Download or read book Paleoceanographic Proxy Development in Scleractinia Stony Corals Throughout the Pacific Ocean written by Logan Brenner and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is necessary to consider the environmental specifics of a given region before blindly interpreting paleo-proxy data. Furthermore, coral-based proxy records are supremely powerful tools in exploring and uncovering past climate histories of a given region. Coral-records can supplement and extend the limited instrumental record with centuries to millenia long information on SST and hydroclimate. These data can improve climate models, further our knowledge of coral reef growth, and deepen our understanding of regional hydroclimate, which are all vital to our understanding of global climate.
Download or read book Scleractinia of the Temperate North Pacific written by Stephen Cairns and published by . This book was released on 1994 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemistry of Soft Corals and Black Corals and Implications for Paleoceanography in the Western Tropical Pacific written by Branwen Williams and published by . This book was released on 2009 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Changes in the chemical and biological oceanography accompanying shifts in ENSO conditions in the western tropical Pacific are not well understood and this understanding would be enhanced by high resolution, century-scale proxy records spanning the euphotic zone. Soft corals and black corals are abundant in the western tropical Pacific from the near surface to thousands of meters deep, deposit organic skeleton in concentric bands, and live for hundreds to thousands of years. Geochemical measurements across colony growth axes can serve as proxies for the biogeochemistry of particulate organic matter (POM). Yet, proxy records from these corals in the climatically-sensitive western tropical Pacific have not yet been developed. Here, quantifying the natural variability in organic skeletal [delta]13C and [delta]15N values facilitated comparisons of skeletal records from multiple taxa across a depth transect within the euphotic zone. Similar [delta]15N values between black corals and soft corals collected from a reef offshore of Palau suggest these orders feed at the same trophic level while lower [delta]13C values in black corals than soft corals indicate a correction of +1.5% is needed to compare [delta]13C values between orders. In addition, due to chemical alteration of their food, suspended POM, with depth, a +0.25 %/10 m correction needs to be applied to [delta]13C values and -0.15 %/10 m correction needs to be applied to [delta]15N values to compare records from multiple depths. Stable isotopes ([delta]13C and [delta]15N) and trace elements (Br, I, Pb, Mn, Cd, Zn, and B) were measured in one Antipathes black coral colony from 5 m and two Muricella soft coral colonies from 85 m and 105 m, all collected offshore of Palau. Records were dated with a radiocarbon (14C)-derived chronology. The [delta]13C records decreased at rates consistent with the oceanic 13C-Suess effect, indicating anthropogenic carbon was a primary control on the [delta]13C of suspended POM through the top 105 m of the water. Very different [delta]15N records were derived from the shallow Antipathes colony than the deeper Muricella colonies. Since all three colonies fed on suspended POM in the water column, the dissimilar records indicated different controls on [delta]15N values of suspended POM within and below the mixed layer. While changes in the source of POM to the 5 m Antipathes colony with shifts in the relative strength of currents bathing Palau within the mixed layer may drive increases and decreases in shallow [delta]15N record, gradually decreasing [delta]15N values in both of the deeper Muricella records indicated a shoaling of the mean nutricline depth in recent decades. Three radial transects measured by LA-ICP-MS were only reproducible in the Antipathes colony, supporting these corals for trace element reconstructions. This research is the first to develop soft corals and black corals in the western Pacific as proxies of seawater chemistry across the euphotic zone. Together, these corals provide paleoceanographic information on annual to centennial timescale changes in seawater chemistry across the depth range from near surface to thousands of meters deep.
