hey welcome to the outer banks
yeah so this is the real outer banks not like the tv show outer banks that was
actually filmed in like south carolina or something like that
this is the real outer banks off the coast of north carolina
the outer banks are a 200 mile long thin strip of barrier islands
these tiny islands are surrounded on one side by the atlantic ocean
with a calmer lagoon or sound side on the opposite side of the islands
right now we're practically in the middle of a tropical storm here it
hasn't quite formed into a tropical storm yet but there's some crazy rip
currents out there and some crazy winds right now actually
you can see the beach patrol coming by here right now
red flag out because we've got a tropical storm that's about to form
there so red flag out for dangerous rip currents
I'm pretty much standing in the middle of tropical storm fay right now it's
like the eye of the storm it's kind of crazy looking to be honest
now a barrier island like this essentially just one giant sand dune
in the middle of the ocean now because this whole thing is made up of just
sand it's very susceptible to changes from the ocean tides
and those changes and shifting sand structures gives this stretch of the
atlantic ocean the notorious name the graveyard of the atlantic off the
coast of the outer banks is an area of shifting sand shoals known as the
diamond shoals which are formed at a geological high
point where the southern gulf stream and the northern labrador ocean currents
converge this area sees opposing wave forces that
move massive undersea sand bars in unpredictable ways
since record keeping began back in 1526 there have been more than 5000
shipwrecks in these waters and countless lives have been lost and this
is a problem that's not just isolated to really old ships sure there
are shipwrecks from the 15 and 1600s there are also shipwrecks from
the civil war era but there are also shipwrecks from just
a few months ago like the ocean pursuit which ran aground
in april of 2020. one kind of interesting
thing about the ocean pursuit is actually because the sands shift so
easily it's not sinking in water but it's actually sinking
in the sand i really wanted to understand why this area of the atlantic
was so treacherous and so for that i got in touch with keeper james this is
james charlet and locally he's known as keeper james he's an authority on the
united states life-saving service which eventually morphed into today's u.s
coast guard and he's written a book called
shipwrecks of the outer banks dramatic rescues and fantastic wrecks in the
graveyard of the atlantic it's really pretty fascinating stuff i'm about
halfway through it on my kindle so if you're into that history kind of stuff
there's a link in the description below but in the book
he talks about the many reasons why there were so many shipwrecks in
this area they're two major currents and they meet right here at
cape hatteras and when i say they meet they don't just meet
they explode they create uncharted sand dunes underwater that you can't see
and they extend out for 20 miles offshore
so you can be well out of sight of the shore and you think you're in
in deep ocean water and it can be four feet deep captains knew that this was a
dangerous area of shoals so you could either go 20 miles outside
of that area or you could risk it and try to cut
in close many decisions were made poorly
and resulted in shipwrecks we call the outer banks the barrier islands
that's exactly what they are they are barriers it's actually 301 nautical
miles there is no port no safe port anywhere along there
in a sailing ship that could take you three or four days you could leave on a
very nice day and weather can change very quickly
this is what keeper james calls the treacherous choice
you see ship captains of the time knew that this area was dangerous but the
pressure to risk it and rush through was a real problem
whether that was rushing to get their product to a certain destination faster
or trying to avoid storms in the area or maybe they were trying to outrun some
german u-boats although a lot of shipwrecks in
this area were due to natural causes a lot of them were caused by humans you
see ships passing close to shore would have very narrow passageways that they
could go through the diamond shoals and german
u-boats in world war one and world war ii knew that and they could just hang
out and wait in fact the area right off of cape
hatteras was nicknamed torpedo junction these narrow passages
that ships pass through though could change at any time one of the
problems is you can go through one day but the
next day the shoals have shifted and changed so
you can't count on any of that this is so crazy
and i really feel like we need to know how
sand works so we need an expert for that but
where do you find an expert on sand for that i turn to tim
kana who's the president of coastal science and engineering
he's got a phd in geology and he's been doing coastal projects
for over 30 years the capes the famous capes of the
carolina hatteras cape lookout cape fear they're what
the geologists refer to as cuspate forelands and
they tend to form in areas where there's bi-directional winds
we have a plentiful sand supply coming out of the chesapeake ridges
offshore and they're moving south under those northeast waves
meanwhile when the waves are from the southwest they're also
trying to push sand but they're pushing sand in a northeasterly direction so
when they converge that accumulates some sand in that area
i think it's important to note that we're talking about
three different ocean water concepts here
there's waves there's currents and there's tides
waves are generally caused by winds sometimes over huge distances or even by
storms that are far off in the distance ocean currents can
get pretty complicated but that's generally the direction you would travel
in a boat if you shut off your engines or put down
your sails there are both surface level currents
and deep water currents and sometimes those are not the same
then there are tides which is the level or the height of the water and that can
rise or fall depending on the position of the moon
