Search Results (47)

Background/Objectives: African American women are less likely to breastfeed in general and to breastfeed exclusively for the first six months of infancy. Racial and ethnic breastfeeding disparities are especially pronounced in the South, particularly in rural communities. These differences are attributed largely to structural lactation impediments that include less breastfeeding support in healthcare settings, workplaces, and communities. While a great deal of research has explored racial differences in breastfeeding, minimal attention has been paid to the social correlates and racial disparities associated with the 2022 U.S. infant formula shortage. Our study explores racial distinctions in the formula shortage’s effect on breastfeeding support among Gulf Coast Mississippians. Methods: We use data from the second wave of the Mississippi REACH (Racial and Ethnic Approaches to Community Health) Social Climate Survey to determine if racial differences are evident in the formula shortage’s influence on breastfeeding support. We predict that the infant formula shortage will have prompted African American respondents to become much more supportive of breastfeeding than their White counterparts, net of sociodemographic controls. This hypothesis is based on the lower prevalence of exclusive breastfeeding among African Americans, thereby indicating a greater reliance on formula. The study uses a general population (random digit dial) sample and purposive (exclusively African American) oversample to analyze validated data from a cross-sectional survey. Sampling took place between September and December 2023, with a sample population of adult male and female Mississippians. A series of binary logistic regression models were employed to measure the association of race with breastfeeding support changes resulting from the infant formula shortage. Results: The study results support the hypothesis, as seen by a positive association between African Americans and increased breastfeeding support directly related to the infant formula shortage. Further, the baseline statistical model reveals African American respondents to be five times more likely than White respondents (p < 0.001) to report that the formula shortage increased their support of breastfeeding. Conclusions: We conclude by discussing this study’s implications and promising directions for future research. Full article

We investigated the impacts of a rapidly changing hydrometeorological regime on coastal erosion in the shallow, seasonally freezing Sea of Azov from 2000 to 2025. Our comparative approach integrated numerical modeling (SWAN), satellite remote sensing, and long-term field observations at two high-erosion sites: the Northern Site in Taganrog Bay and the Southern Site at the open sea boundary. The results demonstrate that coastal erosion is governed by complex, site-specific interactions rather than direct regional climatic trends. A major regime shift characterized by declining fast ice and increasing storm activity during the extended warm season has amplified coastal vulnerability, particularly after 2010. Despite high long-term average erosion rates at both sites, 1.1 to 1.6 m/year in the north and 1.5 to 1.8 m/year in the south, their annual erosion patterns were largely non-synchronous. The Northern Site is controlled by geological structure and surge phenomena, with peak rates reaching 8.5 m/year, while the Southern Site is governed by storm waves and extreme surges, enduring dynamic loads up to 10.0 tf/m². These results provide complex interaction nature of coastal processes and hydrometeorological components and its response to climate change in periodically freezing sea. These findings are vital for improving vulnerability models and underscore the necessity of site-specific hazard assessments for seasonally freezing coasts under a warming climate. Full article

Coastal erosion poses a significant threat to global shorelines, exacerbated by anthropogenic pressures and climate change. The Sea of Azov, a shallow, semi-enclosed basin with coastlines composed of weakly consolidated sediments, represents a highly vulnerable and understudied hotspot for abrasion processes. This study provides a comprehensive, multi-decadal assessment of coastal retreat rates for the Sea of Azov by synergistically integrating long-term field observations with a multi-temporal analysis of satellite imagery from 1971 to 2022. We employed a diverse array of satellite data, including declassified CORONA, SPOT, Sentinel-2, and high-resolution Resurs-P imagery, which were processed and analyzed within a GIS framework using the Digital Shoreline Analysis System (DSAS). Our results quantify extreme coastal abrasion, revealing maximum retreat rates of 1.0–3.5 m/yr along the eastern Sea of Azov coast and specific sectors of Taganrog Bay. The spatiotemporal analysis identified the period of 2013–2014, marked by two major storms, as a peak of erosional activity across all coastal sectors. This study demonstrates that the spatial distribution of erosion is controlled by a convergence of high-energy wind-wave forcing, low geotechnical resistance of Quaternary sedimentary deposits, and unfavorable coastal morphometry. This research underscores the critical value of merging historical field data with modern geospatial technologies to establish baseline rates, identify erosion hotspots, and inform future coastal zone management strategies in vulnerable marine environments. Full article

