News Detail
What are lake stars?
You’re looking out over a beautiful frozen lake when you spot a crooked shape with long, gnarled fingers stretching out from it. That’s a lake star. But what is it exactly, and how did it get there? Shawnigan’s Environmental Lead, Patricia Hanbidge explains the origins of these fascinating additions to our winter surroundings.
This being my first experience of all the seasons at Shawnigan, 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 were then blessed with quite a bountiful layer of snow: another first for me as I had never experienced snow on Vancouver Island.
For the following few days, my view from the auxiliary building that adjoins the Growing Dome overlooking Lake Omar was very wintry. 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 definitely octagons or eight-sided shapes, while others were clearly 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. The lake surface reminded me of a rolled-out piece of dough, 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 SLS for the 360 (arts and activities) – Growing Green session. In our 360 group, we are always discussing interesting topics that reflect on 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 that 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 of Harvard University and J.S. Wettlaufer of Yale University 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 for lake stars to occur.
How fascinating to have the opportunity to experience a meteorological Goldilocks situation right here at Shawnigan!
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 is followed by warmer temperatures that 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 temperature conditions exist, there is a gradual melting and water is able to gently flow through the snow. Snow contains pockets of air and, just like water seeps through soil within the soil pores, so 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!
Please click here for more about Shawnigan’s environmental initiatives and experiential learning programs.
For the following few days, my view from the auxiliary building that adjoins the Growing Dome overlooking Lake Omar was very wintry. 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 definitely octagons or eight-sided shapes, while others were clearly 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. The lake surface reminded me of a rolled-out piece of dough, 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 SLS for the 360 (arts and activities) – Growing Green session. In our 360 group, we are always discussing interesting topics that reflect on 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 that 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 of Harvard University and J.S. Wettlaufer of Yale University 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 for lake stars to occur.
How fascinating to have the opportunity to experience a meteorological Goldilocks situation right here at Shawnigan!
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 is followed by warmer temperatures that 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 temperature conditions exist, there is a gradual melting and water is able to gently flow through the snow. Snow contains pockets of air and, just like water seeps through soil within the soil pores, so 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!
Please click here for more about Shawnigan’s environmental initiatives and experiential learning programs.
Patricia Hanbidge is Shawnigan Lake School's Environmental Lead and Horticulturalist. She has worked extensively around the world, helping people develop food sovereignty, enhance food security, and build more sustainable communities.
We acknowledge with respect the Coast Salish Peoples on whose traditional lands and waterways we live, learn and play. We are grateful for the opportunity to share in this beautiful region, and we aspire to healthy and respectful relationships with those who have lived on and cared for these lands for millennia.
Shawnigan Lake School is an independent co-educational boarding school for ages 13 –18 on Canada’s beautiful West Coast. Our diverse, interdisciplinary and innovative programming helps shape the next generation of global leaders.
