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- Erosion (2)
- Atlantic Coastal Plain; bedding; Cenozoic; Chesapeake Bay; deformation; earthquakes; Eocene (1)
- Atlantic Coastal Plain; buried channels; Cenozoic; Quaternary geology (1)
- Barrier islands (1)
- Basin (1)
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- Climate (1)
- Coastal resilience (1)
- Coastal zone (1)
- Delmarva peninsula (1)
- Ecogeomorphology (1)
- Erosion rates (1)
- Flluvial sediment (1)
- Fluxes (1)
- Hyperpycnal discharge (1)
- Lithology (1)
- Oregon Coast Range; Digital Elevation Models; New-Zealand; Gully Erosion; Sediment Discharge (1)
- Overwash (1)
- Paleovalley (1)
- Quaternary sea-level (1)
- Rates (1)
- Saltmarsh restoration (1)
- Seagrass. barrier islands (1)
- Sediment (1)
- Sediment load (1)
- Sediment transport; wetland geomorphology; wetland stability; estuarine hydrodynamics (1)
- Sediment yield (1)
- Tidal flats (1)
- Tidal inlet (1)
- US Mid-Atlantic shelf (1)
Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Leveraging The Interdependencies Between Barrier Islands And Backbarrier Saltmarshes To Enhance Resilience To Sea-Level Rise, Christopher J. Hein, Michael S. Fenster, Keryn B. Gedan, Jeff R. Tabar, Emily A. Hein, Todd Demunda
Leveraging The Interdependencies Between Barrier Islands And Backbarrier Saltmarshes To Enhance Resilience To Sea-Level Rise, Christopher J. Hein, Michael S. Fenster, Keryn B. Gedan, Jeff R. Tabar, Emily A. Hein, Todd Demunda
VIMS Articles
Barrier islands and their backbarrier saltmarshes have a reciprocal relationship: aeolian and storm processes transport sediment from the beaches and dunes to create and build marshes along the landward fringe of the island. In turn, these marshes exert a stabilizing influence on the barrier by widening the barrier system and forming a platform onto which the island migrates, consequently slowing landward barrier migration and inhibiting storm breaching. Here, we present a novel framework for applying these natural interdependencies to managing coastal systems and enhancing barrier-island resilience. Further, we detail application of these principles through a case study of the design …
Molluscan Aminostratigraphy Of The Us Mid-Atlantic Quaternary Coastal System: Implications For Onshore-Offshore Correlation, Paleochannel And Barrier Island Evolution, And Local Late Quaternary Sea-Level History, John F. Wehmiller, Laura L. Brothers, (...), Christopher J. Hein, Justin L. Shawler
Molluscan Aminostratigraphy Of The Us Mid-Atlantic Quaternary Coastal System: Implications For Onshore-Offshore Correlation, Paleochannel And Barrier Island Evolution, And Local Late Quaternary Sea-Level History, John F. Wehmiller, Laura L. Brothers, (...), Christopher J. Hein, Justin L. Shawler
VIMS Articles
The Quaternary record of the US Mid-Atlantic coastal system includes onshore emergent late Pleistocene shoreline deposits, offshore inner shelf and barrier island units, and paleovalleys formed during multiple glacial stage sea-level lowstands. The geochronology of this coastal system is based on uranium series, radiocarbon, amino acid racemization (AAR), and optically stimulated luminescence (OSL) methods. We report over 600 mollusk AAR results from 93 sites between northeastern North Carolina and the central New Jersey shelf, representing samples from both onshore cores or outcrops, sub-barrier and offshore cores, and transported shells from barrier island beaches. AAR age estimates are constrained by paired …
Impacts Of Seagrass Dynamics On The Coupled Long‐Term Evolution Of Barrier‐Marsh‐Bay Systems, I.R.B. Reeves, L. J. Moore, E. B. Goldstein, A. B. Murray, Matthew L. Kirwan
Impacts Of Seagrass Dynamics On The Coupled Long‐Term Evolution Of Barrier‐Marsh‐Bay Systems, I.R.B. Reeves, L. J. Moore, E. B. Goldstein, A. B. Murray, Matthew L. Kirwan
VIMS Articles
