Étude de la variation spatio-temporelle des paramètres physico-chimiques caractérisant la qualité des eaux d'une lagune côtière et ses zonations écologiques : cas de Moulay Bousselham,Maroc     

Hanane Labbardi  Omar Ettahiri  Said Lazar  Zakia Massik  Said El Antri 《Comptes Rendus Geoscience》2005,337(5):505-514

Our interest is related to the hydrological characteristics of the Moulay Bousselham lagoon. Water samples were taken monthly from July 2001 to June 2002 in 15 stations distributed along the lagoon. The various measured hydrological parameters (temperature, salinity, suspended matter, chlorophyll a) showed significant monthly variations ($p<0.001$), whereas spatially among all sampled stations, only the salinity showed significant variations. The variability analysis approached by the analysis of the normalized principal components combined with discriminate analysis showed very small inter-stations variability. Its percentage is 11% and 9% of the total variance during high and low tide, respectively. To cite this article: H. Labbardi et al., C. R. Geoscience 337 (2005).  相似文献   

Study of Shoreline Changes Through Digital Shoreline Analysis System and Wave Modeling: Case of the Sandy Coast of Bou-Ismail Bay,Algeria     

Kaddour  Said  Hemdane  Yacine  Kessali  Nasser  Belabdi  Khalid  Sallaye  Miloud 《Ocean Science Journal》2022,57(3):493-527

Ocean Science Journal - This work aims to analyze the evolution of Bou-Ismail coastline in Algeria using aerial photographs and quick-bird satellite image during the elapsed period from 1959 to...  相似文献   

Wake II model for hydrodynamic forces on marine pipelines including waves and currents     

Said R. Sabag  Billy L. Edge  Iwan Soedigdo 《Ocean Engineering》2000,27(12)

The Wake II model for the determination of the hydrodynamic forces on marine pipelines is extended to include currents and waves. There are two main differences between the Wake II and the traditional model. First, in the Wake II model the velocity is modified to include the pipe's encounter with the wake flow when the velocity reverses. Second, the model uses time dependent drag and lift coefficients. The flow field is assumed to be the linear superposition of regular waves and uniform current and is treated as wave only but in two different phases. The model requires eight empirical parameters that are obtained from comparisons with field data for various Keulegan–Carpenter numbers and current to wave ratios. The effective velocity and the force predictions are compared with field data from Exxon Production Research Company and with the conventional model. The model gives satisfactory results and predicts lift forces that in shape, magnitude and phase relative to the velocity are in very close agreement with measured forces. For the horizontal forces the results are very accurate. A substantial improvement is obtained over the predictions with the conventional model. This work is applicable to the design of submarine pipelines laying on the sea bottom in water depths where waves or waves and currents contribute to the hydrodynamic forces.  相似文献   

Identification of cytochrome P450 1B-like sequences in two teleost fish species (scup, Stenotomus chrysops and plaice, Pleuronectes platessa) and in a cetacean (striped dolphin, Stenella coeruleoalba).     

C A Godard  M J Leaver  M R Said  R L Dickerson  S George  J J Stegeman 《Marine environmental research》2000,50(1-5):7-10

The cytochromes P450 (CYP) constitute a multigene family of enzymes playing a critical role in the oxidation of many endogenous and xenobiotic substrates. The CYP1 family is of particular interest in environmental toxicology because its members are dominant in the metabolism of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and aryl amines. Three members of the CYP1 family, CYP1A1, CYP1A2, and CYP1B1, have been identified in mammals. We report here on the identification and cloning of cytochrome P4501B-like sequences from two teleost fish species and a marine mammal. Sequences clustering with CYP1B1 in phylogenetic analysis were obtained from liver cDNA of scup (Stenotomus chrysops), genomic DNA of plaice (Pleuronectes platessa), and liver cDNA of striped dolphin (Stenella coeruleoalba).  相似文献   

Relocation of hypocenters from DOMERAPI and BMKG networks: a preliminary result from DOMERAPI project          下载免费PDF全文

Mohamad Ramdhan  Sri Widiyantoro  Andri Dian Nugraha  Jean-Philippe Métaxian  Asep Saepuloh  Said Kristyawan  Andry Syaly Sembiring  Agus Budi Santoso  Antoine Laurin  Ahmad Ali Fahmi 《地震科学（英文版）》2017,30(2):67-79

Merapi volcano located in central Java, Indonesia, is one of the most active stratovolcanoes in the world. Many Earth scientists have conducted studies on this volcano using various methods. The geological features around Merapi are very attractive to be investigated because they have been formed by a complex tectonic process and volcanic activities since tens of millions of years ago. The southern mountain range, Kendeng basin and Opak active fault located around the study area resulted from these processes. DOMERAPI project was conducted to understand deep magma sources of the Merapi volcano comprehensively. The DOMERAPI network was running from October 2013 to mid-April 2015 by deploying 46 broad-band seismometers around the volcano. Several steps, i.e., earthquake event identification, arrival time picking of P and S waves, hypocenter determination and hypocenter relocation, were carried out in this study. We used Geiger’s method (Geiger 1912) for hypocenter determination and double-difference method for hypocenter relocation. The relocation result will be used to carry out seismic tomographic imaging of structures beneath the Merapi volcano and its surroundings. For the hypocenter determination, the DOMERAPI data were processed simultaneously with those from the Agency for Meteorology, Climatology and Geophysics (BMKG) seismic network in order to minimize the azimuthal gap. We found that the majority of earthquakes occurred outside the DOMERAPI network. There are 464 and 399 earthquakes obtained before and after hypocenter relocation, respectively. The hypocenter relocation result successfully detects some tectonic features, such as a nearly vertical cluster of events indicating a subduction-related backthrust to the south of central Java and a cluster of events to the east of Opak fault suggesting that the fault has an eastward dip.  相似文献   

Better constrained selection of the Paleozoic West Gondwana (South America) paleomagnetic poles for the APWP determination     

Bernard Henry  Mohamed E. M. Derder  Mohamed Amenna  Said Maouche  Boualem Bayou 《Studia Geophysica et Geodaetica》2017,61(2):185-198

The reliability of an Apparent Polar Wander Path (APWP) obviously depends on the paleomagnetic poles used to determine it. The APWP of Africa and South America are fairly well defined for the 330–260 Ma interval. However, this study pointed out a moderate shift between these two curves, and an incoherency of the South American data, contrary to the African ones, which are homogeneous. A number of South American pole positions were re-evaluated in an effort to better constrain the APWP for the entire continent. Most of discarded poles correspond to sites at the area of the junction of Cordillera with the stable craton. That could have structural implications for the evolution of the western margin of the Gondwana. A new criterion for the evaluation of paleomagnetic poles reliability for APWP is presented. Based on comparison of data from different continents and labeled “coherence” criterion, it is independent from Van der Voo’s ones.  相似文献