Coastal flooding risk is intensifying under climate change, especially along the low sandy Senegalese coastline. This study explores the spatiotemporal variability of extreme coastal water levels (ECWL) from 1993 to 2023 by combining ERA5 reanalysis (waves, wind, pressure), tide gauge and meteorological data, and applying a generalized Pareto distribution (GPD) to estimate the 99th percentile and return levels for 50 and 100 year events. The analysis of the upper 1% of ECWLs reveals significant spatial heterogeneity: 99th percentile values exceed 1.2 m in the Dakar region (Yoff, Ouakam, Ngor) and around Saint-Louis/Langue de Barbarie, with 95% confidence intervals ranging from approximately 1.15 m to 1.30 m, while Casamance and the Saloum Delta exhibit much lower extremes (0.8–1.0 m). For return periods, ECWLs vary between 1.6 m and 2.3 m, with the 100 year return level (T100) exceeding 2.25 m in Dakar, above 2.0 m in Saint-Louis, and intermediate values (1.5–1.9 m) along the Petite Côte (Mbour–Toubab Dialaw) and in the Saloum Delta. The 50 year return level (T50) follows a similar spatial pattern but is 5–10 cm lower than T100 in the most exposed areas. Sensitivity analysis shows that ECWLs are primarily controlled by astronomical tide along much of the coast, whereas wave runup dominates in the southern estuarine zones (Saloum, Casamance, Mbour). Trend analysis using the Mann–Kendall test reveals a latitudinal gradient: stronger positive slopes in the south, weaker trends in central and northern sections, but all p values lie between 0.1 and 0.4, meaning none of the trends reach conventional significance. These findings point to a potential intensification of extreme water levels in socio-economically critical areas (Dakar, Saint-Louis, Mbour) but should be interpreted with caution given the lack of robust statistical significance. The results provide a quantitative basis for coastal risk management in light of projected sea level rise. Full article

BU–MIT whistler wave injection experiments, which were conducted at Arecibo Observatory, started with the joint US–USSR Active Space Plasma Program Experiment on 24 December 1989. In this experiment, a satellite-borne VLF transmitter injected radio waves at the frequency and power of 10 kHz and 10 kW. A series of controlled whistler wave experiments with the Arecibo HF heater were subsequently carried out during 1990–1998 until the HF heater was damaged by Hurricane Georges in 1998. In these ionospheric HF heating experiments, 28.5 kHz whistler waves were launched from the nearby naval transmitter (code-named NAU) located at Aguadilla, Puerto Rico. HF heater waves were used to create ionospheric ducts (in the form of parallel-plate waveguides) to facilitate the entry of NAU whistler waves from the neutral atmosphere into the ionosphere. Conjugate whistler wave propagation experiments were conducted between Arecibo, Puerto Rico and Trelew, Argentina in 1997. After 1999, whistler wave experiments in the absence of an HF heater had been conducted. Naturally-occurring large-scale ionospheric irregularities due to spread F or Traveling Ionospheric Disturbances (TIDs) were relied on to guide NAU launched 40.75 kHz whistler waves to propagate from the ionosphere further into the radiation belts, to cause 390 keV charged-particle precipitation. A train of TIDs, resulting from the 9.2 Mw earthquake off the west coast of Sumatra, Indonesia, was observed in our 26 December 2004 Arecibo experiments, about a day after the earthquake-launched tsunami waves traveled across the Indian Ocean, then into remote parts of the Atlantic Ocean. The author’s recent research efforts, motivated by Arecibo experiments, focus on Solar Powered Microwave Transmitting Systems, to simulate Solar Energy Harvesting via Solar Power Satellite (SPS) (also known as Space Based Solar Power (SBSP)) These experiments involved a large number of the author’s BU and MIT students working on theses and participating in the Undergraduate Research Opportunities Program (UROP), in collaboration with other colleagues at several universities and national laboratories. Full article

