A number of ocean front homes were destroyed or severely damaged during Hurricane Sandy on Fire Island, NY. The photo shows what remains of houses in the community of Davis Park. Photo by Cheryl Hapke, USGS.

The USGS conducts research on the natural processes that cause coastal change, but to understand and adapt to such changes, accurate information regarding the past and present shorelines is essential.  Consequently,  USGS research focuses on understanding the magnitude and variability of the impacts of hurricanes on the sandy beaches of the United States, and how short-term events like storms can influence the long-term vulnerability of our coasts.

Barrier islands line about half of the U.S. coast, including most of the region impacted by Hurricane Sandy. In their natural state, these islands are mobile and change constantly through historical and geologic time in response to the natural forces of wind, waves, tides, and sea level. In fact, mid-Atlantic barrier islands owe their very existence to storms and the long-term rise in sea level of the past several thousand years. However, much of today’s coastline is a complex hybrid of a natural, dynamic landform overprinted with decades of human development. Recognizing the dynamic nature of barrier islands can help reduce the vulnerability of the infrastructure to the inevitable “next time.”

Hurricane Sandy’s landfall brought devastation to many residents of the mid-Atlantic’s barrier islands. The large area that superstorm Sandy affected does not have a recent equal, but the impacts are similar to many other U.S. storms, such as Ivan, Katrina, and Ike. To those who study coastal processes, examining the impacts helps us understand how barrier islands function and where the highest hazard areas are located.

What does an island have to do, geologically speaking, to survive? 

Looking seaward from an island’s interior – where people and infrastructure are usually located – beaches and dunes are the first line of defense from ocean waves and storm surge. When dunes erode and fail, much of the sand is carried into the island interior as overwash. While a failed dune makes a coastal community more exposed to the next storm, it makes an undeveloped barrier island stronger by adding elevation to its core. This is how the barrier islands were built in the first place.

During superstorm Sandy, broad swaths of the coastline from North Carolina to Massachusetts experienced dune failure and massive overwash. The sand that washed onto and across the barrier islands – filling roads, yards, and living rooms – instantly added several feet of elevation. On a natural barrier island, this new elevation capital reduces the chance of inundation from the next storm. And as was learned in New Jersey and New York, a couple of feet can make all the difference between inconvenience and catastrophe.

Oblique aerial photographs of Seaside Heights, NJ. View looking west along the New Jersey shore. Storm waves and surge destroyed the dunes and boardwalk, and deposited the sand on the island, covering roads. The red arrow points to a building that was washed off of its foundation and moved about a block away from its original location. The yellow arrow in each image points to the same feature.

As the army of bulldozers and other earth-moving equipment deployed along the coast suggests, current efforts appear headed to restore the islands to their pre-storm state. Pushing the sand off the streets and back onto the beach removes the elevation that would have added protection against future floods. For this storm and on other developed shores, such excavation of the roads is absolutely necessary to regain the dunes that are the first line of defense. But this resetting of an islands’ “morphological clock” back to pre-storm conditions decreases resilience and increases long-term vulnerability and risk.

Then, there is sea-level rise

Sea level has risen six to nine inches along the New Jersey coast since the last big storm in 1962. Some residents say the 1962 storm barely reached their doorstep, while this time Sandy flooded them by a foot. Although Sandy and the 1962 storm differ in their details, 50-years of sea-level rise certainly allowed water to reach areas that would not have been reached otherwise.

What we know about storms, sea-level rise, and barrier island response can be applied to redevelopment of the New Jersey coast, potentially exploiting the natural dynamics to our economic and environmental benefit. The pressure on humans will be to either try and thwart the natural response – requiring increasing investment in construction and maintenance of storm protection structures – or adapt to that response by moving both horizontally and vertically as the barrier islands move. There is historical precedent for the latter. In New Jersey, some pre-WWII beachfront communities had moveable houses. In 1888, the Brighton Beach Hotel on Coney Island was moved several hundred feet back from the ocean by six steam locomotives.

Using science to help with difficult choices

The USGS provides scientific support for hurricane planning and response. By using observations of beach changes and models of waves and storm surge, predictions can be made on how the coast will respond to hurricanes and vulnerable coastal areas can be identified.

There are difficult choices to be made in response to Sandy. Doing nothing other than rebuilding is an easy choice and least expensive in the near-term, unless the next “superstorm” comes next year – or even this winter. Hundreds of miles of the East Coast where dunes were eroded or no longer exist are now more vulnerable than ever. Protecting the entire coast with coastal structures is likely not feasible or even desirable.

