The Azores archipelago is a classic expression of a hotspot that has interacted with a mid-ocean ridge. A variety of geochemical studies and geophysical observations point to the influence of some sort of mantle plume on the formation of the Azores Plateau and the adjacent Mid-Atlantic Ridge (MAR), but the mantle structure beneath the Azores has not heretofore been imaged tomographically at a s...

We investigate the plasma dynamics (outflow speed and turbulence) inside polar plumes. We compare line profiles (mainly of O VI) observed by the UVCS instrument on SOHO at the minimum of solar cycle 22-23 with model calculations. We consider Maxwellian velocity distributions with different widths in plume and inter-plume regions. Electron densities are assumed to be enhanced in plumes and to ap...

Produced water, a pollutant associated with offshore oil production, has been shown to have adverse effects on marine organisms. We conducted a study of the dispersion of a produced water plume from an outfall in the Santa Barbara Channel near Carpinteria, CA. Biological effects were studied previously in a series of experiments which examined the toxicity of ocean waters near the outfall. To d...

To facilitate the research of mobile robot based odor source localization (OSL) and evaluate different strategies for the OSL, numerical simulation of odor plume in indoor ventilated environments is addressed. On the basis of the FLUENT software package, the 3-D wind field of an indoor ventilated environment is calculated using the Reynolds average approach, where the real wind velocity measure...

A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes, gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in...

Continental flood basalt eruptions have resulted in sudden and massive accumulations of basaltic lavas in excess of any contemporary volcanic processes. The largest flood basalt events mark the earliest volcanic activity of many major hot spots, which are thought to result from deep mantle plumes. The relative volumes of melt and eruption rates of flood basalts and hot spots as well as their te...

The cloud condensation nuclei concentrations predicted by global aerosol models are sensitive to how new particle formation in subgrid anthropogenic SO(2) plumes is parameterized. Using a state-of-the-art kinetic nucleation model, we carried out two case studies to investigate the large difference in the number concentrations of ultrafine particles observed in the plumes from the Horne smelter:...

The Vejen Landfill leachate plume was characterized in detail in 1989 in terms of redox zones and distribution of organic pollutants. Strong natural attenuation was observed for most organic compounds in the strongly anaerobic part of the plume. A visit to the plume 10 years later revealed that the NVOC plume had spread further, but that most of the chemical compounds still were attenuated in t...

Hotspot tracks represent plate motions relative to mantle sources, and paleomagnetic data from magmatic units along those tracks can quantify motions of those mantle anomalies relative to the Earth’s magnetic field and rotational axis. The Ediacaran Period is notable for rapid and large paleomagnetic apparent polar wander (APW) for many continents. Whereas magmatic units attributed to the “Sutt...