Landslide impacts into water generate impulse waves that, in confined basins and along steep coasts, escalate swiftly into hazardous near-shore surges. In this study, we present a scenario-aware workflow using gradient boosting and k-means clustering, and explain them using Shapley additive explanations (SHAPs). Two cases are addressed: forecasting at water entry (Scenario I) with predictors Froude number $Fr$, relative effective mass M, and relative thickness S; and pre-event assessment (Scenario II) with predictors Bingham number $Bi$, relative moving length L, and relative initial mass $Mi$. Using 270 controlled physical-model experiments, we benchmark six learning algorithms under 5-fold cross-validation. Gradient boosting delivers the best overall accuracy and cross-scenario robustness, with XGBoost close behind. Scenario I attains a coefficient of determination $R^2$ of 0.941, while Scenario II achieves $R^2=0.865$. Residual analyses indicate narrower spreads and lighter tails for the top models. SHAP reveals physics-consistent controls: M and $Fr$ dominate Scenario I, whereas initial mass and the $Bi$ dominate Scenario II; interactions $Fr\times S$ and $Mi\times Bi$ clarify non-linear amplification of wave amplitude and height. The cluster–predict–explain framework couples predictive skill with physical transparency and is directly applicable to coastal hazard screening and integration into shoreline early-warning workflows. Full article

Coarse-grained beaches consisting of gravel, pebbles, and cobbles play a crucial role in coastal protection. On the Croatian Adriatic coast, there are artificial gravel pocket beaches created for recreational and protective purposes. However, these beaches are subject to constant morphological changes due to natural forces and human intervention. This study investigates the morphodynamics of artificial gravel pocket beaches, focusing on berm formation and crest build-up processes characteristic for low to moderate wave conditions. Despite mimicking natural formations, artificial beaches require regular maintenance due to sediment shifts dominantly caused by wave action and storm surges. Structure-from-Motion (SfM) photogrammetry and UAV-based surveys were used to monitor morphological changes on the artificial gravel pocket beach Ploče (City of Rijeka). The XBeach-Gravel model, originally adapted to simulate the effects of high-energy waves, was calibrated and validated to analyze low to moderate wave dynamics on gravel pocket beaches. The calibration includes adjustments to the inertia coefficient (ci), which influences sediment transport by shear stress at the bottom; the angle of repose (ϕ), which controls avalanching and influences sediment transport on sloping beds; and the bedload transport calibration coefficient (γ), which scales the transport rates linearly. By calibrating XBeach-G for low to moderate wave conditions, this research improves the accuracy of the model for the cases of morphological responses “berm formation” and “crest build-up”. Full article

Sediment transportation on coasts can be significantly affected by rivers, wave–wind effects, and human activities. As a result, undesirable effects such as shoaling or erosion may occur in fishery shelters. This study examines the “Sandıktaş a Fishery Shelter”, a coastal structure in the Eastern Black Sea region of Turkey, and its susceptibility to shoaling. Bathymetric measurements were performed within the nearshore and onshore, and sediment samples were taken periodically from selected points and analyzed in the laboratory. The characteristic grain diameters of the sedimentation were obtained. It was revealed that the average grain diameter was d₅₀ = 0.30–0.91, caused by an increase of 11,611 m³ in shoaling, which caused the decrease of 8 cm water depth that occurred between 2019 and 2022. The entrance of the fishery shelter has become progressively shallower, making it difficult for boats to navigate. Existing breakwater configurations played a role in trapping sediments, requiring optimized breakwater designs/modifications for improved sediment control. The Mann–Kendall test showed an increasing trend in sediment accumulation, particularly in coarser fractions. The findings highlight the necessity of periodic dredging and potential structural modifications to mitigate shoaling and ensure the long-term sustainability of the fishery shelter. Moreover, they emphasize the critical challenges caused by sedimentation in fishery shelters and provide data-driven recommendations for enhancing coastal engineering practices and maintenance strategies. Full article

The need for real-time and scalable oceanographic monitoring has become crucial for coastal management, marine traffic control and environmental sustainability. This study investigates the integration of sensor technology into marine cables to enable real-time monitoring, focusing on tidal cycles and wave characteristics. A 2000 m cable demonstrator was deployed off the coast of Portugal, featuring three active repeater nodes equipped with pressure sensors at varying depths. The goal was to estimate hourly wave periods using fast Fourier transform and calculate significant wave height via a custom peak detection algorithm. The results showed strong coherence with tidal depth variations, with wave period estimates closely aligning with forecasts. The wave height estimations exhibited a clear relationship with tidal cycles, which demonstrates the system’s sensitivity to coastal hydrodynamics, a factor that numerical models designed for open waters often fail to capture. The study also highlights challenges in deep-water monitoring, such as signal attenuation and the need for high sampling rates. Overall, this research emphasises the scalability of sensor-integrated smart marine cables, offering a transformative opportunity to expand oceanographic monitoring capabilities. The findings open the door for future real-time ocean monitoring systems that can deliver valuable insights for coastal management, environmental monitoring and scientific research. Full article

