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951.
A stochastic prognostic model of the atmospheric precipitation in the tropical area of the Atlantic Ocean is developed on the basis of a large data array. The data represent a series of monthly precipitation rates for 31 towns in the Republic of Guinea covering a period of 35–64 years as well as satellite data on the meridional displacement of the Intertropical Convergence Zone during 11 years. The model takes into account major regularities of the tropical precipitation: their impulsive periodic regime, trends, and the modulation of the stochastic component by the determined variability.Translated by Mikhai M. Trufanov. 相似文献
952.
The problem of monitoring of the mesoscale variability of hydrophysical fields in the shelf zone is considered. The usefulness of the data available in regional information centres is discussed. The possibility of monitoring the dynamics of the oceanic fields in the tropical Atlantic encompassing separate observation sites is demonstrated using the oceanographic databank of the scientific research centre (CERESCOR) in Conakry-Rogbane as an example. The results of assimilation of the hydrophysical survey data derived on the shelf in a telescopic model of the region are given.Translated by Mikhail M. Trufanov. 相似文献
953.
954.
In 1980, a large earthquake caused extensive sediment failure on the shallow continental shelf off the Klamath River in northern
California. Side-scan sonography was used to complement detailed geophysical profiling in identifying specific features and
resolving modes of failure. The features include a nearly flat failure terrace mantled with sand boils, collapse craters and
sediment flows, and bounded on the seaward side by a meandering continuous toe ridge. Seaward of the terrace lies a compression
zone delineated by small pressure ridges. Our findings indicate a temporal progression of failure from lique-faction of shallow
subsurface sand to lateral spread of intact blocks to sediment collapse and flow. 相似文献
955.
The Three Kings Ridge has been described as a remnant arc or an east-facing arc on the western side of the South Fiji Basin
under which symmetric South Fiji Basin magnetic anomaly lineations have been lost. We find evidence of neither arc-trench
morphology on the eastern flank of the ridge nor collision tectonism within the adjacent South Fiji Basin that might have
obliterated it. We believe there is room for the missing magnetic lineations within the South Fiji Basin and we recognize
the distinctive island-arc morphology characteristic of a west-facing arc on the western flank of the Three Kings Ridge. Our
interpretation requires that arc volcanism postdated formation of much of the South Fiji Basin and that oceanic lithosphere
from the adjacent Norfolk Basin must have been subducted beneath the west-facing Three Kings Arc. 相似文献
956.
Dorrik A. V. Stow 《Geo-Marine Letters》1983,3(2-4):217-222
The Brae oilfield reservoir in the North Sea comprises Upper Jurassic resedimented conglomerates and sandstones interbedded with organic-rich silstone and mudstone thin-bedded turbidites. The system represents a series of small overlapping fans that form a thick (300 m) slope-apron accumulation of sediments deposited in a narrow (<10 km wide) belt along an active fault zone. The complex lateral and vertical distribution of facies was due mainly to variable tectonic activity, and partly also to sediment supply and sea-level changes. 相似文献
957.
Several aspects of the Maryland ridge field are pertinent to the problem of ridge genesis in response to Holocene sea-level
rise. There is a systematic morphologic change fromshoreface ridges throughnearshore ridges tooffshore ridges, which reflects the changing hydraulic regime. Grain size is 90° out of phase with topography, so that the coarsest sand
lies between the axis of each trough and the adjacent seaward ridge crest, while the finest sand lies between each ridge crest
and the axis of the adjacent seaward trough. Finally, analysis over a 43-year period on an outer ridge reveals a systematic
pattern of landward flank erosion, seaward flank deposition, and seaward crest migration.
These relationships support a model which explains the ridges as consequences of the up-current shift of maximum bottom shear
stress with respect to the crests of initial bottom irregularities. The oblique orientation of the ridges with respect to
the beach may be at least partly due to the more rapid migration rate of the ridges’ inshore ends. 相似文献
958.
959.
960.
A multidisciplinary study in the Gulf of Cadiz is revisited, using additional diagnostic modelling tools. The dissolved trace metal (Cu, Ni, Zn, Co) distributions in the Gulf of Cadiz are analysed using modelled tracer evolutions, field observations and the concept of tracer ages. This study shows that a significant part of the observed metal distributions can be explained by the metal inputs of three river systems (Guadiana, Rio Tinto and Odiel, Guadalquivir) discharging into the Gulf of Cadiz, while the remainder of the signal is most likely associated with the benthic metal remobilisation along the shelf of this coastal region. 相似文献