Access and Park Issues
and their equipment fan out on
Cape Point beach to survey coastal processes….WITH SLIDE SHOW
white metal monster rolls across the broad expanse of Cape Point,
following a sandy road along southern Hatteras Island. Its giant wheels
sink into the wet sand as it approaches the ocean, but it does not slow
down. It heads straight into the surf, wheels churning the water, and
soon it is in deep water. It does not sink, however. Its wheels no
longer visible, it now floats like a boat as its engine propels it
toward its destination.
The LARK, as it is called, is a 35-foot long amphibious vehicle owned
by the U.S. Army Corps of Engineers. Its captain, Ray Townsend of Duck,
is carrying U.S. Geological Survey divers and technicians from Woods
Hole, Mass., to a buoy that bobs in the waves.
The buoy marks the spot where, anchored on the ocean floor, new
state-of-the-art instrumentation measures and records wave action. The
divers will soon suit up and go below the surface to check on the
equipment. Bottle-nose dolphins dance around the vehicle as it reaches
The southern portion of Hatteras Island at Cape Point is the site of
some intriguing studies this winter, trying to further scientific
understanding of coastal processes and how they affect coastal areas,
in particular the Outer Banks of North Carolina.
The study area includes12 sites for what are called the nearshore
instruments, of which this is one. The sensors look up at the ocean
surface from below, measuring currents, wave direction, height, and
period (how close together the waves come in).
The project is a collaborative effort headed up by the USGS, in
participation with the U.S. Army Corps of Engineers, North Carolina
State University, the University of South Carolina, and Georgia Tech
Its final goal will be to provide information that can be used for
planning future coastal management strategies. It includes, along with
the 12 nearshore instrument sites, two offshore instrument sites, a
video camera situated in the Hatteras Lighthouse, and a site for the
WERA radar. There will also be several beach surveys and a dye study.
The USGS chose Cape Hatteras as the site for this study because it is
an extremely dynamic system, with strong currents and wave action and
rapid erosion rates. The results of the study, however, will be
relevant to other coastlines as well.
Sixty to 80 percent of the coastlines in this country are eroding,
according to USGS geologist Robert Thieler, because of sea level rise
and unsustainable development. With approximately $9 trillion invested
in infrastructure and resources and with most of our major ports at sea
level, the economic and social impacts of their loss could be immense.
Understanding the processes that cause the erosion is important.
The study, which was ongoing for most of the month of February, is
being supervised by USGS civil engineer and oceanographer John Warner
of Woods Hole Institute.
Warner studied ocean processes in undergraduate and graduate school and
researched sediment transfer in San Francisco Bay to earn his
doctorate. He did mapping surveys at Hatteras last September to
establish the depths he would be working in -- depths that he says were
changed considerably in November by the coastal storm, now called
Nor’Ida. Warner returned to set up the equipment for this study
up in late January, with the assistance of about 25 co-workers from the
On Feb. 4, the National Park Service sponsored a public meeting at the
Avon Fire House so that Warner and Thieler could explain what the
project was about, how long it would last, and what it would involve.
The meeting was well attended, with an audience of more than 50
interested residents, mainly from Hatteras and Ocracoke islands.
National Park Service ranger Laura Sturtz opened the meeting and
introduced the speakers.
The main goals of the project, as explained by the scientists, are to
improve the understanding of the processes which lead to coastal
changes and of their interactions with geology, so we can improve the
capability to predict coastal change and vulnerability, for emergency
planning and more sustainable development.
The study, they said, will look at the interactions of shoreline,
nearshore, and offshore sediment transport processes through the use
geophysical surveys, oceanographic surveys, and predictive models. Dune
erosion, overwash, island breaching, and threshold crossing will be
among the activities studied.
Using a PowerPoint projection system, the speakers showed images of
what lies beneath the islands, Pamlico Sound, and the ocean. It was
fascinating to learn about this unseen but vitally important underwater
landscape. Ancient river beds, substrate materials, and geologic
features have a big effect on how currents flow, sediments are
transported, and erosion occurs. Understanding more about these effects
will help in predicting where a storm might cut an inlet or where
houses might be most at risk of washing away. Other factors that affect
how vulnerable particular coastal areas are include tidal range, wave
height, and coastal slope.
One of the topics discussed was the concern about climate change and
resultant sea level rise. Temperatures have been relatively stable for
the last 10,000 years, making possible human expansion across most of
the globe. With temperatures rising globally and glaciers melting,
however, there will be more free water in the oceans.
Scientists are not able to say at what rate or how much sea level will
rise, but projections based on computer models suggest a rise of from
three to six feet in the next century. Looking at historical rates of
relative sea level rise that corresponds to global and local tectonic
processes (land motion such as uplift or subsidence) can help
scientists make predictions. For example, Alaska’s coastline is,
for geologic reasons, rising faster than sea level and thus will not be
affected nearly as much as the mid-Atlantic shoreline.
Warner and Thieler want residents and visitors at Cape Hatteras to
understand their project. Most of the sites are identified by signs.
"Don’t be surprised if you see us or our equipment on the
beaches," the signs state, "and please have respect for our
John Warner and his crew got a great chance to observe first hand what
a bad Outer Banks storm could do to the island when, on Feb.10, a
system with strong northwest winds flooded much of Hatteras Island and
held up their work. Two days later, driving across the Cape and
visiting the research sites, ocean overwash still stood in roads and
After watching the LARK and its diving crew get under way on a recent
visit to the site, Warner explains a little about ocean dynamics. At
Cape Hatteras, the waves can approach from opposite directions.