An automatic identification system (AIS) is often installed on merchant ships and fishing boats to prevent collisions and ensure safe navigation. The location information of ships transmitted from AIS equipment can help maritime traffic control prevent accidents. The southern coast of Korea comprises a complex coastline with numerous fishing boats and transit vessels. In particular, the Tongyeong and Geoje Islands include high-altitude mountains and islands, resulting in several radio-shaded areas where AIS signals cannot be received, owing to geographical effects. However, only a few studies have explored this region and performed practical experiments on the reception status of AIS locations in radio-shaded areas. In this study, we performed an experiment in the Geoje Island Sea on the southern coast to analyze the impact of high terrain on the reception rate and status of automatic identification devices. Two identical pieces of AIS equipment were installed to generate multiple radio waves, and the location data transmitted via different antennae were compared. The experimental analysis forms the basis for identifying the exact location of ships in the event of maritime accidents, facilitating rapid rescue. Moreover, the accuracy of the location transmitted by the AIS equipment can aid in detecting the cause of accidents. Full article

Studies on the variability in ocean wave climate provide engineers and policy makers with information to plan, develop, and control coastal and offshore activities. Ocean waves bear climatic imprints through which the global climate system can be better understood. Using the recently updated ERA5 dataset, this study evaluated the spatiotemporal distribution and variability in significant wave height (SWH) in the Eastern Tropical Atlantic (ETA). The short-term trends and rates of change were obtained using the Mann–Kendall trend test and the Theil–Sen slope estimator, respectively, and decadal trends were assessed using wavelet transformation. Significant, positive monthly and yearly trends and a prevailing decadal trend were observed across the domain. Observed trends suggest that stronger waves are getting closer to the coast and are modulated by the Southern and Northern Atlantic mid-latitude storm fields. These observations have implications for the increasing coastal erosion rates on the eastern coast of the Tropical Atlantic. Full article

Tidal flats are accumulations of fine-grained sediment formed under the action of tides and play a very important role in coastal protection. The northern part of Jiangsu coast, as a typical example of muddy coasts found all over the world, has experienced serious erosion since the Yellow River shifted northward, and the range of erosion has been gradually extending southward, now reaching the south of the Sheyang River estuary (SYRE). In order to address coastal erosion near the SYRE through protective measures, there is an urgent need for research on the spatial and temporal variation of coastal erosion processes and their control mechanisms in the SYRE and adjacent coastal areas. For this study, the tidal flats on the south side of the SYRE were selected as the study area, and the sediment dynamics in the upper and lower intertidal flat were observed in different seasons to investigate the erosion processes and their dynamic mechanisms. The results show that the tidal current and wave action in the observed intertidal flats are stronger in winter than in summer, and these intertidal flats erode under the combined action of waves and currents. During winter, the net transport of the near-bottom suspended sediment and bedload is primarily towards the southeast, while in summer, the direction tends toward the north and northeast. The net transport fluxes are larger in the lower part of the intertidal flat than in the upper part in summer and also larger in winter than in summer within the lower intertidal flat. Furthermore, the tidal flat erosion in the study area manifests as shoreline retreat and flat surface erosion. The average shoreline retreat rate increased from 23.3 m/a during 2014–2019 to 43.5 m/a during 2019–2021, and the average erosion depth of the lower and upper parts of the intertidal flat over a tidal cycle is, respectively, 1.98 cm and 0.24 cm in winter and 1.65 cm and 0.26 cm in summer. The ratio of the wave-induced bottom shear stress to the tidal current-induced bottom shear stress is 0.40~0.46 in the lower intertidal flat and increases to 0.66~0.67 in the upper intertidal flat, indicating that the intertidal flat erosion in the study area is primarily driven by tidal currents, with significant contributions from wave action, especially in the upper intertidal flat. Full article