A practical response will be a blend of all the options. This requires identifying which areas can adapt best, and prioritizing which will receive the most protection and which will receive the least, or even none. This will be a challenging process. But, when undertaken jointly by citizens, policymakers, and scientists it could be a refreshing response to the problem, and yield a coastal environment that is more resilient and economically and environmentally sound.

This map shows recorded earthquakes in the central and eastern United States lain over the USGS earthquake hazard maps.

Last year’s M5.8 Virginia earthquake came as a surprise for many in the area, but in the past 400 years, there have been more than 30 damaging earthquakes in the eastern U.S., ranging from the M6.0 near Boston in 1755, to M7.3 in Charleston, S.C. in 1886. Despite this history of earthquakes the faults on which these earthquakes are occurring are poorly known, and scientists do not have a clear understanding of the causes of earthquakes in the eastern U.S. Scientists are using seismic data from the August 2011 M5.8 Virginia earthquake to answer some of these questions and to refine estimates of the of the region’s seismic hazard. Futures damaging eastern earthquakes are inevitable; join us on September 5 to find out what scientists are learning and how you can prepare for the next big one.

Time: Wednesday, September 5, 2012 • 7-8pm
Speaker: Robert Williams
Location: 12201 Sunrise Valley Drive Reston, VA 20192
Phone:  703-648-4748

Please Note: This event takes place at a Federal Facility — Photo Id is Required
FREE and Open to the Public

Follow this event live on Twitter @USGSLive
This announcement and directions can be found online.

Requests for accommodations (i.e. sign language interpreting) require notice at least two weeks before the event. Please email jcorley@usgs.gov or call 703-648-7770.

The USGS public lectures are held monthly in Reston, Virginia. These evening events are free to the public and intended to familiarize a general audience with science issues that are meaningful to their daily lives. USGS speakers are selected for their ability and enthusiasm to share their expertise with an audience that may be unfamiliar with the topic; speakers are encouraged to thoroughly explain the subject matter and to define any words or terms that may be unfamiliar.

The USGS lecture series provides the public an opportunity to interact with USGS scientists and ask questions about recent developments in Natural Hazards; Water; Energy Minerals and Environmental Health; Climate and Land Use Change; Ecosystems; and Core Science Systems. Ultimately, the goal is to create a better understanding of the importance and value of USGS science in action.

USGS ShakeMap for the August 23, 2011 M5.8 Virginia Earthquake. ShakeMap shows approximate levels of shaking in areas affected by an earthquake. It then pairs this information with estimated building damages.

The magnitude 5.8 earthquake that struck Louisa County was among the largest to occur along the  eastern seaboard of the United States. It caused extensive damage in central Virginia and was likely  felt by more people than any other earthquake in U.S. history. Join USGS scientists Mike Blanpied and Mark Carter on November 2nd  to discuss the seismology of the earthquake, its effects, and its context in the geology of Virginia. Mike Blanpied is the associate program coordinator for the Earthquake Hazards Program at USGS, and Mark Carter is a research geologist with USGS who lives in Mineral, VA, near the epicenter of the earthquake.

FREE and Open to the Public

Follow this event LIVE! @USGSLive

Date: Wednesday, November  2nd, 2011, 7:00-8:00 PM
Location: 12201 Sunrise Valley Drive Reston, VA 20192
Phone:  703-648-4748

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About the Lecture Series

The USGS Science in Action public lecture series in Reston, VA is a monthly event. These evening events are free to the public and intended for a general audience to familiarize them with science issues that are meaningful to our daily lives.
The USGS speakers are selected for their ability and enthusiasm to share their expertise with an audience that may be unfamiliar with the topic.

The USGS lecture series provides the public an opportunity to interact with scientists and ask questions about recent developments in biology, geography, geology, water resources, climate change, energy and more. Ultimately, the goal is to create a better understanding of the importance and value of USGS Science in Action.

Contact: Melanie Gade

August 23, 2011 USGS Community Internet Intensity Map

Tuesday, August 23, 2011 at 01:51 PM a 5.8 Earthquake occurred 38 miles outside of Richmond, VA.
Learn More

Let us know, Did You Feel It?

Portable Seismometers:

Over the next few days, the USGS will be deploying portable seismometers around northern Virginia in order to better characterize and monitor all aftershock activity and to better define the fault zone from which Tuesday’s earthquake originated.