Late Holocene Evolution of Currituck Sound, North Carolina, USA

Late Holocene Evolution of Currituck Sound, North Carolina, USA PDF Author: Kelli Moran
Publisher:
ISBN:
Category : Currituck Sound (N.C.)
Languages : en
Pages : 102

Get Book Here

Book Description
Coastal evolution is an increasingly important area of study, especially with the projected rise in sea level, increase in storm intensity, and population increases along the nation's coasts. In order to predict how the coastal environment will respond to these changes in the future, we need to first understand the evolution of coastal systems in the past. Here I address the late Holocene evolution of Currituck Sound, North Carolina, by examining time periods with different barrier island and inlet configurations interpreted from core data. Chirp seismic data and 13 vibracores have been used to interpret the Holocene development of this region. Four depositional units have been defined, based on lithofacies, biofacies, geophysical, and geochronologic data. The lowermost depositional unit (Unit I) is represented by quartz sand, barren of foraminifera, and is Pleistocene in age based on an OSL age estimate of 33.7 ka. Unit II consists of slightly muddy sand that fines upward to slightly sandy mud; it is barren of foraminifera, contains rooted horizons in several cores, and is interpreted as a fresh water swamp forest deposit (radiocarbon dating provide age estimates of ca. 4000 to 2800 cal y BP). Unit III is characterized by slightly sandy mud to mud containing a calcareous foraminiferal assemblage and oyster bioherms; these characteristics indicate a back-barrier estuarine environment with high salinity (ca. 25 to 35) due to open inlets in the barrier islands to the east. Radiocarbon age estimates for Unit IV range from ca. 1700 to 500 cal y BP. The topmost unit (Unit IV) is composed of sediment with variable composition, ranging from clean quartz sand to mud, and contains foraminiferal assemblages that are generally mixed calcareous/agglutinated at the base overlain by entirely agglutinated assemblages. This unit represents the modern (post- ca. 1827), mid- to low salinity (less than 10), back-barrier lagoon with no inlets open in the barrier island. Sediment and microfossil-based paleoenvironmental and geomorphic reconstructions, including variable numbers of inlets, have been used as input into the Delft3D hydrodynamic model to understand inlet related changes to tides and currents within the Sound. This modeling indicates that impacts of inlets are very localized and only inlets in the direct vicinity of Currituck Sound (i.e., between historic Caffey's Inlet and Kill Devil Hills) have a significant impact on the water levels and currents in the study area.

Late Holocene Evolution of Currituck Sound, North Carolina, USA

Late Holocene Evolution of Currituck Sound, North Carolina, USA PDF Author: Kelli Moran
Publisher:
ISBN:
Category : Currituck Sound (N.C.)
Languages : en
Pages : 102

Get Book Here

Book Description
Coastal evolution is an increasingly important area of study, especially with the projected rise in sea level, increase in storm intensity, and population increases along the nation's coasts. In order to predict how the coastal environment will respond to these changes in the future, we need to first understand the evolution of coastal systems in the past. Here I address the late Holocene evolution of Currituck Sound, North Carolina, by examining time periods with different barrier island and inlet configurations interpreted from core data. Chirp seismic data and 13 vibracores have been used to interpret the Holocene development of this region. Four depositional units have been defined, based on lithofacies, biofacies, geophysical, and geochronologic data. The lowermost depositional unit (Unit I) is represented by quartz sand, barren of foraminifera, and is Pleistocene in age based on an OSL age estimate of 33.7 ka. Unit II consists of slightly muddy sand that fines upward to slightly sandy mud; it is barren of foraminifera, contains rooted horizons in several cores, and is interpreted as a fresh water swamp forest deposit (radiocarbon dating provide age estimates of ca. 4000 to 2800 cal y BP). Unit III is characterized by slightly sandy mud to mud containing a calcareous foraminiferal assemblage and oyster bioherms; these characteristics indicate a back-barrier estuarine environment with high salinity (ca. 25 to 35) due to open inlets in the barrier islands to the east. Radiocarbon age estimates for Unit IV range from ca. 1700 to 500 cal y BP. The topmost unit (Unit IV) is composed of sediment with variable composition, ranging from clean quartz sand to mud, and contains foraminiferal assemblages that are generally mixed calcareous/agglutinated at the base overlain by entirely agglutinated assemblages. This unit represents the modern (post- ca. 1827), mid- to low salinity (less than 10), back-barrier lagoon with no inlets open in the barrier island. Sediment and microfossil-based paleoenvironmental and geomorphic reconstructions, including variable numbers of inlets, have been used as input into the Delft3D hydrodynamic model to understand inlet related changes to tides and currents within the Sound. This modeling indicates that impacts of inlets are very localized and only inlets in the direct vicinity of Currituck Sound (i.e., between historic Caffey's Inlet and Kill Devil Hills) have a significant impact on the water levels and currents in the study area.

