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Particle-settling through a diffusive-type thermohaline system in the ocean is studied. Results show that the number of suspended particles in a convecting layer decreases exponentially with time, with a decay rate equal to the quotient of the settling velocity and layer depth. The rate of sedimentation also approaches the rate in a non-convecting fluid as the number of layers in the staircase increase.

Thermal and fluid-dynamical analyses suggest that for viscosities and density contrasts spanning the range considered typical for many calc-alkalic granitoids, dike ascent is a viable mechanism for the transport of large volumes of granitoid melt through the continental crust. We present calculations showing that a granitoid melt with calculated viscosity of the order of |10.sup.6~ Pa |center dot~ s and a density contrast between magma and crust of 200 kg/|m.sup.3~ can be transported 30 km through the crust in |approximately~1 month, corresponding to a mean ascent velocity of 1 cm/s. Using analysis modified from numerical studies of the flow of basaltic magmas in dikes, we also present an expression that allows the calculation of the critical (minimum) dike or fault width required for granitic magma to ascend without freezing. For all reasonable estimates of Cordilleran granitoid viscosity and density contrast, the critical dike width is determined to be between |approximately~2 and 7 m. Calculated peak batholith-filling rates are orders of magnitude greater than mean cavity-opening rates based on estimated fault slippage, which is consistent with chemical evidence for intermittent supply of magma pulses.

Thermal and fluid-dynamical analysis of the Cordillera Blanca batholith construction demonstrates the viability of an alternative mechanism for the rapid transport of large volumes of granitoid melts. The aseismic, centralized and discordant-margin characteristics of the Cordillera Blanca batholith indicate diapirism as the dominant magma ascent mechanism. However, magma ascent and emplacement in the Cordillera Blanca batholith by diking has also been considered to be a thermally viable transport mechanism due to the typical viscosities and density contrasts of granitic melts.

We investigate the effect of an external freshwater plume on the dissolution of a vertical ice wall in salty water using laboratory experiments. We measure the plume velocity, the ablation velocity of the ice and the temperature at the ice wall. The freshwater volume flux, Qs, is varied between experiments to determine where the resultant wall plume transitions from being dominated by the distributed buoyancy flux due to dissolution of the ice, to being dominated by the initial buoyancy flux, Bs. We find that when Bs is significantly larger than the distributed buoyancy flux from dissolution, the plume velocity is uniform with height and is proportional to B1/3s, the interface temperature is independent of Bs, and the ablation velocity increases with Bs. [ABSTRACT FROM AUTHOR]

We experimentally investigate the turbulent wall plume that forms next to a uniformly distributed source of buoyancy. Our experimental results are compared with the theoretical model and experiments of Cooper & Hunt (J. Fluid Mech., vol. 646, 2010, pp. 39-58). Our experiments give a top-hat entrainment coefficient of 0:048 ± 0:006. We measure a maximum vertical plume velocity that follows the scaling predicted by Cooper & Hunt but is significantly smaller. Our measurements allow us to construct a turbulent plume model that predicts all plume properties at any height. We use this plume model to calculate plume widths, velocities and Reynolds numbers for typical dissolving icebergs and ice fronts and for a typical room with a heated or cooled vertical surface. [ABSTRACT FROM AUTHOR]

The influence of cooling on lava-flow dynamics is studied using a hot viscous syrup flow sprawling radially into a cold environment. The syrup flows were found to be considerably influenced by a rapidly developing viscous thermal boundary layer immediately after extrusion started. A number of spreading laws for cooling currents of various Newtonian and non-Newtonian rheologies have been derived from scaling arguments, although the time it takes for solidification and non-Newtonian rheology to affect the spread of a lava flow still has to be determined.