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The effects of the interaction between sandy, mobile, low-relief (sorted) bedforms and two sewage outfalls were investigated along the south shore of Long Island, NY. Sand bedforms at scales from ripples to ridges are common on continental shelves. In dynamic environments, these features can migrate 10s to 100s of meters per year, especially during storms. Beyond engineering considerations, little is known of the interaction between these mobile features and anthropogenic structures. Modification of bedform topography and sediment grain-size distribution can be expected to alter the species composition, abundance, and diversity of the benthic community. At the study site, the interaction increased the scour of modern fine- to medium-grained sediments extending out to a kilometer and uncovered coarser-grained late Pleistocene sediments. This alteration of the seafloor in turn resulted in changes in composition, higher abundance, and lower diversity in the species assemblage found in the impacted area. The most advantaged species was Pseudunciola obliquua, a sightless, tube-building, surface deposit-feeding amphipod that is known to prefer a dynamic coarse sand habitat. Overall, the ecological effects of artificial structures on a wave-dominated seabed with sorted bedforms have not been adequately assessed. In particular, and of great importance, is the pending large-scale development of wind farms off the East Coast of the U.S.

This study addresses the impact of spatial scale on explaining variance in benthic communities. In particular, the analysis estimated the fraction of community variation that occurred at a spatial scale smaller than the sampling interval (i.e., the geographic distance between samples). This estimate is important because it sets a limit on the amount of community variation that can be explained based on the spatial configuration of a study area and sampling design. Six benthic data sets were examined that consisted of faunal abundances, common environmental variables (water depth, grain size, and surficial percent cover), and sonar backscatter treated as a habitat proxy (categorical acoustic provinces). Redundancy analysis was coupled with spatial variograms generated by multiscale ordination to quantify the explained and residual variance at different spatial scales and within and between acoustic provinces. The amount of community variation below the sampling interval of the surveys (< 100 m) was estimated to be 36-59% of the total. Once adjusted for this small-scale variation, > 71% of the remaining variance was explained by the environmental and province variables. Furthermore, these variables effectively explained the spatial structure present in the infaunal community. Overall, no scale problems remained to compromise inferences, and unexplained infaunal community variation had no apparent spatial structure within the observational scale of the surveys (> 100 m), although small-scale gradients (< 100 m) below the observational scale may be present.

The dynamics of lateral circulation in the Passaic River estuary is examined in this modeling study. The pattern of lateral circulation varies significantly over a tidal cycle as a result of the temporal variation of stratification induced by tidal straining. During highly stratified ebb tides, the lateral circulation exhibits a vertical two-cell structure. Strong stratification suppresses vertical mixing in the deep channel, whereas the shoal above the halocline remains relatively well mixed. As a result, in the upper layer, the lateral asymmetry of vertical mixing produces denser water on the shoal and fresher water over the thalweg. This density gradient drives a circulation with surface currents directed toward the shoal, and the currents at the base of the pycnocline are directed toward the thalweg. In the lower layer, the lateral circulation tends to reduce the tilting of isopycnals and gradually diminishes at the end of the ebb tide. A lateral baroclinic pressure gradient is a dominant driving force for lateral circulation during stratified ebb tides and is generated by differential diffusion that indicates a lateral asymmetry in vertical mixing. Over the thalweg, vertical mixing is strong during the flood and weak during the ebb. Over the shoal, the tidally periodical stratification shows an opposite cycle of that at the thalweg. Lateral straining tends to enhance stratification during flood tides and vertical diffusion maintains the relatively well-mixed water column over the shoal during the stratified ebb tides.

