title: What Role do Hurricanes Play in Sediment Delivery to Subsiding River Deltas?
abstract: The Mississippi River Delta (MRD) has undergone tremendous land loss over the past century due to natural and anthropogenic influences, a fate shared by many river deltas globally. A globally unprecedented effort to restore and sustain the remaining subaerial portions of the delta is now underway, an endeavor that is expected to cost $50-100B over the next 50 yr. Success of this effort requires a thorough understanding of natural and anthropogenic controls on sediment supply and delta geomorphology. In the MRD, hurricanes have been paradoxically identified as both substantial agents of widespread land loss, and vertical marsh sediment accretion. We present the first multi-decadal chronostratigraphic assessment of sediment supply for a major coastal basin of the MRD that assesses both fluvial and hurricane-induced contributions to sediment accumulation in deltaic wetlands. Our findings indicate that over multidecadal timescales, hurricane-induced sediment delivery may be an important contributor for deltaic wetland vertical accretion, but the contribution from hurricanes to long-term sediment accumulation is substantially less than sediment delivery supplied by existing and planned river-sediment diversions at present-day river-sediment loads.
authors.affiliation: Department of Geology and Geophysics and Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Smith
authors.affiliation: Department of Geology and Geophysics and Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Bentley
authors.affiliation: U.S. Geological Survey, National Wetlands Research Center, Baton Rouge LA 70803 USA.
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Snedden
authors.affiliation: Department of Geology and Geophysics and Coastal Studies Institute, Louisiana State University, Baton Rouge, LA 70803 USA.
authors.forename: Crawford
authors.initials: C
authors.lastname: White