Physical Sciences and Mathematics Commons^™

Shifting Sands: Coastal Dunes In Motion, Elizabeth Davis

Reports

Grades: 5+ Subjects: General Science, Geology, Environmental Science

Students will use “before & after” dune profile graphics to determine how the dune has changed and hypothesize why this change occurred.

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 …

The Effect Of Coastal Landform Development On Decadal- To Millennial-Scale Longshore Sediment Fluxes: Evidence From The Holocene Evolution Of The Central Mid-Atlantic Coast, Usa - Sediment Core And Chronology Data, Justin L. Shawler, Christopher J. Hein, Chloe Obara, Mahina Robbins, Jennifer E. Connell, Sebastien Huot, Michael Fenster

Data

These data are sediment core, radiocarbon, and optically stimulated luminescence (OSL) data from the barrier islands and backbarrier lagoons, bays, and marshes of Assateague Island (VA, USA), Chincoteague Island (VA, USA), and Wallops Island (VA, USA). Vibracore data from Tom’s Cove, a backbarrier bay, were collected using a vibracore system with the ability to core through a ‘moonhole’ on a flat bottom boat. Geoprobe cores were collected using a track-mounted 66DT Geoprobe direct-push drill rig. Select samples from the sediment cores (associated with figures and tables in Shawler et al., 2021) were analyzed using a Beckman-Coulter Laser Diffraction Particle Size …

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

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 …

A Hydrodynamic-Sediment Transport Numerical Model For The Waipaoa Shelf, New Zealand: Model Archive, Julia Moriarty, Courtney K. Harris, Mark G. Hadfield

Data

No abstract provided.

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

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

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

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

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 …

The Chesapeake Bay : A Synopsis, William J. Hargis Jr.

Reports

No abstract provided.

Investigations Of Offshore Beach Sands : Virginia Beach And Sandbridge, Virginia, C. S. Hardaway, C. H. Hobbs Iii, D. A. Milligan

Reports

The City of Virginia Beach is faced with an ongoing problem of erosion along its ocean beaches. The "Resort Strip," the backbone of beach-going tourism in the Commonwealth, must be renourished annually. Steel bulkheads or seawalls have been constructed along most of the 7 km (4.5 mile) ocean shoreline of Sandbridge, a semi-private, ocean-side community. The City is looking for beach material to reestablish its sandy coast. Maintaining a protective and recreational beach is the_primary goal in both locales.

Previous sources of sand for the "Resort Strip" have been upland borrow pits that either have closed or are located too …

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 …

Sediments And Shallow Stratigraphy Of A Portion Of The Continental Shelf Of Southeastern Virginia, Carl H. Hobbs Iii

Reports

A network of high-resolution, seismic-reflection profiles and grab samples of the surficial sediments of the inner continental shelf of southeastern Virginia demonstrate that the Quaternary geology of the region is more complex than indicated by earlier studies. The spatial variability of the surficial sediments depicts active processes, such as outflow from Chesapeake Bay, as well as the underlying geology in outcrops of finer grained sediments near False Cape.

The complexity of the Quaternary geology results from large and small scale fluctuations in sea level. Individual, relatively large-scale, seismostratigraphic units are separated by erosional surfaces formed during the major changes in …

Geological And Geophysical Character Of The East China And Yellow Seas, John D. Milliman, Nicole D. Scott

Reports

The East China and Yellow seas represent one of the broadest shallow seas in the global ocean, with water depths generally less than 80 m and stretching nearly 750 km from the Shandong Peninsula to the Okinawa Trough (Fig. 1). This area is also unique in terms of the vast amount of sediment it receives from the Huanghe (Yellow River; presently discharging in the adjacent Gulf of Bohai) and the Changjigang (Yangtze River, which flows into the East China Sea). Together, this region receives about ten percent of the river-derived sediment reaching the ocean, and as such, the region has …

Yellow Sea & East China Sea Bibliography, Nicole D. Scott, Patricia T. Carrier, John D. Milliman

Reports

No abstract provided.

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 …

Pliocene And Pleistocene Depositional Environments On The York-James Peninsula, Virginia; A Field Guidebook, Gerald H. Johnson, Carl H. Hobbs Iii

Reports

The late Cenozoic deposits of southeastern Virginia represent a wide variety of depositional environments and record numerous marine transgressions. The formations range in age from Miocene to Holocene. This fieldguide provides an opportunity to visit and sample highly fossilferous marine bay and fluvial-estuarine sediments exposed in river bluffs and borrow pits on the York-James Peninsula.

Study Of Economic Heavy Minerals Of The Virginia Inner Continental Shelf, C. R. Berquist, C. H. Hobbs Iii

Reports

No abstract provided.

Reconnaissance Of Economic Heavy Minerals Of The Virginia Inner Continental Shelf, C. R. Berquist, C. H. Hobbs Iii

Reports

No abstract provided.

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 …

Occurrence And Distribution Of Shell In The Vicinity Of Parker's Rock, Pocomoke Sound, Carl H. Hobbs Iii

Reports

This is a summary report on the investigation of the occurrence and distribution of shell in the vicinity of Parker's Rock. Pocomoke Sound. The investigation was performed by the Virginia Institute of Marine Science at the request and with the financial support of the Virginia Marine Resources Commission. The site (Figure 1) was selected. primarily. at the direction of the Commission. acting on the recommendation of its shell-dredging contractor and. secondarily. with supporting reconnaissance seismic data from VIMS.