The Argentine margin contains important sedimentological, paleontological and chemical records of regional and local tectonic evolution, sea level, climate evolution and ocean circulation since the opening of the South Atlantic in the Late Jurassic–Early Cretaceous as well as the present-day results of post-depositional chemical and biological alteration. Despite its important location, which underlies the exchange of southern- and northern-sourced water masses, the Argentine margin has not been investigated in detail using scientific drilling techniques, perhaps because the margin has the reputation of being erosional. However, a number of papers published since 2009 have reported new high-resolution and/or multichannel seismic surveys, often combined with multi-beam bathymetric data, which show the common occurrence of layered sediments and prominent sediment drifts on the Argentine and adjacent Uruguayan margins. There has also been significant progress in studying the climatic records in surficial and near-surface sediments recovered in sediment cores from the Argentine margin. Encouraged by these recent results, our 3.5-day IODP (International Ocean Discovery Program) workshop in Buenos Aires (8–11 September 2015) focused on opportunities for scientific drilling on the Atlantic margin of Argentina, which lies beneath a key portion of the global ocean conveyor belt of thermohaline circulation. Significant opportunities exist to study the tectonic evolution, paleoceanography and stratigraphy, sedimentology, and biosphere and geochemistry of this margin.

Investigations of the geology and physical limnology of a field of sedimentary furrows in Lake Superior have provided information on the characteristics of these bedforms and their relationship to the wind-driven currents and associated turbulence structures in the bottom boundary layer. The results generally support the existing conceptual model for furrow formation. Furrows in the study area (2 km2) at 100-m depth are spaced 20-100 m apart and exceed 800 m long, the troughs being$\\thicksim 0.5m$deep and 3-5 m wide. Sediment cores collected by submersible are poorly sorted, cohesive, terrigenous silts with a mean grain size of 20 μ m. Relative to sediments in the interfurrow area, those in the trough contain higher fractions of sand and coarse debris and accumulate at a rate 15% slower. Strong bottom currents$(speed > 6 cm s^-1)$usually flow within 20⚬of the furrow direction and are most frequent between late October and early February, when wind-forced currents reach the bottom; annual peak speeds approach 30 cm S-1. The relationship of the current and temperature records to the wind field is consistent with predictions of coastal jet theory. Profiling current meters, deployed on either side of a furrow showed near-bottom, cross-stream flow converging over the furrow with divergence higher in the boundary layer when the current speed exceeded 6 cm s-1. A preliminary numerical model exhibits a cross-stream flow pattern consistent with the profiler observations.

The Hudson River is one of the major rivers in North America and has been used by humans since long before Europeans arrived. But the exploration of the river by Henry Hudson in 1609 and the European colonization that followed marks a transition to more direct modification and major impacts on river morphology and sediment transport. As described by other papers in this volume, during the eighteenth and nineteenth centuries the Hudson River became the dominant route connecting Europe via New York City to the northern Midwest and the Great Lakes region. Over the last four centuries, changes in technologies,

Reconnaisance side-scan sonar records from the Hudson River Estuary show that there are substantial variations in bed morphology throughout the estuarine system. The records show regional variations in long-term sediment source and net sediment transport direction in the estuary. Upstream from New York Harbor in the Hudson River, downriver currents have created fields of sedimentary furrows in sandy/silty muds. In lower New York Harbor, upriver currents have created upriver-migrating sand waves. Off Manhattan these flows meet, creating interfingered zones of furrows (created by downstream flows) and sand waves (created by upstream flows). This meeting of sediment transport pathways suggests rapid sediment accumulation, a conclusion substantiated by other studies.

Sediments cored along the southwestern Iberian margin during Integrated Ocean Drilling Program Expedition 339 provide constraints on Mediterranean Outflow Water (MOW) circulation patterns from the Pliocene epoch to the present day. After the Strait of Gibraltar opened (5.33 million years ago), a limited volume of MOW entered the Atlantic. Depositional hiatuses indicate erosion by bottom currents related to higher volumes of MOW circulating into the North Atlantic, beginning in the late Pliocene. The hiatuses coincide with regional tectonic events and changes in global thermohaline circulation (THC). This suggests that MOW influenced Atlantic Meridional Overturning Circulation (AMOC), THC, and climatic shifts by contributing a component of warm, saline water to northern latitudes while in turn being influenced by plate tectonics.

Coastal flooding around NYC during cool season wind events is considered a major forecast problem for the National Oceanic and Atmospheric Administration (NOAA)/National Weather Service (NWS). The National Ocean Service (NOS) of NOAA also recently developed a real-time ocean modeling system for the NYC metropolitan region (Wei 2003).\\n The atmospheric ensemble uses a variety of initial conditions [NCEP GFS, NAM, Canadian, U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS)] combined with various convective, boundary layer, and microphysical parameterizations.