Community Structure of the Subtidal Macroinfauna in an Estuarine Mussel Bed in Southern Chile     

Eduardo  Jaramillo  Carlos  Bertrán Alejandro  Bravo 《Marine Ecology》1992,13(4):317-331

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Editorial to the second PECS 2004 special issue of Ocean Dynamics     

Paulo Salles  Alejandro Souza 《Ocean Dynamics》2006,56(3-4):151-152

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Source parameters of the M_W= 6.1 1910 Adra earthquake (southern Spain)     

Daniel Stich  Josep Batlló  Jose Morales  Ramon Macià  Savka Dineva 《Geophysical Journal International》2003,155(2):539-546

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Further absolute geomagnetic paleointensities from Baja California: evaluation of Pliocene and Early/Middle Pleistocene data     

Juan Morales  Avto Goguitchaichvili  Edgardo Cañon-Tapia  Raquel Negrete 《Comptes Rendus Geoscience》2003,335(14):995-1004

From a large collection (more than 300 oriented cores) of Baja California Mio-Pliocene volcanic units, sampled for magnetostratigraphy and tectonics, 46 samples were selected for Thellier paleointensity experiments because of their low viscosity index, stable remanent magnetization and close to reversible continuous thermomagnetic curves. 19 samples, coming from 4 individual basaltic lava flows, yielded reliable paleointensity estimates with the flow-mean virtual dipole moments (VDM) ranging from 3.6 to 6.2 ×10²² A m². Our results, although not numerous, are of high technical quality and comparable to other paleointensity data recently obtained on younger lava flows. The NRM fractions used for paleointensity determination range from 38 to 79% and the quality factors vary between 4.8 and 16.7, being normally greater than 5. The combination of Baja California data with the available comparable quality Plio-Plesitocene paleointensity results yields a mean VDM of 6.3 ×10²² A m², which is almost 80% of the present geomagnetic axial dipole. Reliable paleointensity results for the last 5 Ma are still scarce and of dissimilar quality, which makes it hard to draw any firm conclusions regarding the Pliocene and Early/Middle Pleistocene evolution of the geomagnetic field. To cite this article: J. Morales et al., C. R. Geoscience 335 (2003).  相似文献   

Reply to the Discussion to “Proterozoic–Early Paleozoic evolution in western South America—a discussion” by Astini and Rapalini     

Florencio G. Aceolaza  Hubert Miller  Alejandro J. Toselli 《Tectonophysics》2003,366(1-2):149-150

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Carbon stable isotopes ratios of pelagic and littoral communities in Alchichica crater-lake, Mexico     

Elva Escobar Briones  Javier Alcocer  Edith Cienfuegos  Pedro Morales 《International Journal of Salt Lake Research》1998,7(4):345-355

Carbon stable isotope ratios were determined in dominant biotic components of pelagic and littoral systems in Alchichica crater-lake. Results showed that carbon signatures were significantly different between both systems. The pelagic environment was more depleted (−26.15 to −15.14 per mille) than the littoral zone (−21.03 to −17.91 per mille). The potential source end-point in the simplified pelagic community was established to be diatomaceous phytoplankton; its predicted value was −21.7 per mille. There is a clear evidence thatNodularia does not sustain the pelagic food chain. In contrast, the highly diverse littoral community was sustained by epiphytes. No allochthonous sources seemed to influence this food web.¹³C enrichment was observed along the components of both systems with fractionations of 0.8 to 1.4 per mille. The contribution of the seagrassRuppia maritima is probably associated with the detritus pathway. Carbon source partitioning between both systems was not recorded. The δ¹³C in Alchichica crater-lake was more enriched than in other saline lakes and could be attributed to different salinity and CO₂ concentrations among lakes.  相似文献   

EURD: First Year Results     

Carmen Morales  José F. Gómez  Joaquín Trapero  Stuart Bowyer  Jerry Edelstein  Eric Korpela 《Astrophysics and Space Science》1998,263(1-4):393-396