Underwater currents may move in different directions, and rip currents
are common along this coast. Offshore of the tip of most capes, such as
Cape Lookout, Cape Fear, and Cape Hatteras, is a big pile of sand,
deposited there by the wave action. Diamond Shoals, lying off the coast
from Cape Hatteras, is an example.
Why the sands stay in the shoals is something scientists would like to
better understand and hope to learn from this project.
Hatteras and Ocracoke are not typical barrier islands, he adds, because
of the 90-degree bend at Cape Point.
"Most barrier islands follow the coastline,” He says.” The ocean
usually tries to straighten things out."
Farther up the beach, near the spot where the Cape Hatteras Lighthouse
used to stand, two groups of pipes protrude from the sand near a small
trailer. This is the WERA Radar Site, set up by researchers from the
University of South Carolina. Here high frequency radar signals are
transmitted across 10 kilometers of ocean and along 10 kilometers of
the shore, bouncing off the ocean surface and measuring surface
currents and wave heights. The trailer houses the control units, where
the signals are processed and data stored.
The next stop is the top of the Cape Hatteras Lighthouse, where Georgia
Tech Savannah researchers monitor a video camera. The camera lens is
directed at the ocean surf zone. It films and tracks breaking waves,
transmitting the images to a computer inside the lighthouse, in order
to better predict coastal erosion.
Offshore studies, contracted out to a group of researchers called the
Woods Hole Group, use deep water instruments to measure currents and
waves that have not yet interacted with the ocean bottom.
Warner discusses two other methods that are being used for the research.
The U.S. Army Corps of Engineers is conducting beach surveys,
measuring the heights of dunes and offshore water depths (bathymetry).
Using a truck equipped with lidar and X-band radar systems, they
measure sand formations and determine ocean depths by measuring the
height of the waves above.
A dye project, Warner explains, will involve shooting a bag of
florescent green uranine dye into the surf with a giant slingshot. The
dye is non-toxic, and the bag will biodegrade within minutes. He plans
to use an airplane to view and photograph what happens to the dye once
it enters the surf and hopes to learn about what he calls lateral
mixing and longshore transport, measuring how fast the dye moves down
the coast, how wide it spreads across the surf zone, and which
direction it travels in when it reaches Cape Point.
An additional part of the project, not related to coastal change
processes, is being done for the U.S. Navy. It involves microbial fuel
cell technology -- designing a battery which would use marine microbes
in a chemical reaction to create an electric current.
The field work of the Cape Hatteras Coastal Study will be completed
about the end of February, but analysis will take much longer, probably
at least a year.
Meanwhile, Warner requests that if anyone sees anything that seems to
be wrong with the instruments that it be reported to him at 508-
360-1631 or [email protected].
(For more information on the project, check the Web site at:
Click Here To View Slide Show
January 28, 2010
will be many interesting pieces of equipment and plenty of activity on
the Cape Hatteras National Seashore beach near Cape Point next month.
U.S. Geological Survey coastal
erosion study is coming to Cape Point
It will all be part of the U.S. Geological Survey’s ongoing research on
Carolina Coastal Change Processes.
You can find out more about the project at a special National Park
Service Know Your Parks citizen science program series presentation by
the researchers on Thursday, Feb. 4, at 7 p.m. at the Avon Fire
In a nutshell, this project is investigating the interactions of
shoreline, nearshore, and offshore sediment transport processes driving
coastal change in the Carolinas using geophysical surveys,
oceanographic studies, and predictive models.
Equipment and scientists will begin working on the beach near Cape
Point on Monday, Feb. 1, and work will continue through much of the
“Starting Feb.1, some unusual looking equipment will be on the
beach between the former site of the Cape Hatteras lighthouse, south to
access ramp 45,” according to a media release from USGS.
“This equipment is part of a U.S. Geological Survey coastal
erosion research study, under special use permit from the National Park
Service. The goal of this study is to gain a better understanding of
how to predict the hazards of beach erosion.”
Scientists will have equipment at about 17 sites offshore, in the surf
zone, and on the beach. The equipment will be marked and signs will be
posted on the beach throughout the month of February.
The presentation on Thursday will be by USGS scientists Dr. John Warner
and Dr. Rob Thieler. The hour-long program is free and open to the
public. A question-and-answer session will follow the talk.
Warner and Thieler will discuss the offshore mapping completed last
fall and preview the fascinating scientific activities that will
include sand dunes rigged with radar, a green dye study, a lighthouse
camera, divers, and amphibious vehicles deploying sensors.
These instruments will measure the speed and direction of
currents, waves, and other forces acting on the beach, in the surf
zone, and beyond. Cutting edge instruments have been
specifically for this study, to measure forces during normal conditions
and during storms.
The instruments, beach surveys, and offshore mapping will reveal many
things about the sandy beaches of the seashore – how much sand
there is, how fast it travels, where it comes from, and where it
The goal of the research is to better understand, predict, and mitigate
the hazards of beach erosion at Cape Hatteras.
The research study is being led by the USGS in Woods Hole, Mass., and
is just one component of the much larger Carolina Coastal Change
Project. The USGS, U.S. Army Corp of Engineers, along with
academic institutions of the University of South Carolina, North
Carolina State University, and Georgia Tech Savannah, are collaborating
on the project to investigate coastal processes, focusing on the Outer
Banks of North Carolina.
information, check the Web site at: