Hurricane Dennis (1999)
In terms of peak magnitude, Dennis was a marginal hurricane that
deteriorated into a tropical storm before coming ashore in North Carolina. However, its
duration was remarkable, sitting off the northern Outer Banks for about a week generating
large waves that pounded the coast. In fact, at the U.S. Army Corps of Engineers Field
Research Facility at Duck, North Carolina, wave height was the third highest in the
20 years of record, reaching 6.3 m at a buoy in 20 m of water.
Selected Survey Locations: Click on one of the two locations above,
Rodanthe, NC or Buxton, NC
to see photographs and data plots from lidar.
Three types of field surveys were conducted during the week of 9/6 to 9/10/99:
Coastal Change From Lidar:
NASA, USGS and NOAA surveyed the Dennis impact zone on the Outer Banks of North
Carolina using NASA's Airborne Topographic Mapper (ATM), a scanning airborne laser
altimeter. The survey extended from near the North Carolina/Virginia state line to Ocracoke
Inlet, about 50 km southwest of Cape Hatteras. The total swath width of the survey was
500-600 m including the beach and the first foredune ridge. Click on one of the
locations on the map above (Rodanthe | Buxton)
to see examples of lidar results.
Oblique Aerial Photography: USGS personnel
aboard a small plane acquired oblique video and still photography for the
NC coast from Cape Lookout, NC to Sand Bridge, VA. Results from that mission are
compared to pre-storm July, 1996 photography on these pages:
(see map at right:
Storm Response Flight Airphotos: Click on a boxed area on the map above
to view the index of pre- and post-storm airphotos in that area.
[Area 1 |
Area 2 |
A USGS ground crew visited impacted sites and mapped storm features using handheld
GPS. They focused on the reach from Cape Hatteras, NC to Oregon Inlet, NC including
Hatteras National Seashore and Pea Island National Wildlife Refuge.