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25

Found an answer by Minnesota's Department of Natural Resources. For new, clear ice, 4 inches should be good for ice skating or any activity involving just a person's weight. They recommend double that thickness (8 inches) for white ice which has about half the strength.


20

It's "foam line" (though I believe there are other names) It occurs when there are surfactants in water, which is then agitated, resulting in foam forming. This foam then tends to clump together and collect debris along the way. It happens naturally, especially in fast-flowing rivers or larger lakes in boggy areas. It can also be caused by pollution - ...


17

First of all, if the wind suddenly starts blowing, realize that this is a case of bad planning. You should never find yourself in the middle of an open lake when the weather patterns may lead to powerful winds. But it's too late now, and you have to make a decision where to paddle to. (This answer focuses on longer type kayaks (5m), because I've never used ...


12

Those are just aquatic plants, not algae, and you'll find them in any healthy lake anywhere in the world. They pose no danger to you. No, you won't get tangled in them and drown. People swim through stuff like that all the time. And I really can't imagine what might be lurking in a lake in France that should concern you.


12

For the specific question of drifting on the Great Lakes, doing so is effectively suicide. First, there's the matter of traffic. The Great Lakes are a major shipping lane, with upwards of a hundred lake freighters, numerous ocean-going freighters, barge traffic, and other ships traveling at all times -- not counting small private vessels. There's a very ...


11

As gerrit notes, swimming in lakes is common in Scandinavia, and there's not a lot of fauna in them that could even potentially be harmful. Some lakes in southern Sweden apparently do have leeches, which can attach themselves to exposed human skin or, in some cases, to the insides of body cavities. If you were planning to swim in a leech-infested lake (a ...


10

What constitutes “best and easiest?” I suspect you don’t want to pay for a proper boat lift to drive down to the beach and pick up the boat. If feasible that would be the best safety wise and easiest in terms of physical effort. I once watched a crew of Peruvian fishermen pull a beached fishing trawler all the way onto the shore. Like you suggested in your ...


10

It's similar to sea foam; nothing to worry about. This usually results from the build up of broken down organic matter that has dissolved in the water and foamed up due to turbulence (i.e. wind/waves, tides, ect.). For example, breakdown of organic material including microscopic critters, like algae, yields proteins that can foam up when agitated - kind of ...


10

I was always taught that it is best when possible to "three quarter" the waves, whether your intended direction of travel is up or down wind -- either way this avoids most splashing, and the boat will float over surprisingly large waves. It also allows you better control, as the wave is less likely to "catch up" to your forward speed and broach you, as it ...


10

Conditions in which you can handle the boat depend on the style of boat and the paddler The range of what defines a "covered cockpit kayak" includes play boats from under 2 meters to over 5 meter touring and racing boats. A considerably greater variety than "open canoe" covers. Paddlers range from total novices to the highly experienced or internationally ...


9

Looks very similar to a bird nesting facility I've seen before in nature reserves. Purpose: allow for safe nesting for (probably a specific, possible endangered, species of) birds. Safe, because it is not attached to the land so some predators won't be able to reach it. Not sure if there is an official name for it. Also I've seen similar looking devices ...


9

The topics of navigation and cartography are two sides of the same coin, and there are entire books written about each. It is interesting to study the history of cartography because it very graphically shows the corresponding improvements in navigation over time. In order to make an accurate map, you need to know first where you are making your ...


8

Swimming is a popular summer pas-time in Sweden and Finland. In rural areas, it's still common for schools to have swimming lessons outside, in lakes. I'm pretty sure there's no risk from fauna in Swedish lakes. If you go too far north, you could risk hypothermia ;).


8

Oh there are lots of fish in there. I grew up only 70km from the glacier that feeds the Elk River, and I've spent a lot of time up at the lakes just below the glacier. In the winter, the water is crystal clear, the clearest I've ever seen in my life. After spring run off however the water turns grey with all the limestone rock flour from the mountains, and ...


8

Just thought to expand the topic a little more. What is pictured in Sue's question is floating nest for birds. There are a number of birds that prefer the safety of raising their young away from the shore because of predators. Ideally they are not attached to land and are anchored in order to keep it that way. Although floating nest platforms are accessible ...


