Showing papers on "Shore published in 2014"
TL;DR: Adapting to, and potentially mitigating, low water level conditions requires improved quantification of the factors that drive the imbalance in the water budget of the Great Lakes.
Abstract: As marine coastal populations experience and plan for rising ocean levels ( 1 ), residents along the coasts of Earth's largest lake system are encountering the opposite problem: persistent low water levels and a receding shoreline. In January 2013, federal agencies from the United States and Canada documented the lowest water levels ever recorded on lakes Michigan and Huron ( 2 ). Only 6 years earlier, historically low water levels were recorded on Lake Superior ( 3 ), which feeds into the Lake Michigan-Huron system. These low water levels are symptoms of an imbalance in the water budget of the Great Lakes. Adapting to, and potentially mitigating, low water level conditions requires improved quantification of the factors that drive the imbalance.
98 citations
TL;DR: In this paper, the authors applied two behavior-oriented equilibrium shoreline models that relate the rate of cross-shore shoreline displacement to the wave energy and wave energy disequilibrium.
90 citations
TL;DR: In this paper, the results from nearly three decades of marine geological research in the northwestern Gulf of Mexico are compiled in an effort to understand those factors (e.g., sea-level rise, sediment supply, subsidence, antecedent topography) that influenced coastal evolution during the last eustatic cycle.
89 citations
TL;DR: The results in this paper show that zones of high to very-high susceptibility around the island of Crete are related to: offshore bathymetric features, including the presence of offshore scarps and seamounts; shoreline geology, and the presence near the shore of sedimentary basins filled with unconsolidated deposits of high permeability.
87 citations
TL;DR: In this article, the impact of wave energy and littoral current on shorelines along the south-west coast of Kanyakumari, Tamil Nadu, India was investigated using multi-temporal Landsat TM, ETM+ images acquired from 1999 to 2011.
Abstract: The present study investigates the impact of wave energy and littoral current on shorelines along the south-west coast of Kanyakumari, Tamil Nadu, India. The multi-temporal Landsat TM, ETM+ images acquired from 1999 to 2011 were used to demarcate the rate of shoreline shift using GIS-based Digital Shoreline Analysis System. The statistical analysis such as net shoreline movement and end point rate were determined from the multi-temporal shoreline layers. Moreover, the wave energy and seasonal littoral current velocity were calculated for each coastal zone using mathematical equations. The results reveal that the coastal zones, which include Kanyakumari, Kovalam, Manavalakurichi and Thengapattinam coasts, consisting of maximum wave energy along with high velocity of littoral current, have faced continuous erosion processes. The estimated wave energy along these zones ranges from 6.5 to 8.5 kJ/km2 and the observed current velocity varies from 0.22 to 0.32 m/s during south-west and north-east monsoons. The cumulative effect of these coastal processes in the study area leads to severe erosion that is estimated as 300.63, 69.92, 54.12 and 66.11 m, respectively. However, the coastal zones, namely Rajakkamangalam, Ganapathipuram, Muttam and Colachel, have experienced sediment deposits due to current movement during the north-east monsoon. However, the trend changes during the south-west monsoon as a result of sediment drift through backwash. The spatial variation of shoreline and its impact on wave energy and the littoral current have been mapped using the geo-spatial technology. This study envisages the impact of coastal processes on site-specific shorelines. Hence, the study will be effective for sustainable coastal zone management.
83 citations
TL;DR: In this article, a detailed and extensive survey at a regional scale on a tideless rocky shore is performed to identify the most relevant abiotic factors associated with vertical littoral zonation.
Abstract: Vertical variation in the distribution of rocky shore assemblages is greater than horizontal variation, as shown by univariate and multivariate analysis performed with data obtained along 1000 km of shoreline and covering from the upper supralittoral to the upper infralittoral zone (� 1 m). Consequently, vertical littoral zonation is a consistent pattern at a regional scale within the same biogeographical zone. While their distribution varies at the same shore height, marine species and assemblages from rocky shores show a specific vertical sequence known as zonation. A key question in ecology is how consistent is zonation along large spatial scales. The aim of this study is to show distribution patterns of littoral assemblages at a regional scale and to identify the most relevant abiotic factors associated to such patterns. The study is based on a detailed and extensive survey at a regional scale on a tideless rocky shore. Benthic
81 citations
TL;DR: In this article, an eddy covariance (EC) mesonet on Lake Taihu, a large (area 2400 km2) and shallow (depth 2 m) lake situated in the heavily populated Yangtze River Delta, China, is described.