Download or read book Biogeochemical Proxies in Scleractinian Corals Used to Reconstruct Ocean Circulation written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We utilize monthly 14C data derived from coral archives in conjunction with ocean circulation models to address two questions: (1) how does the shallow circulation of the tropical Pacific vary on seasonal to decadal time scales and (2) which dynamic processes determine the mean vertical structure of the equatorial Pacific thermocline. Our results directly impact the understanding of global climate events such as the El Nino-Southern Oscillation (ENSO). To study changes in ocean circulation and water mass distribution involved in the genesis and evolution of ENSO and decadal climate variability, it is necessary to have records of climate variables several decades in length. Continuous instrumental records are limited because technology for continuous monitoring of ocean currents has only recently been available, and ships of opportunity archives such as COADS contain large spatial and temporal biases. In addition, temperature and salinity in surface waters are not conservative and thus can not be independently relied upon to trace water masses, reducing the utility of historical observations. Radiocarbon (14C) in sea water is a quasi-conservative water mass tracer and is incorporated into coral skeletal material, thus coral 14C records can be used to reconstruct changes in shallow circulation that would be difficult to characterize using instrumental data. High resolution [Delta]14C timeseries such as these, provide a powerful constraint on the rate of surface ocean mixing and hold great promise to augment onetime surveys such as GEOSECS and WOCE. These data not only provide fundamental information about the shallow circulation of the Pacific, but can be used as a benchmark for the next generation of high resolution ocean models used in prognosticating climate change.
Download or read book Scleractinia of Andaman and Nicobar Islands written by K. Venkataraman and published by . This book was released on 2012 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tempo and Mode of Coral reef Development in the Pacific Ocean written by Christopher Matthew Kovalik and published by . This book was released on 2015 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The full effects of climate change are still unknown, but the future of coral-reefs appears bleak. Recently, there have been major episodes of coral bleaching and coral disease around the world. The recent loss of coral has been extreme, but there is some precedent for coral-reef collapse in the geologic record; several millennial-scale hiatuses in reef growth have been found throughout the Pacific Ocean in the late Holocene. A ~2,500-year hiatus in reef growth was found at multiple sites in Pacific Panamá, Costa Rica, Australia and Hawaii, as well as several small-scale hiatuses in the northern Ryukyu Islands. I used push-coring to compare the Holocene histories of two sites on opposite sides of the Pacific Ocean to see if they experienced this same millennial-scale hiatus in reef growth. The first site was Coiba Island, Panamá. This site has some of the oldest and thickest reefs in the eastern Pacific, in part due to its relatively stable year-round sea-surface temperatures. Coiba is not affected by tropical cyclones, as they move westward across the Pacific. The second coring site was Kumejima, Japan. Kumejima is bathed by the warm waters of the Kuroshio Current. Kumejima is part of the Ryukyu Island Arc, which is highly exposed to storm activity, experiencing numerous tropical cyclones annually. The climatic conditions at each site were examined through wavelet analysis. Wavelet analysis of sea-surface temperature anomalies, using monthly data from 1870-2012, was undertaken for each site, highlighting the periodicity and timing of trends in anomalous temperatures. These records were then compared with each other using wavelet-coherence analysis. Wavelet-coherence analysis revealed correlations between the two wavelets, highlighting the periodicity and time period when these sites were experiencing similar anomalous temperatures. Using two different forms of wavelet coherence, it was shown that these sites experienced anomalous temperatures at the ENSO (El Niño/Southern Oscillation) timescale only periodically throughout the past century and a half. There was also visible correlation at the decadal timescale twice, likely reflecting the Pacific Decadal Oscillation. Wavelet analysis made shared climatic trends between these sites much easier to detect and also revealed that these two dissimilar sites are linked climatically. Using cores taken from coral-reef framework to assess coral growth of the past ~6000 cal BP (calibrated calendar years before 1950), a hiatus in reef growth was found from ~4290-2024 cal BP at Coiba. Even with some of the best conditions for coral growth in the eastern Pacific, Coiba Island also experienced this millennial-scale hiatus in reef