Monster or Monster Wave?
Both Lake Champlain in North America and Loch
Ness in Scotland have been the location of many sightings
of what appears to be a strange underwater creature. While some
cryptozoologists think they may be surviving plesiosaurs from
the age of the dinosaurs, a group of physicists believe the sightings
at these lakes may be of something else entirely.
Both Loch Ness and Champlain are unusually long,
deep and narrow bodies of water compared to other lakes. Cryptozoologists
have used this to support their theories that these bodies of
water are the homes of monsters. A deep lake gives a mysterious
creature a place to hide, right? Both Loch Ness and Champlain
also have a deep layer of cold water, called the hypolimnion,
under a layer of warm water, called the epilimnion. Perhaps
these characteristics, suggest supporters of the lake monster
theory, are needed for the creature's survival.
The long, deep and layered nature of these two lakes
also make them susceptible to another strange phenomenon. A wave
called a seiche.
A seiche is a standing wave in an enclosed body
of water, such as a lake. The term "standing wave" means
that the wave goes back and forth between two fixed boundaries.
You can observe a standing wave whenever you watch a guitar string
being plucked. The wave goes back and forth from one fixed point
on the guitar string to another.
the case of Loch Ness and Champlain, the fixed points are the
farthest ends of the lakes. The wave moves back and forth between
them. To picture what is happening in the lakes, imagine what
goes on when you sit at one end of a bathtub and suddenly get
up. The water your body displaced at one end of the tub comes
rushing in to fill the void. As the wave hits the end of the tub,
it turns around and heads back to where it originated. This wave
goes sloshing back and forth in the tub many times before it loses
energy and levels out. By standing up, you have created a seiche
in your tub.
The same kind of wave occurs in the lakes. In the
case of Lake Champlain, the wave may be from 30 feet to 300 feet
high! Why does nobody notice a wave that high in the lake? Because
the wave doesn't happen on the surface, but underwater. This huge
wave moves along the boundary between the warm water layer and
the cold water layer.
The warm and cold layers of these lakes do not usually
mix. The boundary is very much like the boundary between the surface
of the lake and the air above it. In the same way the waves we
usually see move along the water-air boundary, the giant seiche
wave moves along the warm water-cold water boundary. A giant 300-foot
wave might be roaring along underneath the water, while the surface
is smooth and placid.
What starts these waves? Scientists think that prevailing
winds running the length of the lake can cause a build-up of the
epilimnion (warm water) at the end forcing the hypolimnion (cold
water) to the opposite end. When the wind stops, the warm water
on the surface starts flowing back to its regular position. This
is very much like getting out of the bathtub in our example. The
cold water layer then suddenly rushes back to the end the warm
water vacated. This giant, powerful wave of water then bounces
back and forth between the ends of the lake to make a seiche.
It can take 4 days for the wave to go the entire 60-mile length
of the main part of Lake Champlain.
What does this have to do with lake monsters? Skeptics
of the Champlain and Loch Ness monsters argue that this powerful,
but unseen wave, throws stuff laying around on the bottom of the
lake up to the surface. This might make an old log appear to jump
out of the water or move across the surface. An moving log could
resemble a living creature from a distance. Skeptics also point
out that most sightings of the Lake Champlain monster occur during
the summer. While some of that may be the result of more tourists
at the lake which increases the chance of somebody observing the
creature, it is also the time of year when the seiches are most
likely to occur.
So far nobody has been able to prove that the water
monsters in these lakes are giant waves. Either way it is safe
to say that something big lies under the surface at both Loch
Ness and Lake Champlain.
Copyright Lee Krystek, 2000. All