Per-and polyfluoroalkyl substances (PFAS) are a group of synthetic chemical compounds known for their persistent, bioaccumulation and toxic characteristics in all environmental compartments. As ...industrial and domestic applications of PFAS increase, their discharge into water bodies becomes of human and ecological concerns. Our research focuses on providing better understanding on the occurrence, vertical distribution, and dispersion of PFAS in surface and bottom water from inshore and offshore area of Biscayne Bay, Miami, Florida. We screened a total of 30 PFAS from inshore (N = 38) and offshore (N = 48) water samples using a semi-automated solid phase extraction (SPE) followed by instrumental analysis using Liquid chromatography-mass spectrometry techniques (LC-MS/MS). Our findings show a general surface-enrichment and depth-depletion pattern from inshore to offshore area. Average ∑PFAS loadings inshore (surface vs bottom; 29.52 ± 15.26 ng/L vs 21.45 ± 7.85 ng/L) is significantly greater than offshore (surface vs bottom; 5.18 ± 2.68 ng/L vs 2.42 ± 2.11 ng/L). PFOS had the highest mean concentration both inshore (6.36 ± 4.23 ng/L) and offshore (0.83 ± 0.87 ng/L). The most frequently detected (D·F > 91 %) PFAS are Perfluorooctane sulfonic acid (PFOS), Perfluorooctanoic acid (PFOA), Perfluoroheptanoic acid (PFHpA), Perfluorohexanoic acid (PFHxA), Perfluorobutanoic acid (PFBA), Perfluorobutane sulfonic acid (PFBS) and Perfluorohexane sulfonic acid (PFHxS) in surface water samples. PFOS/PFOA >1 suggests that point sources are the major contribution to PFAS burden in the Biscayne Bay. An innovative Inverse distance weighted interpolation (IDW) special modelling approach was implemented to predict the potential contribution of oceanic current on the dispersion of ∑PFAS loadings in surface and bottom profiles from canals (inshore) to offshore areas. This will provide insights into transport mechanisms of PFAS from source emissions, and risk assessments of potential impacts on human and aquatic life in the Bay.
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•Vertical PFAS profile shows surface-enrichment, depth-depletion pattern.•PFOS/PFOA >1 suggests that point sources are the major contribution to PFAS burden.•IDW model predicted the contribution of oceanic current on the dispersion of ∑PFAS.•K-Means clustering shows location with common PFAS fingerprints.•LDI suggests source contribution of PFAS contamination in the Biscayne Bay.
Miami-Dade County is highly susceptible to storm surge flooding. The current Federal Insurance Rate Map (FIRM), used to determine flood insurance rates for buildings, is an excellent resource yet ...lacks attributes that could provide a finer-resolution of actual vulnerability for building level characteristics from one parcel to the next within the same flood zone. This study developed a novel Storm Surge Building Vulnerability (SSBV) model to provide initial protocols for developing storm surge vulnerability county maps. The model was tested on transversal sections of 1254 buildings selected from Miami Beach, East Little Havana, and Sweetwater. Buildings in the county were determined to be moderately vulnerable to storm surge flooding. High-rises, masonry buildings, and buildings whose first habitable space is elevated above the ground constitute the majority of low and very low vulnerability buildings, but 97% of high and very high vulnerability buildings are between 0 and 2 story tall and three-quarters of these have slab-on-grade finished floor elevation. Our model exposes limitations of FIRM designated hazard zones: buildings within the same zone exhibit different vulnerability characteristics. This indicates the importance of creating initial protocols to consider upgrading flood insurance rate requirement from zonal categories to individual building level.
•A Storm Surge Building Vulnerability (SSBV) model was developed to characterize the vulnerability of buildings to storm surge flooding in Miami-Dade County.•High-rises, masonry buildings, and buildings whose first habitable space is elevated above the ground constitute the majority of low and very low vulnerability buildings.•97% of high and very high vulnerability buildings are between 0 and 2 story tall and three-quarters of these have slab-on-grade finished floor elevation.•In general, Miami-Dade County is moderately vulnerable to storm surge flooding.
We assessed IgM detection in Zika patients from the 2016 outbreak in Miami-Dade County, Florida, USA. Of those with positive or equivocal IgM after 12-19 months, 87% (26/30) had IgM 6 months later. ...In a survival analysis, ≈76% had IgM at 25 months. Zika virus IgM persists for years, complicating serologic diagnosis.