growth. The hiatus found at Coiba occurred contemporaneously with the millennial-scale hiatuses in reef growth observed in other areas of Pacific Panamá. This hiatus in reef growth took place during a time of increased ENSO activity; a similar increase in ENSO activity is predicted under future climate-change conditions. Extreme El Niño and extreme La Niña events are predicted to increase with climate change, threatening the precious coral-reef ecosystem that is already sparse in the equatorial eastern Pacific. Nearly all corals in the cores analyzed from Kumejima were in very poor taphonomic condition and were comprised nearly entirely of Acropora spp. encrusted in coralline algae. Radiocarbon ages from the Kumejima cores revealed a mixed deposition. All dates collected from depths ranging from 30-235 cm below the surface were between the ages of 2966-3775 cal BP. All of these corals dated within the time frame of the hiatus observed in Panamá, showing that there was coral growth at Kumejima during this time. The dates obtained from coral from Kumejima were also during the short-term hiatus found at nearby Kodakarajima, in the Northern Ryukyus, meaning the hiatus at Kodakarajima was likely a localized event. Every coral dated from Kumejima was alive during the Pulleniatina Minimum Event (PME), which is believed to have resulted in the slowing of the Kuroshio Current. Any alteration in the flow of the Kuroshio could have altered reef growth at Kumejima: my record from this site may represent rubble deposits during this event. Both of these sites are largely controlled by oceanic-atmospheric processes taking place on a large scale. Reef dynamics at Coiba Island were likely controlled by ENSO activity, especially Eastern Pacific El Niño, and this site has low coral diversity. On the other hand, reef development at Kumejima is influenced by storm activity, mainly tropical cyclones, which, in both frequency and intensity, can be attributed to the same forces controlling ENSO activity in the eastern equatorial Pacific. With the current projections of climate change the oceanic waters will warm, storm intensity will increase, ENSO events will become more extreme, and patterns of precipitation will likely change. Similar changes have occurred in the past, driving corals beyond their threshold of survival. The prediction of a more El Niño-like conditions in the future could be disastrous for both Coiba and Kumejima. Coiba would face higher than normal temperatures whereas Kume would experience an increase in the intensity of typhoons. These reefs have been resilient to temperature changes in the past, with Panamanian reefs recovering from an over 2000 year hiatus; if we can slow or reverse the current rate of climate change in the immediate future, these reefs still may stand a chance to survive.
Download or read book Catalog of the Type Specimens of Stony Corals Milleporidae Stylasteridae Scleractinia in the National Museum of Natural History Smithsonian Institution written by National Museum of Natural History (U.S.) and published by . This book was released on 1991 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Ocean Ground Truthing of Nitrogen Isotopes in Scleractinian Corals written by Victoria Hoi-Yee Luu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coral Records of Central Tropical Pacific Sea surface Temperature and Salinity Variability Over the 20th Century written by Intan Suci Nurhati and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate forecasts of future regional temperature and rainfall patterns in many regions largely depend on characterizing anthropogenic trends in tropical Pacific climate. However, strong interannual to decadal-scale tropical Pacific climate variability, combined with sparse spatial and temporal coverage of instrumental climate datasets in this region, have obscured potential anthropogenic climate signals in the tropical Pacific. In this dissertation, I present sea-surface temperature (SST) and salinity proxy records that span over the 20th century using living corals from several islands in the central tropical Pacific. I reconstruct the SST proxy records via coral Sr/Ca, that are combined with coral oxygen isotopic (d18O) records to quantify changes in seawater d18O (hereafter d18Osw) as a proxy for salinity. Chapter 2 investigates the spatial and temporal character of SST and d18Osw-based salinity trends in the central tropical Pacific from 1972-1998, as revealed by corals from Palmyra (6°N, 162°W), Fanning (4°N, 159°W) and Christmas (2°N, 157°W) Islands. The late 20th century SST proxy records exhibit warming trends that are larger towards the equator, in line with a weakening of equatorial Pacific upwelling over this period. Freshening trends revealed by the salinity proxy records are larger at those sites most affected by the Inter-Tropical Convergence Zone (ITCZ), suggesting a strengthening and/or an equatorward shift of the ITCZ. Taken together, the late 20th century SST and salinity proxy records document warming and freshening trends that