EURD (Espectrógrafo Ultravioleta extremo de Radiación Difusa), one of the instruments onboard the Spanish satellite MINISAT-01, is a spectrograph specially designed to detect diffuse radiation, covering the wavelength range of 350-1100 Å, with a spectral resolution of 6-8 Å. Its main scientific objectives are the detection of the emission line spectrum from the hot phase of the interstellar medium and the spectrum of the upper atmospheric airglow. In order to reduce geocoronal noise, EURD always observes in the anti-sun direction and only when the satellite is in orbital eclipse. After more than one year of observation we have obtained the best spectrum of the upper atmospheric nightglow in this wavelength range, the spectrum of 15 OB stars and the spectrum of the full Moon throughout the year. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Geochemical characteristics of heavy metal pollution in surface sediments of the Tinto and Odiel river estuary (southwestern Spain)   总被引：1，自引：0，他引：1  

J. Borrego  J. Morales  M. de la Torre  J. Grande 《Environmental Geology》2002,41(7):785-796

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First results on the LPO-derived seismic properties of iron ores from the Quadrilátero Ferrífero region, southeastern Brazil     

Luiz F.G. Morales  Leonardo E. Lagoeiro  Issamu Endo   《Tectonophysics》2008,460(1-4):21-33

The role of hydrothermal fluids in assisting the activity of strike-slip faults is investigated using a range of new geological, geophysical, and geochemical data obtained on the Argentat fault, Massif Central, France. This fault zone, 180-km-long and 6 to 8 km-width, has experienced coeval intense channeling of hydrothermal fluids and brittle deformation during a short time span (300–295 Ma). According to seismic data, the fault core is a 4-km-wide, vertical zone of high fracture density that rooted in the middle crust (~ 13 km) and that involved fluids in its deeper parts (9–13 km depth). If stress analyses in the fault core and strain analyses in the damage zone both support a left-lateral movement along the fault zone, it is inferred that hydrothermal fluids have strongly influenced fault development, and the resulting fault has influenced fluid flow. Fluid pressure made easier fracturing and faulting in zones of competent rocks units and along rheological boundaries. Repeated cycles of increase of fault-fracture permeability then overpressure of hydrothermal fluids at fault extremity favored strong and fast development of the crustal-scale strike-slip fault. The high permeability obtained along the fault zone permitted a decrease of coupling across the weak fault core. Connections between shallower and lower crustal fluids reservoirs precipitate the decrease of fault activity by quartz precipitation and sulfides deposition. The zones of intense hydrothermal alteration at shallows crustal levels and the zones of fluid overpressure at the base of the upper crust both controlled the final geometry of the crustal-scale fault zone.  相似文献   

Consequences of Climate Change on the Ecogeomorphology of Coastal Wetlands     

John W. Day  Robert R. Christian  Donald M. Boesch  Alejandro Yáñez-Arancibia  James Morris  Robert R. Twilley  Larissa Naylor  Linda Schaffner  Court Stevenson 《Estuaries and Coasts》2008,31(3):477-491

Climate impacts on coastal and estuarine systems take many forms and are dependent on the local conditions, including those set by humans. We use a biocomplexity framework to provide a perspective of the consequences of climate change for coastal wetland ecogeomorphology. We concentrate on three dimensions of climate change affects on ecogeomorphology: sea level rise, changes in storm frequency and intensity, and changes in freshwater, sediment, and nutrient inputs. While sea level rise, storms, sedimentation, and changing freshwater input can directly impact coastal and estuarine wetlands, biological processes can modify these physical impacts. Geomorphological changes to coastal and estuarine ecosystems can induce complex outcomes for the biota that are not themselves intuitively obvious because they are mediated by networks of biological interactions. Human impacts on wetlands occur at all scales. At the global scale, humans are altering climate at rapid rates compared to the historical and recent geological record. Climate change can disrupt ecological systems if it occurs at characteristic time scales shorter than ecological system response and causes alterations in ecological function that foster changes in structure or alter functional interactions. Many coastal wetlands can adjust to predicted climate change, but human impacts, in combination with climate change, will significantly affect coastal wetland ecosystems. Management for climate change must strike a balance between that which allows pulsing of materials and energy to the ecosystems and promotes ecosystem goods and services, while protecting human structures and activities. Science-based management depends on a multi-scale understanding of these biocomplex wetland systems. Causation is often associated with multiple factors, considerable variability, feedbacks, and interferences. The impacts of climate change can be detected through monitoring and assessment of historical or geological records. Attribution can be inferred through these in conjunction with experimentation and modeling. A significant challenge to allow wise management of coastal wetlands is to develop observing systems that act at appropriate scales to detect global climate change and its effects in the context of the various local and smaller scale effects.  相似文献