8

In all of these cases it's because they are Endorheic, which is a fancy way of saying that they have inputs but no outputs. The salt that is carried down by the precipitation is trapped in the lake with no where to go and so over time, the lakes become saline. Endorheic lakes are usually in the interior of a landmass, far from an ocean in areas of ...


8

This is a dragonfly. Damselflies place their wings alongside their body when resting. Dragonflies can not do this, once they had their first flight after hatching. So when you see their wings pointing to their back, it's a damselfly or maybe a freshly hatched dragonfly (in these cases you can tell the difference by the cocoon, or just wait to see the wing ...


8

Conditions that can lead to clear ice such as this are: Water with few impurities causing less scattering of light: This lake does not have any water flowing into it, therefore rain is the only source of water Freeze the water slowly so that impurities and air bubbles can rise to the surface, and in the case of air, escape. The area of the lake in the video ...


7

Its just the result of pressure on the ice pushing the slabs up like that. It could also have been a solid non melting object underneath like a rock, but I can't see one in the picture. Ice will do all sorts weird things under pressure like pressure ridges or ice shove/heaves or spring tectonic cracks. Since its melting, it would seem that the pressure ...


6

According to the National Oceanic and Atmospheric Administration The water levels of the Great Lakes fluctuate at different time scales to different forces. Very short-term water level changes, viewable in the interactive charts above, are caused by wind and storms. These short-term (hours to days) effects can be dramatic, and can cause the lake levels ...


6

It looks like it will depend on the beach, some beaches have restrictions on where you can launch, some don't and some do not allow kayaks or paddles sports. It would probably be easiest to ask the park department which beaches allow kayaks or you could go through the list and see if a particular beach allows it.


5

I used to have a marine (reef) aquarium. One part of filtration is called a foam fractionator. By blowing fine bubbles in a thin column, you produce a great deal of surface area where air and water touch at an interface. This affects the entire volume of water in the cup so stuff in the water can’t circulate away or avoid the (normal) surface. Thus the ...


5

To me it looks like the first bit or a small version of what we call in Dutch 'kruiend ijs' (stacked drift ice). The corresponding English Wikipedia page is 'Ice Shove' which seems the result rather than the action. This happens when there is a big surface of ice which gets broken up in strong winds. If the wind is from the same direction for a while, the ...


5

The most likely cause of death would be a crash landing. When geese come in for a landing after a long flight they are exhausted and look for lakes or ponds to land on because they can glide in onto the water and come to an easy stop without much effort. For geese to land on solid ground they have to slow their speed significantly and flap a bunch before ...


5

There are a lot of factors to consider in a situation like this, so there will never be only one best answer but: In this case you have 3 issues, wind, waves, and distance. Wind Wind usually causes more problems than waves. Most canoes will tend to turn broadside to the wind if left to their own devices so your paddling will have to correct for this in ...


5

As said elsewhere “It depends”—-on the paddler’s fitness and skill, the geography of the lake, and whether the equipment (boat and clothing) make capsizing inconvenient or dangerous. Generally speaking, paddling into the wind and waves requires greater fitness and less skill (you must maintain a pace and minimze rests to make headway, but it is easy to keep ...


5

Those look like Wood Frog eggs. You would expect to find Wood Frogs breeding in ponds, vernal pools, and marsh edges in or near forested habitat at a wide range of elevations as soon as the snow melts and the ground thaws. A typical egg mass can have between 500 and 2000 eggs. The embryos start out black on top and white on the bottom, as do most open-...


4

You can indeed get sick from swimming in algae, if the algae is a bloom. Not all algae in lakes is harmful - in fact, it shows that the lake's ecosystem is alive. But too much algae can be dangerous, as it deprives the water of oxygen, and introduces harmful bacteria. Here is a warning from New York State: Harmful Algal Blooms (HABs) FAQs And another ...


4

Rock flour does not seem to be much of an impediment for fish living in rock flour alpine lakes. Lake Louise for example is known as the Lake of the Little Fishes: Lake Louise, named Lake of the Little Fishes by the Stoney Nakota First Nations people, is a glacial lake within Banff National Park in Alberta, Canada. It is located 5 km (3.1 mi) west of the ...


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