A 3.5-m gravity core (DJ6-93SF-6) from San Francisco Bay reveals a complex paleoclimatic history of the region over the last 3870 cal YBP. A polynomial equation based on 11 AMS ¹⁴C ages provides an excellent age model for the core, and environmental proxies for water temperature and salinity are derived from various foraminiferal abundances, stable carbon and oxygen isotopes, and Mg/Ca ratios. Two foraminiferal associations were identified by Q-mode cluster analysis: a colder-water Elphidium excavatum association and the warmer-water Ammonia beccarii–Elphidium gunteri association. The E. excavatum association dominates the core for all but about 600 years out of the last four millennia.

At 3870 cal YBP, water temperatures were warm (13.9°C) and freshwater inflow was reduced compared with today. From 3590 to 2860 cal YBP, temperatures dropped 0.5°C and the climate remained dry. This was followed by a period of pronounced lower δ¹³C values, indicating that conditions became considerably wetter from 2860 to 2170 cal YBP. During this interval, the temperature oscillated frequently, peaking at 13.9°C at 2710 cal YBP, then dropping shortly thereafter to 12.8°C at 2420 cal YBP. Freshwater inflow gradually decreased between 2170 and 1950 cal YBP with a minimal rise in temperature, then changed quickly to colder and wetter conditions at 1900 cal YBP. Drier conditions then prevailed until 1480 cal YBP with water temperatures fluctuating between 13.1°C and 13.8°C, followed by wetter climate from 1480 to 1320 cal YBP.

A significant faunal shift from the E. excavatum association to the A. beccarii–E. gunteri association occurred from 1250 to 650 cal YBP, possibly due to regional warming, decreased oxygen availability, and/or a change in the phytoplankton community. Associated with this change in faunal composition were warm and dry conditions, representative of the Medieval Warm Period (Medieval Climatic Anomaly). A climatic shift coincident with the onset of the Little Ice Age (LIA I and LIA II) is evident from 650 to 280 cal YBP, with the return of the E. excavatum association and an extreme drop in δ¹⁸O values, all indicating increased precipitation and fresh water inflow. This was followed by generally drier conditions to the present, except for a brief wet period around 100 cal YBP, and fairly consistent water temperatures in the middle 13°C, except for a drop to 12.8°C at 200 cal YBP.

Two significant faunal changes occur near the top of the core. First, there is the reappearance of the A. beccarii–E. gunteri association, suggesting that, once again, regional warming has taken place, oxygen availability has declined, and/or environmental conditions changed such that diatoms have become a scarce food source. Second, there is the first appearance of the invasive Japanese foraminifera Trochammina hadai Uchio, a species that commonly lives in highly polluted areas and is an indicator of eutrophication in its native estuaries. At the same time, freshwater inflow decreased, which may be explained by global warming during the last 100 years, or more likely due to modern water diversion for agriculture in the central valley of California.

We collected modern foraminiferal and environmental data from three back-barrier intertidal sites (Currituck Barrier Island, Oregon Inlet, and Pea Island) of the Outer Banks, North Carolina, United States, which have different salinity settings and a wind-driven tidal regime. The foraminiferal assemblages indicate that a vertical zonation of foraminifera occurs, with several significant site-specific variations of assemblages. The intertidal zone can be divided into two elements: first, an agglutinated assemblage that is restricted to the vegetated marsh and is dominated by Ammobaculites crassus, Ammobaculites subcatenulatus, Arenoparrella mexicana, Jadammina macrescens, Miliammina fusca, and Trochammina inflata and, second, a calcareous assemblage that dominates the mudflats and sandflats of the intertidal zone, characterized by Ammonia parkinsoniana, Elphidium excavatum, and Haynesina germanica. We used canonical correspondence analysis and partial canonical correspondence analyses of the foraminiferal and environmental data from the Outer Banks to support the hypothesis that the distribution of foraminifera in the intertidal zone is a direct function of elevation, with the duration and frequency of inundation as the most important factors. Partial canonical correspondence analyses and Monte Carlo permutation tests suggest that all available environmental variables except pH play a significant role in understanding the variations in foraminiferal data.