This study presents an in-depth analysis of the dynamic beach landscapes of Hainan Island, which is located at the southernmost tip of China. Home to over a hundred natural and predominantly sandy beaches, Hainan Island confronts significant challenges posed by frequent marine natural disasters and human activities. Addressing the urgent need for long-term studies of beach dynamics, this research involved the use of CoastSat to extract and analyze shoreline data from 20 representative beaches and calculate the slopes of 119 sandy beaches around the island for the period from 2013 to 2023. The objective was to delineate the patterns of beach evolution that contribute to the prevention of sediment loss, the mitigation of coastal hazards, and the promotion of sustainable coastal zone management. By employing multi-source remote sensing imagery and the CoastSat tool, this investigation validated slope measurements across selected beaches, demonstrating consistency between the calculated and actual distances despite minor anomalies. The effective use of the finite element solution (FES) in the 2014 global tidal model for tidal corrections further aligned the coastlines with the mean shoreline, underscoring CoastSat’s utility in enabling precise coastal studies. The analysis revealed significant seasonal variations in shoreline positions, with approximately half of the monitored sites showing a seaward progression in summer and a retreat in winter, which were linked to variations in wave height. The southern beaches exhibited distinct seasonal variations, which contrasted with the general trend due to differing wave impacts. The western and southern shores showed erosion, while the northern and eastern shores displayed accretion. The calculated slopes across the island indicated that the southern beaches had steeper slopes, while the northern areas exhibited more pronounced slope variations due to wave and tidal impacts. These findings highlight the critical role of integrated coastal management and erosion control strategies in safeguarding Hainan Island’s beaches. By understanding the mechanisms driving seasonal and regional shoreline changes, effective measures can be developed to mitigate the impacts of erosion and enhance the resilience of coastal ecosystems amidst changing environmental conditions. This research provides a foundational basis for future efforts aimed at the sustainable development and utilization of coastal resources on Hainan Island. Full article

The integration of multiple data sources, including satellite imagery, aerial photography, and ground-based measurements, represents an important development in the study of landslide processes. The combination of different data sources can be very important in improving our understanding of geological phenomena, especially in cases of inaccessible areas. In this context, the study of coastal areas represents a real challenge for the research community, both for the inaccessibility of coastal slopes and for the numerous drivers that can control coastal processes (subaerial, marine, or endogenic). In this work, we present a case study of the Conero Regional Park (Northern Adriatic Sea, Ancona, Italy) cliff-top retreat, characterized by Neogenic soft rocks (flysch, molasse). In particular, the study is focused in the area between the beach of Portonovo and Trave (south of Ancona), which has been studied using aerial orthophoto acquired between 1978 and 2021, Unmanned Aerial Vehicle (UAV) photographs (and extracted photogrammetric model) surveyed in September 2021 and 2012 LiDAR data. Aerial orthophotos were analyzed through the United States Geological Survey’s (USGS) tool Digital Shoreline Analysis System (DSAS) to identify and estimate the top-cliff erosion. The results were supported by the analysis of wave data and rainfall from the correspondent period. It has been found that for the northernmost sector (Trave), in the examined period of 40 years, an erosion up to 40 m occurred. Furthermore, a Digital Elevation Model (DEM) of Difference (DoD) between a 2012 Digital Terrain Model (DTM) and a UAV Digital Surface Model (DSM) was implemented to corroborate the DSAS results, revealing a good agreement between the retreat areas, identified by DSAS, and the section of coast characterized by a high value of DoD. Full article

Previously, paired spits have been described at the mouths of bays, estuaries, and deltas. This study analyzed the worldwide distribution and morphodynamic patterns of paired spits located at the mouths of interdistributary bays of deltas (three systems) and within coastal channels (24 systems). The methodology was based on the detailed analysis of satellite images, nautical charts, and tidal-range databases. The paired spits found were mainly located on microtidal coasts at high or mid latitudes. Waves were the main factor controlling convergent progradation and breaching of the spits, while the hydraulic blockage for the development of these paired spits was mainly due to tide-induced currents, as well as minor fluvial outlets in the interdistributary bays. Three morphodynamic patterns were identified: (i) stable, with low progradation rates, generally without breaching or degradation of any of the spits; (ii) stationary, with high progradation rates, alternating degradation or breaching of any of the spits with the formation of new spits or closure of the breaches; and (iii) instable or ephemeral, which included three subtypes, the severe erosion of one or both spits, the joining of the head of the two spits forming a single barrier, and the merging of each with its channel margin. Full article