Volcanic rocks from the Miami-Davarzan area are basalts to trachyandesites interlayered with fossiliferous beds and bear significant implications on the Eocene geodynamic evolution of northern ...central Iran. The rocks constitute two distinct groups, a low-Nb and a high-Nb suite. The least evolved low-Nb suite includes clinopyroxene-olivine phyric samples and is characterized by higher CaO and lower Al2O3 as compared to peridotite partial melts. The high-Nb suite includes more evolved plagioclase-clinopyroxene phyric samples. Fractional crystallization modeling using least-squares mass balance calculations for major elements suggests that the high-Nb suite was formed from a low-Nb parental melt by differentiation of a clinopyroxene-dominated mineral assemblage. The Miami-Davarzan volcanic rocks are characterized by significant large ion lithophile elements (LILE) and light rare earth elements (LREE) enrichment and high field strength elements (HFSE) depletion, which are typical signatures of subduction-related settings. Immobile, highly to moderately incompatible elements such as NbTa, LaCe, PrNd are higher in the Miami-Davarzan volcanic rocks as compared to the typical magmatic arcs, which is an indication of slab melt involvement and metasomatism of the mantle source. The Sr-Nd-Pb isotopic data also confirm a common mantle source involving the addition of subducted sediments into a depleted mantle source for both the low-Nb and high-Nb suites. The geochemical characteristics such as high CaO, low Al2O3, and the isotopic data can be best explained by derivation of the low-Nb suite parental melt from a pyroxenite mantle source. The pyroxenite mantle source was probably developed as a result of interaction between shallow depleted mantle and slab plus sediment-derived melts. It is suggested that the extensional phase that dominated the northern central Iran during the Eocene prompted partial melting of a pyroxenite mantle source.
•The Miami-Davarzan volcanic show subduction-related geochemical affinity.•Geochemical and isotopic data suggest the presence of pyroxenite in their mantle source.•Fractional crystallization played the major role in evolution of the volcanic rocks.
•Two wave models, containing five different source term packages of Sin+Sds+Snl are evaluated under Hurricane Ivan (2004).•Drawbacks of UMWM and ST2 are identified.•The strength of negative wind ...input is discussed within the framework of ST6.•Drag coefficient estimated by each wave model is also inter-compared.
Using the well-observed hurricane case Ivan (2004) as an example, we investigate and intercompare the performance of two wave models under hurricane conditions. One is the WAVEWATCH III model (WW3) and the other is the University of Miami Wave Model (UMWM). Within WW3, four different source term packages (ST2/3/4/6) of wind input, wave breaking dissipation and swell decay are chosen for comparison purposes. Based on the comparisons between model results and measurements from various platforms, we concluded that UMWM shows less accuracy than WW3 in specification of bulk wave parameters. This is possibly because (i) UMWM-estimated drag coefficient does not clearly show a saturation trend when wind speeds are beyond ∼ 35 m s−1 and (ii) the four-wave interaction term of UMWM disagrees evidently with the full solution of the Boltzmann integral in detail. Among the four WW3 source term packages, the older parameterization ST2 is basically the least accurate because of its systematic underestimation of high waves. The remaining three packages (ST3/4/6) are performed well under Ivan. However, we also find that they tend to overestimate energy of waves traveling in the oblique and opposing winds. It is shown that enhancing the strength of negative wind input properly can effectively improve model skills in such situations. Limited by the uncertainty in the wind forcing, we could not determine the most accurate package among ST3/4/6 unambiguously.
Groundwater is a primary source of drinking water worldwide, but excess nutrients and emerging contaminants could compromise groundwater quality and limit its usage as a drinking water source. As ...such contaminants become increasingly prevalent in the biosphere, a fundamental understanding of their fate and transport in groundwater systems is necessary to implement successful remediation strategies. The dynamics of surface water‐groundwater (hyporheic) exchange within a glacial, buried‐valley aquifer system are examined in the context of their implications for the transport of nutrients and contaminants in riparian sediments. High conductivity facies act as preferential flow pathways which enhance nutrient and contaminant delivery, especially during storm events, but transport throughout the aquifer also depends on subsurface sedimentary architecture (e.g. interbedded high and low conductivity facies). Temperature and specific conductance measurements indicate extensive hyporheic mixing close to the river channel, but surface water influence was also observed far from the stream‐aquifer interface. Measurements of river stage and hydraulic head indicate that significant flows during storms (i.e., hot moments) alter groundwater flow patterns, even between consecutive storm events, as riverbed conductivity and, more importantly, the hydraulic connectivity between the river and aquifer change. Given the similar mass transport characteristics among buried‐valley aquifers, these findings are likely representative of glacial aquifer systems worldwide. Our results suggest that water resources management decisions based on average (base) flow conditions may inaccurately represent the system being evaluated, and could reduce the effectiveness of remediation strategies for nutrients and emerging contaminants.
