Download or read book HOLOCENE SEA LEVEL CHANGE IN T written by Yiying Sun and published by Open Dissertation Press. This book was released on 2017-01-26 with total page 166 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 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 Sea level Changes and Their Effects written by John Noye and published by World Scientific. This book was released on 2001 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains updated, reviewed versions of some selected papers on OC Sea-Level Changes and their EffectsOCO presented at the International Ocean and Atmosphere Pacific Conference (OAP 95), held in Adelaide, South Australia, 23OCo27 October 1995. In addition several reviewed articles on important topics not covered by the papers presented at OAP 95 were invited. The articles in this volume will find an audience among coastal developers, marine biologists and environmentalists. They cover a range of topics including the efforts of long-term sea-level rise on coastal flows and its impact on mangrove communities, the determination of long-term sea-level change relative to the vertical motion of the land, to the numerical modelling of short term sea-level changes due to tides, tsunamis and the weather. Contents: Sea-Level Change in the Pacific (P D Nunn); Effects of Sea-Level Rise on the Hydrodynamics of a Coral Reef Lagoon: Kaneohe Bay, Hawaii (C J Hearn & M J Atkinson); Possible Impacts of Predicted Sea-Level Rise on South Pacific Mangroves (J Ellison); Monitoring Sea Level: Who''s Monitoring the Land? (S M Turner & G M Homes); Relative Sea-Level Change and Geologic Corrections to South Australian Tide Gauge Records (E J Barnett & N Harvey); Low Frequency Sea Level Variability in the Western Tropical Pacific 1992OCo1998 (J-M Verstraete); An Analysis of Variance in Pacific Tide Gauge Data (J L Luick); Hindcast Modelling of Recent Tsunamis in the Australian Region (W M Mitchell et al.); Adaptation Policies-Addressing Climate Change Impacts in the Pacific Region (C Kaluwin). Readership: Students and scientists working on sea level-changes and their effects."

Download or read book The Ocean and Cryosphere in a Changing Climate written by Intergovernmental Panel on Climate Change (IPCC) and published by Cambridge University Press. This book was released on 2022-04-30 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for assessing the science related to climate change. It provides policymakers with regular assessments of the scientific basis of human-induced climate change, its impacts and future risks, and options for adaptation and mitigation. This IPCC Special Report on the Ocean and Cryosphere in a Changing Climate is the most comprehensive and up-to-date assessment of the observed and projected changes to the ocean and cryosphere and their associated impacts and risks, with a focus on resilience, risk management response options, and adaptation measures, considering both their potential and limitations. It brings together knowledge on physical and biogeochemical changes, the interplay with ecosystem changes, and the implications for human communities. It serves policymakers, decision makers, stakeholders, and all interested parties with unbiased, up-to-date, policy-relevant information. This title is also available as Open Access on Cambridge Core.

Download or read book Sea Level Rise for the Coasts of California Oregon and Washington written by National Research Council and published by National Academies Press. This book was released on 2012-12-06 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tide gauges show that global sea level has risen about 7 inches during the 20th century, and recent satellite data show that the rate of sea-level rise is accelerating. As Earth warms, sea levels are rising mainly because ocean water expands as it warms; and water from melting glaciers and ice sheets is flowing into the ocean. Sea-level rise poses enormous risks to the valuable infrastructure, development, and wetlands that line much of the 1,600 mile shoreline of California, Oregon, and Washington. As those states seek to incorporate projections of sea-level rise into coastal planning, they asked the National Research Council to make independent projections of sea-level rise along their coasts for the years 2030, 2050, and 2100, taking into account regional factors that affect sea level. Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future explains that sea level along the U.S. west coast is affected by a number of factors. These include: climate patterns such as the El Niño, effects from the melting of modern and ancient ice sheets, and geologic processes, such as plate tectonics. Regional projections for California, Oregon, and Washington show a sharp distinction at Cape Mendocino in northern California. South of that point, sea-level rise is expected to be very close to global projections. However, projections are lower north of Cape Mendocino because the land is being pushed upward as the ocean plate moves under the continental plate along the Cascadia Subduction Zone. However, an earthquake magnitude 8 or larger, which occurs in the region every few hundred to 1,000 years, would cause the land to drop and sea level to suddenly rise.

Download or read book Holocene Sea level Climate and Estuarine Stratrigraphy of Baffin Bay Texas written by Daniel North Livsey and published by . This book was released on 2015 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within Baffin Bay, five flooding surfaces making periods of abrupt environmental change, between 1.1--1.0 ka, 2.7--2.1 ka, 3.8--3.0 ka, 5.2--4.9 ka, and 6.5--5.7 ka occur through a time-period of ever decreasing rates of relative sea-level rise and within error of periods of drying in southern Texas at ca. 1.0 ka, 2.6 ka, 3.4 ka, 4.8 ka, and 5.5 ka (Chapter 4). I hypothesize that these flooding surfaces, occurring when sea level in the Gulf of Mexico was rising

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.

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 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 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: An important overview of Quaternary climates including detailed Pleistocene and Holocene sea-level changes, for researchers and graduate and advanced undergraduate students.

