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Aerial Photos of Outer Banks Show Coastal Damage from Hurricane Irene



Aerial Photos of Outer Banks Show Coastal Damage from Hurricane Irene

OUTER BANKS, N.C.A series of before and after aerial photos of the Outer Banks show the impact of Hurricane Irene on the coastline, highlighting several breaches that severed a state highway and moved large volumes of sand inland. 

The series features five photo pairs that show coastal change in areas from Cape Lookout to Oregon Inlet.

Hurricane Irene made direct landfall near Cape Lookout on August 27. Because of the right-angle shape of the Outer Banks, barrier islands facing southeast experienced different coastal changes than those islands facing east. 

The southeast-facing coast, from Cape Lookout to Cape Hatteras, was exposed to waves and surge from the ocean. Photographs of Ocracoke Island show large volumes of sand removed from the beach system and deposited over roads and grass marshes. Flooding by storm surge in these areas was minimal however, as surge crested above dunes in only limited locations.

The east-facing coast, from Cape Hatteras to Oregon Inlet, also experienced waves and surge from the ocean, but surge was higher in the sound. Sections of Rodanthe and Pea Island National Wildlife Refuge were exposed to storm surge in Pamlico Sound of roughly six feet that contributed to the carving of channels through the island that breached a state highway at several locations. A total of five breaches were cut through the coastal landscape between Cape Hatteras and Oregon Inlet.

“Such multiple breaches, or new inlets, cut through the Outer Banks could take weeks to months to close on their own,” said Asbury (Abby) Sallenger, a U.S. Geological Survey oceanographer. “And without intervention like pumping sand, some could even persist indefinitely depending on the channel’s cross-section and the amount of water flushed through it on every tide.”

Three days after the landfall of Hurricane Irene, USGS scientists acquired detailed information of coastal change through aerial photography and an airborne lidar survey mission conducted with the National Oceanic and Atmospheric Administration. 

Lidar, light detection and ranging, is a remote-sensing tool attached to an aircraft that uses laser pulses to collect highly detailed ground elevation data. Information obtained from the surveys allow scientists to discern the degree of changes to beaches and coastal environments and determine how much the land has eroded and where new inlets have cut through. The photo and lidar information should be useful in mitigation and restoration efforts like rebuilding N.C. Highway 12, which was severed in several locations by breaches cut through the barrier islands by Hurricane Irene.

Data acquired will also be used to make more accurate predictive models of future coastal impacts from severe storms and identify areas vulnerable to extreme coastal change.

Before and after photographs illustrating coastal changes and damage from Hurricane Irene can be viewed online.  

For more information on hurricane preparedness, visit ready.gov.

USGS Newsroom



More information

Parameter Value Description
Magnitude mb The magnitude for the event.
Longitude ° East Decimal degrees longitude. Negative values for western longitudes.
Latitude ° North Decimal degrees latitude. Negative values for southern latitudes.
Depth km Depth of the event in kilometers.
Place Textual description of named geographic region near to the event. This may be a city name, or a Flinn-Engdahl Region name.
Time 1970-01-01 00:00:00 Time when the event occurred. UTC/GMT
Updated 1970-01-01 00:00:00 Time when the event was most recently updated. UTC/GMT
Timezone offset Timezone offset from UTC in minutes at the event epicenter.
Felt The total number of felt reports
CDI The maximum reported intensity for the event.
MMI The maximum estimated instrumental intensity for the event.
Alert Level The alert level from the PAGER earthquake impact scale. Green, Yellow, Orange or Red.
Review Status Indicates whether the event has been reviewed by a human.
Tsunami This flag is set to "1" for large events in oceanic regions and "0" otherwise. The existence or value of this flag does not indicate if a tsunami actually did or will exist.
SIG A number describing how significant the event is. Larger numbers indicate a more significant event.
Network The ID of a data contributor. Identifies the network considered to be the preferred source of information for this event.
Sources A comma-separated list of network contributors.
Number of Stations Used The total number of Number of seismic stations which reported P- and S-arrival times for this earthquake.
Horizontal Distance Horizontal distance from the epicenter to the nearest station (in degrees).
Root Mean Square sec The root-mean-square (RMS) travel time residual, in sec, using all weights.
Azimuthal Gap The largest azimuthal gap between azimuthally adjacent stations (in degrees).
Magnitude Type The method or algorithm used to calculate the preferred magnitude for the event.
Event Type Type of seismic event.
Event ID Id of event.
Event Code An identifying code assigned by, and unique from, the corresponding source for the event.
Event IDS A comma-separated list of event ids that are associated to an event.

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