Another conflicting theory......

[5bass]

craw's thread about conflicting theories got me thinking.....

How many of you believe that rocks heat up when in direct sunlight and hold heat? I always hear people talking about it and personally,I believe the rock/heat thought process.However,I have also read that rocks do not heat up nor hold heat when underwater......

......so which is it?

[Hawg_Hunter]

I think the rocks warm and hold heat  

Darrin

[KU_Bassmaster.]

What about docks??? .................. They warm up and hold heat during the fall, but provide cool shade in the summer?????  Huh?????

[SneakySnook]

Well I know that in saltwater fish hold close to the rocks in the winter to warm up. In the winter most of my fishing is around the rocks so I would have to say that it would be the same for bass also.

[Hillbilly_Hooker]

I've also always heard, and I also believe, that any exposed rock, in direct sunlight, will heat up and will hold heat.  I would think that, to a certain level, heat within the rock would transfer to other parts of the rock that are under water.  Beyond a few inches, though, I would think that the part of the rock underwater would remain roughly the same temperature as the water.  Any geologists want to tell us the truth?   :-?

[RoLo]

It's physics, there is no doubt that rocks absorb heat and transfer their heat to water.

The principle of solar homes is based on that identical principle.

So called "trombe walls" are masonry walls that store the sun's energy to heat the home.

Roger

[Nick_Barr]

direct Light waves get absorbed by dark objects and than hold that radiated heat/energy, then dispersing it. I am thinking that to the extent of how deep and how long rock is exposed to sunlight determines wether they hold an extensive amount heat or not, Therefore drawing fish to warmer water.

[roadwarrior]

What about docks??? .................. They warm up and hold heat during the fall, but provide cool shade in the summer????? Huh?????

If you pour hot liquids into a thermos, the thermos keeps them hot.

If you pour cold liquids into a thermos, the thermos keeps them cold.

How do it know?

[Matt Fly]

I have heard and read that my self a few times.     Although alot of my winter fishing is around bridge pilings, its because of the baitfish that gather around them in the winter.

I have always felt that bridge pilings have alot of steel and in winter, the steel transfers cold just as easy as it would heat.      I love rock piles, rip around rocks on the dams.

Is there a way I could rig a test for a swimming pool and thermometer to monitor warming trends and how pieces of concrete warm up?

One thing we do know, if it asorbs heat, it will warm up some at least around the surface, but how deep does that heat transfer to?

I like these theoretical questions, makes for nice discussions.

Matt.

[Valascus]

Rocks definately hold heat and act as nature's little furnace for the fish. Heck when we get a few "warmer", sunny days in the winter time, one of the first places I hit is the rocks...usually with some measure of success.

[Siebert Outdoors]

This is a density question.  A rock is denser then the water so yes it will hold heat longer.  On the flip side it takes longer to warm.

Same with air and water.  

You also have to inclued color  a darker object will warm up more/faster then a lighter color.  Thats why I wear darker colors in the winter and lighter colors in the summer.

For example  This is why snow melts off the black top driveway before a concrete one.

[FIN-S-R]

Rock and water temperature change is all an issue of specific heat, physical material phase and density. For instance, have you ever built a campfire w/ rock around it. The rock will stay warm long after the fire has burned out and the surrounding area has cooled. This is because of the higher density of the rock in comparison to the material around it.

So more dense=holds heat longer or holds more heat.

Rocks in general have a bulk density, or just density for simplicty sake, of around 2.0 g/cm3 or greater. Water has a density of around 1.0 g/cm3. So in general a denser substance will be exerting stored energy (in the form of heat) to a less dense substance (which will be absorbing the energy) if the two are in direct contact.

Now to further complicate the situation, you have to consider physical phase of matter and specific heat. These two factors relate directly back to the density issue.

Water has the second highest specific heat (energy required to raise the temperature of a given amount of a sustance) of any common liquid. This is to say that water needs lots of energy input to raise the temperature.

When dealing with matter in the liquid state, much heat energy will be diverted from "heating" into changing bond structures. In the case of water hydrogen bonds start getting "bent" in route to the water becoming a gas (steam). This bond movement absorbs energy that would be otherwise used for "heating"

In the case of a solid material (rock), the more static structure of the material allows for less bond movement and more efficient "heating", but not always quicker "heating".

The last piece of this puzzle has to do with energy absorbsion from light energy (ie. sun)

Rocks are generally "darker" than the surrounding water meaning they absorb multiple wavelengths of light and convert it to heat energy, then this energy is translated to the water.

This the case for both rocks at the shore line as well as dark colored rocks under the surface.

For the guy who wanted to do an experiment, try this, put a glass of water in the fridge after taking the temp. After 5min in the fridge take the temp again. Then put a new glass of water into a warmed water bath at a constant low warming temp on the stove, or set it on a heating pad. The heat SOURCE doesnt matter as much as the fact that the temp must be CONSTANT and not extreme. Take the temp of the water before and 5min after exposing to the heating source. You should see that the water will drop further than it will rise in a 5 min period. It helps if you make sure the temps of the warm and cold places are about equidistant from the ambient temp of the water. Also the best results can be achieved if both the cold and hot exposures are done to the glass in water baths of the desired raised and lowered temps to get full surface exposure.

[5bass]

FIN S R,thats deep man.....my brain got a little scrambled in paragraph 2 but I was able to regroup.  ;D

So,in short,you are saying that rocks will absorb and retain heat but to warm the water around the rock,it will take a good bit of time.

[bassnleo]

I always assumed that the sun heated the rock then the heat was transferred to surrounding water through conduction.

FIN-S-R, I agree, that's deep....but it makes sense.

[Guest avid]

I think that a rock near a dock is chock full of bass.

[Chris]

Docks are the same situation just because the top or exposed potion of the dock is hot it is not enough surface area to raise the temp of the water volume under it. Fish do use docks for the shade but not because the temp is cooler than the surrounding water. They use the dock for the shade to give the bass cover or an edge over baitfish. If you are sitting in a dark room it is easy to see out into a lite room. If you are sitting in a lite room it is harder to look into the dark room and see things inside it with great detail. Bass hang around rocks in cooler water because it has crawfish, and other baitfish that use it. Most of the vegetation is gone and baitfish tend to gravitate to hard cover and structure.

[5bass]

I think that a rock near a dock is chock full of bass.

.....but is that rock by that dock warming the water?  :-?