A5080797458- Geological formations and processes
- Oceanographic and Atmospheric Processes
- Coastal and Marine Dynamics
- Geology and Paleoclimatology Research
- Marine and coastal ecosystems
- Geochemistry and Elemental Analysis
- Geomagnetism and Paleomagnetism Studies
- Lattice Boltzmann Simulation Studies
- Particle Dynamics in Fluid Flows
- Methane Hydrates and Related Phenomena
- Hydrology and Sediment Transport Processes
- Solar and Space Plasma Dynamics
- Tropical and Extratropical Cyclones Research
- Geophysics and Gravity Measurements
- Micro and Nano Robotics
- Electrostatics and Colloid Interactions
- Pickering emulsions and particle stabilization
- Underwater Acoustics Research
- Fluid Dynamics and Turbulent Flows
- Soil erosion and sediment transport
- Paleontology and Stratigraphy of Fossils
- Nanofluid Flow and Heat Transfer
- Material Dynamics and Properties
- Fluid dynamics and aerodynamics studies
- Aquatic and Environmental Studies
Massachusetts Institute of Technology
2021-2024
University of California, Santa Barbara
2017-2021
University of California System
2020
Japan Agency for Marine-Earth Science and Technology
2020
Yokohama City University
2020
Abstract Deep-sea polymetallic nodule mining research activity has substantially increased in recent years, but the expected level of environmental impact is still being established. One concern discharge a sediment plume into midwater column. We performed dedicated field study using from Clarion Clipperton Fracture Zone. The was monitored and tracked both established novel instrumentation, including acoustic turbulence measurements. Our studies reveal that modeling can reliably predict...
Fluid mechanics lies at the heart of many physical processes associated with nascent deep-sea mining industry. The evolution and fate sediment plumes that would be produced by seabed activities, which are central to assessment environmental impact, entirely determined transport processes. These processes, include advection, turbulent mixing, buoyancy, differential particle settling, flocculation, operate a multitude spatiotemporal scales. A combination historical recent efforts combine...
An in situ study to investigate the dynamics of sediment plumes near release from a deep seabed polymetallic nodule mining preprototype collector vehicle was conducted Clarion Clipperton Zone Pacific Ocean 4500-m deep. The experiments reveal that excess density released sediment-laden water leads low-lying, laterally spreading turbidity current. At time measurement, 2 8% mass were detected m or higher above and not observed settle over several hours, with remaining 92 98% below some fraction...
Abstract
We develop and investigate an advection–diffusion-settling model of deep-sea mining collector plumes, building on the analysis midwater plumes in Part 1. In case deposition plays a predominant role controlling mass sediment suspension, thus setting extent plume. first discuss competition between settling, which leads to deposition, vertical turbulent diffusion, stretches plume vertically reduces deposition. The time evolution concentration at seabed is found be highly nonlinear function that...
We employ direct numerical simulations of the three-dimensional Navier-Stokes equations, based on a continuum formulation for sediment concentration, to investigate physics turbidity currents in complex situations, such as when they interact with seafloor topography, submarine engineering infrastructure and stratified ambients. In order obtain more accurate representation dynamics erosion resuspension, we have furthermore developed grain-resolving simulation approach representing flow...
The evolution of midwater sediment plumes associated with deep-sea mining activities is investigated in the passive-transport phase using a simplified advection–diffusion-settling model. Key metrics that characterize extent are defined based on concentration threshold. Namely, we consider volume flux fluid ever exceeds threshold, furthest distance from and maximum depth below intrusion where plume instantaneous excess Formulas derived for provide insight into parameters most strongly affect...
Abstract This study presents in situ, high-resolution optical measurements of particle size distributions (PSD) within sediment plumes generated by a pre-prototype deep seabed nodule collector vehicle operating the abyssal Pacific Ocean. These were obtained using cutting-edge instrument, LISST-RTSSV sensor. The data collected situ reveal marked differences compared to previously reported laboratory-based, ex measurements. grain and other key shape characteristics are found be dependent on...
Abstract As the only deep hypersaline, halite‐precipitating lake on Earth today, Dead Sea is single modern analog for investigating mechanisms by which large‐scale and thick salt deposits, known as “salt giants”, have accreted in geological record. We directly measure hydroclimatic forcing physical limnologic processes leading to halite sedimentation, vertical thermohaline structure, fluxes Sea. demonstrate that changes these lead strong seasonal regional variations stratification stability...
Abstract We employ direct numerical simulations in order to analyze the role of double‐diffusive salt fingering halite precipitation from hypersaline lakes. Guided by field observations Dead Sea, which represents only modern deep stratified lake that precipitates under hydrological crisis, we consider a saturated layer warm, salty brine (epilimnion) overlying colder, less (hypolimnion) is also saturated. The instability originating metalimnion gives rise an asymmetrical pattern ascending...
Abstract
Abstract We provide a new perspective on the transition of hyperpycnal flows into saline turbidity currents, which permits longer runout lengths than might be otherwise expected. This mechanism relies differential turbulent diffusion salt and sediment, in contrast to ambient saltwater entrainment it enables salinification freshwater current without diluting sediment concentration field by corresponding amount. The freshness‐to‐sediment ratio is introduced order quantify process. results...
Abstract The oceanic bottom mixed layer (BML) is a well mixed, weakly stratified, turbulent boundary layer. Adjacent to the seabed, BML of intrinsic importance for studying ocean mixing, energy dissipation, particle cycling and sediment-water interactions. While deep-seabed mining polymetallic nodules anticipated commence in Clarion-Clipperton Zone (CCZ) northeastern tropical Pacific Ocean, knowledge gaps regarding form its potentially key influence on dispersal sediment plumes generated by...
The settling of a pair particles through density interface is analyzed for various particle positions and stratifications. decelerate the as surface fluid remains attached to particles. Heightened transport found occur vertically aligned
Abstract
We investigate the interaction of a downslope gravity current with an internal wave propagating along two-layer density jump. Direct numerical simulations confirm earlier experimental findings reduced mass flux, as well partial removal head from its body by large-amplitude waves (Hogg et al. , Environ. Fluid Mech. vol. 18 (2), 2018, pp. 383–394). The is observed to split into intrusion diluted fluid that propagates interface and hyperpycnal continues move downslope. provide detailed...
<title>Abstract</title> Results and key insights are presented from in situ, high-resolution optical measurements of particle size distributions (PSD) for sediment plumes generated by a pre-prototype deep seabed nodule collector vehicle operating the abyssal Pacific Ocean. The data show marked differences compared to previously reported laboratory-based, ex situ measurements. suspended grain other shape characteristics found be dependent on multiple factors such as maneuvers, time elapsed...