Abstract: Lakes are an important component of the climate system. They provide moisture for precipitation, buffer temperature variations, and contribute to regional atmospheric carbon budgets. This article describes an eddy covariance (EC) mesonet on Lake Taihu, a large (area 2400 km2) and shallow (depth 2 m) lake situated in the heavily populated Yangtze River Delta, China. The mesonet consists of five lake sites, representing different biological attributes and wind–wave patterns, and a land site near the lake shore. Common to all the sites are standard EC instruments for measurement of the momentum, sensible heat, water vapor, and CO2 flux. One site is also equipped with laser-based analyzers for precise measurement of the CO2, CH4, and H2O mixing ratios and their isotopic compositions. To the authors' best knowledge, this is the first lake eddy flux mesonet. Early results reveal evidence of biological and pollution controls on the surface–air fluxes of energy, momentum, and greenhouse gases across the lake. The...
72 citations
TL;DR: In this paper, the authors investigated wishful identification and parasocial relationships with Jersey Shore cast members as mediators in the relationship between exposure to Jersey Shore and permissive sexual attitudes.
Abstract: Exposure to highly sexualized television programs has been correlated with emerging adults' sexual attitudes and behaviors. However, little is known about the variables that may mediate these relationships. The studies presented here investigated wishful identification and parasocial relationships withJersey Shore cast members as mediators in the relationship between exposure to Jersey Shore and permissive sexual attitudes. In Study 1, a secondary examination of content analysis data suggested that sex was pervasive on Jersey Shore. Analyses revealed that, on average, one sexual instance occurred every minute on Jersey Shore. The frequency of sexual instances on Jersey Shore was significantly higher than the frequency of sexual instances in other popular primetime television programs. In Study 2, data collected from a sample of emerging adults revealed a positive relationship between Jersey Shore exposure and permissive sexual attitudes mediated by participants' wishful identification and parasocial relat...
64 citations
TL;DR: In this paper, the authors conclude that the lack of red tide along the west coast of Florida in 2010 was due to anomalously large and protracted upwelling of nutrient-rich waters of deep ocean origin caused by Loop Current and eddy interactions with the shelf slope.
63 citations
TL;DR: Shoreline changes along the south Gujarat coast has been analyzed by using USGS Digital Shoreline Analysis System (DSAS) version 4.3. as discussed by the authors used the Linear Regression Method (LRR) to calculate shoreline change rate.
Abstract: Shoreline changes along the south Gujarat coast has been analyzed by using USGS Digital Shoreline Analysis System (DSAS) version 4.3. Multi-temporal satellite images pertaining to 1972, 1990, 2001 and 2011 were used to extract the shoreline. The High water line (HTL) is considered as shoreline and visual interpretation of satellite imageries has been carried out to demarcate the HTL based on various geomorphology and land use & land cover features. The present study used the Linear Regression Method (LRR) to calculate shoreline change rate. Based on the rate of shoreline changes, the coastal stretches of study area has been classified in to high erosion, low erosion, stable, low accretion and high accretion coast. The study found that about 69.31 % of the South Gujarat coast is eroding, about 18.40 % of coast is stable and remaining 12.28 % of the coast is accreting in nature. Field investigation was carried out which confirmed the coastal erosion/accretion derived from the analysis. The high erosion area are mostly found along the Umergaon (near Fansa, Maroli, Nargol, Varili river mouth, Umergaon light house) and Pardi (Kolak, Udwara)Taluka in Valsad district. Stable coastal length of the study area is 21.59 km and mostly found in Nani Dandi and near Onjal. High accretion (3.70 %) was only found near Hajira and low accretion (8.58 %) are distributed the study area. The main causes of coastal erosion of the study area were the strong tidal currents accompanied by wave action and reduced the sediment load of the river.
TL;DR: In this paper, a detailed Simulating WAves Nearshore (SWAN) model was developed to assess the wave resource in the west coast of Canada, at a 3-h time resolution.