Barrier Dynamics and Response to Changing Climate

Barrier Dynamics and Response to Changing Climate PDF Author: Laura J. Moore
Publisher: Springer
ISBN: 3319680862
Category : Science
Languages : en
Pages : 407

Get Book Here

Book Description
This book presents chapters, written by leading coastal scientists, which collectively depict the current understanding of the processes that shape barrier islands and barrier spits, with an emphasis on the response of these landforms to changing conditions. A majority of the world’s population lives along the coast at the dynamic intersection between terrestrial and marine ecosystems and landscapes. As narrow, low-lying landforms, barriers are especially vulnerable to changes in sea level, storminess, the geographic distribution of grass species, and the rate of sand supply—some barriers will undergo rapid changes in state (e.g., from landward migrating to disintegrating), on human time scales. Attempts by humans to prevent change can hasten the loss of these landforms, threatening their continued existence as well as the recreational, financial and ecosystem service benefits they provide. Understanding the processes and interactions that drive landscape response to climate change and human actions is essential to adaptation. As managers and governments struggle to plan for the future along low-lying coasts worldwide, and scientists conduct research that provides useful guidance, this volume offers a much-needed compilation for these groups, as well as a window into the science of barrier dynamics for anyone who is generally interested in the impacts of a changing world on coastal environments.

Erosional Scour and Geologic Evolution of Croatan Sound, Northeastern North Carolina

Erosional Scour and Geologic Evolution of Croatan Sound, Northeastern North Carolina PDF Author: Stanley R. Riggs
Publisher:
ISBN:
Category : Coast changes
Languages : en
Pages : 238

Get Book Here

Book Description


Late Holocene Geologic Evolution of Central Ocracoke Island, Outer Banks, North Carolina

Late Holocene Geologic Evolution of Central Ocracoke Island, Outer Banks, North Carolina PDF Author: Michael E. Hale
Publisher:
ISBN:
Category : Archaeological geology
Languages : en
Pages : 426

Get Book Here

Book Description


Coastal Sediments 2019 - Proceedings Of The 9th International Conference

Coastal Sediments 2019 - Proceedings Of The 9th International Conference PDF Author: Ping Wang
Publisher: World Scientific
ISBN: 9811204497
Category : Technology & Engineering
Languages : en
Pages : 3050

Get Book Here

Book Description
This Proceedings contains over 260 papers on cutting-edge research presented at the 9th International Conference on Coastal Sediments 2019 (CS19), held in Tampa/St. Petersburg, Florida, USA from May 27-31, 2019. This technical specialty conference is devoted to promoting an interdisciplinary exchange of state-of-the-art knowledge among researchers in the fields of coastal engineering, geology, oceanography, and related disciplines.With the theme of 'Advancing Science & Engineering for Resilient Coastal Systems', this Proceedings covers a wide range of research topics on coastal sediment processes from nearshore sediment transport and modelling to beach processes, shore protection, and coastal management.

Holocene Evolution of a Drowned Tributary Estuary, Croatan Sound, North Carolina

Holocene Evolution of a Drowned Tributary Estuary, Croatan Sound, North Carolina PDF Author: Greg L. Rudolph
Publisher:
ISBN:
Category : Croatan Sound (N.C.)
Languages : en
Pages : 474

Get Book Here

Book Description


The North Carolina Historical Review

The North Carolina Historical Review PDF Author:
Publisher:
ISBN:
Category : North Carolina
Languages : en
Pages : 130

Get Book Here

Book Description


Extension of the Late Holocene Sea-level Record in North Carolina, USA

Extension of the Late Holocene Sea-level Record in North Carolina, USA PDF Author: Jessica Kegel
Publisher:
ISBN:
Category : Cedar Island (Carteret County, N.C. : Island)
Languages : en
Pages : 83

