Kilometre-scale

Park et al. (1990) suggested an alternative mechanism that may induce free convection in the subsurface the methanogenesis-driven convection system. By numerically simulating reaction-transport equations. Park et al. (1990) calculated that the generation of methane from kerogen maturation can induce kilometre scale flow in a porous medium because of the density dependence of groundwater on methane concentration. 

Gussow, W.C., 1954. Differential entrapment of oil and gas a fundamental principle. The American Association of Petroleum Geologists Bulletin, Vol. 38, no. 5, pp. 816-853 Hanor, J.S., 1987a. Kilometre-scale thermohaline overturn of pore waters in the Louisiana Gulf Coast. Nature, Vol. 327, pp.501-503... 

The features created by crustal movements may be mountain chains, like the Himalayas, where collision of continents causes extensive compression. Conversely, the depressions of the Red Sea and East African Rift Basin are formed by extensional plate movements. Both type of movements form large scale depressions into which sediments from the surrounding elevated areas ( highs ) are transported. These depressions are termed sedimentary basins (Fig. 2.3). The basin fill can attain a thickness of several kilometres. 

In each case we can choose a scale above which the material may be considered homogeneous, but below which the structure needs to be considered. Roughly, for the list given the scale is a few nanometres, a few microns, a few millimetres, tens of millimetres, a tenth of a metre, several kilometres. 

The Rayleigh and Love waves propagate at the surface of the Earth. Because of their mechanism, which is essentially symmetrical, and in contrast to earthquakes, the explosions generate very few surface waves. The amplitude of the surface waves enables the magnitude of an earthquake on the Richter scale to be calculated. An earthquake of = 7.0 (approximately 30 earthquakes of magnitude greater than this value occur per year in the world) causes ground displacements of approximately 100 pm at 10,000 km. This is not the case for explosions, for which the surface waves are almost undetectable their amplitude is only a few micrometres at 1000 kilometres from a 100-kt explosion. 

Other factors that can affect SP surveys tend to be less significant than the problems due to moisture. Magnetic storms (Burr, 1982), radar and other electromagnetic radiation can cause induction in the long SP wire, particularly when it is fully extended. Telluric currents, which are global-scale electrical currents in the Earth induced by the Earth s magnetic field, could conceivably affect SP surveys but typically result in a SP difference of only a few millivolts per kilometre. 

In this paper, we are mainly interested in the blob when it is about to pond that is, when it is thin and it has cooled somewhat so that its viscosity is higher than that of fresh plume material. These are the conditions for which lubrication theory applies. The blob is near this final state for much of its existence as the initial flow is fairly rapid. For somewhat cool plume material, which is a few tens of kilometres thick and has a spread over 1000 km, the criterion that II in (A9) is less than unity is likely to be satisfied and the scaling results in the text apply. 

Sunlight is absorbed when it hits ozone. This occurs on a large scale a few tens of kilometres above the Earth s surface (depending on latitude). The energy input makes the ozone warm, and it warms the rest of the air at this level. This effect, and also the various effects of the radiative budget in the air, especially the upper air, and the albedo of the surface, give the Earth s atmosphere a very odd thermal structure (Lewis Prinn 1984) (Fig. 2). 

Manganese and iron oxides typically comprise one-quarter to one-third of rock varnish with high point-to-point variability at scales from nanometres to kilometres. 

Prof. Julian Hunt (University College London) introduces a classification of the types of turbulent flow through canopies of different kinds of geometry and length scale. He shows how, by integrating recently developed concepts by many authors, a more comprehensive understanding of eddy structure and turbulence statistics is now emerging. In the atmosphere where canopies may extend over tens of kilometres in... 

Ovoid and elongate concretions and type 1 tabular units appear to have formed principally in the phreatic zone, because they have poikilotopic and blocky spar cements, are associated with coarser, better sorted units, show preservation of original sedimentary structures, and are not associated with rhizocretions. In the Zia, preferential cementation of coarser, better sorted layers operates on the scale of both thin section and outcrop, something also noticed by Lynch (1996). Elongate concretions have been noted by other workers and attributed to groundwater flow in the phreatic zone (McBride et al., 1994, 1995 Mozley Davis, 1996). Orientations of these elongate concretions tend to be uniform within a single outcrop, often on the scale of several kilometres, as would be unexpected in vadose-zone cementation (Mozley Davis, 1996). 

The surface motion of the sea takes place on a variety of scales from mm capillary waves to mesoscale eddies. At low wind conditions it seems that there are some scales that dominate with regard to slick-formation. They give rise to long filamentary structures observed on optical- as well as SAR-images of the sea surface, where they have a transverse dimension of the order of 100 m and longitudinal coherence for several kilometres (Scully-Powers 1986). 

For the release of CWAs into the atmosphere, we are mainly concerned with effects on scales ranging from metres to a few kilometres. In this range, the influence of obstacles such as hills, buildings and trees becomes significant. 

Spatial scales range from metres to a few kilometres. 

Quinn settled back in his regal, velvet-padded acceleration couch and gave the order to jump away. Twenty seconds after they completed the operation, the holoscreens showed him the little purple pyramid which represented the squadron s lone pursuit ship lit up at the centre of the empty cube. According to the scale, it was three thousand kilometres away. 

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