TL;DR: In this article, the authors summarize the results of studies of rates and processes of rocky coasts of the countries overlooking the Mediterranean and Black Seas and review the current knowledge concerning rock coasts in the MBS area.
Abstract: Rock coasts and shore platforms are conspicuous landforms along the Mediterranean and Black Sea (MBS) coasts. These coasts have been fashioned by changes in sea level because of vertical movements of the land and variations in eustatic and isostatic sea-level. For this reason, the Quaternary evolution of MBS coasts has been extensively studied, even starting from geomorphological markers, while very few researches have addressed the processes related to their origin and evolution. Despite most of the Mediterranean coast being rocky, studies about rocky shore processes are almost completely lacking, except for limited areas. Data on sea cliff retreats have mainly been collected to study the susceptibility of cliff failures or to prevent landslides, in particular along shores used for tourism. Data on erosion rates and processes on shore platforms are generally scarce and restricted to limestone bedrocks. In this paper, we summarize the results of studies of rates and processes of rocky coasts of the countries overlooking the Mediterranean and Black Seas and review the current knowledge concerning rock coasts in the MBS area.
TL;DR: In this article, the authors developed an exploratory model of plan view, millennial-scale headland and bay evolution on rocky coastlines, which is built around two concurrent negative feedbacks that control headland amplitude: (1) wave energy convergence and divergence at headlands and bays, respectively, that increases in intensity as cross-shore amplitude grows and (2) the combined processes of beach sediment production by sea cliff erosion, distribution of sediment to bays by waves, and beach accumulation that buffers sea cliffs from wave attack and limits further sea cliff retreat.
Abstract: We have developed an exploratory model of plan view, millennial-scale headland and bay evolution on rocky coastlines. Cross-shore coastline relief, or amplitude, arises from alongshore differences in sea cliff lithology, where durable, erosion-resistant rocks protrude seaward as headlands and weaker rocks retreat landward as bays. The model is built around two concurrent negative feedbacks that control headland amplitude: (1) wave energy convergence and divergence at headlands and bays, respectively, that increases in intensity as cross-shore amplitude grows and (2) the combined processes of beach sediment production by sea cliff erosion, distribution of sediment to bays by waves, and beach accumulation that buffers sea cliffs from wave attack and limits further sea cliff retreat. Paired with the coastline relief model is a numerical wave transformation model that explores how wave energy is distributed along an embayed coastline. The two models are linked through genetic programming, a machine learning technique that parses wave model results into a tractable input for the coastline model. Using a pool of 4800 wave model simulations, genetic programming yields a function that relates breaking wave power density to cross-shore headland amplitude, offshore wave height, approach angle, and period. The goal of the coastline model is to make simple, but fundamental, scaling arguments on how different variables (such as sea cliff height and composition) affect the equilibrium cross-shore relief of headland and bays. The model's generality highlights the key feedbacks involved in coastline evolution and allows its equations (and model behaviors) to be easily modified by future users.
TL;DR: In this article, the authors demonstrate the potential of remote sensing, geospatial and statistical techniques for monitoring the shoreline changes and sea level rise along Digha coast, the eastern India.
Abstract: Shoreline is one of the rapidly changing linear features of the coastal zone which is dynamic in nature. The issue of shoreline changes due to sea level rise over the next century has increasingly become a major social, economic and environmental concern to a large number of countries along the coast, where it poses a serious problem to the environment and human settlements. As a consequence, some coastal scientists have advocated analyzing and predicting coastal changes on a more local scale. The present study demonstrates the potential of remote sensing, geospatial and statistical techniques for monitoring the shoreline changes and sea level rise along Digha coast, the eastern India. In the present study, multi-resolution and multi temporal satellite images of Landsat have been utilized to demarcate shoreline positions during 1972, 1980, 1990, 2000, and 2010. The statistical techniques, linear regression, end-point rate and regression coefficient (R2) have been used to find out the shoreline change rates and sea level change during the periods of 1972–2010. Monthly and annual mean sea level data for three nearby station viz., Haldia, Paradip and Gangra from 1972 to 2006 have been used to this study. Finally, an attempt has been made to find out interactive relationship between the sea level rise and shoreline change of the study area. The results of the present study show that combined use of satellite imagery, sea level data and statistical methods can be a reliable method in correlating shoreline changes with sea level rise.