Get Book Here

Book Description
Future sea-level rise will dramatically affect coastal landscapes and populations. The coast of North Carolina (USA) is particularly vulnerable to sea-level rise because its low-lying coastal plain is expansive, has a low gradient, provides significant ecosystem services and is economically important. In order to understand how future sea-level rise may affect the coast, it is necessary to study past sea-level rise. Widespread salt-marshes compose much of North Carolina's coastal system, providing an excellent environment from which to produce relative sea-level reconstructions using salt-marsh foraminifera, whose distribution is controlled by tidal elevation. Distinctive assemblage zones related to different tidal ranges can be recognized in salt-marsh foraminiferal assemblages, allowing them to be used as a proxy for reconstructing sea level as sea-level indicators. Foraminiferal assemblages from surface samples along two transects at Sand Hill Point on Cedar Island, North Carolina added to an existing modern training set of paired observations of foraminiferal assemblages and tidal elevation; these data provide local analogues for interpreting fossil assemblages using a locally weighted-weighted average (LWWA) regression model. Foraminiferal assemblages preserved in a radiocarbon-dated core of salt-marsh peat from Sand Hill Point were used to produce a continuous, high-resolution late Holocene relative sea-level reconstruction. The existing late Holocene RSL reconstruction from North Carolina is based on two sites: Sand Point on Roanoke Island and Tump Point on Cedar Island. The Sand Point record spans the last ~2200 years, but the Tump Point record spans only the last ~1000 years. Therefore, the sea-level history described from 200 BC to 1000 AD is based on only one site. The new sea-level reconstruction from Sand Hill Point extends the existing record from nearby Tump Point, NC by 1400 years, producing a high resolution, continuous record of sea-level change spanning 1500 BC - 1915 AD. This new record tests whether patterns and rates of late Holocene sea-level changes reconstructed elsewhere in North Carolina are consistent throughout the region. The calculated average rate of relative sea-level rise for Sand Hill Point of 0.7 mm/year is consistent with patterns of regional rates along the US Atlantic coast, which may be partly attributed to isostatic response to deglaciation of the Laurentide Ice Sheet.

Using Sediment Organic Geochemistry to Interpret Late Holocene Barrier Island and Estuarine Evolution, North Carolina, USA

Using Sediment Organic Geochemistry to Interpret Late Holocene Barrier Island and Estuarine Evolution, North Carolina, USA PDF Author: Jeffrey J. Minnehan
Publisher:
ISBN:
Category : Albemarle Sound (N.C.)
Languages : en
Pages : 136

Get Book Here

Book Description
Deconvolving the relationship between meteorological and oceanographic phenomena and associated impacts to coastal systems is critical to understanding the future of coastal systems worldwide. North Carolina's barrier islands, commonly known as the Outer Banks, and the associated Albemarle-Pamlico estuarine system is an example of a coastal ecosystem that will be affected in the future by such phenomena. Based on sedimentological and micropaleontological proxies, past research suggests that intense storm activity may have caused extensive segmentation of the Outer Banks during the Holocene. To gain a better understanding of meteorological and oceanographic factors affecting the evolution of North Carolina's coastal system, organic geochemical techniques were applied to sediments from two cores collected within Pamlico Sound. Specifically, down-core trends in total organic carbon (TOC), refractory black carbon (BC), refractory soot carbon, labile organic carbon (OC), total nitrogen (TN), and their stable isotopic signatures ([delta]13C and [delta]15N) were analyzed in order to assess the varying inputs of marine and terrestrial organic matter into Pamlico Sound. In Chapter 1, TOC, BC/TOC, soot/TOC, TOC/TN, and [delta]13C[subscript]TOC were compared to a paleoclimatological proxy of El Niño Southern Oscillation (ENSO) and interpretations of stages of the North Atlantic Oscillation (NAO) throughout the mid-to-late Holocene. These phenomena have been suggested to influence southeast U.S. temperature, precipitation, and Atlantic hurricanes, all of which ultimately affect barrier island and estuarine evolution, as recorded in Pamlico Sound sediments. In general, there has been little consideration of carbon sequestered in coastal systems throughout the Holocene, a period that shows anthropogenic changes in the carbon cycle. This is an important omission, as most of the sediments exported by the world's major rivers are currently deposited on continental shelves (e.g., deltas and estuaries). Chapter 2 examines how the degree of barrier island segmentation affects abundance and source of carbon sequestered in Pamlico Sound throughout the mid-to-late Holocene. Total organic carbon sequestered in Pamlico Sound was calculated over the past 3500 years. Since the ultimate fate of TOC depends on its composition (e.g., whether it is labile or refractory), both OC and BC in sediments were quantified down-core. Results show that greater continuity of a barrier island chain significantly increased the amount of carbon sequestered in sediments. To our knowledge, this chapter provides the first quantitative estimate of the amount of carbon sequestered as a function of its composition since the mid-Holocene in any coastal system. The results of both chapters suggest that ENSO, NAO, eastern North Carolina temperature and precipitation, Atlantic storm activity, Outer Banks barrier island evolution, and coastal carbon sequestration were linked throughout the mid-to-late Holocene.

Late Holocene Evolution of a Retrograding Barrier

Late Holocene Evolution of a Retrograding Barrier PDF Author: Benjamin Adam McGinnis
Publisher:
ISBN:
Category : Barrier islands
Languages : en
Pages : 194

Get Book Here

Book Description