Analyses of three sediment cores collected from a tidal salt marsh located on the western edge of San Pablo Bay in the San Francisco Bay estuary have produced long-term records of late Holocene marsh development. The records from these cores include a suite of elements, organic carbon content, fossil seeds, pollen, and stable carbon isotopes. The stratigraphy indicates fresher water conditions than present between 3400 and 2000 cal YBP. A tidal marsh became established at China Camp after about 2000 cal YBP; between 2000 cal YBP and approximately 700 cal YBP, conditions in the estuary were apparently more saline and variable. This interval was terminated by at least three or possibly five flood events, as evidenced by coarse clastic materials most likely washed down from the surrounding uplands. These floods represent high rainfall events, possibly El Niño years, and occurred during the late Medieval Climatic Anomaly. Greater plant diversity and pollen from some species with low salt tolerance are found in a core collected near the upland edge of the marsh and date to about 200 years ago, suggesting fresher conditions than today. Over the past 50 years, the diversity of marsh vegetation has decreased, and salt tolerant plants (especially Salicornia virginica) have become the dominant species. These changes are likely a result of the impacts of water diversions and upstream dams in the San Francisco Bay watershed.

To create maps of nearshore benthic habitats of Broward County, Florida, from 0 to 35 m depth, we combined laser bathymetry, acoustic ground discrimination, subbottom profiling, and aerial photography data in a geographic information system (GIS). A mosaic of interpolated, sun-shaded, laser bathymetry data served as the foundation upon which acoustic ground discrimination, limited subbottom profiling and aerial photography, and groundtruthing data aided in interpretation of habitats. Mapping criteria similar to NOAA biogeographic Caribbean mapping were used to allow for a comparable output. Expert-driven visual interpretation outlined geomorphological features at a scale of 1 : 6000 with a minimum mapping unit of 1 acre. Acoustic data were then used to differentiate areas of similar geomorphology by their acoustic diversity into areas of high and low scatter, which could be equated to rugosity created by either the substratum or benthic fauna. Of the approximately 112 km² mapped, 56.62 km² were coral reef and colonized hard bottom (50.42%), 54.78 km² were unconsolidated sediments (46.80%), and 0.43 km² were other categories (2.78%). Three linear reef complexes exist. The outermost linear reef has a mature windward reef morphology including a drowned spur and groove system, which was absent on the other two reef lines. The acoustic ground discrimination and groundtruthing showed different benthic habitats on the outer vs. middle and inner reefs. Higher acoustic scatter could be related to taller benthos and more rugose substratum. A considerable amount of colonized pavement (nearshore hard grounds) was found inshore. The map of Broward County yielded a high overall accuracy of 89.6%, only slightly less than the photo-interpreted NOAA Caribbean maps (overall accuracy of 91.1%). User and producer accuracies within each category were also similar. The combined technique approach was effective and accurate, and similar methodology can be used in other areas where photo interpretation is not feasible because of turbidity or depth limitations.

Composition of sand grains from the beaches, reef flat, and fore reef of south Molokai, Hawaii, provides key information about the origin and transport history of sediment on the reef and adjacent beach. The most common grain types include coralline algae, coral, chemically altered carbonate, and siliciclastic grains. Minor components include calcareous algal plates (Halimeda), mollusk fragments, and foraminifera; in selected areas, these components are abundant. Similarities in composition indicate that sand grains are freely transported between the beach and the reef-flat environments, whereas the fore reef has limited exchange of sand with either the beach or the reef flat.

Overall, the calcium carbonate fraction of the sand, silt, and clay increases with distance offshore from 400 to 650 m, where the percentages plateau and remain relatively stable across the fore reef. The calcium carbonate content of bottom sediment indicates that sand transport on the reef flat is generally shore parallel with little shore-normal movement. This study has implications for management of beaches and coastal resources along fringing coral reefs in that it documents the effectiveness of the wide reef flat and reef crest in blocking sand transport with the fore reef. It also indicates that sediment introduced to the inner reef flat is not quickly dispersed seaward and therefore has a relatively high residence time in that setting.