TL;DR: The upwelling event resulted in adverse water quality along some stretches of the northern shoreline of Lake Erie with persistent anoxia, which was mainly responsible for the mortality of fish as mentioned in this paper.
Abstract: Many coral reef communities thriving in inshore coastal waters characterised by chronically high natural turbidity (>5 mg l−1) have adapted to low light (<200 μmol photons m−2 s−1) and high sedimentation rates (>10 mg cm−2 d−1). Yet, short (hours) acute sediment stress events driven by wind waves, dredging operations involving suction or screening, or shipping activities with vessel wake or propeller disturbance, can result in a rise in turbidity above the natural background level. Although these may not be lethal to corals given the time frame, there could be a considerable impact on photo-trophic energy production. A novel sediment delivery system was used to quantify the effects of 3 acute sediment resuspension stress events (turbidity = 100, 170, 240 mg l−1; sedimentation rates = 4, 9, 13 mg cm−2 h−1) on 3 inshore turbid water corals common in the Indo-Pacific (Merulina ampliata, Pachyseris speciosa and Platygyra sinensis). Coral photo-physiology response (respiration, net photosynthesis, and maximum quantum yield) was measured immediately after 2 h of exposure. The respiration rate increased (from 0.72−1.44 to 0.78− 1.76 μmol O2 cm−2 h−1) as the severity of the acute sediment resuspension event increased, whereas the photosynthetic rate declined (from 0.25−0.41 to −0.19−0.25 μmol O2 cm−2 h−1). Merulina was the least tolerant to acute sediment resuspension, with a photosynthesis and respiration ratio (P/R ratio) of <1.0 when turbidity levels reached >170 mg l−1, while Platygyra was most tolerant (P/R > 1.0). Fluorescence yield data suggest that the rapid photo-acclimation ability of Platygyra enabled it to maintain a positive carbon budget during the experiments, illustrating species-specific responses to acute sediment stress events.
Journal Article•
TL;DR: The results show that remote imagery with a low sampling frequency may be sufficient to characterize prominent morphological changes in planform beach configuration of reef islands, and suggest that changes in beach width on Taku Atoll are dependent on local control.
Abstract: Atoll islands are subject to a variety of processes that influence their geomorphological development. Analysis of historical shoreline changes using remotely sensed images has become an efficient approach to both quantify past changes and estimate future island response. However, the detection of long-term changes in beach width is challenging mainly for two reasons: first, data availability is limited for many remote Pacific islands. Second, beach environments are highly dynamic and strongly influenced by seasonal or episodic shoreline oscillations. Consequently, remote-sensing studies on beach morphodynamics of atoll islands deal with dynamic features covered by a low sampling frequency. Here we present a study of beach dynamics for nine islands on Taku Atoll, Papua New Guinea, over a seven-decade period. A considerable chronological gap between aerial photographs and satellite images was addressed by applying a new method that reweighted positions of the beach limit by identifying “outlier” shoreline positions. On top of natural beach variability observed along the reweighted beach sections, we found that one third of the analyzed islands show a statistically significant decrease in reweighted beach width since 1943. The total loss of beach area for all islands corresponds to 44% of the initial beach area. Variable shoreline trajectories suggest that changes in beach width on Taku Atoll are dependent on local control (that is, human activity and longshore sediment transport). Our results show that remote imagery with a low sampling frequency may be sufficient to characterize prominent morphological changes in planform beach configuration of reef islands.
TL;DR: In this paper, the authors report on the observation and offline detection of the meteotsunami off the New Jersey coast on June 13, 2013, using coastal radar systems and tide gauges.
Abstract: We report here on the observation and offline detection of the meteotsunami off the New Jersey coast on June 13, 2013, using coastal radar systems and tide gauges. This work extends the previous observations of tsunamis originating in Japan and Indonesia. The radars observed the meteotsunami 23 km offshore, 47 min before it arrived at the coast. Subsequent observations showed it moving onshore. The neighboring tide gauge height reading provides confirmation of the radar observations near the shore.
TL;DR: In this paper, a simple numerical model of sea cliff retreat is presented that incorporates mechanical abrasion of a basal notch, threshold-controlled failure of the cantilevered block, and a feedback mechanism wherein retreat is dependent on the rate of sediment comminution within the surf zone.
