Download or read book Reconstruction of Holocene Sea level Changes Using Foraminifera and Vertical Tectonic Movements Ohiwa Harbour Bay of Plenty New Zealand written by Emma Wiggins and published by . This book was released on 2002 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantifying Holocene Sea level Change Using Intertidal Foraminifera written by Benjamin P. Horton and published by . This book was released on 2006 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Salt Marsh Foraminiferal Proxy Record of Late Holocene Sea level Rise South Island New Zealand written by Brigida Orioli Figueira and published by . This book was released on 2012 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Day Assemblages of Foraminifera and the Reconstruction of Sea levels in Ohiwa Harbour New Zealand thesis written by Katherine Southall and published by . This book was released on 2002 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Sea Level Change in the Western North Pacific Marginal Seas and Coastal Responses to Recent Sea Level Change in the Deep Bay Wetlands written by Yiying Sun and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Holocene Sea Level Change in the Western North Pacific Marginal Seas and Coastal Responses to Recent Sea Level Change in the Deep Bay Wetlands" by Yiying, Sun, 孙奕映, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The coast of East and Southeast Asia is a far-field region and thus a scientifically valuable site for sea level and coastal study. The high population density in low-lying coastal areas of this region means a high vulnerability to human society if sea level is going to rise in the future. This research is designed to tackle two scientific issues: (1) Analyze the past local land level change including the levering effect and tectonic movements; and (2) Investigate how coastal system have responded to past sea level change. In order to tackle the first issue, three glacial isostatic adjustment (GIA) models were simulated to produce a series of predictions for the study area, and 560 sea level data from published sources were re-analyzed and re-calibrated to convert them into useable sea level index points for sea level reconstructions. After a comparison between the model predictions and the reconstructed sea level histories, the effects of GIA, levering effects and tectonic movements are identified and assessed. The results show the three coastal sectors have had different responses to sea-level change. The Sundaland Block as a teconically stable region is more sensitive to GIA intensity changes. The Cathaysian Block is also sensitive to GIA intensity changes. But the coast was affected by small magnitude, localized uplift and subsidence. These tectonic movements can be clearly distinguished from the GIA processes, paving the way for eventual quantification of land movements. The Yangtze Block and North China Craton are located in low to middle latitudes, but still show characteristics of far-field GIA. Tectonic movement in this sector is relatively negligible, except the west Bohai Bay where subsidence is more obvious. For the second issue, the sedimentary sequence of a protected coastal wetland (Mai Po) in Hong Kong was investigated. Its developmental history and how it has responded to the past sea level change were examined. The results show, before 1000 years ago, the Mai Po area was a subtidal area, with sandy silt and abundant marine shells deposited in seabed implying an environment under deeper water and with better sea water exchange. A change took place about 800 years ago, and the area became a low energy environment with finer sediment and no marine shell. Soon after this, the sedimentation slowed down markedly possibly due to a fall in sea level. By about 200 years ago, mangrove vegetation colonized the site and kept expanding seawards progressively. In the past 100 years, due to human activity in the Deep Bay area, sedimentary supply from both Hong Kong and Shenzhen has increased. As sea level has also risen, another phase of rapid sedimentation takes place in the lower part of the mangrove forest and current mudflats. Subjects: Sea level - South China Sea Sea level - Yellow Sea Sea level - East China Sea Geology, Stratigrahic - Holcene
Download or read book A Reconstruction of Holocene Sea Level Change Between 6 180 to 3 640 Cal Years BP for the Gordano Valley Using Foraminifera written by Joel Pimm and published by . This book was released on 2007 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Level Change written by National Research Council and published by National Academies Press. This book was released on 1990-02-01 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea-level rise may be one of the consequences of global warming. To understand changes in sea level caused by the "greenhouse effect," we must understand the factors that have caused the sea level to fluctuate significantly throughout history. This new volume explores current views among scientists on the causes and mechanisms of sea-level change. The authors examine measurement programs and make recommendations aimed at improving our understanding of the factors that affect sea level. It will be welcomed by scientists, engineers, and policymakers concerned about "greenhouse" issues and sea-level change, the environmental community, researchers, and students.
Download or read book Holocene Sea Level Changes in the Netherlands written by Saskia Jelgersma and published by . This book was released on 1961 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extension of the Late Holocene Sea level Record in North Carolina USA written by Jessica Kegel and published by . This book was released on 2015 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Quaternary Sea Level Changes written by Colin V. Murray-Wallace and published by Cambridge University Press. This book was released on 2014-01-30 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Foraminiferal Modern Analogue for Reconstructing Holocene Relative Sea level Change in South Wales UK written by Adrian Kolander and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea level Changes written by Cheryl K. Wilgus and published by . This book was released on 1988 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Sea level Change in the Pacific Northwest written by Ian Hutchinson and published by . This book was released on 1992 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Sea level Change in the New Zealand Archipelago and the Geomorphic Evolution of a Holocene Coastal Plain Incised valley System written by Alastair John Hopton Clement and published by . This book was released on 2011 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Cycles written by Charles W. Finkl and published by . This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Land ocean Interaction and Environmental Change Around the North Sea written by Geological Society of London and published by Geological Society of London. This book was released on 2000 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Holocene Sea level Change Across the Indo pacific written by Juliette Harrington and published by . This book was released on 2014 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Utilising reconstructed sunspot data, a statistically significant correlation between sunspot forcing and both palaeo and modern sea-level change was found. Evidence suggests that Indo-Pacific highstands occur over decadal to centennial timescales. The cause of these sea-level highstands (or maximum sea-level height prior to sea-level fall) is still under debate. Previous observational studies suggested that the underlying mechanisms of ENSO are responsive to solar forcing variations over decades to centuries. Here it is shown that sunspot forcing and low-frequency ENSO results in highstands across the Indo-Pacific. Operating at interannual timescales, El Nino relates to sea-level fall in the west Pacific and positive IOD relates to sea-level fall in the east Indian Ocean, while La Nina and negative IOD have the opposite effect. A statistically significant correlation between modern sunspot and both El Nino/posIOD and La Nina/negIOD has been identified. The latter may suggest a low-frequency correlation between sunspot increase and sea-level rise in addition to the correlation between sunspot decrease and sea-level fall. Thus, parameters used in current models may need to be adjusted to include the effects of solar forcing on sea-level change for past and future quantification. Decadal to centennial sea-level change has been shown to occur at a meter-scale level. Predicted global warming and an increase in sunspot forcing may have critical future implications for low-lying coastal and island communities across the Indo-Pacific, including high-density locations such as Sydney, Darwin, and Broome. This new empirical theory that suggests a pattern of sea-level change may act as a guide to understanding prehistoric movements across the Pacific and elsewhere. Decreased solar forcing and sea-level fall over decades to centuries is associated with widespread aridity, diminished reef fishing and island abandonment in the mid to west equatorial Pacific. During this time weakened southeast Tradewinds may have facilitated seafaring networks, and both eastward and higher latitude maritime migrations. The timing of these statistically correlated environmental occurrences is co-incident with Pacific migrations including the Lapita migration, and both pulses of the Polynesian expansion. These results suggest that long-term environmental change was an important contributing factor on the timing and motivation for prehistoric Pacific maritime migration. Further these findings suggest that the hotly debated AD1300 event was not an isolated incident but rather one of a number of sustained environmental conditions that occurred over the Holocene in response to decreased solar forcing.