The response of surface water‐groundwater exchange processes in glacial aquifers to sediment heterogeneity and hydrologic hot moments are critically evaluated using spectral and flow pattern analyses. Results indicate that significant flows during storms alter groundwater flow patterns, even between consecutive storm events, and that sediment heterogeneity strongly controls the magnitude of flow and solute transport.
Among the nearly 90,000 Cubans who settled in New York City and Miami in the 1940s and 1950s were numerous musicians and entertainers, black and white, who did more than fill dance halls with the ...rhythms of the rumba, mambo, and cha cha cha. In her history of music and race in midcentury America, Christina D. Abreu argues that these musicians, through their work in music festivals, nightclubs, social clubs, and television and film productions, played central roles in the development of Cuban, Afro-Cuban, Latino, and Afro-Latino identities and communities. Abreu draws from previously untapped oral histories, cultural materials, and Spanish-language media to uncover the lives and broader social and cultural significance of these vibrant performers.Keeping in view the wider context of the domestic and international entertainment industries, Abreu underscores how the racially diverse musicians in her study were also migrants and laborers. Her focus on the Cuban presence in New York City and Miami before the Cuban Revolution of 1959 offers a much needed critique of the post-1959 bias in Cuban American studies as well as insights into important connections between Cuban migration and other twentieth-century Latino migrations.
Coastal cities are increasingly vulnerable to natural disasters because of climate change. For many, this includes storm surge flooding fueled by tropical storms and hurricanes. A complex mesh of ...social, geomorphic, and climatic factors are driving this increase in vulnerability, such as population growth, irresponsible urban development, a decrease in essential service provision, shoreline erosion, sea level rise, and changing storm regimes. The purpose of this paper is to explore the interrelationships between these factors, highlighting the many ways in which they contribute to somewhat unexpected vulnerabilities for coastal settlements. This includes a discussion and several examples of how short-term strategic planning, which dominates political action and economic decision-making, can exacerbate coastal vulnerability.
•Many coastal cities are becoming increasingly vulnerable to natural disasters.•Climatic (e.g. sea level rise) and social (e.g. migration) factors cause this.•Existing political and economic incentives exacerbate the problem.•Solutions require radical new approach, especially at local level.
Despite the growing power of finance over cities and housing, the relationships between finance, climate risk management, and urban governance have yet to be examined from a climate gentrification ...perspective. Putting the practices of a wide array of property finance stakeholders in conversation with the foundational concept of the rent gap, we identify two real estate rent dynamics that are emerging against the prospect of climate-driven urban restructuring: risk rents, or new forms of value capture crafted against future risk, and rent at risk, or the anticipated loss of rent due to risk. We in turn illustrate how climate risk-rent dynamics constitute new or intensified processes of gentrification in Greater Miami, Florida. Through three vignettes, we show how configurations of real estate and finance climate risk management produce variegated yet interrelated opportunities for devaluation and revaluation, displacement, and downgrading. Such strategies push the gentrification frontier into new physical as well as institutional spaces. The Greater Miami story underscores the need for new forms of knowledge, coalition building, and integrated urban climate risk management practices that directly confront underlying financial drivers of housing and spatial injustice in risky real estate markets.
In light of police violence and injustice, criminologists tend to focus on masculine and violent police cultures, the lack of democratic oversight and on social processes of dehumanization. Yet much ...less attention, however, is given to the objects commonly used in violent and lethal police encounters: guns. Drawing on long-term ethnographic fieldwork with police officers in Miami, I suggest that police officers tend to re-contextualize police gun violence in terms of individual liability and legal culpability-as a question of what constitutes a legal shot. While a legal framing might protect police officers from prosecution, the legal shot first and foremost enables state institutions to explain police brutality as "incidents": as unintentional and exceptional outcomes of an otherwise warranted form of policing. Recognizing how the legal shot attunes our attention to individual misconduct and legal solutions to systemic and racialized police violence, I suggest, is an important step in exploring the possibilities to disarm the police, and to organize around the question of how to imagine and push for a more inclusive form of public safety.
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