and the sun and then the other big factor is the tidal range in the outer
banks we have much lower tide range but the
waves are much bigger and the waves are what really build the
barrier beaches and they're actually like bulldozers
they're pushing sand up the profile and if you put enough
sand in the system it will actually build the beach
it will build the dunes up and so on so as we've been out here for the week i've
kind of been tracking the tides high tide and low tide particularly because
this week there has been a huge sandbar out here that my kids who are pretty
small can go out and walk around in the ocean surf it got me thinking
about how high tide and low tide work because
as i'm tracking it i noticed there are two high tides
now i've always known that the moon has been responsible for a lot of the tides
i think most of us have heard that the moon's gravity pulls on the water
and create some of the ocean movement but that doesn't explain why there are
two high tides on most days because the moon is only overhead once
so then what creates the second high tide
so let's take a moment to review how ocean tides work
the moon has its own gravity and the side of the earth that's closest to the
moon will be pulled upwards towards the moon
a little now land masses they don't move so easily
but water can so you would have high tide
essentially when the moon is directly overhead and low tide would
be on the adjacent sides but what about the opposite side of the
earth this side feels the least amount of
gravitational pull from the moon but this is where the other
high tide occurs and what's actually happening here is that the earth itself
is being pulled towards the moon and leaving the water behind
creating another high tide bulge now the moon
is not the only factor at play though because the sun and its gravity
also play a big part when the moon and the sun
are lined up in either a full moon or a new moon
orientation this can increase the tidal variations
meaning that the peak to trough range will be larger between high tide and low
tide this is called a spring tide not spring
like the season but spring like the action to spring up
alternatively when the moon is at a half moon on either side
the sun's gravity will actually counteract some of the moon's gravity
creating a smaller tidal range known as neap tides for a place like the
outer banks tides and storms in general can be super important to track
because they are barrier islands and those sands are shifting all over the
place and with storms like this happening you can get a sand bar that
forms overnight now one really cool instance of this was
just down the beach here in buxton near the cape hatteras lighthouse
and it was something called shelly island which actually just recently
formed again here in 2020 but it formed a couple years back
out in the ocean just off of cape point down by the hatteras lighthouse that
was essentially the beginnings of a whole brand new
island now this is something that could grow in size or it could just as easily
be washed away with another storm like the
one today if the storm comes along it's going to
move the sand around some of it's going to go offshore
without question but what we found in nags head is
some also moved and actually built up the beach at the toe of the
dune so the profile was just adjusting this is a really cool concept which tim
calls the sandbox which describes how the sand moves both
on shore and offshore now if you've ever built a sand castle near the ocean
you've probably seen them destroyed the next time high tide comes up and for me
i've always pictured the ocean as less of a constructive force and more
of a destructive force but that's not necessarily the case one
of the things that tim's company does really well is plan out beach
nourishment projects which is where they will dredge sand from really far
offshore and bring it back into the sandbox
or the littoral zone to build up the beaches
and the dunes you're basically measuring a sandbox and if that quantity
stays constant over time you've got a zero
erosion rate during storm conditions sand is moving offshore
but importantly they haven't taken it way out into deeper water and during
fair weather conditions sand is coming back onshore, it forms bars
and then those bars come ashore build the beach
back up and it just keeps going through the cycle so throughout the year you'll
have opposing changes in this area in the summertime
you'll typically have calmer weather which would help build up the beaches
and transport that sand onto the seashore but the wintertime is
storm season and that's when you can see dramatic shifts in the shape
or the location of those sands and you start mixing shifting sands with winter
storms and that's just another recipe for
shipwrecks we have conflicting winds as well so in the summertime we
have the southwest winds and in the winter time we have the northeast winds
those are the winds that create the the famous nor'easters which are
actually much more devastating than most hurricanes and at some point no matter
what you do you're going to have either conflicting
currents or conflicting wind and unfortunately the graveyard of the
atlantic still exists today and there's hardly a day that goes by
that i do not see a coast guard helicopter or coast guard airplane
go over fortunately these days shipwrecks aren't a frequent occurrence
modern technology gps systems and tracking sand movement has all become
commonplace but we've still not eliminated this threat completely
as for the islands themselves well as tim says with enough sand in the system
they should stick around the beaches may change they may even move closer to the
mainland entirely but for the foreseeable future many visitors
will still be able to enjoy this beautiful area
and observe the wildlife
hey buddy what's going on hey there dude look at this guy that's
a ghost crab right here look at this we're getting everything
ghost crab coast guard
oh no the ghost crab is getting away where are you going
oh there's another one two of them look at this one there
one there all right let's leave them alone
all right that's gonna do it for me i will see you on the next video. goodbye/
goodbye
you