greasy, closed system, man made lake.

[Redfrog]

"
What weighs more? A 10lb bag of feathers, or a 10lb bag of hammers? "

This is a trick question.

They both weigh the same. BUT which would you want to get hit with when you were on flood ice?

[Sundancefisher]

Originally Posted by Redfrog

"
What weighs more? A 10lb bag of feathers, or a 10lb bag of hammers? "

This is a trick question.

They both weigh the same. BUT which would you want to get hit with when you were on flood ice?

lol

[freeones]

Originally Posted by The Fisherman Guy

My contribution to this thread is this.

When the temperature of water dips below zero degrees Celsius, it changes states from a liquid to a solid.

Snow is ice. With assistance from air resistance the water takes on a solid state with each it's own individual shape, as we know it - snow.

Before you throw hail at this; Hail is caused by updrafts which, if strong enough will continue to cycle the hail up and down within a storm cell. With each rise and fall, and dependant on the ambient moisture, the hail grows in size before it overcomes the force of the updrafts and falls to Earth.

Now.

What weighs more? A 10lb bag of feathers, or a 10lb bag of hammers?

Water in a solid state floats. That would include snow, as it is solid water because water in a solid state is less dense than when it is a liquid.

SO! It does not matter how much solid water accumulations there are above the liquid water level, it will continue to float above the liquid level.

This is as close to a simple accurate answer as you are likely to get. Without bringing in the unmitigated opinion of a topic that is brimming with intelligence.

I didn't realize a degree in biology also entitled some to the belief that they are absolutely correct in what they believe based on a case study of a greasy, closed system, man made lake.

Wow. I can only shake my head at this, especially given the arrogance of it.

Our high school physics teachers are failing us.

[Sundancefisher]

Originally Posted by The Fisherman Guy

My contribution to this thread is this.

When the temperature of water dips below zero degrees Celsius, it changes states from a liquid to a solid.

Snow is ice. With assistance from air resistance the water takes on a solid state with each it's own individual shape, as we know it - snow.

Before you throw hail at this; Hail is caused by updrafts which, if strong enough will continue to cycle the hail up and down within a storm cell. With each rise and fall, and dependant on the ambient moisture, the hail grows in size before it overcomes the force of the updrafts and falls to Earth.

Now.

What weighs more? A 10lb bag of feathers, or a 10lb bag of hammers?

Water in a solid state floats. That would include snow, as it is solid water because water in a solid state is less dense than when it is a liquid.

SO! It does not matter how much solid water accumulations there are above the liquid water level, it will continue to float above the liquid level.



This is as close to a simple accurate answer as you are likely to get. Without bringing in the unmitigated opinion of a topic that is brimming with intelligence.

I didn't realize a degree in biology also entitled some to the belief that they are absolutely correct in what they believe based on a case study of a greasy, closed system, man made lake.

Sorry about offending you with the discussion. I found the topic fun as you can easily see how one can postulate either option.

Still if it makes you feel any better...I have seen the same thing on McGregor, Lac St. Anne, Pigeon, Wabamun, South Buck, Gull, Hasse and Lac La Nonne to name a few. The pothole lakes referred to at the first post is most indicative of a man made lake. Neither has inflow/outflow streams normally.

As alluded to before...I actually parked to close one winter on Lac St Anne and was almost frozen in over night. I was catching a ton of whites and when I opened my tent there was a dozen cars around me. Everyone thought I had the honey hole. It was so cold...but in the tent I was oblivious. After chipping out my tent and auger... I started the car and went no wheres fast. Used a large screw driver to chip enough away to get up on the ice.

Cheers

Sun