In wave riding, trying to find the right waves at
the right time is really a scientific exploration.
There's a lot of information that is needed to sort of
make the right choices, to find the right waves at the right times.
I'm Jon Warrick.
I'm a Research Geologist at the the US Geological Survey,
and I work a lot on coastal change here at USGS.
My experience with wave riding goes way back to when I was a kid.
As soon as I could ride a bike, I was down at the beach all the time,
riding waves, surfing, body surfing. Wave riding is really
what got me interested in the ocean and in science.
I often think of, as a surfer, I think of needing to be
sort of knowledgeable about a number of sciences: oceanography,
meteorology, geology, geomorphology, because they all combine
to make up, where the right waves are at the right time.
Finding good waves is all about understanding, you know,
the wave conditions at any one time, but also the physical setting
of the beaches and the coasts. I think about it in two different ways.
There's the waves,
the offshore waves or the wave field, that are approaching the coast.
So the waves, as they move into the coast, how big they are,
where they're coming from, And then there's the other element,
which is the shape of the coast, both way offshore
and really close to shore, because both of those things influence
how waves will break as they get along the shore.
So the first element is the wave field.
And one thing that surfers are really interested in,
you know, swell and where it's coming from and when the next swell is coming, etc..
The ocean is actually delivering swell from all kinds of different directions
at the same time.
The waves at any one time are a combination of
of waves coming from all over the Pacific Ocean.
So we can have waves coming from the north and the west in the south
and contributing in different amounts at the same time.
And it's really that combination of waves that produce
the details of the conditions. Not only just wave size,
but how the waves are breaking, is really a function of how
those waves are combining together as they approach the shore.
We're able to understand and predict where waves are coming from and how big
they'll be, because we know that waves are generated by the wind
and that we're getting better and better models of wind fields across the ocean.
We can see that when there are storms in various places of the ocean
and how those wind fields will generate waves
and those waves will move across the ocean and approach our shore.
And again, those waves will combine in ways where,
you can have different types of conditions at different spots.
So we have
these waves approaching the coast, and when they get toward the coast,
they start feeling the bottom, the seafloor.
And that's a really important aspect of sort of where the waves will
break well, is sort of how they feel the bottom of the ocean
and how that, that the bottom of the ocean actually kind of modifies the waves.
It changes the waves.
The classic example is Mavericks up the coast or Steamer Lane
or even Pleasure Point here in Santa Cruz, where we have these offshore reefs,
these offshore rock shelves, and those focus
the waves on to a certain spot, and so the waves at that spot,
where the waves are focused, are much bigger than in adjacent areas.
So that's one way that sort of the morphology of the shelf
of the of the offshore bathymetry influences the wave field.
Another way that the offshore bathymetry, or that water depths,
the shape of shelf, will influence the waves
is the way that waves break.
And so waves break in sort of different ways.
And that's generally a function of how steep the sea floor is.
And so where the sea floor is really flat,
waves will sort of come in slow and crumble.
We call that a spilling wave, where the wave doesn't break very fast.
And an example locally is like Cowells. And so when a wave
will come through and spill slowly, it's a very gentle place,
it's a good place for beginners to learn to surf, or for longboard surfing
It generally is a slower wave, a safer wave.
And as the sea floor gets steeper and steeper, we'll get plunging waves.
The waves will overtop and make a barrel, a tube,
which is obviously something that surfers are always looking for.
But you could see, you know, once you get steeper, it gets even
it can overtop even faster and can get dangerous.
And so we're always sort of trying to find places where that slope is just right.
It's not too slow and not too steep.
So you can get that breaking just right.
Another aspect of how waves are influenced
by the sea floor is by, in a sense, how long the wave will be.
There are different types of coastal settings from beaches
to, you know, rocky shorelines and coral reefs, and each of those
different settings will have an influence on how the waves break.
Because seafloor is really important for a number of things, habitats
and resources, and of course, in surfing for how the waves
will transform to the coast, we've done a lot of mapping of the continental shelf
to try to understand its shape and its morphology.
And that's primarily done using
sonar systems that are deployed from boats and they send signals
to the bottom of the ocean and those reflect back up.
And from those signals you can interpret the
the shape and morphology of this shelf.
And those types of data have been really important in terms of understanding
where various resources are, but also, you know, how waves transform
as they come to the coast.
That type of data we've collected up and down the coast and it can be useful
for understanding waves and other marine resources.
One of the tricky things in these
in collecting these data is getting it real close to shore.
And so if you look at the maps of the offshore bathymetry,
you'll note that there's typically regions closest to shore
where the waves are breaking, where we don't have a lot of data.
And that's just because it's really hard to get in those regions.
There's a lot of kelp, it’s often not a safe place to work
because the waves are breaking.
And so it's been really challenging to get good data right in the surf
breaks to know exactly what the seafloor looks like there.
And so we do have a gap in our data and our understanding
for what the seafloor is like.
right in those, those surf breaks.
Another interesting element to the bathymetry
and how it influences waves here in the Santa Cruz region
is sort of the way that the shelf has evolved over time.
And here we have this rocky coastal setting.
And on top of that we've had tens of thousands of years
of evolution of that that include during the ice ages, when the glaciers
were up on the lands, the ocean was much lower than where it is now.
And many of our rivers along our coast were carving through
and forming valleys way offshore.
So, you know, what's under the water now was on land
and we had our rivers, carving through that.
As the ocean is now much higher, we still have
those channels carved into our offshore platform.
And those channels can be seen in the data we collect.
And they're also very important
for influencing how the waves are breaking along the coast.
And some of our more popular surf breaks like Natural
Bridges, Four Mile, Scott Creek and even Steamer
Lane, are all formed on sort of the walls of those little canyons.
And so one of the interesting things to think about, those surf
breaks are actually formed on side walls of river valleys.
And that, of course, have been changed with time because of the waves
modifying them, but really are a function of sort of river
processes during the ice ages rather than current conditions.
One of the really neat things about being a scientist and a surfer
is that every time I go surfing, I'm actually doing a little science.
I'm thinking about, Why are the waves doing the things they're doing today?
And, it really relates to all those factors,
the oceanography and the meteorology, the weather,
what the shape of that seafloor and shelf offshore are.
Because every day is different, it provides a new sort of data
point for me to think about how waves react to all those variables