During the Holocene, the western part of the present-day Thessaloniki coastal plain (north-central Greece) was flooded by the rising sea level and formed a bay as a consequence of the last postglacial transgression. The rate of the sealevel rise subsequently decelerated, and this bay began to fill with sediments delivered by the Aliakmon and Axios, as well as by other smaller rivers.

The palaeogeographic and palaeoenvironmental reconstruction of the Thessaloniki Plain was the focus of several studies published during the past century. Most of these studies are based on the interpretation of historical sources and support the assumption of a fast filling of the bay between the fifth century BC and the fifth century AD.

In this work, we first present the results of the analysis of data collected from six boreholes recently drilled in the western part of the plain, up to the western bank of the Axios River. Our study was mainly based on sedimentological and palaeontological analyses and accelerator mass spectrometry and conventional radiocarbon dating of shells and peat. Second, we evaluate the results of this study, as well as of other geological studies, which permit the description of the large-scale stratigraphic pattern of the plain. Data were evaluated on the basis of a geographic information system, used for the first time in such type of work, and were supplemented and assessed with analysis of Landsat imagery.

Based on this evidence, we propose a new, detailed palaeogeographic reconstruction for the evolution of the Thessaloniki Plain during the Late Holocene. This plain corresponded to a wide marine bay during the Neolithic times (6000 BP), and later it was characterised by a fast displacement of the shoreline, mainly during Late Bronze Age, Iron Age, and Classical–Archaic periods (2650–2300 BP). A slowing down of the progradation of the alluvial plain occurred during Roman times (2100–1600 BP), and the plain obtained its present-day topography during the second part of the 20th century.

Turkey was greatly affected by the earthquake disaster of Izmit, a 7.4–moment magnitude earthquake that occurred in the southeast Marmara region on August 17, 1999. A shallow seismic survey using a 0.65-lt air-gun was carried out in September 1999. The results of this investigation were compared with the conclusions obtained from seismic studies conducted along the same profiles in 1994 (using a 0.65-lt air-gun). The main objective of this research was to investigate structural and tectonic differences.

Izmit Bay is seismically under the control of the North Anatolian Fault. This regime developed within the former pull-apart structures. Seismic surveys reveal the presence of intensive gas formation in the Izmit Basin. The gas formation was overlaid by sediments in some areas of the basin and migrated from active fault fractures through the sea bottom. The penetration depth is rather shallow due to the acoustic masking effect of the gas formation. It is believed that the fractures caused by the 1999 Izmit earthquake will be reactivated along the existing tracks of the active fractures of the previous periods. It is accepted that the North Anatolian Fault was a single, deep, dextral strike-slip fault. This fault cuts the former pull-apart basins, which are the residuals of the former Thrace Basin. Occasionally, the Izmit segment of the North Anatolian Fault constitutes flower structures using some of the faults of the former pull-apart structures. It is suggested that this fracture, which was constituted with these alterations, continues toward the town of Ulaşli.

Research on land use or land cover changes in the coastal areas of China has received little attention. The Laizhou Gulf, located in Shandong Province of China, was investigated to assess land use change dynamics by using Landsat™ satellite images of two periods, 1988 and 2002; ground-based information; and geographical information systems. The land uses were grouped into six categories: cropland, forestland, grassland, urban and/or built-up land, water, and barren land. The results indicated that land use since 1988 has changed significantly. The total area of cropland rapidly decreased from 2249.9 km² in 1988 to 2223.5 km² in 2002, decreasing by 26.4 km²; water area decreased from 433.5 km² in 1988 to 414.8 km² in 2002, decreasing by 18.7 km²; and barren land area decreased from 128.3 km² in 1988 to 93.6 km² in 2002, decreasing by 34.7 km². Concurrently, continuous increases of other land use types occurred between 1988 and 2002: grassland increased by 13.6 km² from 99.7 km² to 113.3 km², and urban and/or built-up land increased by 94.9 km² from 824.4 km² to 919.3 km². These alterations were natural and human induced. These factors expose coastal areas of Laizhou Gulf to environmental hazard, namely, saltwater intrusion. Manmade interventions and actions, such as construction of coastal structures and exploitation of aquifers without adequate knowledge of the hydrology setting and an adequate management program, worsen this natural hazard. Uncontrolled human activity induces environmental damage to the overall coastal plains. The impact of saltwater intrusion on land use changes in the area is also discussed.