TL;DR: In this paper, the authors used spatial-statistical models to identify estuarine shoreline characteristics that explain variations in submerged aquatic vegetation abundance among subestuaries of the Chesapeake Bay and mid-Atlantic Coastal Bays.
Abstract: Submerged aquatic vegetation (SAV) provides many important ecosystem functions, but SAV has been significantly reduced in many estuaries. We used spatial–statistical models to identify estuarine shoreline characteristics that explain variations in SAV abundance among subestuaries of the Chesapeake Bay and mid-Atlantic Coastal Bays. We summarized digital spatial data on shoreline construction, shoreline land use, physical characteristics, watershed land cover, and salinity for each subestuary. We related SAV abundance to shoreline characteristics and other stressors using univariate regression and multivariate models. The strongest univariate predictors of SAV abundance were percent shoreline forest, percent shoreline marsh, the percentage of shoreline that is 5–10 m tall, percent riprap, the percentage of subestuary area 5.4 % riprap. SAV abundance has increased steadily since 1984 in subestuaries with 5.4 % riprap. Some shoreline characteristics interact with larger-scale factors like land cover and salinity zone to affect the distribution of SAV, while the effects of other shoreline characteristics are consistent among subestuaries with different salinities or local watershed land covers. Many shoreline characteristics can be controlled by management decisions, and our results help identify factors that managers should consider in efforts to increase SAV abundance.
TL;DR: A sand balance coastal profile model for estimating cliff and shoreline retreats considering sea level rise is discussed in this paper, specifically designed for cliffed coasts fronted by sandy beaches, conditionally permits beach and cliff retreat to occur independently, and includes subaerial cliff erosion and external beach sand sources.
TL;DR: An unexpected abundance of life in submarine springs exists, which in turn explains microbial moderated geo-bio-chemical processes in the Dead Sea sediments, affecting the highly variable chemical composition of on- and offshore spring waters.
TL;DR: In this article, the authors describe a review on the coastal erosion process, parameters' affecting, and methodologies are adopted to identify the erosion process and recommend a solution to solve it.
Abstract: The land ward displacement of the shoreline caused by the forces of waves
and currents is termed as Coastal Erosion. The Coastal areas have become more
prone and vulnerable to natural and human made hazards which lead to Coastal
Erosion. The Shoreline retreat is recognized as a burgeoning threat because of global
climate change and other anthropogenic activities that alter the natural
processes of sustaining beaches and coasts. Coastal Erosion mainly occurs when
wind, waves and long shore currents move sand from shore and deposit it
somewhere else. The sand can be moved to another beach, to the deeper ocean
bottom, into an ocean trench or onto the landside of a dune. The removal of the
sand from the sand sharing system results in permanent changes in beach shape
and structure. The impact of the event is not seen immediately as in the case
of Tsunami or Storm Surge but it is equally important when we consider loss of
property. It generally takes months or years to note the impact of Erosion;
therefore, this is generally classified as a “Long Term Coastal Hazard”. The
present paper attempts to describe a Review on Coastal Erosion Process,
Parameters’ affecting, and methodologies are adopted to identify the erosion
and recommend a solution.
TL;DR: In this article, a low-cost video monitoring system is used to monitor the shoreline response to a nourishment operation on a dynamic gravel embayed beach in Central Italy, where video-derived shorelines were collected over a 15-month period to measure the evolution of the beach with regards to three specific parameters: dry beach width, the dry beach area and the beach orientation.
Abstract: On beaches where natural shoreline variability is significant, beach nourishment is a useful engineering method to augment the dry beach and protect infrastructure and/or unstable cliffs. In this study, a low-cost video monitoring system is used to monitor the shoreline response to a nourishment operation on a dynamic gravel embayed beach in Central Italy. Video-derived shorelines were collected over a 15-month period to measure the evolution of the beach with regards to three specific parameters: the dry beach width, the dry beach area and the beach orientation. Moderate increases in the dry beach width of 3.6 m and 6.7 m across the embayment were observed in response to two different gravel nourishments of approximately 40,000 m3 and 46,000 m3 respectively. The orientation of the beach meanwhile was found to rotate rapidly in the clockwise direction and more gradually in the counter-clockwise direction. Analyses of individual storm events suggest these rapid clockwise rotations are caused by ESE storms, which result in beach retreat particularly at the southern end. The combination of an overall narrow beach width and a clockwise beach orientation is observed to cause a cliff erosion event at a vulnerable point along the embayment.
