California Surfers in Pacific Ocean
is a about the wave and catching it. Sometimes a
rush hour is created when all the surfers get
into a groove and find the same location optimal
for surfing. There are a few near-collisions,
occasional confrontations and some yelling. It's
about skill, cooperation and courtesy. It
takes a bit of practice and knowledge to surf
properly. If you are learning, you might
consider going to a beginners section of the
water so you don't tick off the professionals
and competitive surfing regulars.
Waves are the movement
of energy through water. The term wave refers to a
series of vibrations, pulses or undulations in the
water or some other medium. A wave is made up of a
top, known as the crest, and a bottom, known as the
trough. The horizontal distance between two
successive crests is defined as the wavelength. The
vertical distance between the crest and the trough
is defined as the wave height.
Surfers in California tend to define wave height in
terms of a person's body length. For example, 4-5
foot waves might be described as shoulder high, 7-8
foot waves as overhead, 10-12 foot waves as
double-overhead. In Hawaii, waves are measured from
the back of the wave, generally underestimating the
wave size and height.
The speed of a wave is how far it moves in a given
amount of time. Small waves tend to move slowly at a
few knots (1 knot equals 1 nautical mile per hour).
Medium-size waves may move at tens of knots; large
waves move 30 - 50 knots and more. Tsunamis, which
are the largest waves of all, can reach speeds up to
The period of a wave provides many important clues
about surf conditions. The wave period is the time
between successive crests. For example, if you stand
on the end of a pier, start your stopwatch when a
wave hits a fixed spot, and stop your stopwatch when
the next wave hits that point, you will have
measured the wave period. Long-period waves tend to
be larger and stronger, while short-period waves are
smaller and less energetic. By measuring the period
of waves, surfers can get an idea of the swell to
come within the next several hours, and determine
whether different swells (waves that originated in
different locations out at sea) are hitting the
beach at the same time. Generally, longer period
waves travel longer distances, have more energy, and
create higher breakers on the shore.
Wave frequency is important to ocean engineers and
architects who construct jetties, piers, and other
man-made objects in or near the ocean. The wave
frequency is defined as the number of waves passing
a fixed point in a given amount of time. Again,
taking a stopwatch, count the number of waves that
pass a fixed point over a 30-second interval. Divide
by 30 and you have the wave frequency, the number of
waves that pass a point every second.
When the wind blows across the surface of the water,
the water begins to ripple. These tiny ripples are
called capillary waves. Factors that affect wave
formation are: 1) wind speed; 2) wind duration, and
3) the fetch, which is defined as the area over
which the wind blows.
The importance of the fetch can be realized when you
consider that the biggest waves don't come from
hurricanes, which have the fastest winds, but from
large storm systems that blow over hundreds,
possibly thousands of miles. Hurricanes are a local
wave generator and will make waves over a small
area, but for the most part, the really big waves
that hit our beaches come from big storms in the
Antarctic or the North Pacific Ocean.
How waves might be
generated far out at sea: prevailing meteorological
conditions during the winter in the northern
hemisphere give rise to vast low pressure systems
that generate lots of wind over vast areas of the
ocean. Typically, these weather systems travel
northwest to southeast, generating ocean swell,
sometimes called groundswell. These winter storms
may generate waves thousands of miles away, yet over
a 24 hour day, a wave can cover 720 miles. Given a
distance of roughly 3000 miles (for the sake of
argument) between the North Pacific Ocean and
Huntington Beach, these newly generated waves might
be crashing on our shores in just over four days.
More times than not, the best surfing in winter
comes from that northwest swell.
What about summer surfing? Remember the big waves
mentioned above? In our summer, winter storms brew
in the southern hemisphere (because our summer is
their winter). Storm systems traveling from
southwest to northeast pack a mighty punch as they
wreak havoc over a much larger ocean area than is
even possible in our paltry northern Pacific Ocean.
Take a look at a world map. More than 60% of the
oceans reside in the southern hemisphere. The
greater extent of the South Pacific Ocean allows
larger fetch and creates even bigger swell than we
find in the northern hemisphere. Thus, south swell
tends to really get things rolling around here (i.e.
the waves tend to be bigger when they come from the
Hurricanes and typhoons don't necessarily generate
the largest waves, though the wind speeds in excess
of 100 knots are possible in a hurricane or typhoon,
the wind energy tends to be concentrated in a much
smaller area than a typical weather system. In other
words, the fetch for hurricanes and typhoons is
smaller. While these powerhouses create incredible
wind speeds, their action is limited to the specific
areas in which they occur. Waves may be larger in
the region of the storm for a limited time, but the
large and consistent swell generated by long-fetch
winds just doesn't occur.
One other feature in the formation of wave swell is
worth noting. A given wind speed can only generate
waves of a certain size. After a period of time, the
waves get no bigger. In this case, the seas are said
to be fully formed, the largest waves that can be
created for a given wind speed are being created.
Once formed, the swell is free to travel as far as
it can, altered only by friction with the bottom or
obstacles, such as islands or continents.
The generation of waves from the time the wind
starts blowing to the time that fully-formed seas
developed gives rise to a series of waves with
different wave periods and speeds. Since the longer
period waves tend to be faster, these waves move out
ahead of the rest of the waves. For this reason,
groups of wave trains develop. A wave train is a
group of waves traveling at the same speed across
the ocean. These waves, obviously, hit the beach at
the same time and, hence, create the well-known
phenomenon of wave sets.
Waves travel out from these storms for thousands of
miles before they hit the California Beaches.