Surface moisture contents measured on a macrotidal beach with multiple intertidal bars and troughs over three semidiurnal tidal cycles are strongly dependent on the cross-shore topographic variations induced by the bar–trough couplets. The bars show low to moderate moisture contents compared with the lower-lying troughs, with an overall seaward increase in contents with distance from the beach–dune contact. Neap tides are associated with lower moisture contents on the upper beach, but both topography and tidal range effects are less important on the lower beach below mean sea level (MSL), which is dominated by near-saturated conditions. In the upper beach zone, above MSL, where aeolian sand supply is critical to the foredune sediment budget, the topographically controlled cross-shore surface moisture pattern leads to segmentation of the aeolian fetch, with a narrow dry upper beach ramp and bar surfaces characterised by aeolian entrainment potential, alternating with troughs, which capture sand and act as aeolian-muting zones. Infill of the uppermost trough on the beach may lead to expansion of the upper beach ramp, and consequently, of the aeolian fetch zone.

Wind erosion is strongly governed by water adsorbed onto the surfaces of sedimentary particles and held by capillarity in lenses at interparticle contacts. Unfortunately, conventional measurement techniques cannot adequately characterize the distribution of surface pore water content over a continuous, horizontal plane. The present field study, carried out on two beaches on the north shore of Lake Ontario, confirms that the water table level plays an important role in governing this distribution in the absence of precipitation. The maximum extent of the capillary fringe was determined to be about 400–500 mm, consistent with prediction from a physically based model for which the pore radius is assumed to be one-fifth of the mean grain diameter. The brightness of the sand surface also was confirmed to be a good indicator of the amount of pore water present. A simple remote sensing method is described that is nondestructive and continuously tracks pore water variability at the beach surface through time and space. In further testing of the method developed by Cheryl McKenna Neuman and G. Langston, this study examines the dependency of the accuracy of measurement upon the scale of its application.

Frequent leveling data of beach profiles is collected from Nanwan Beach, which is characterized by a large seasonal variation in wave climate. Variability of the bar crest position obtained from the data of measured profiles is examined to quantify seasonal changes of the sandbar by empirical orthogonal function (EOF) analysis. The first eigenfunction showed that a rhythmic bar is a common feature of the beach all year round. The second eigenfunction effectively indicated that the two-dimensional variability of the bar behavior is of seasonal changes. The cross-shore bar movement ranged −30∼40 and −2∼60 m in summer and in winter, respectively. The next two eigenfunctions represented three-dimensional components of the bar behavior with a range of −21∼21 and −30∼21 m in summer and in winter, respectively.

Gold Coast Seaway and Jumpinpin Bar are two tidal inlets that connect the Pacific Ocean to the extensive Gold Coast estuarine system. While the Gold Coast Seaway has been stabilized in the mid-1980s by two rock walls, Jumpinpin Bar has remained a highly dynamic tidal inlet. A detailed study of these two tidal inlets is overdue and has been hindered for a long time by the lack of comprehensive field data. This study provides an extensive hydrodynamic data set, which on one side provides an insight into the hydrodynamic behavior of these two tidal inlets and on another side provides a base for their further study. The measured data show relatively high flow velocities at both locations exceeding 2 m/s. It also shows a strong spatial asymmetry in flow velocity distribution across the Gold Coast Seaway during the ebb tide, which accounts for some of the morphological changes at the study area. A five-month water-level measurement indicates a mixed, predominantly semidiurnal tidal regime at these tidal inlets. Examination of tidal variation shows minor temporal tidal asymmetry at both inlets with potential impact on the sediment transport regime at the inlets. In terms of stability, investigation into the tidal prism and cross-sectional area relationship for both inlets can be described using existing relationships obtained from regression analysis of tidal inlets on Pacific and Atlantic coasts. In regards to stability analysis based on tidal prism–littoral drift relationship, the Gold Coast Seaway seems to be approaching stability while Jumpinpin Bar seems to be more of a dynamic inlet.

