2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 7
Presentation Time: 8:00 AM-12:00 PM


FENSTER, Michael S.1, GONZÁLEZ, Mauricio2, DOLAN, Robert3 and MEDINA, Raúl2, (1)Environmental Studies/Geology, Randolph-Macon College, Ashland, VA 23005, (2)Instituto de Hidráulica Ambiental (IH), E.T.S. Ingenieros de Caminos, C. y P., Dpto. Cien. y Téc. del Agua y del Medio Ambiente, University of Cantabria, Av. de los Castros, s/n, Santander, 39005, Spain, (3)Environmental Sciences, University of Virginia, Clark Hall, Charlottesville, VA 22904, mfenster@rmc.edu

The thirteen mixed-energy Virginia Barrier islands comprise some of the most dynamic, mobile and consequently, vulnerable islands in the world. The sand-deficient barriers migrate landward over backbarrier marsh deposits at rates that average 2.7 m/yr and reach as high as 32 m/yr on Cobb Island. Extensive duneless reaches, marshes and tidal creeks that outcrop on the foreshore, dead trees in standing position on the foreshore, and large boulder-sized marsh rip-up clasts originating from the nearshore attest to the highly erosional nature of the islands. Most of these islands have retained their pristine nature because of federal, state, and non-profit organization ownership/management. The NASA-managed Wallops Island constitutes the only island along this chain with relatively major development. Severe erosion on this island has forced NASA to stabilize the island using various methods including a 3.5 k long seawall. In anticipation of NASA's most recent launch of a 22 m tall Minotaur 1 rocket with an Air Force spy satellite as payload (December, 2006), NASA leveled dunes and cleared vegetation to create unobstructed beach views. Almost immediately, NASA had to respond with seawalls and truck-hauled sand to counter the new coastal response. Two weeks after the placing the sand on the beach, a spring high tide completely eliminated the artificially-placed sand. This paper chronicles the land uses along these islands, discusses the situation at Wallops Island, and relates land-use practices to newly modeled coastal risk factors.