are consistent with a trend towards a weakened tropical Pacific zonal SST gradient under continued anthropogenic forcing. Chapter 3 characterizes the signatures of natural and anthropogenic variability in central tropical Pacific SST and d18Osw-based salinity over the course of 20th century using century-long coral proxy records from Palmyra. On interannual timescales, the SST proxy record from Palmyra tracks El Niño-Southern Oscillation (ENSO) variability. The salinity proxy record tracks eastern Pacific-centered ENSO events but is poorly correlated to central Pacific-centered ENSO events - the result of profound differences in precipitation and ocean advection that occur during the two types of ENSO. On decadal timescales, the coral SST proxy record is significantly correlated to the North Pacific Gyre Oscillation (NPGO), suggesting that strong dynamical links exist between the central tropical Pacific and the North Pacific. The salinity proxy record is significantly correlated to the Pacific Decadal Oscillation (PDO), but poorly correlated to the NPGO, suggesting that, as was the case with ENSO, these two modes of Pacific decadal climate variability have unique impacts on equatorial precipitation and ocean advection. However, the most striking feature of the salinity proxy record is a prominent late 20th century freshening trend that is likely related to anthropogenic climate change. Taken together, the coral data provide key constraints on tropical Pacific climate trends, and when used in combination with model simulations of 21st century climate, can be used to improve projections of regional climate in areas affected by tropical Pacific climate variability.
Download or read book Branching Growth in Stony Corals written by Roeland Mattheus Hermanus Merks and published by . This book was released on 2003 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cold Water Corals and Ecosystems written by André Freiwald and published by Springer Science & Business Media. This book was released on 2006-01-17 with total page 1242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold-water coral ecosystems figure the formation of large seabed structures such as reefs and giant carbonate mounds; they represent unexplored paleo-environmental archives of earth history. Like their tropical cousins, cold-water coral ecosystems harbour rich species diversity. For this volume, key institutions in cold-water coral research have contributed 62 state-of-the-art articles on topics from geology and oceanography to biology and conservation, with some impressive underwater images.
Download or read book Encyclopedia of Modern Coral Reefs written by David Hopley and published by Springer Science & Business Media. This book was released on 2010-11-26 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coral reefs are the largest landforms built by plants and animals. Their study therefore incorporates a wide range of disciplines. This encyclopedia approaches coral reefs from an earth science perspective, concentrating especially on modern reefs. Currently coral reefs are under high stress, most prominently from climate change with changes to water temperature, sea level and ocean acidification particularly damaging. Modern reefs have evolved through the massive environmental changes of the Quaternary with long periods of exposure during glacially lowered sea level periods and short periods of interglacial growth. The entries in this encyclopedia condense the large amount of work carried out since Charles Darwin first attempted to understand reef evolution. Leading authorities from many countries have contributed to the entries covering areas of geology, geography and ecology, providing comprehensive access to the most up-to-date research on the structure, form and processes operating on Quaternary coral reefs.
Download or read book Advances in the Studies of the Benthic Zone written by Luis Soto and published by BoD – Books on Demand. This book was released on 2020-06-10 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an unpretentious editing venture to fill the gap in our current knowledge on the ecological implications caused by anthropogenic disturbances upon benthic communities in several regions of the world, including the Western Atlantic, the Mediterranean Sea, and the Eastern Pacific Ocean, as well as the pristine environments of the Andes in South America. The common goal of the contributing authors in this book was to unravel the complex processes that make possible the life existence of bottom-living animals in different environmental scenarios. To achieve such a goal, the authors focus their attention on the emerging issues inherent to global climate change or the pollution of aquatic systems. These are all themes that might be of interest to scientists active in a wide range of oceanographic subdisciplines. Well-established researchers would appreciate the innovative approach adopted in each chapter of the book, which extends from the ecosystem level to refined molecular interpretations.