Assessment Of Economic Heavy Minerals Of The Virginia Inner Continental Shelf, C. R. Berquist, C. Hobbs

Reports

The Virginia Division of Mineral Resources and the Virginia Institute of Marine Science jointly made three cruises over the Virginia continental shelf in April and July of 1985 to sample known heavy-mineral sites for minerals of potential economic and/or strategic value. In addition to sampling, side-scan sonar and sub-bottom profiling surveys were performed at a site off Smith Island. At the Smith Island site, as many as four acoustic horizons were detected within the upper 6 meters of sediment. The uppermost seismostratigraphic layer consists of fine and very fine sand and contains the higher concentrations of heavy minerals. There are …

Metal Inventory And Fate Of Suspended Sediment In Chesapeake Bay, Maynard M. Nichols, Galen Thompson, Bruce Nelson

Reports

This report aims to provide new information that meets selected objectives of the EPA-States Taxies Plan of Action: i.e. (1) to determine the state of the Bay with respect to the distribution and concentration of selected metals in suspended material and fluid mud; (2) to establish the temooral variations of sediment and metal loading: (3) to identify potential zones of metal accumulation and trace their transport routes, and (4) to provide recommendations for monitoring contaminated sediment.

Field observations provide longitudinal coverage of the Bay with transects into Baltimore Harbor and Hampton Roads. They include contrasting conditions of seasonal high-low river …

Baseline Sediment Studies To Determine Distribution, Physical Properties, Sedimentation Budgets And Rates In The Virginia Portion Of The Chesapeake Bay : Final Report, Robert J. Byrne, Carl H. Hobbs Iii, Michael J. Carron

Reports

No abstract provided.

Heavy Metal Inventory Of Suspended Sediment And Fluid Mud In Chesapeake Bay, Richard Harris, Maynard M. Nichols, Galen Thompson, John Banacki, George Vadas

Reports

Heavy metals have been found associated with suspended material, sediments and fluid mud in the Chesapeake Bay. A series of field observations were made along the Bay axis to determine the metal concentrations and their distributions at relatively high and at average river inflow between March 27-April 9 and May 2-10, 1979.

Metal concentrations in suspended material per unit volume of water relate to the concentrations of suspended material. They are higher in the zone of the turbidity maximum than landward in river water or seaward in estuarine water. Thus, metals associated with suspended material tend to accumulate in the …

Estuarine Fluid Mud : Its Behavior And Accumulation, Maynard M. Nichols, Richard Faas, Galen Thompson

Reports

A study of fluid mud in Virginia estuaries was conducted to determine how the mud accumulates in a dynamic tidal flow regime. The mud occurs as lenses and blanket deposits in zones of fast sedimentation, i.e. on channel floors and in the turbidity maximum zone. Viscosity measurements indicate resuspension potential of the mud is greater in the turbidity maximum than elsewhere.

Middle Atlantic Outer Continental Shelf Environmental Studies Volume Ii-C: Chemical And Biological Benchmark Studies, E. M. Burreson, D. F. Boesch, B. L. Laird

Reports

The Middle Atlantic Outer Continental Shelf Environmental Studies is comprised of three volumes.

• Volume I. Executive Summary.
• Volume IIA, IIB, IIC and IID. Chemical and Biological Benchmark Studies.
• Volume III. Geologic Studies.

This is the third of four sections of the Chemical and Biological Benchmark Studies

• CHAPTER 9. COMMUNITY STRUCTURE ANALYSIS AND FOOD HABITS OF FISHES by George R. Sedberry, Eric J. Foell and John A. Musick
• CHAPTER 10. HISTORICAL COMMUNITY STRUCTURE ANALYSIS OF FINFISHES by John A. Musick, James A. Colvocoresses and Eric J. Foell
• CHAPTER 11. BACTERIOLOGY by Howard J. Kator

Chapters of …

Middle Atlantic Outer Continental Shelf Environmental Studies Volume Iii: Geologic Studies, Harley J. Knebel, Et Al

Reports

The Middle Atlantic Outer Continental Shelf Environmental Studies is comprised of three volumes.

• Volume I. Executive Summary.
• Volume IIA, IIB, IIC and IID. Chemical and Biological Benchmark Studies.
• Volume III. Geologic Studies.

This third volume in the study contains the following:

• CHAPTER 1. INTRODUCTION by Harley J. Knebel
• CHAPTER 2. BOTTOM CURRENTS AND BOTTOM SEDIMENT MOBILITY IN THE OFFSHORE MIDDLE ATLANTIC BIGHT, 1976-1977 by Bradford Butman and Marlene Noble
• CHAPTER 3. SESTON IN MIDDLE ATLANTIC SHELF AND SLOPE WATERS 1976-1977 by John D. Milliman, Michael H. Bothner, and Carol M. Parmenter
• CHAPTER 4. SUBMERSIBLE OBSERVATIONS …