Seagrass provides a wide range of economically and ecologically valuable ecosystem services, with shoreline erosion control often listed as a key service, but can also alter the sediment dynamics and waves within back‐barrier bays. Here we incorporate seagrass dynamics into an existing barrier‐marsh exploratory model, GEOMBEST++, to examine the coupled interactions of the back‐barrier bay with both adjacent (marsh) and nonadjacent (barrier island) subsystems. While seagrass reduces marsh edge erosion rates and increases progradation rates in many of our 288 model simulations, seagrass surprisingly increases marsh edge erosion rates when sediment export from the back‐barrier basin is negligible because the …
Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan
Inferring Tidal Wetland Stability From Channel Sediment Fluxes: Observations And A Conceptual Model, Nk Ganju, Nj Nidzieko, Matthew L. Kirwan
VIMS Articles
Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater …
Water And Sediment Discharge From Small Mountainous Rivers, Taiwan: The Roles Of Lithology, Episodic Events, And Human Activities, S. J. Kao, John D. Milliman
Water And Sediment Discharge From Small Mountainous Rivers, Taiwan: The Roles Of Lithology, Episodic Events, And Human Activities, S. J. Kao, John D. Milliman
VIMS Articles
Taiwan’s natural setting creates highly vulnerable watersheds whose rivers discharge disproportionately large quantities of sediment to the coastal ocean. The 16 Taiwanese rivers analyzed in this article discharge ∼180 Mt yr-1 of sediment to the coastal ocean, although totals over the past 20 years have varied between 16 and 440 Mt yr-1. The mean annual sediment yield of 9500 t km-2 yr-1 for the 16 rivers is 60-fold greater than the global yield of 150 t km-2 yr-1, but mean yields for the individual rivers vary by more than 2 orders of …
Geology, Geography, And Humans Battle For Dominance Over The Delivery Of Fluvial Sediment To The Coastal Ocean, James P.M. Syvitski, John D. Milliman
Geology, Geography, And Humans Battle For Dominance Over The Delivery Of Fluvial Sediment To The Coastal Ocean, James P.M. Syvitski, John D. Milliman
VIMS Articles
Sediment flux to the coastal zone is conditioned by geomorphic and tectonic influences (basin area and relief), geography (temperature, runoff), geology (lithology, ice cover), and human activities (reservoir trapping, soil erosion). A new model, termed “BQART” in recognition of those factors, accounts for these varied influences. When applied to a database of 488 rivers, the BQART model showed no ensemble over‐ or underprediction, had a bias of just 3% across six orders of magnitude in observational values, and accounted for 96% of the between‐river variation in the long‐term (±30 years) sediment load or yield of these rivers. The geographical range …
Geomorphologic Controls On The Age Of Particulate Organic Carbon From Small Mountainous And Upland Rivers, El Leithold, Ne Blair, Dw Perkey
Geomorphologic Controls On The Age Of Particulate Organic Carbon From Small Mountainous And Upland Rivers, El Leithold, Ne Blair, Dw Perkey
VIMS Articles
To assess the role that erosion processes play in governing the character of particulate organic carbon (POC) discharged from small mountainous and upland rivers, a suite of watersheds from Oregon, California, and New Zealand was investigated. The rivers share similar geology, tectonic setting, and climate, but have sediment yields that range over 3 orders of magnitude. The (14)C age of the POC loads is highly correlated with sediment yield. Carbon isotope mass balances reveal that the rivers carry bimodal mixtures of modern-plant-and ancient-rock-derived OC. At lower yields, modern plant OC dominates the material delivered to the river by sheetwash and …
Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao
Hyperpycnal Discharge Of Fluvial Sediment To The Ocean: Impact Of Super‐Typhoon Herb (1996) On Taiwanese Rivers, John D. Milliman, Shuh-Ji Kao
VIMS Articles
Hyperpycnal events (when suspended sediment concentrations exceed 40 g/L) occur in small‐ and medium‐sized rivers throughout the world but are particularly common in Taiwan; they are often related to landslides or debris flows initiated and transported by typhoon floods. Super‐Typhoon Herb, which swept across Taiwan on July 31–August 2, 1996, triggered floods and landslides throughout the southern part of the island. Sediment concentrations in at least seven rivers (Taan, Choshui, Pachang, Erhjen, Tsengwen, Kaoping, and Peinan) approached or exceeded 40 g/L. Calculated sediment discharged from nine rivers (these seven as well as the Wu and Houlung, neither of which apparently …
