Plate boundaries and evolution of the Solomon Sea region     

E. Honza  H. L. Davies  J. B. Keene  D. L. Tiffin 《Geo-Marine Letters》1987,7(3):161-168

The Solomon Sea Plate was widely developed during late Oligocene, separating the proto-West Melanesian Arc from the proto-Trobriand Arc. Spreading in the Bismarck Sea and in the Woodlark Basin resulted from interaction between the Pacific and Australian Plates, specifically from the collision of the proto-West Melanesian Arc with north New Guinea, which occurred after arc reversal. This model explains the extensive Miocene, Pliocene, and Quaternary volcanism of the Papua New Guinea mainland as it related to southward subduction of the Trobriand Trough. Our interpreted plate motions are concordant with the geological evidence onshore and also with complex tectonic features in the Solomon Sea Basin Region.  相似文献   

A random walk model for simulating simultaneous currents at several depths     

Richard B. Olsen 《Ocean Engineering》1987,14(6)

Empirical orthogonal function (EOF) analysis is used in conjunction with Markov chains to generate simultaneous current time series at several depths with a random walk model. Duration statistics and probability distributions for EOF modes obtained from real data are used to generate transition probability matrices for the random walk model. New time series of EOF modes are generated, and then combined to produce current time series. The technique has been tested on data from Haltenbanken. Statistical properties of real and simulated time series were compared. Results indicate that the model is acceptable as a tool in simulating current time series to be used in offshore operation models.  相似文献   

Gravity anomalies over inactive fracture zones in the central North Atlantic     

Th. F. A. Mulder  B. J. Collette 《Marine Geophysical Researches》1984,6(4):383-394

The basement topography and the free-air gravity along two profiles in the central North Atlantic between 16° and 25° N, crossing a number of fracture zones, were divided in three wavelength intervals. Two-dimensional modelling shows that the short wavelength (>50 km) gravity is well explained by uncompensated topography (mainly spreading topography). For the long wavelengths (>200 km) there is no correlation of topography and gravity. In principle this topography is compensated. Residual anomalies comprise the Ridge effect as well as regional anomalies related to depth anomalies. The 50 to 200km band-pass filtered topography and gravity contain relevant information on fracture zones. Models require a base of the crust that parallels the topography rather than a form of regional compensation. For an explanation of this crustal model that has the appearance of frozen in normal faults we have to consider the typical morphology as created in the transform domain. The geophysical processes that cause this morphology are still an object of study.  相似文献   

Design and performance analysis of a Digital Acoustic Telemetry System for the short range underwater channel   总被引：1，自引：0，他引：1  

Catipovic  J. Baggeroer  A. Von Der Heydt  K. Koelsch  D. 《Oceanic Engineering, IEEE Journal of》1984,9(4):242-252

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Standardized measures of relative abundance based on modelling log (c.p.u.e.), and their application to Pacific ocean perch (Sebastes alutus)     

Kimura  Daniel K. 《ICES Journal of Marine Science》1981,39(3):211-218

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Geographic variability in trace element levels in Spartina alterniflora     

J.E. Drifmeyer  B. Redd 《Estuarine, Coastal and Shelf Science》1981,13(6):709-716

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Abandonment and recovery solution of submarine pipelines   总被引：1，自引：0，他引：1  

T.K. Datta 《Applied Ocean Research》1982,4(4):247-252

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The shape of deep-water siliciclastic systems: A discussion     

K. T. Pickering 《Geo-Marine Letters》1982,2(1-2):41-46

Deep-water siliciclastic systems are classified primarily on their shape as: submarine fans with well developed or poorly developed morphology, slope drapes, for example, over relatively stable basin margins, fault-scarp aprons, canyons and large channels, under-supplied sheet systems such as abyssal plains, non-fan ponded systems such as over-supplied perched basins, and fan deltas. Collectively, or separately, these systems may form sedimentary basin fills that can be over or under-supplied with respect to the sediment input although most systems will tend toward over-supply/overflow with time. Finally, the sum total of the siliciclastic systems and basins can be used to define the tectonic milieux such as passive, strike-slip and convergent margins.  相似文献   

Improved in situ gamma-ray transmission densitometer for marine sediments     

T.J. Hirst  M. Perlow Jr.  A.F. Richards  B.S. Burton  W.J. van Sciver 《Ocean Engineering》1975,3(1):17-27

The first-generation University of Illinois gamma-ray transmission densitometer, designed for the in situ measurement of sediment bulk density, was modified by incorporating in the detector probe (1) an Americium-241 alpha particle pulser and an anti-walk gain stabilization control to maintain better temperature stability and (2) a small power supply and a IC preamplifier to eliminate the need for a high-voltage coaxial cable between the detector and external signal conditioning electronics package. This second-generation Lehigh University system has been successfully deployed since 1971 in routine use from ships and submersibles in the Atlantic and Pacific Oceans and the Gulf of Mexico. Results are presented of system operations to (1) measure bulk density over the range of 1.2–1.8 Mg/m³ in the Hudson Canyon, (2) penetrate 1.9 m into the seafloor in the San Diego trough and, (3) be lowered to a water depth of 3.6 km in the Gulf of Mexico.  相似文献   

Relationship between Shot-Induced Noise and Shot Interval in Seismic Refraction Experiments at Sea     

Herber  R.  Weigel  W.  Wong  H. K. 《Marine Geophysical Researches》1997,19(3):257-265

Seismic noise induced by the seismic source during continuous profiling reduces the signal-to-noise ratio and hence the data quality. This noise is largely dependent on the shot interval. In this paper, the noise amplitude of refraction seismic records from a special experiment is analysed as a function of the shot interval. An empirical exponential relationship between mean peak noise amplitude and shot interval is deduced. By increasing the shot interval, the induced noise can be minimized on all successive records. This results in an improvement of the data, predominantly the signal-to-noise ratio. Because the seismic signal and the shot-induced noise have nearly the same spectra, the chance of improving the signal-to-noise ratio by stacking is significantly reduced.  相似文献