Shoreline erosion and wetland loss in Mississippi
- Mississippi State Univ., Mississippi State (USA)
Set within a geologic framework that includes Pleistocene and Holocene barrier complexes, estuarine bays, and fluvio-deltaic tidal wetlands, coastal Mississippi shares environmental problems of shoreline erosion and wetland loss with her neighboring Gulf Coast states. The mainland coast consists of several Pleistocene headlands and barrier complexes interspersed with the St. Louis Bay and Back Bay of Biloxi estuaries. Tidal wetlands are found in the protected bays and tributary streams, as well as in the Pleistocene/Holocene deltaic environments associated with the Escatawpa, Pascagoula, Pearl, and Mississippi fluvial systems. Four barrier islands, formed by erosion and modification of a late Pleistocene/Holocene beach ridge, lie 6 to 12 mi offshore. Historically, these islands with a combined length of 30 mi have both migrated westward in response to prevailing longshore currents and also transgressed across the shallow platform of Mississippi Sound. Wave erosion, both normal and storm-induced, has historically caused shoreline retreat on both the barrier islands and on the mainland. Erosion rates in excess of 30 ft/yr have been measured at the updrift ends of the barrier islands while accretion has characterized the downdrift ends. Net shoreline retreat rates of 6 ft/yr have been measured on the Gulf side of the islands, although the Sound side rates are nearly as high. Since the earliest accurate maps were made in 1848, Mississippi's barrier islands have experienced a 20% reduction in area, amounting to about 2,000 acres (800 ha). Mainland shoreline retreat rates are similarly high, except for along the more stable and now artificially nourished beaches of Harrison County. Erosion rates exceeding 10 ft/yr since 1940 have been noted at the Point aux Chenes headland and the Grand Batture Islands. These islands, which formerly sheltered valuable oyster grounds and protected fragile marshes, have been reduced to shoals over the last several decades.
- OSTI ID:
- 6053348
- Report Number(s):
- CONF-9010204-; CODEN: AABUD
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:9; Conference: Gulf Coast Association of Geological Societies and Gulf Coast Section of SEPM (Society of Economics, Paleontologists, and Mineralogist) meeting, Lafayette, LA (USA), 17-19 Oct 1990; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
COASTAL REGIONS
EROSION
MISSISSIPPI
WETLANDS
ALLUVIAL DEPOSITS
ESTUARIES
GULF COAST
LOUISIANA
MAPS
MARSHES
QUATERNARY PERIOD
REDUCTION
RIFT ZONES
AQUATIC ECOSYSTEMS
CENOZOIC ERA
CHEMICAL REACTIONS
ECOSYSTEMS
FEDERAL REGION IV
FEDERAL REGION VI
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
NORTH AMERICA
SURFACE WATERS
USA
580000* - Geosciences