Even though continental margins cover only about 7–9% of the world ocean area, they are important sites for organic carbon accumulation and hence play a major role in biogeochemical carbon cycling. Surface sediments from the western and eastern continental shelves of India were studied for their total organic matter content and the labile constituents such as total carbohydrates and proteins to get a better understanding of the hydrological and biogeochemical differences of the two regions on the nature of organic matter reaching the surface sediments. The sampling along the west coast was done during September–October 2003, when upwelling signatures were found to be still persisting along the shelf as evidenced by the low-oxygenated, nutrient-rich surface waters. The eastern shelf was sampled during November–December 2002. The shelf was found to be oxygen saturated and oligotrophic during the season. The surface sediments of the west coast contained a greater quantity of total organic matter when compared to the east coast, but the percentages of labile constituents of total organic matter in the sediments were found to be higher in the east coast by a factor of three as compared to the west coast. The differences in the productivity patterns and the hydrographical conditions were found to exert a major influence on the quantity and composition of organic matter in the surface sediments of the western and eastern continental shelves of India.

In order to understand regional variations in coastal behavior on Prince Edward Island, Canada, we investigated the role of Milne Bank, a submarine bank at East Point, the eastern tip of the island. The objective was to determine how the bank might facilitate transfer sediment from the eroding north coast to the adjacent sediment-rich south coast. The study utilized grain-size and seismic data collected on Milne Bank in 1989 and multibeam sonar surveys in 1997 and 1999. The disturbing effect of East Point on the hydrodynamic regime controls sediment transport. The northern boundary of the bank is a steep sand wave located where southward tidal and wave-driven currents rounding East Point suddenly decelerate. Sand from the north coast enters Milne Bank and is carried south in a field of migrating sand waves that are shed from the northern bounding sand wave toward the prograding end of the bank. Milne Bank is a major sediment sink, rather than a link between the eroding north coast and the sediment-rich south-facing coast. Longshore transport in nearshore bars is more likely to be responsible for continued sediment accumulation on the south coast. Embayments on the south coast have filled up in a cascading fashion, each one facilitating sediment bypassing when it has reached full capacity.

Estuarine flow is highly dependent on a number of factors, including freshwater discharge, wind, and tides. In multi-inlet bar-built systems, the flow can further be driven by mutual forcing between adjacent inlets. In the North Inlet–Winyah Bay National Estuarine Research Reserve, two distinct estuaries are connected by a subtidal channel. Within the channel, simultaneous tidal forcing from both ends produces a nodal point. To determine the implications of forcing from both ends on net exchange, we placed an RDI acoustic Doppler current profiler (ADCP) and a SonTek acoustic current profiler (ACP) on either side of the nodal region for 35 days beginning in March 2005. Asymmetries in tidal forcing on either side of the node lead to significant shifts in the timing of flow reversals. The longer ebb associated with the more distorted Winyah Bay tide causes flow reversals to occur at midebb in Winyah Bay. In addition to tidal asymmetries, subtidal flow patterns during periods of strong wind forcing varied greatly, yielding persistent net volume exchange between the two estuaries for periods of up to several days. Application of simple momentum-balance arguments indicates that the observed subtidal exchange is consistent with local setup and setdown in the larger exposed Winyah Bay, in which pressure gradients generated at the fringe of North Inlet drive the observed flow in the channels. However, local forcing alone does not explain the exchange during periods of persistent upwelling conditions, in which the implied setup at the fringe fails to maintain the direction and magnitude of the current. Rather, the low passed filtered exchange in the channel initially vanishes and then reverses direction around the period of maximum wind stress.

