 |
 |
 |
|
||||||
|
|
|||||||
|
||||||||
|
||||||||
|
Seminar on Deltas by Postdoctoral Scholar at Woods Hole Science Center
Deltas, sedimentary landforms that occur along continental margins where rivers discharge sediment to the oceans, have been studied for many decades to understand their origins and evolutionary history and as models for better understanding ancient buried delta deposits that are important for energy exploration. Research has shown that such factors as the volume of river-sediment discharge to the coast, the volume and direction of long-shore transport, tidal range, sea-level history, and wave energy and direction control the three-dimensional form and architecture of deltas. Deltas are receiving renewed attention because they are low-relief regions, commonly densely populated and important for agriculture and extremely vulnerable to accelerated rise in relative sea level forecasted for the near future as a result of climate warming. The USGS has conducted geologic framework and process studies of the 300-km-wide Mississippi River delta plain for more than a decade to understand coastal erosion, wetland loss due to complex natural and manmade processes, habitat change, and, more recently, subsidence as a major factor in relative sea-level rise. Results from these USGS studies are being used as baseline science information for the Louisiana ecosystem-restoration program currently underway. In a talk on February 20, 2002, entitled "Wave-Dominated Deltas," Liviu Giosan, a postdoctoral fellow at the Woods Hole Oceanographic Institution (WHOI), presented new ideas on the evolution and sedimentary records of wave-influenced deltas around the world. In addition to reviewing past delta studies, Liviu presented results of his own, ongoing research on the deltas of the Danube River (which flows into the Black Sea off Romania) and the Brazos River (which flows into the Gulf of Mexico off Texas). Liviu will continue his coastal research for the rest of his postdoctoral appointment and will collaborate with USGS scientists and others to organize a delta session for this fall's annual Geological Society of America meeting (Oct. 27-30, 2002, Denver, CO).
|
 |
in this issue:
Radio Interview Explores African Dust Florida Coastal Storm Defenses Environmental Academy Web Site Congressional Briefing—Sea Otter Research John Hughes Clarke—"Imaging Water Mass Variability" Deltas Seminar |
|||||||||||||||||
U. S. Department of the Interior | U.S. Geological Survey
previous story
cover story:
