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Author: Jessica Kegel
Publisher:
ISBN:
Category : Cedar Island (Carteret County, N.C. : Island)
Languages : en
Pages : 83
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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.
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.
Author: Kelli Moran
Publisher:
ISBN:
Category : Currituck Sound (N.C.)
Languages : en
Pages : 102
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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.
Author: Leslie Reeder-Myers
Publisher: University Press of Florida
ISBN: 0813057264
Category : Social Science
Languages : en
Pages : 308
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Book Description
Using archaeology as a tool for understanding long-term ecological and climatic change, this volume synthesizes current knowledge about the ways Native Americans interacted with their environments along the Atlantic Coast of North America over the past 10,000 years. Leading scholars discuss how the region’s indigenous peoples grappled with significant changes to shorelines and estuaries, from sea level rise to shifting plant and animal distributions to European settlement and urbanization. Together, they provide a valuable perspective spanning millennia on the diverse marine and nearshore ecosystems of the entire Eastern Seaboard—the icy waters of Newfoundland and the Gulf of Maine, the Middle Atlantic regions of the New York Bight and the Chesapeake Bay, and the warm shallows of the St. Johns River and the Florida Keys. This broad comparative outlook brings together populations and areas previously studied in isolation. Today, the Atlantic Coast is home to tens of millions of people who inhabit ecosystems that are in dramatic decline. The research in this volume not only illuminates the past, but also provides important tools for managing coastal environments into an uncertain future. A volume in the series Society and Ecology in Island and Coastal Archaeology, edited by Victor D. Thompson
Author: Nicholas Zaremba
Publisher:
ISBN:
Category :
Languages : en
Pages : 109
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Book Description
Holocene Stratigraphy and Paleoenvironmental Change of Pamlico Sound, North Carolina, USA by Nicholas Zaremba September, 2014 Directors of Thesis: David Mallinson and Eduardo Leorri Major Department: Geological Sciences. Understanding how coastal systems respond to changes in climate is becoming more important due to the current increased rate of sea-level rise and possible increased hurricane intensity in the future. While coastal ecosystems represent only 10% of Earth's surface, more than 20% of the world's population resides within 100 km of the coastline and within 100 m of sea level, which highlights the need to understand the past effects of sea-level rise and climate change on barrier island systems. In North Carolina, USA the barrier island system in the northern portion of the state (the Outer Banks) extends for ca. 270 km of the state's coast and provides a dynamic boundary between the ocean and two large estuarine water bodies, Albemarle and Pamlico Sound. This study expands upon previous work which identified two periods of increased marine influence within Pamlico Sound interpreted to be the result of extensive barrier island segmentation synchronous with periods of rapid climate change (RCC) during the late Holocene. Approximately 470 km of high resolution geophysical data, 850 bulk sediment magnetic susceptibility sediment samples and ca. 600 sediment analyses were constrained by 108 radiocarbon age estimates derived from 52 vibracores to better understand the Holocene stratigraphy of Pamlico Sound and how the periods of RCC affected the stratigraphic architecture of the Sound. According to previous work, estuarine waters prevailed within the paleovalleys of Pamlico Sound as early as ca. 7500 cal BP and Pleistocene interfluves provided protection for the paleovalleys from the Atlantic Ocean until ca. 5500 cal BP, when the interfluves were flooded by rising sea-level, this interpretation is based on a conservative sea-level rise. However, the data provided in this study indicates that there is no evidence of a change in depositional environment at ca. 5500 cal BP. If the 5500 cal BP flooding of the Pleistocene interfluves is accurate, then Holocene barrier islands must have been present to explain the presence of estuarine deposits within the paleovalleys. At ca. 4000 cal BP, an increase in marine influence and sand content is detected in multiple cores within the northern basin and is interpreted to be the result of increased segmentation of barrier islands. This deposit is mainly recorded within the paleovalleys of Pamlico Sound; and is only preserved on a few interfluves as a result of base level being too low. Reformation of the barrier islands occurred sometime from 3500 to 2500 cal BP; suggested by muddy deposits with low brackish estuarine foraminiferal assemblages. At ca. 1200 cal BP, a sudden increase in marine influence is detected throughout southeastern Pamlico Sound; a sandy deposit is interpreted to be the result of extensive segmentation of the barrier islands during the Medieval Climate Anomaly (MCA). Geophysical data suggests the segmentation of the barriers was large in magnitude to allow for deposition of large lobate shoals (the MCA shoals). Further refinement of a local sea-level curve is required to understand the mechanisms responsible for the 4000 cal BP marine influenced deposit. The error range of the North Carolina sea-level curve loosely constrain the initial flooding of the Pleistocene interfluves anytime from 5500 to 4000 cal BP rather than before 7000 cal BP as previously postulated. Therefore, it is difficult to hypothesize about the mechanism responsible for the 4000 cal BP sandy deposit without a more refined local sea level curve. However, data from this study combined with other research suggest that the 1200 cal BP deposit was likely caused by an increase in hurricane activity or intensity during the MCA. Furthermore this study has provided an estimate on the volume (1.1x109 km3) of silt and clay deposited within the northern basin of Pamlico Sound since ca. 4000 cal BP; this has aided in creating a carbon sequestration budget for the system.
Author: Simin Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 96
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Book Description
Author: D.B. Scott
Publisher: Springer Science & Business Media
ISBN: 9400908733
Category : Science
Languages : en
Pages : 232
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Book Description
A NATO Advanced Study Institute, "Late Quaternary Sea-level Correlation and Applications", was held together with the Final Meeting of IGCP Project 200 in Halifax, Canada, 19-30 July 1987. This Volume is a collection of the NATO Keynote Papers presented at this meeting. The authors of these papers are from seven of the NATO countries - two each from France, the U. K. , Canada, and the U. S . A. , and one each from Spain, Germany and the Netherlands. With these authors, we are able to assemble work from virtually all of the world's oceans with several different approaches. The Volume is dedicated to Walter S. Newman, one of the best known and best liked sea-level workers of our time who died shortly before this Conference. This Volume contains one of his last contributions and all contributors to this Volume are honoured to be in the company of Walter's last work. There are several papers from North Atlantic countries dealing with Holocene sea level in a variety of ways. Shennan summarizes data from the U. K. and makes a preliminary effort to place the data in the context of a model. Zazo & Goy present new data from the coast of Spain and place it in a stratigraphical context. Van de P1assche re assesses previous data and adds new data to the very sea-level sensitive Dutch coast. Leatherman uses sea-level information in the Chesapeake Region to assess coastal management problems.
Author: Charles W. Finkl
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 440
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Author: R. Scott Anderson
Publisher:
ISBN:
Category : Sea level
Languages : en
Pages : 22
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Author:
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 592
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Book Description
Author: Colin V. Murray-Wallace
Publisher: Cambridge University Press
ISBN: 1139867156
Category : Science
Languages : en
Pages : 503
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Book Description
There have been significant changes in sea level over the past two million years, and a complete understanding of natural cycles of change as well as anthropogenic effects is imperative for future global development. This book reviews the history of research into these sea-level changes and summarises the methods and analytical approaches used to interpret evidence for sea-level changes. It provides an overview of changing climates during the Quaternary, examines processes responsible for global variability of sea-level records, and presents detailed reviews of sea-level changes for the Pleistocene and Holocene. The book concludes by discussing current trends in sea levels and likely future sea-level changes. This is an important and authoritative resource for academic researchers and graduate and advanced undergraduate students working in tectonics, stratigraphy, geomorphology, physical geography, environmental science and other aspects of Quaternary studies.
