03-09-2023, 03:37 PM
(This post was last modified: 03-09-2023, 04:09 PM by Piscophilic.)
Hi Jeff,
The best description of S1 and S2 I found comes from the same site, but a different article: http://lakeice.squarespace.com/types-of-ice.
The S stands for secondary (ice formed under the initial or primary layer is secondary ice) and the 1 and 2 stand for small versus large grains in the ice. There didn't seem to be a lot of info on how small is small or how large is large.
From my experience with metal deposition in electronics (very pure materials) grains are small pieces of single crystal material in a larger area like a metal or ice layer. If the material cools very quickly formation of small grains occur. Slower cooling results in larger grains.
The triple junction idea comes from a location where 3 grains touch each other at the same point. The higher salt (or other impurity) concentration found at a triple junction comes from the fact that impurities tend to be forced out of a grain as it forms because they disrupt the perfect lattice structure that is the lowest energy state for the solid. At a triple junction the impurity is being pushed to a single location from three directions at once.
From an ice melting standpoint any imperfection in the crystal structure interacts differently with incoming light, usually absorbing it more and thus being heated by it. So a triple junction (or other imperfection) becomes a little hot spot leading to the ice around it melting.
This whole process occurs initially on a microscopic scale, less than millimeter sizes, but leads to the larger things we can easily see. However weakening of the ice can definitely be caused by the microscopic changes. Ice becoming cloudy results in part from the invisible imperfections getting larger and more numerous.
I didn't read far enough to get to something useful to predict ice safety, but knowing the weather history is clearly useful to try to stay safe.
One item I didn't see mentioned, that is likely more prevalent in shallow water bodies is the simple fact the the ground is constantly being heated by the higher temperatures of the earth deeper down. A cold event lowers the surface temperature, but if those low temperatures are not maintained the surface (the ground and the water) will gradually heat from underneath. Nothing stays constant.
I guess this discussion in general is not very clear. It is easier to just say clear ice is better than cloudy and new ice is stronger than old ice.
The best description of S1 and S2 I found comes from the same site, but a different article: http://lakeice.squarespace.com/types-of-ice.
The S stands for secondary (ice formed under the initial or primary layer is secondary ice) and the 1 and 2 stand for small versus large grains in the ice. There didn't seem to be a lot of info on how small is small or how large is large.
From my experience with metal deposition in electronics (very pure materials) grains are small pieces of single crystal material in a larger area like a metal or ice layer. If the material cools very quickly formation of small grains occur. Slower cooling results in larger grains.
The triple junction idea comes from a location where 3 grains touch each other at the same point. The higher salt (or other impurity) concentration found at a triple junction comes from the fact that impurities tend to be forced out of a grain as it forms because they disrupt the perfect lattice structure that is the lowest energy state for the solid. At a triple junction the impurity is being pushed to a single location from three directions at once.
From an ice melting standpoint any imperfection in the crystal structure interacts differently with incoming light, usually absorbing it more and thus being heated by it. So a triple junction (or other imperfection) becomes a little hot spot leading to the ice around it melting.
This whole process occurs initially on a microscopic scale, less than millimeter sizes, but leads to the larger things we can easily see. However weakening of the ice can definitely be caused by the microscopic changes. Ice becoming cloudy results in part from the invisible imperfections getting larger and more numerous.
I didn't read far enough to get to something useful to predict ice safety, but knowing the weather history is clearly useful to try to stay safe.
One item I didn't see mentioned, that is likely more prevalent in shallow water bodies is the simple fact the the ground is constantly being heated by the higher temperatures of the earth deeper down. A cold event lowers the surface temperature, but if those low temperatures are not maintained the surface (the ground and the water) will gradually heat from underneath. Nothing stays constant.
I guess this discussion in general is not very clear. It is easier to just say clear ice is better than cloudy and new ice is stronger than old ice.