Download or read book Holocene Evolution of the Western Louisiana Texas Coast USA written by John B. Anderson and published by Geological Society of America. This book was released on 2022-08-01 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Western Louisiana and Texas coast is vulnerable to sea-level rise due to low gradients, high subsidence, and depleted sediment supply. This Memoir describes the response of coastal environments to variable rates of sea-level rise and sediment supply during Holocene to modern time. This volume is a wake-up call about the potential magnitude of coastal change over decadal to centennial time scales"--

Download or read book Responding to Changes in Sea Level written by Committee on Engineering Implications of Changes in Relative Mean Sea Level and published by . This book was released on 1987-01-15 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last 100 years, sea level has risen approximately 12 centimeters and is expected to continue rising at an even faster rate. This situation has serious implications for human activity along our coasts. In this book, geological and coastal engineering experts examine recent sea level trends and project changes over the next 100 years, anticipating shoreline response to changing sea level and the consequences for coastal development and uses. Scenarios for future sea level rise and several case studies are presented.

Download or read book Sea Level Variability and Change written by Ivan D. Haigh and published by Frontiers Media SA. This book was released on 2017-04-27 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: In June 2015 we held a workshop on the beautiful island of Mallorca, Spain with a focus on sea level variability and change. Over 120 sea level experts from around the world attended this workshop, from a range of different disciplines. The main aims of the workshop were to: 1.) Evaluate the current state-of-knowledge of sea level science; 2.) Identify gaps and unresolved questions in any aspect of sea level science; and 3.) Design future research to address these issue. All aspects of sea level changes were covered, from global to regional, observations and modelling, processes driving mean sea level changes and extremes, from the geological scale to the instrumental era and future projections and including impacts on the coastal zones. This E-Book presents papers that came out of that workshop. Overall, these papers illustrate the multi-disciplinary nature of sea level research, cross-cutting many fields of research including: oceanography, meteorology, geology, coastal morphodynamics, engineering and the social-economic aspects. Collectively, theses articles represent an interesting range of perspectives and original studies that contribute to understanding the dynamic nature of sea level and its impacts across a wide range of time and space scales. Enjoy reading them!

Download or read book North Pacific Environment and Paleoclimate from the Late Pleistocene to Present written by Miriam Jones and published by Frontiers Media SA. This book was released on 2020-01-13 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vast area of the North Pacific, spanning ~55˚ longitude, represents a challenge for documenting and understanding the geologic history of ocean, atmosphere, and terrestrial environmental change. Nevertheless, its importance for many issues, including our fundamental understanding of ocean and atmospheric circulation patterns and teleconnections with natural modes of climate variability through time, has led to a steady rise in the numbers of study sites and proxy types. By bringing together a wide range of proxies and timescales that examine the impacts of paleoclimate on ecosystems, water, carbon, and humans, and interactions between marine and terrestrial processes, this Research Topic contributes to an improved understanding of the region’s significance at global, hemispheric, and regional scales.

Download or read book Styles of Coastal Evolution in Response to Holocene Changes in Sea Level and Sediment Supply written by Christopher J. Hein and published by . This book was released on 2012 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This study employs a suite of geophysical, sedimentological, and chronostratigraphic tools to investigate the complex interactions among changes in sea level, climate, and sedimentation processes that have driven Holocene coastal evolution. These interrelationships were explored in investigations of three coastal sites with diverse sea-level and sedimentation histories: the Egyptian Red Sea (Wadi Gawasis), southern Brazil (Pinheira) and the Western Gulf of Maine (Plum Island). This study demonstrates the need to quantify the integrated impacts of spatially-diverse changes in global (sea level), regional (climate, sea level), and local (sedimentation) factors if we are to predict large-scale coastal evolution in response to the ongoing acceleration in sea-level rise. The mid-Holocene in both the Red Sea and southern Brazil was characterized by higher-than-present stands of sea level. Sedimentological, malachological, foraminiferal, and rheological studies at Wadi Gawasis reveal that this resulted in the formation of a shallow bay that reached its maximum extent prior to a 1.5-m highstand at 5 ka, demonstrating a dominance of sedimentation processes despite contrary sea-level change. Early bay closure was driven by sediment inputs enhanced by a wetter climate. Slowly falling sea level and coincidental climatic aridization allowed for the establishment of an Egyptian harbor 4 ka, followed by late-stage progradation dominated by sea-level fall. In southern Brazil, an abundant sediment supply and sea-level fall following the mid-Holocene highstand were responsible for the development of the 5-km wide Pinheira strandplain, composed of regular beach and dune ridges. Identification of anomalous barrier, lagoonal, and tidal fill deposits within this plain demonstrates the complex nature of the sedimentological response to a small-scale change in the rate of sea-level fall. By contrast, Plum Island formed in a regime of rapid sea-level rise that reworked shallow shelf and fluvial deposits. Geophysical and sedimentological studies reveal a complex barrier formation (aggradation, spit accretion and progradation), including evidence for inlet migration and closure. Time-transgressive backstripping of backbarrier facies shows that bay sedimentation in a regime of slowly rising sea level reduced tidal-prism and produced inlet closure. This is first study to demonstrate that the direct impact of backbarrier processes influencing barrier island development.

Download or read book Climate Variability and Change and Sea level Rise in the Pacific Islands Region written by John E. Hay and published by . This book was released on 2003 with total page 116 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: