and bottom layers are warmer — and less dense.
And voila! The denser, heavier top layer sinks.
Imagine — water sinking! The surface water pushes
downward and displaces the water at the lake’s
bottom. It actually turns over, and the
water becomes mixed. Chad’s father,
quite the fisherman, was even able to
smell when a lake turned over.
Never one to rely on just
one source, I asked another
mega-fishing friend, Bob, to
make the murky clear. (If Bob
isn’t fishing, he’s sleeping — and I
trust his expertise.) Bob confirmed
everything Chad had said and added
a few more points. He explained that it is
good for lakes to turn over. The highly oxygenated
mber
down
he lake,
uspected,
ng was
ss.
water from the surface is forced to the bottom and
supports animal life down below. Also, during the
spring and fall, the three layers are (another word
not in my daily vocabulary) isothermic — of equal or
constant temperature with respect to space, volume,
or pressure. With no variance in any aspect, the
water does what I thought it always does; it just sits
there.
That’s it, dear reader. If you were like me, you
didn’t understand offshore breezes or lake turnover.
So now I ask, “What is it that causes a lake to
recede?” ●
A native of Red Deer, Alberta, Jock Mackenzie
is constantly amazed at how much he doesn’t
know . . . but he still enjoys finding out. Fly fishing
season awaits and even a little knowledge there
doesn’t hurt. The fishing is always good even if the
catching isn’t.
n layer
ine layer
ion layer
news&views SUMMER 2020 | 19