Postimpact Deformation Associated With The Late Eocene Chesapeake Bay Impact Structure In Southeastern Virginia, Gerald H. Johnson, Sarah E. Kruse, Allison W. Vaughn, John K. Lucey, C. Hobbs, David S. Powars
Postimpact Deformation Associated With The Late Eocene Chesapeake Bay Impact Structure In Southeastern Virginia, Gerald H. Johnson, Sarah E. Kruse, Allison W. Vaughn, John K. Lucey, C. Hobbs, David S. Powars
VIMS Articles
Upper Cenozoic strata covering the Chesapeake Bay impact structure in southeastern Virginia record intermittent differential movement around its buried rim. Miocene strata in a graben detected by seismic surveys on the York River exhibit variable thickness and are deformed above the crater rim. Fan-like interformational and intraformational angular unconformities within Pliocene–Pleistocene strata, which strike parallel to the crater rim and dip2°–3° away from the crater center, indicate that deformation and deposition were synchronous.Concentric, large-scale crossbedded, bioclastic sand bodies of Pliocene age within ~20 km of the buried crater rim formed on offshore shoals, presumably as subsiding listric slump blocks rotated …
Ancient Channels Of The Susquehanna River Beneath Chesapeake Bay And The Delmarva Peninsula, Steven M. Colman, Jeffrey P. Halka, C. Hobbs, Robert B. Mixon, David S. Foster
Ancient Channels Of The Susquehanna River Beneath Chesapeake Bay And The Delmarva Peninsula, Steven M. Colman, Jeffrey P. Halka, C. Hobbs, Robert B. Mixon, David S. Foster
VIMS Articles
Three generations of the ancestral Susquehanna River system have been mapped beneath Chesapeake Bay and the southern Delmarva Peninsula. Closely spaced seismic reflection profiles in the bay and boreholes in the bay and on the southern Delmarva Peninsula allow detailed reconstruction of each paleochannel system. The channel systems were formed during glacial low sea-level stands, and each contains a channel-fill sequence that records the subsequent transgression. The trunk channels of each system are 2 to 4 km wide and are incised 30 to SO m into underlying strata; they have irregular longitudinal profiles and very low gradients within the Chesapeake …
Late Pleistocene Barrier-Island Sequence Along The Southern Delmarva Peninsula: Implications For Middle Wisconsin Sea Levels, Kenneth Finkelstein, Michael S. Kearney
Late Pleistocene Barrier-Island Sequence Along The Southern Delmarva Peninsula: Implications For Middle Wisconsin Sea Levels, Kenneth Finkelstein, Michael S. Kearney
VIMS Articles
Evidence for a middle Wisconsin sea-level high at or above modern limits along the east coast of the United States has long been controversial. Most reports have been dismissed as poorly dated or lacking unequivocal documentation of a marine transgression. We describe here a 14C-dated, middle Wisconsin transgressive sequence with an extant subaerial barrier facies along the southern Delmarva Peninsula. This sequence indicates that sea levels were near their present position between ca. 23 and 34 ka; it may correlate with other inferred similar-age littoral deposits of the area, and it suggests that the evidence for glacioeustatic fluctuations during the …
Possible Late Pleistocene Uplift, Chesapeake Bay Entrance, W. Harrison, Rj Malloy, Ga Rusnak, J Terasmae
Possible Late Pleistocene Uplift, Chesapeake Bay Entrance, W. Harrison, Rj Malloy, Ga Rusnak, J Terasmae
VIMS Articles
Paleontological and lithological studies of engineering borings and boring logs subaerial erosion surface of Pliocene (?)-Pleistocene age cuts across clastic sediments of pre-Yorktownian Miocene age in the subsurface and subbottom of the lower Chesapeake Bay area. When the bore-hole data are coupled with the results of subbottom echo profiling and piledriving records, it is possible to construct accurate cross sections of the buried Miocene-Pleistocene contact. The cross sections show "lows" in the erosion surface that may be correlated with the buried channels of the Pleistocene Elizabeth, James, York, and Susquehanna river valleys. Probable channel depths below mean low water at …