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