Download or read book Coral Bleaching written by Madeleine J. H. van Oppen and published by Springer. This book was released on 2018-07-05 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most serious consequences of global climate change for coral reefs is the increased frequency and severity of mass coral bleaching events and, since the first edition of this volume was published in 2009, there have been additional mass coral bleaching events. This book provides comprehensive information on the causes and consequences of coral bleaching for coral reef ecosystems, from the genes and microbes involved in the bleaching response, to individual coral colonies and whole reef systems. It presents detailed analyses of how coral bleaching can be detected and quantified and reviews future scenarios based on modeling efforts and the potential mechanisms of acclimatisation and adaptation. It also briefly discusses emerging research areas that focus on the development of innovative interventions aiming to increase coral climate resilience and restore reefs.
Download or read book The History and Sedimentology of Ancient Reef Systems written by George D. Stanley Jr. and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the Preface: The chapters of this book contain contributions from an international group of specialists. They address some important themes in both modern and ancient reef systems. Some chapters contain `snapshots' of reefs of particular intervals, while others touch on relevant themes of both modern and ancient reefs - themes that weave their way through reefs of all ages. This book opens and sets the stage with an introduction to both modern and ancient reefs and reef ecosystems. This chapter is also intended as a basic introduction for students, general geologists, and professionals or others who may be unfamiliar with reefs and reef ecosystems. The chapter addresses the living coral reef ecosystem, stressing among other relevant factors, the importance of ecological and physical interactions between the organisms and their environment. The chapter also addresses mass extinction and provides a general overview of the history of reefs.
Download or read book Coral Reefs An Ecosystem in Transition written by Zvy Dubinsky and published by Springer Science & Business Media. This book was released on 2010-12-02 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers in one volume materials scattered in hundreds of research articles, in most cases focusing on specialized aspects of coral biology. In addition to the latest developments in coral evolution and physiology, it presents chapters devoted to novel frontiers in coral reef research. These include the molecular biology of corals and their symbiotic algae, remote sensing of reef systems, ecology of coral disease spread, effects of various scenarios of global climate change, ocean acidification effects of increasing CO2 levels on coral calcification, and damaged coral reef remediation. Beyond extensive coverage of the above aspects, key issues regarding the coral organism and the reef ecosystem such as calcification, reproduction, modeling, algae, reef invertebrates, competition and fish are re-evaluated in the light of new research and emerging insights. In all chapters novel theories as well as challenges to established paradigms are introduced, evaluated and discussed. This volume is indispensible for all those involved in coral reef management and conservation.
Download or read book Mediterranean Climate Variability written by P. Lionello and published by Elsevier. This book was released on 2006-08-22 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: This multi-authored book provides an updated description of climate variability in the Mediterranean basin, focusing on decadal and centennial time scales and on the results available on the impact of future emission scenarios at regional scale. The authors describs both local physical processes responsible for these variability - such as changes in the surface properties and land use- and globalprocesses - such as changes in the large scale atmospheric circulation associated to global warming, NAO, tropical monsoon and ENSO. Regional climate change issues are also addressed. Mediterranean Climate Variability aims to review the research on this region and to provide at the same time both an introduction and a reference for researchers. It covers topics typical of Climatology, Climate history, Meteorology, Oceanography, Environmental Science but the information here provided would also be useful for research in agriculture, social and economic studies. It is addressed to scientists and students interested in the Mediterranean climate and environment. Some topics have interesting connections to nearby regions: Northern Atlantic, West Africa, central and Eastern Europe. Each chapter will contain a summary meant to provide information to policy makers, researchers from other fields, and in general to a wide audience without a technical expertise on climate. * Provides an updated analysis of the Mediterranean climate features and guidelines for future research * Considers both oceanographic and atmospheric aspects * Analyzes the Mediterranean climate in a global perspective