This study addresses the paleogeographic coastal evolution of the coastal plain in the environs of Iskele, Turkey. Eight sediment cores were collected along a north–south and east–west transect and analyzed to determine whether the coastal environment had changed in the recent past. The results illustrate that the coastal environment consisted of a transgressive systems tract, ending approximately 6000 BP and represented by marine transgression, flooding of incised river channels, and marsh development, followed by a high stand systems tract. Five major environmental facies were identified: terrestrial, wetland, lagoon, foreshore, and upper shoreface. The high stand systems tract was characterized by the development of a beach-barrier consecutive series of longshore transport-derived sandbars. These sandbars contributed to the creation and eventual isolation and terrestrial infilling of nearshore lagoons and wetlands. Sea-level indicators indicate rapid sea-level rise reaching a peak approximately 6000 YBP, followed by deceleration of sea-level rise and resulting shoreline progradation. The construction of a causeway connecting Karantina Island to the mainland approximately 2400 years ago has accelerated the process of progradation east of the causeway by decreasing the wave energy. Sediment that would have previously been transported further east is now deposited in the zone immediately east of the causeway.

We examined the hypothesis that nutrients from land sources are enhancing the food supply for fish in coastal reefs of northwestern Cuba. Spatial variation in stable isotope ratios (δ¹³C and δ¹⁵N) was investigated at two sites heavily impacted by mixed pollution sources in Havana City, Cuba, and two reference sites. Significant differences in isotope signatures were found among sites for territorial species, e.g., δ¹⁵N was consistently enriched at impacted sites. The most plausible explanation is enriched nitrogen and carbon sources in the food web derived from organic pollution of the coastal zone by human wastewaters. This supports earlier findings that fish were larger in the vicinity of the harbor because of nutrient additions due to sewage that can increase ecosystem productivity and enhance growth of fish. It is also evidence of the direct land-to-water linkage in coastal zone food webs and illustrates how additional nutrients may affect marine food web functions.

Many beaches have been eroded and the obvious environmental and landscape degradation of many coastal stretches are problems that coastal engineers are spending time solving. With this in mind, different protection methods have been used over time, most on the basis of the artificial nourishment of beaches and the building structures such as groynes and detached breakwaters. Detached breakwaters are artificial structures, generally parallel to the coastline, inspired by the working of natural formations, protecting a certain stretch from wave action and being able to create accretion areas. This is why these structures have been in general use, with different results, since the 1970s in countries such as Japan, the United States, Israel, Spain, Italy, and Australia.

The study undertaken for this research focuses precisely on this type of structure, with the purpose of providing an overall view of the state of the art in this field. In addition, the effects of a detached breakwater on the shoreline for a series of real cases on the Spanish coastline were analysed to check whether the empirical relations given by different researchers for classifying the shoreline's type of response were fulfilled for them all or not. This study only takes formulas on the basis of the geometrical characteristics of breakwaters into consideration as being the most used by design engineers for predesigning a construction. All the formulas studied are based on the nondimensional B/X monomial, which is a ratio between the two most important geometric breakwater parameters (the length of the detached breakwater, B, and its distance to the initial coastline, X), so the result of this work led us to propose the following geometric model for the case of the Catalonian coastline: tombolo formation if B/X ≥ 1.3; salient formation if 1.3 > B/X > 0.5; limited shore response if 0.5 ≥ B/X.

Since 1973, Delray Beach, located on the southeast coast of Florida, U.S.A, has been periodically nourished. The morphological evolution of these nourishments has been influenced by design aspects (e.g., changes in shoreline orientation), extreme events (hurricanes, northeastern storms), and dredging of offshore borrow areas created to provide the nourishment sediments.