TL;DR: This study attempts to identify different linked processes poorly understood in the ecology of Antarctic shores, as the stranding, degradation and consumption of large amount of macroalgal subsidies from highly productive submerged rocky substrates toward low productive intertidal sedimentary shores.
TL;DR: In this paper, a new method for coastal vulnerability assessment (CVA), which relies upon three indicators: run-up distance (as a measurement of coastal inundation), beach retreat, and beach erosion rate, is presented.
Abstract: This paper presents a new method for coastal vulnerability assessment (CVA), which relies upon three indicators: run-up distance (as a measurement of coastal inundation), beach retreat (as a measurement of potential erosion), and beach erosion rate (obtained through the shoreline positions in different periods). The coastal vulnerability analysis of Sele Coastal Plain to storm impacts is examined along a number of beach profiles realized between 2008 and 2009. This particular study area has been selected due to its low-lying topography and high erosion propensity. Results are given in terms of an impact index, performed by combining the response due to coastal inundation, storm erosion, and beach erosion rate. This analysis is implemented on the basis of morphosedimentary characteristics of the beach, wave climate evaluation, and examination of multitemporal aerial photographs and topographic maps. The analysis of the final results evidences different coastal responses as a function of the beach width and slope, which in turn depend on the local anthropization level. The comparison of this method with a Coastal Vulnerability Index method evidences the better attitude of CVA index to take into account the different beach features to explain the experienced damages in specific stretches of the coastline considered.
TL;DR: In this paper, a combination of terrestrial and marine LiDAR data with multibeam sonar data was used to study the submarine landscape of granitic coasts and found that the morphology of granite domes is virtually unaffected by erosion at sea level.
Abstract: Coasts composed of resistant lithologies such as granite are generally highly resistant to erosion. They tend to evolve over multiple sea level cycles with highstands acting to remove subaerially weathered material. This often results in a landscape dominated by plunging cliffs with shore platforms rarely occurring. The long-term evolution of these landforms means that throughout the Quaternary these coasts have been variably exposed to different sea level elevations which means erosion may have been concentrated at different elevations from today. Investigations of the submarine landscape of granitic coasts have however been hindered by an inability to accurately image the nearshore morphology. Only with the advent of multibeam sonar and aerial laser surveying can topographic data now be seamlessly collected from above and below sea level. This study tests the utility of these techniques and finds that very accurate measurements can be made of the nearshore thereby allowing researchers to study the submarine profile with the same accuracy as the subaerial profile. From a combination of terrestrial and marine LiDAR data with multibeam sonar data, it is found that the morphology of granite domes is virtually unaffected by erosion at sea level. It appears that evolution of these landscapes on the coast is a very slow process with modern sea level acting only to remove subaerially weathered debris. The size and orientation of the joints determines the erosional potential of the granite. Where joints are densely spaced (<2 m apart) or the bedrock is highly weathered can semi-horizontal surfaces form.
TL;DR: Most rock coast processes will be affected by climate change during this century, but our ability to distinguish the consequences will be hampered by poor understanding of the mechanisms, their relationships to environmental controls and the lack of long, reliable erosional and depositional records as mentioned in this paper.
Abstract: Most rock coast processes will be affected by climate change during this century, but our ability to distinguish the consequences will be hampered by poor understanding of the mechanisms, their relationships to environmental controls and the lack of long, reliable erosional and depositional records. The most important impact is likely to be by rising sea level, and possibly in some regions increased storminess. The greatest concern is with soft rock coasts but there will also be significant increases in the erosion of hard rock cliffs. Greater precipitation, more extreme rainfall events and stronger wave attack from rising sea level, increasing storminess and decreasing sea ice will promote cliff failures. Commensurate changes to wave refraction patterns, longshore transport paths and the availability and productivity of sediment sources with higher sea level will trigger rapid changes to beaches on rocky coasts and to the width of shore platforms. Other changes are likely to be fairly imperceptible in this century. Most weathering processes will be modified and marine organisms will migrate longitudinally and altitudinally with corresponding changes in the nature and degree of their bioerosional and bioprotectional activities.