- #1
DaveC426913
Gold Member
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Full disclosure: it's not tidal; I'm pretty sure it's a longitudinal harmonic wave - but I don't know the terminology.
So today my bro and I went for a sail to Centre Island in Lake Ontario, as we often do. Lake Ontario is currently at its highest level in a long time - certainly in my lifetime. We go to Long Pond - an area of the islands that is 1.33km long and 100m wide and about 20ft depth - it's often used from dragon boat racing.
Where we usually pull up to the wall is currently awash. When we stepped out to tie off, we were standing in two inches of water - the tie-off cleats were submerged. We grabbed some food at the village to eat on the boat.
When we got back to the boat, we were standing on dry land. The water level had dropped by 5 inches. So I took a pic. A half hour later the wall was once again submerged. I watched it carefully, taking pictures every few minutes, and indeed the water level crept back down again.
At first I assumed it was wind surge - assuming the wind was changing direction and pushing the water up then down at this end of the pond, but since the wind was very light and didn't really change direction, yet the water level rose and fell with regularity, I've since concluded that this is a harmonic wave running back and forth along the pond.
I've read about this before - very long, very narrow lakes have this phenomenon - Lake Champlain has one, Loch Ness has one.
I'm now curious if there is a correlation between the dimensions of the body of water and its harmonic wave.
I made a thing:
So today my bro and I went for a sail to Centre Island in Lake Ontario, as we often do. Lake Ontario is currently at its highest level in a long time - certainly in my lifetime. We go to Long Pond - an area of the islands that is 1.33km long and 100m wide and about 20ft depth - it's often used from dragon boat racing.
Where we usually pull up to the wall is currently awash. When we stepped out to tie off, we were standing in two inches of water - the tie-off cleats were submerged. We grabbed some food at the village to eat on the boat.
When we got back to the boat, we were standing on dry land. The water level had dropped by 5 inches. So I took a pic. A half hour later the wall was once again submerged. I watched it carefully, taking pictures every few minutes, and indeed the water level crept back down again.
At first I assumed it was wind surge - assuming the wind was changing direction and pushing the water up then down at this end of the pond, but since the wind was very light and didn't really change direction, yet the water level rose and fell with regularity, I've since concluded that this is a harmonic wave running back and forth along the pond.
I've read about this before - very long, very narrow lakes have this phenomenon - Lake Champlain has one, Loch Ness has one.
I'm now curious if there is a correlation between the dimensions of the body of water and its harmonic wave.
I made a thing: