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Coastal areas contain interfaces between complex depositional systems as a consequence of the convergence of marine and continental environments. The knowledge of such complex depositional systems is important in understanding of coastal evolution and for coastal management. The present study deals with the subsurface identification of interfaces between fluvial and beach/shallow marine systems, using Ground Penetrating Radar (GPR). GPR profiles were measured along dip direction, at two sites on the coastal plain of Santa Catarina state (Pinheira and Passo de Torres), where deposits of fluvial and beach/foredune ridge systems occur. GPR data showed that fluvial and beach deposits are interdigitated in subsurface, with reflectors showing different downlap directions. The results of this study allow a more complete knowledge of the complex interfaces between marine and continental systems. Also, the identification of hidden older fluvial deposits in the subsurface of coastal plains gives important geotechnical information to be considered in the use and occupation of coastal areas and during prospection for placer deposits. [ABSTRACT FROM AUTHOR]

Tidal inlets are defined as major tidal channels separating individual barrier islands or barrier spits and adjacent headlands. Two types of barrier islands are recognized: (1) those that consistently migrate landward (transgressive), and (2) those that build seaward (prograding or regressive). The most common types include those that formed from (1) elongation of sand spits from major headlands; (2) drowning of coastal sand ridges; and (3) landward migrating transgressive barriers that stabilized and then prograded seaward during the mid-Holocene on the interfluves between the major lowstand valleys. Large tidal inlets developed in these former river valleys. The influence of tidal range vs. average wave height plays an important role in determining the morphology of the barrier islands and the character of the tidal inlets. As an example, the outer margins of the Georgia Bight, where the tidal range is microtidal and wave heights are greatest, most barrier islands are long (28-30 km), wave-dominated, and transgressive. Toward the mixed-energy head of the Bight, where the tidal range is mesotidal and waves are relatively small, barrier islands tend to be short (<15 km), regressive, and drumstick-shaped. Tidal inlets having large flood-tidal deltas are mostly restricted to the microtidal margins of the Bight, whereas inlets with large ebb-tidal deltas dominate the mesotidal head of the Bight. Most tidal inlets form by the following mechanisms: (1) storm-generated scour channels; (2) spit growth across the entrances to flooded valleys during the mid-Holocene; (3) intersection of major tidal channels by landward-migrating transgressive barrier islands; and (4) tidal prism-controlled, evenly spaced inlets that evolve in regions lacking major former river valleys. [ABSTRACT FROM AUTHOR]

The main goal of this study is to estimate the coastal vulnerability on a stretch of coastline by using two different methodologies and to check if both methodologies give rise to similar results or if notably dissimilar assessments are obtained. To reach the above mentioned objective, a new experimental methodology (Benassai et al, 2009) based on inundation of the inshore land and the well known USGS methodology (Gornitz et al, 1994) are applied and compared. In the first approach, a new parameter, named as impact index, is calculated by using wave climate and geomorphologic data. In general, impact index depends on run-up height, seasonal and long term erosion index and the efficiency of existing structures for coastal defence. The relative value of this parameter is contrasted with that of the often used coastal vulnerability index, CVI, which includes geological and physical variables. The application of these methods gives rise to significantly different levels of vulnerability for the same zone. This situation must be attributed mainly to the distinctive nature of the used methods. Thus, taking into account the results, it is remarked that the procedure to choose a methodology for assessing the vulnerability of a given coastal zone must be based on the available information and on the characteristics of the zone. Furthermore, the use of the same method to do risk and vulnerability comparisons is recommended. [ABSTRACT FROM AUTHOR]

The coastline of Hai Hau District, located on the northeast coast of Vietnam with about 30 km of shoreline, is chronically eroding. Previous studies have tried to highlight the main causes of the erosion along this coastline, and several hypotheses exist. To examine the hypothesis that gradients in the longshore sediment transport rate and cross-shore fine sediment lost offshore are the main causes generating the serius erosion at Hai Hau Beach, a newly developed numerical model of shoreline change based on the one-line theory was applied and compared with data. Sea dike segments, reinforced by stones and mortar, were modeled using a seawall boundary condition, and the sediment continuity equation was modified to take into account the offshore transport of fine-grained sediment. The simulated shorelines agreed well with the measured shorelines, both for the calibration and validation periods. The calculated sediment budget shows that the net sediment transport is in the southward direction and that a large amount of finegrained sediment is lost into deep water. These two sinks of sediment are believed to be the main causes of the serious erosion at Hai Hau Beach. [ABSTRACT FROM AUTHOR]

The geomorphology and processes of land loss in the Pontchartrain Basin for the period 1990-2001 are mapped and the results of the classification presented. This data set is compared to an earlier classification, which covered the period 1932-1990 to determine the status and trends of wetland loss in the Pontchartrain Basin between 1932 and 2001. Results of the land loss classification indicate land loss rates have remained steady between the two periods (13 km2/y between 1932 and 1990 and 12 km2/y between 1990 and 2001). The geomorphology and processes of loss have shifted from primarily interior loss as a result of direct removal and submergence in the first period to primarily shoreline loss as a result of erosion in the second period. Three areas of concentrated land loss between 1990 and 2001 represent portions of the upper, middle, and lower basin. Land loss at all three locations shifts from interior to shoreline loss between the two periods. In the second period, interior loss through the process of submergence is still occurring but at much reduced rates at locations 1 and 2. Interior loss through the process of direct removal is only occurring at location 1 during the second period and accounts for less that 2% of the loss. At location 3, land loss is completely in the form of shoreline erosion during the second period. [ABSTRACT FROM AUTHOR]

There are more than 15,000 barrier islands in fetch-limited nearshore environments around the world. About half that number are actively evolving (eroding, accreting, migrating) in response to oceanographic processes and are the subject of this study. The remaining half consists of inactive islands protected by surrounding salt marsh or mangroves. Despite their global abundance these islands have not been previously systematically studied or even recognized as a major landform type. More than 70% of fetch-limited barrier islands are found on trailing edge coasts because conditions there are favorable for formation of sheltered waters. Fully 50% are found in the coastal zone of Australia, Mexico, and Russia. We identify eight different types of fetch-limited barrier islands based on genesis and mode of occurrence. Most of the active islands form in estuaries or bays (Spencer Gulf Australia), behind open ocean barrier islands (Pamlico Sound, North Carolina), or on flood tidal deltas of open ocean tidal inlets (Tapora Bank, New Zealand). Others occur on river deltas sheltered by offshore islands (Menderes Delta, Turkey), in sheltered bays with thermokarst topography (Yensei Bay, Russia), and on glacial outwash plains in fjords (Golfo Esteban, Chile). Due to a Holocene sea level drop, some southern hemisphere islands have been stranded above mean sea level and are intermittently active (Maputo Bay, Mozambique); they are only surrounded by water during spring tides and storms. Intermittent islands also form under conditions of high tidal amplitude (Kings Bay, Australia). Fetch-limited barrier islands are much smaller than their open ocean counterparts, averaging roughly 1 km long and 50 m wide and 1 to 2 m maximum elevation. They evolve in similar fashion to ocean barriers except that overwash is almost always the dominant island building process and dune formation is much less important. The two biggest distinctions between open-ocean and fetch-limited barrier islands are (1) complete evolutionary dependence on storms and (2) the important role of salt marsh and mangrove vegetation in controlling the shape and location of fetch limited barrier islands. Stabilized by salt marshes and mangroves, vegetative control is responsible for the irregular shape of some fetchlimited barrier islands and often plays a role in creating the foundation upon which the island evolves. Few of these islands are settled or developed at present, but it is likely that in midlatitudes they will soon be under development pressure. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyse the shoreline response of a beach protected by a system of low crested structures (LCS) and to apply the results to the management of coastal stability problems. This contribution aims to provide heretofore scarce detailed data and observations of the shoreline variability of coasts protected by LCS. These aims are acheived by selecting and monitoring the appropriate Coastal State Indicator (CSI) to describe the state of the beach. The CSI used is the Mean Intertidal Position (MIP), which has been detected by the ARGUS system installed in Lido di Dante, Italy. The error in the shoreline estimation from video was assessed by comparing shorelines detected with global positioning system (GPS) and image analysis over a large number of cases. The horizontal error in the shoreline detection is estimated to be on the order of 0.90 ± 0.74 m, which is acceptable because it is on the same order of magnitude as the swash width. The MIP, which has been monitored over a forty month period with elevated spatial and temporal resolution, was monitored in several transects of the beach protected by a system of LCS and boundary groins, creating two cells. The behaviour of the section in the middle of the cell was comparable to the behaviour of the total beach. Results were analysed with respect to the fixed beach state of the initial beach position (January 2004). The MIP regression rate is around 2.3 m/y, which is modest considering the local subsidence magnitude (1.8 cm/y). Therefore, the actual data do not show any evidence of immediaste risk, either for the present structures on the beach or for the infrastructure immediately behind; however, the results do show a risk for the sustainability of the characteristics that permit tourist development. The use of video-derived CSIs is confirmed to offer a valuable tool for coastal management. [ABSTRACT FROM AUTHOR]

The indentation index, which is the ratio between the real length of a coast and its Euclidean length, is a parameter applied to characterize rock coasts and to study their evolution. Rather than subjectively selecting two or more sectors of a rock coast, the method proposed in this paper considers analyzing the indentation index on the same coastline previously split into several adjacent tracts with equal Euclidean length. By digitizing the coastline in a GIS environment, it becomes possible to test several Euclidean length values on the same coastline, obtaining a different spatial variability of the indentation index with each trial. The best length values that maximize the spatial variability of the indentation index are those that determine an indentation index pattern characterized by high variance and low spatial autocorrelation. The spatial distribution of the indentation index can eventually be analyzed considering known littoral forces acting on the studied coast. When more than one Euclidean length value is found to maximize the variability of indentation index within the same coast, it is likely that there are one or more littoral forces acting or interacting differently at different scales. [ABSTRACT FROM AUTHOR]

A ground-penetrating radar survey of a newly formed series of beach ridges along the southern Azerbaijan coast, Caspian Sea, illustrates rapid coastal response to the most recent sea level fall of 0.8 m in the Caspian Sea between 1995 and 1999. Effects of seasonal sea level fluctuations as well as individual storm occurrences can be linked to depositional beds on the ground-penetrating radar profiles. The beach ridge system is swash built and formed primarily under fair weather conditions. Ridge and swale topography can be related to seasonal sea level change. The rapid sea level change in the Caspian Sea combined with surface and subsurface data on coastal beach ridges provides a unique opportunity to observe and reconstruct coastal evolution at a resolution not possible along other oceanic coasts. [ABSTRACT FROM AUTHOR]

A series of partially drowned drumlins forms the backbone of the inner islands within Boston Harbor. The shoreline of these rounded glacial deposits is composed of actively retreating bluffs formed by continual wave attack. Comparisons of bluffs reveal variability in their height and lateral extent, as well as in the dominant mechanism causing their retreat. Two processes are responsible for bluff erosion and yield distinct bluff morphologies: (1) wave attack undercuts the bluff and causes episodic slumping, yielding planar bluff slopes, and (2) subaerial processes such as rainfall create irregular slopes characterized by rills and gullies. We propose a model of drumlin bluff evolution that is based on processes of erosion and physical characteristics such as bluff height, slope morphology, and the orientation of the bluff with respect to the long axis of the drumlin and its topographic crest. The four phases of drumlin bluff evolution consist of (1) initial formation of bluff, with retreat dominated by wave notching and slumping processes; (2) rill and gully development as bluff heights exceed 10 m and slumped sediment at bluff base inhibits wave attack; (3) return of wave notching and slumping as bluff heights decrease; and (4) final development of boulder retreat lag as last remnants of drumlin are eroded by wave action. These phases capture the important physical processes of drumlin evolution in Boston Harbor and could apply to other eroding coastal drumlin deposits. [ABSTRACT FROM AUTHOR]

Twenty-six parameters have been selected that delineate coastal scenery. These were obtained via consultation between coastal users and experts in the field. The parameters were assessed as to their priorities and weightings given. Application of fuzzy logic techniques enabled a decision parameter (D) to be calculated for any coastal scene. Over 100 worldwide coastal sites were analysed via the technique and a five-class differentiation obtained from D values. [ABSTRACT FROM AUTHOR]

Historical sources indicate that, in the late 19th century, the portion of the southern California coastline between Palos Verdes Peninsula and San Mateo Point was composed of a series of barrier spits backed by estuaries, beaches backed by cliffs, and occasional rocky headlands. Nearly natural conditions, a reflection of minimal human impact, prevailed during this relatively stormy interval. US Coast [and Geodetic] Survey materials, early scientific work, newspaper articles, and the accounts of travelers provide much of the information utilized to reconstruct the shoreline. Serving as a major roadway, the beach that extended between San Juan Creek and San Mateo Creek was especially well known. The barrier spits were capped by low dunes and were separated by migrating inlets connecting the ocean with the backing estuaries. Rivers discharged into the estuaries at times, decreasing salinities and depositing sediments. Rocky coastlines are believed to have experienced substantial erosion as high levels of bioerosion and vigorous attack by storm waves is inferred, giving rise to notched cliffs, sea caves, and other erosional forms. Forming part of the seaward fringe of the greater Los Angeles region, today this shoreline is completely developed, serving the commercial and recreational needs of millions of residents and visitors. [ABSTRACT FROM AUTHOR]

The greatest change in particle roundness, sphericity, and size in most fluvial systems generally occurs in the initial first few kilometers of sediment transport. Observations in natural settings and laboratory experiments have shown that changes, such as increased grain rounding and decreased size due to particle breakage, wear, and attrition, tend to be progressive along the dispersal path. In marked contrast, this study records highly variable and poorly developed particle-texture trends downslope along short (<5 km) channels that extend directly from a high-relief carbonate source area down to the shore of Lake Annecy in the western Alps, SE France. The observed inconsistent patterns are measured in both a region-wide analysis using all collected samples and also in a more specific survey of samples in six different channels incised on the steep, topographically irregular mountain flanks that border the lake. The major factor responsible for the irregular downslope patterns of roundness, sphericity, and size in the Annecy study area is the lateral introduction of sediment into the fluvial channels along dispersal paths. Episodic failure of mechanically unstable sediments and their transport down steep valley walls bring less-abraded sediment of variable shape and size along the dispersal paths. The valley wall sediment influx factor warrants further examination to better interpret sedimentation processes in dissected, high-gradient terrains that border coastal areas. [ABSTRACT FROM AUTHOR]

Dredged materials from maintenance and deepening of inlets on coastal barriers are typically transported for disposal in deep water or on land. An alternative is to treat dredged materials as a resource, placing them on the ebb-tidal delta or subtidal shoals at depths where they are retained within the long-shore transport system and can nourish eroding down-drift beaches. Deposition of sediments onto subtidal shoals may, however, bury and selectively kill populations of benthic invertebrates, or indirectly alter assemblages by modifying sediment characteristics. Core sampling of the eastern (control) and western (disturbed) sides of Beaufort Inlet, North Carolina, twice before and once 8 months after a large (660,000 m³) disposal revealed significant coarsening of sediments and associated changes to assemblages of benthic macroinvertebrates in response to the perturbation. Impacts to sediments and macroinvertebrates were closely correlated and, although greatest where sediment was directly deposited, extended over a wider (at least 1 km to the east) area than the deposition. Of the taxa comprising faunal assemblages, spionid polychaetes were most affected by the disposal, declining in abundance. These results, which tie the deposition and dispersal of coarse sediments on an ebb-tidal delta to changes in benthos, imply a biological cost that may be less than that of direct nourishment of biologically productive intertidal beaches. [ABSTRACT FROM AUTHOR]

Sorting of sediment on a beach occurs when the cross-shore profile consists of graded sediments. Each grain-size fraction within a mixture responds differently to the same hydrodynamic regime. Sorting of sediment under wave action takes several forms. Stratified layers of finer and coarser sediment are formed, depending on wave climate, grain size, and beach slope. Grain size and sorting studies are of great importance in characterizing the dynamic beach environment. Some field data have been reported in the literature. In the present study, the cross-shore distribution of sediments, as well as the corresponding beach profiles, were measured in a wave basin on 1:5 beach slope for regular waves. Eighteen sets of experiments were performed on cross-shore sorting mechanisms using two different sand beds. The sorting of bed material and the formation of armor coats along beach profiles were defined by grain-size distribution and dimensionless parameters in this study. The experiments showed that finer material was deposited on the crest of bar-type beach profiles, but coarser grains accumulated on the foreshore, trough, ridge, and toe sections. Finer materials settled on the foreshore and crest of step-type profiles while coarser grains were deposited on the ridge and toe sections. The effect of the movement of a particular fraction on the sediment transport rate was also studied. Calculated sediment transport, modified to include the effects of sorting, was compared with transport rates measured in the wave basin. This suggested that the results under the experimental conditions were satisfactory for the description of sediment transport in the surf zone using the partial sediment transport mechanism over the beach profiles. [ABSTRACT FROM AUTHOR]

Low Isles Reef is the most southerly located of 46 coral reef platforms unique to the inner shelf of the northern Great Barrier Reef Province, Australia, which support both sea grass and mangrove growth. Such reefs develop in areas that are influenced by river flood plumes and where interreef sediments are dominated by terrigenous mud. Low Isles Reef has long been a popular tourist destination. Informal reports of decreasing visibility, a decline in scleractinian corals, and increases in soft coral and macroalgae have sparked speculation that agricultural activities in coastal catchments are affecting the reef. Comparison of the modern surface of Low Isles Reef with historical surveys and photographs dating back to 1928 allows quantification of modern sedimentary processes, rates of change, and factors influencing reef development. Results indicate that changes on Low Isles Reef are related to remobilization of coarse sediment during storm events and gradual shoreline retreat associated with rising sea level. Retreat of shingle ram-parts and elongate ridges of coral debris toward the reef interior has led to the infilling of subtidal ponds on the reef top, which supported hard coral colonies in 1928. The gradual development of a composite shingle rampart along the windward margin has promoted an increase (∼150%) in the area of the reef top covered by mangroves. On the leeward margin, a decrease in hard corals since 1950 may reflect a rising contribution of organic debris from the expanding mangrove swamp. Results suggest that recent changes on Low Isles Reef can be explained in the context of natural processes. Further study is needed before the effects of agricultural activities in coastal catchments on reef health can be confirmed. [ABSTRACT FROM AUTHOR]

Australian reef flats on the Cocos (Keeling) Islands atoll, Indian Ocean; Warraber Reef, Torres Strait; and Lady Elliot Island, Great Barrier Reef vary greatly in morphology (width, elevation) and hydrodynamic setting (wave and tidal regime). This study describes results from detailed wave and current measurements, under nonstorm conditions, along five reef flat transects on these reef systems and examines implications for surface geomorphic processes. Results show that wave frequency and transformation varies between reefs in a consistent manner dependent on tidal elevation, reef elevation, and reef width. A nondimensional reef energy window index (Ψ) is developed that incorporates these critical factors (water depth at spring high tide and reef width). A statistically significant relation (95% confidence interval) between Ψ and the proportion of time that wave energy propagates across reefs illustrates the index ability to characterise the wave process regime of reef flats and provide a physically meaningful descriptor of the efficacy of geomorphic processes on reefs. High values of Ψ indicate narrow and low-elevation reef flats, which are exposed to high wave energy and are geomorphically active. Low values reflect wide and high-elevation reef flats associated with less active wave and geomorphic processes. Results show that while incident energy is undoubtedly an important factor for reef geomorphology, the nature of wave modification across reef flats is equally important in governing levels of geomorphic activity that control development of surface geomorphic features on reef platforms. [ABSTRACT FROM AUTHOR]

Management of uncertainty in model predictions of long-term coastal change begins by admitting uncertainty. In the case of geometric mass-balance models, the first step is to relax restrictive assumptions to allow for open sediment budgets, time-dependent morphology, effects of mixed sediment sizes, and variable resistance in substrate material. These refinements introduce new uncertainty regarding the choice of parameter values. The next step is to actively manage uncertainty using techniques readily available from information science. The final step requires a shift in coastal management culture to accept decision making based on risk-management protocols. Stochastic simulation was applied to manage predictive uncertainty in cases involving complications resulting from open sediment budgets, rock reefs, and seawalls. In these examples, the respective effects caused between 20% and 60% difference from conventional predictions based solely on equilibrium assumptions and substrates comprised entirely of sand. Stochastic simulation makes it possible to establish confidence limits and determine the statistical significance of differences caused by varying effects such as substrate resistance and shoreface geometry. It also enables the likelihood of critical impacts to be specified in terms of probability. Moreover, probabilistic forecasts provide a transparent basis for coastal management decisions by revealing the consequences if quantitative estimates prove to be wrong. [ABSTRACT FROM AUTHOR]

Caleta Valdés is an area constituted by a set of Holocene and Pleistocene gravel beach ridges, which form part of a harrier spit system. Longshore drift has been predominantly north to south for the last 5700 years. Evolution of the area has been monitored during the last 28 years. In this period, the northern spit has been growing southward, and its rate has increased from 25-meter per annum (1971–87), to 89-meter per annum (1987–96). During the 1996–9 time span, growth has increased up to 167-meter per annum. This growth rate implies an average movement of approximately 1400 metric tons of gravel a day during the last four years. The growth rate during the time span under study can he represented by a polynomial equation of the third order. Spit evolution can he predicted from this equation. It is thus possible to suggest that Caleta Valdes is likely to close by 2002 (±). Such a morphological change will cause drastic changes in hydrodynamics, and environmental conditions due to changes in both water salinity and temperature. [ABSTRACT FROM AUTHOR]

A port complex was implanted in the coast region of Suape, PE-Brasil, in 1979–80, which altered the geomorphological and hydrodynamic conditions of the area, mainly in the estuary of the Ipojuca River. Water samples were collected from the surface and the deep layer to determine the salinity, pH, dissolved oxygen, transparency, and temperature from three fixed stations in the estuary of the Ipojuca River during the summer and winter before (1978) and after (1986–87) the port's construction, in order to evaluate the effects of the port-induced changes. The data were subjected to a principal component analysis and to individual t tests. The first principal component, the axis of maximum information, alone explained 50% of the total variance, being associated with the generalized increase of the chemical parameters after the port's construction, mainly the salinity. Despite the fact that the results of the t tests presented significant differences only for the dissolved oxygen, pH, and temperature, the increased salinity produced the greatest ecological effects in the estuary. The water flow of the Ipojuca River was diverted toward the ocean, decreasing the river-flow velocity at the mouth. This decrease in flow caused a sedimentation in the area, a decrease in the circulation and depth, and a transformation of the mouth of the river into a coastal lagoon with an increase in evaporation and salinity. A delay of more than 2 hours was observed in the dynamic tide in relation to the normal 6-hour cycles. Despite an increase in the concentration of dissolved oxygen and transparency values, effects that theoretically improve environmental conditions, a morphological transformation occurred that caused drastic changes in the estuary's circulation and in the tidal currents. [ABSTRACT FROM AUTHOR]

This work aims to improve the knowledge of sediment circulation in the coastal zone, focusing on the quantification of sediment movement due to longshore drift. The studied field site is the Praia de Faro beach on the Peninsula do Ancão in Algarve (Portugal), which is located on the updrift coast of the Barra Nova tidal inlet. The main objective of the study was to quantify the sediment transport rate that will enter in the inlet system. Measurements were undertaken during low hydrodynamic conditions prevailing in this area and permitted to estimulate a longshore transport rate of 2.6-4.2 m/s, consistent with other transport estimations in Algarve. Four theoretical models for longshore transport rate calculation were confronted to tracer results to choose a extrapolation tool. KAMPHUIS (1991) formation appeared to be the more appropriate in this area. It was used to extrapolate the results in order to be compared to the observed morphological evolutions. The calculate short term sediment flux (10500 m³/month) corresponds to the accretion on the updrift swash platform of the Barra Nova tidal inlet and is thus considered to be the contribution of the adjacent coast to this system. Moreover, the estimated longshore transport rate permit us to predict a spit progradation of 60-70 m/year. This result is consistent with the observed migration rate of the Barra Nova inlet during the last 25 years. This study shows that, with a good knowledge of the environmental context, sediment fluxes obtained by sand tracers are accurate enough to estimate the long term longshore transport and long term morphological response of a stretch of shoreline. [ABSTRACT FROM AUTHOR]

The European Spare Agency (ESA) founded two projects in 1991 and 1994 concerning the observation of the Argentine coastal environment with synthetic aperture radar (SAR). Studies were carried out for the periods 1992-1994 and 1994-1997. Several ERS-1/2 satellite SAR images were acquired over the San Matías Gulf in the Patagonian coast during these two periods. SAR is a side-looking imaging radar that operates from either a satellite or an aircraft. The instrument emits a series microwave pulses toward the earth in a direction perpendicular to the flight path. Imagery is constructed from the strength and time delay of the returned signals, which depend primarily on the roughness and dielectric properties of the surface under observation and the distance from the radar. Ocean surface roughness wave-like patterns, imaged as a series of bright and dark linear features by SAR, are persistently observed over the San Matías Gulf mouth region. A total of thirty-three (3) ERS-1/2 SAR images (100 km x 100 km) from 15 different orbits from 1992 to 2000 were analyzed. This series of observations has allowed for a detailed examination of the location, persistence, and the conditions involved in the imaging of the observed wave-like patterns. Very strong tidal currents tidal currents of the order of 2 m/s characterize the gulf region. The characteristics of recurrent surface patterns in the SAR images indicate that they are caused by the interaction of the tidal currents with bed forms in the bottom topography of the gulf. The location of these bed forms is poorly documented in the available bathymetric charts of the region. The SAR images show the significant potential that satellite radar observations have as a tool for detecting unmapped coastal ocean bottom features, particularly, where bathymetric mapping activities can be extremely difficult, dangerous, or costly. [ABSTRACT FROM AUTHOR]

Coastal landscape evolve over wide-ranging spatial and temporal scales in response to physical and biological processes that interact with a wide range of variables. To develop better predictive models for these dynamic areas, we most understand the influence of these variables on coastal morphologies and ultimately how they influence coastal processes. This study defines the influence of geologic framework variability on a classic mixed-energy coastline, and establishes four categorical scales of spatial and temporal influence on the coastal system. The near-surface, geologic framework was delineated using high-resolution seismic profiles, shallow vibracores, detailed geomorphic maps, historical shorelines, aerial photographs, and existing studies, and compared to the long- and short-term development of two coastal compartments near Charleston, South Carolina. Although it is clear that the imprint of a mixed-energy tidal and wave signal (basin-scale) dictates formation of drumstick barriers and that immediate responses to wave climate are dramatic, island size, position, and longer-term dynamics are influenced by a series of inherent, complex near-surface stratigraphic geometries. Major near-surface Tertiary geometries influence inlet placement and drainage development (island-scale) through multiple interglacial cycles and overall channel morphology (local-scale). During the modern marine transgression, the balo of ebb-tidal deltas greatly influence inlet region dynamics, while truncated beach ridges and exposed, differentially erodable Cenozoic deposits in the active system influence historical shoreline dynamics and active shoreface morphologies (block-scale). This study concludes that the mixed-energy imprint of wave and tide theories dominates general coastal morphology, but the underlying stratigraphic influences on the coast provide site-specific, long-standing imprints on coastal evolution. [ABSTRACT FROM AUTHOR]

The article offers information on the adventures and peregrinations during coastal fieldwork in South Australia. Topics discussed include research into the age and origin of the River Murray estuary, a study involving collecting sub-surface samples by vibracoring and trenching across a tidally dominated shoreline, and a study of the Cooring to Mt. Gambier coastal plane.

A personal narrative is presented which explores the author's experience of living in Baton Rouge, Louisiana while undertaking graduate studies in Geography at Louisiana State University (LSU).