This paper describes a thorough analysis of the physical processes influencing nourishment performance using the process-based model Delft3D. The analysis distinguishes three steps: (1) a wave analysis, (2) a hydrodynamic analysis, and (3) a morphological analysis. The wave analysis shows that the oldest, deeper, borrow pits (dredged in 1973 and 1978) have the largest effect on the nearshore wave climate, while the effects of the reefs can be considered negligible. Results from the hydrodynamic analysis indicate that differences in wave height cause variations in alongshore current velocities related to differences in wave setup and local wave angle. The morphologic analysis also shows a large influence of the older borrows on fill performance. Bar formation behind the borrows is predicted by the model; however, this feature couldn't be confirmed with 300-m spaced beach profile data. Higher current velocities were predicted in the shadow zone behind borrow areas because of gradients in wave-induced water levels and changes in wave direction induced by the borrows. The higher than average erosion in the southern end of the fill appears to be caused by changes in shoreline orientation and to a lesser degree, borrow area effects.

Modeling played a key role in understanding the observed morphological development of the fill. The use of different bathymetric scenarios proved to be a useful method in isolating the physical processes relevant to nourishment performance and assessing their relative effects.

A recently developed remote-sensing instrument acquires high-quality digital photographs in shallow-marine settings within water depths of 15 m. The technology, known as the Along-Track Reef-Imaging System, provides remarkably clear, georeferenced imagery that allows visual interpretation of benthic class (substrates, organisms) for mapping coral reef habitats, as intended. Unforeseen, however, are functions new to the initial technologic purpose: interpretable evidence for real-time biogeologic processes and for perception of scaled-up skeletal self-similarity of scleractinian microstructure. Florida reef sea trials lacked the grid structure required to map contiguous habitat and submarine topography. Thus, only general observations could be made relative to times and sites of imagery. Degradation of corals was nearly universal; absence of reef fish was profound. However, ∼1% of more than 23,600 sea-trial images examined provided visual evidence for local environs and processes. Clarity in many images was so exceptional that small tracks left by organisms traversing fine-grained carbonate sand were visible. Other images revealed a compelling sense, not yet fully understood, of the microscopic wall structure characteristic of scleractinian corals. Conclusions drawn from classifiable images are that demersal marine animals, where imaged, are oblivious to the equipment and that the technology has strong capabilities beyond mapping habitat. Imagery acquired along predetermined transects that cross a variety of geomorphic features within depth limits will (1) facilitate construction of accurate contour maps of habitat and bathymetry without need for ground-truthing, (2) contain a strong geologic component of interpreted real-time processes as they relate to imaged topography and regional geomorphology, and (3) allow cost-effective monitoring of regional-and local-scale changes in an ecosystem by use of existing-image global-positioning system coordinates to re-image areas. Details revealed in the modern setting have taphonomic implications for what is often found in the geologic record.

The inlet modeling system, developed by the U.S. Army Corps of Engineers Coastal Inlets Research Program, was used to investigate the intermittent movement of sediment throughout the Shinnecock Inlet ebb shoal complex. Circulation, sediment transport, and morphology change were calculated by a two-dimensional finite-difference model that was coupled with a steady state finite-difference model based on the wave action balance equation for computation of wave-driven currents. The inlet modeling system, forced with various combinations of incident waves and tide, was applied to three configurations of Shinnecock Inlet (13 August 1997, 28 May 1998, and 3 July 2000) to determine the distribution of hydrodynamic forces and investigate the dominant pattern of morphology change. This pattern was previously identified through principal component analysis of five scanning hydrographic operational airborne LIDAR (light detection and ranging) system surveys of Shinnecock Inlet from June 21, 1994, to July 3, 2000. The numerical simulations suggested these dominant variations in morphology could be generated through the integration of tidal transport, wave transport, and sediment movement associated with the deflection of the ebb jet by longshore currents. The ebb jet generated sand waves within the interior of the ebb shoal and supplied sediment to the most seaward regions of the system. Longshore currents induced by incident waves from the east and west quadrants redirected the tidal transport, resulting in a supply of sediment to the bypass and attachment bars. During less energetic incident wave conditions, both tide and wave patterns of transport coexisted and interacted, resulting in a broad range of morphologic features. As wave energy increased, the tidal transport pattern was overshadowed and morphology change was concentrated along the western barrier and bypass bars.