Being that this is my first experience of all of the seasons on Vancouver Island, it is with great pleasure that I am seeing all sorts of things that are both new and unique. With the recent blast of cold temperatures, I wondered if I was really on Vancouver Island. Being from Saskatchewan, cold weather is not anything new – but to experience -13 C. in this land of mild temperatures was a bit of a shock. To top off the extreme cold, we then were blessed with quite a bountiful layer of snow. Another first for me as I have never experienced snow on Vancouver Island.
For the following few days, the view from my “office” was very wintery. The axillary building that adjoins the growing dome overlooking Lake Omar is my amazing daily view. I noticed that within a few days, some very weird, but interesting things began happening on the frozen lake. Small holes seemed to magically appear over the entire lake surface. These holes appeared to be geometric shapes with a varying number of sides. Some were octagons or eight-sided shapes while others were pentagons or five-sided. Looking more closely from the slightly elevated view out the window, the shapes were all slightly different but the outside angles of the holes were definitely not what we typically see appear in nature. It came to mind that the lake surface reminded me of a rolled-out piece of cookie dough that had been cut with a multitude of geometrically shaped cookie cutters.
On Monday and Wednesday afternoons, I am joined by some of the most interesting students at Shawnigan Lake School for the 360 – Growing Green. In our 360 club, we are always discussing interesting topics that surround the environment we live in and how fascinating all things green can be. As we were talking, and looking out over Lake Omar, the lake stars made it into our conversation. One of the students asked the typical question of why these weird but interesting holes with the spiky, radiating fingers had formed. This curiosity which is such a necessary step to learning new things got me motivated to try to find the answer to his question.
After quite a bit of digging, I finally unearthed a study done by Victor C. Tsai in March of 2007. It was in this study with pages of mathematical calculations that caused my eyes to cross and my brain to hurt that I understood this amazing phenomenon. Somewhat like the stars that form in our heavens, growing under immense pressure in hot, collapsing clouds, both temperature and precipitation have to be just right.
How fascinating to have the opportunity to experience a meteorological Goldilocks situation right here at Shawnigan Lake School!
Lake stars are born when warm water wells up from beneath a just-right thin layer of ice covered with just the right amount of snow and slush. This is caused by a short but mighty cold snap that quickly freezes the lake water into ice that is an inch or two thick. This cold snap followed by warmer temperatures warm the ice to above 0°C. which softens the ice and makes it a bit leaky.
It is not agreed upon how that initial central hole is formed. It is thought that it could be formed by an animal, a rock or branch splashing into the water, or even convection within the water due to water layers shifting due to temperature changes. The many pages of mathematical calculations, were the result of science trying to develop a mathematical model to explain this natural phenomenon. To date, there is no agreement on exactly why or how the centre hole is formed. However, there is somewhat of a consensus on how the fingers form.
When mimicking this natural formation in a controlled environment, the following conclusions have been reached. We know that heat likes to distribute itself evenly in space, which is the reason behind only a few fingers forming at each central hole. If heat did not distribute itself evenly then there would be many fingers radiating from each central hole. As these perfect humidity and temperatures exist, there is a gradual melting and water can gently flow through the snow. Snow contains pockets of air and just like water seeps through soil within the soil pores, so will water will seep through the pores within the snow. Water will always travel down the easiest path wherever water flows.
Lake stars, like the stars in the sky, are beautiful. What a pleasure it is to view one of winter’s loveliest mysteries.
Hanbidge is the Lead Horticulturist with Orchid Horticulture. Find us at ; by email at [email protected]; on Facebook @orchidhort and Instagram at #orchidhort. Tune into GROW Live on our Facebook page or check out the Youtube channel GROW
