Ocean dynamics constantly generates seismic and acoustic noise (e.g. vie wave-seafloor interaction, surface wave activities, ice-noise and anthropogenic sources). This ubiquitous ambient noise waves, which can be measured continuously with hydrophones and seismic stations, travel around the earth and can be used to monitor their generating sources and image the propagating medium. This project will characterize the spatial and temporal generation mechanism of seismic and acoustic ocean noise sources which can be used for passive remote sensing and monitoring purposes.
Advection and biological consumption are both important sinks for oil and gas released from natural seeps in the Gulf of Mexico. We will use a combination of stable isotope measurements and high resolution modeling with both passive and positively buoyant tracers to study the interaction between physical and biological processes in distributing and transporting the carbon released from natural seeps. We will focus on three major seep fields in the Northern Gulf with different water depths –GC185 (ca. 400 m), GC600 (ca. 1200 m), and GC767 (ca.
Many densely populated coastal areas around the world are low lying and susceptible to relative sea level rise (SLR) associated with climate change, land level subsidence or tectonic subsidence. Coastal defense structures have been constructed as barriers to certain design storm surge, storm wave or tsunami heights. Typically even without SLR the design criteria change over time as hazards get reanalyzed or remodeled. The decrease in risk reduction due to relative SLR and the performance of existing defense barriers under loading conditions beyond the design need to be determined.
Deep subsurface methane hydrate-bearing sediments contain microbial communities that are distinct from shallow marine sediments and hydrate-free environments. DNA evidence suggests that novel bacterial phyla (e.g. Atribacteria) are highly enriched in methane hydrate-bearing sediments. Recent genome assemblies by the Glass group at Georgia Tech are providing insights into the metabolic potential of samples drilled from gas hydrate stability zone 70 mbsf below Hydrate Ridge (IODP Leg 204).
The recently completed resource assessment for ocean current energy (Haas et al. 2013) utilized fairly simplistic analytical methods to estimate the extractable energy from the Gulf Stream System as well as to analyze the relative impacts of large scale energy extraction. This level of analysis can be considered to be accurate to an order of magnitude and only provides an idea on the overall trends of the impacts of extraction. Much higher resolution modeling is required to accurately determine the overall impacts of extraction for both localized and far field effects.
Single-celled marine algae are especially chemically rich, producing toxins that kill fish, marine mammals, and seabirds, contaminate shellfish, and threaten human health. Many predators of these algae – copepods – selectively consume less toxic algae, which in turn sense copepods via an excreted blend of copepod-specific molecules. These algae then become up to 20X more toxic when they sense copepod cues in the open ocean.
Creating sustainable and resilient cities depends on understanding the properties of food, energy, water and other infrastructure networks. Ecological network analysis ENA is a tool that can be used to understand the connections between network structure, material and energy flow, and resilience. ENA is increasingly applied to both understand and design more sustainable and resilient human infrastructure.
Seaweeds create toxic compounds to deter consumers (fish) and poison competitors (corals). However specific fishes resist these toxins, and some corals also are resistant to their effects. These tolerances may be due to unusual microbes in the gut microbiomes of fishes and in coral mucus coverings. GT has an unusual mixture of marine ecologists, chemists and microbiologists to address these issues.
This study seeks to develop a location independent scalable framework for Community based Sustainable Coastal Area Resilience Planning (C-SCARP).
The data-driven framework is adaptable to other locations and/or scales in the future. The proposed C-SCARP framework will make use of an adapted and expanded version of the GoldSET suite of decision support tools that incorporates multi-criteria analysis in a sustainability evaluation framework. Three distinct uses of GoldSET are anticipated:
In coastal areas, data are very sparsely available for flow and wave conditions during storm events due, in part, to the logistical challenge of deploying instruments in such conditions. The questions proposed are centered around the strength and consequences of the flow conditions during storm events and the influence of vegetation on mitigating the effects.
