Assessment of Geogenic and Anthropogenic Pollution Sources Using an Aquatic Plant Along the Sonora River Basin: Insights from Elemental Concentrations and Pb Isotope Signatures

Natural Resources Research - Mining is an important activity in Mexico; however, despite its economic benefits, it carries potential environmental risks, including mine spills. On August 6,...     

Artificial Marine Micro‐Reserves Networks (AMMRNs): an innovative approach to conserve marine littoral biodiversity and protect endangered species

Coastal engineering works, especially the outer breakwaters of ports where environmental conditions are usually good, often constitute new habitats for marine littoral species. Their potential indirect contribution to the regeneration and conservation of protected species opens up a new perspective in protection of marine biodiversity. This is particularly true when these works harbour, as we show here, important reproductive populations of species that are threatened or even in danger of extinction. We provide integrated data on protected marine species in Southern Iberia established on different substrata (quarried dolomitic rocks, concrete cubic blocks, concrete tetrapods and vertical concrete walls) that are used in the construction of artificial levees that could potentially be Artificial Marine Micro‐Reserves (AMMRs). We also present the first evidence of the ‘reserve effect’ in potential AMMRs and we discuss the need for the creation of AMMRs including their effective networking (AMMRNs), supporting data for which has been observed by studying coastal facilities subjected to strict access restrictions (for security reasons, not conservation). These facilities have acted as valuable proxies and, in reality, potentially act as AMMRs, as well as having a role in helping to detect and control invasive species. We discuss the ecological engineering aspects related to the design and type of materials used in coastal constructions with a view to aiding the integration of these into existing coastal ecosystems as well as promoting greater settlement of species and therefore increases in biodiversity. Finally, the environmental implications of AMMRNs within the future implementation strategy of the Water Framework Directive 2000/60 EC are also discussed.     

Resolution of MRS applied to the characterization of hard-rock aquifers

The performance of the Magnetic Resonance Sounding (MRS) method applied to the investigation of heterogeneous hard-rock aquifers was studied. It was shown using both numerical modeling and field measurements that MRS could be applied to the investigation of the weathered part of hard-rock aquifers when the product of the free water content multiplied by the thickness of the aquifer is >0.2 (for example, 10-m-thick layer with a 2% water content). Using a currently available one-dimensional MRS system, the method allows the characterization of two-dimensional subsurface structures with acceptable accuracy when the size of the subsurface anomaly is equal to or greater than the MRS loop. However, the fractured part of hard-rock aquifers characterized by low effective porosity (<0.5%) cannot be resolved using currently available MRS equipment. It was found that shallow water in the weathered part of the aquifer may screen MRS signals from deeper water-saturated layers, thus further reducing the possibility of investigating deeper fractured aquifers. A field study using the NUMIS(plus) MRS system developed by IRIS Instruments was carried out on an experimental watershed in southern India. A heterogeneous unconfined aquifer in a gneissic formation was successfully localized, and MRS results were confirmed by drilling shortly after the geophysical study. The top of the aquifer revealed by MRS was found to be in a good agreement with observed static water level measurements in boreholes.     

Analysis of recent vessel arrivals and ballast water discharge in Alaska: toward assessing ship-mediated invasion risk

Ships are a dominant vector for biological invasions through ballast water discharge (BWD) and hull fouling. Here, we provide a first comprehensive analysis of shipping in Alaska, summarizing (a) the number, type and origin of vessel arrivals to Alaska for 2003 and 2004, (b) the spatial and temporal variation in vessel traffic, and (c) the available data on ballast water discharge in order to prioritize locations for tracking biological invasions. Most arrivals were passenger vessels, followed by ferries and fishing vessels, all of which carried little ballast water. Regional and seasonal patterns in arrivals and BWD were unevenly distributed among vessel types. The majority of vessels reporting BWD were from foreign ports, and most of this ballast was untreated. The largest volumes of ballast were from tankers at Valdez and Kenai Peninsula ports. Although Alaska has few documented invasions, opportunities for ship-mediated transfer now appear high and warrant further scrutiny.     

Ostracods as tsunami tracers in Holocene sequences

This review analyses the ostracod record in Holocene tsunami deposits, using an overview of the 2004 Indian Ocean tsunami impact on its recent populations and the associated tsunamigenic deposits, together with results from numerous investigations of other Holocene sequences. Different features such as the variability of the local assemblages, population density, species diversity, age population structure (e.g., percentages of adults and juvenile stages) or taphonomical signatures suggest that these microorganisms may be included amongst the most promising tracers of these high-energy events in marshes, lakes, lagoons or shallow marine areas.     

Measuring ΩM and ΩΛ with long‐duration gamma‐ray bursts

Gamma‐ray bursts (GRBs) are one of the most luminous events in the Universe. In addition, the Universe itself is almost transparent to γ ‐rays, making GRBs detectable up to very high redshifts. As a result, GRBs are very suitable to probe the cosmological parameters. This work shows the potential of long‐duration GRBs for measuring the cosmological parameters Ω_M and Ω_Λ by comparing the observed log N ‐log P distribution with the theoretical one. Provided that the GRBs rate and luminosity function are well determined, the best values and 1σ confidence intervals obtained are Ω_M = 0.22^+0.05_–0.03 and Ω_Λ = 1.06^+0.05_–0.10. Finally, a set of simulations show the ability of the method to measure Ω_M and Ω_Λ (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The role of small‐scale fold and fault development in seismogenic zones: example of the western Huércal‐Overa Basin (eastern Betic Cordillera,Spain)

The NW–SE shortening between the African and the Eurasian plates is accommodated in the eastern Betic Cordillera along a broad area that includes large N‐vergent folds and kilometric NE–SW sinistral faults with related seismicity. We have selected the best exposed small‐scale tectonic structures located in the western Huércal‐Overa Basin (Betic Cordillera) to discuss the seismotectonic implications of such structures usually developed in seismogenic zones. Subvertical ESE–WNW pure dextral faults and E–W to ENE–ESW dextral‐reverse faults and folds deform the Quaternary sediments. The La Molata structure is the most impressive example, including dextral ESE–WNW Neogene faults, active southward‐dipping reverse faults and associated ENE–WSW folds. A molar M1 assigned to Mimomys savini allows for precise dating of the folded sediments (0.95–0.83 Ma). Strain rates calculated across this structure give ～0.006 mm a^?1 horizontal shortening from the Middle Pleistocene up until now. The widespread active deformations on small‐scale structures contribute to elastic energy dissipation around the large seismogenic zones of the eastern Betics, decreasing the seismic hazard of major fault zones. Copyright © 2009 John Wiley & Sons, Ltd.     

Influence of the spatial distribution of energy-dissipating bracing elements on the seismic response of multistorey frames

Several reinforced concrete frames with different dissipator distributions, and a conventional moment-resisting frame, are compared in order to select the best dissipator distribution from the point of view of seismic response and structural design. The structures with dissipators are designed according to a criterion proposed in the present paper. Each frame is excited with a set of eleven simulated accelerograms. The choice of the best dissipation distribution is based mainly on the differences between the mean of the maximum overturning moments developed at the base of the frames and between the weights of steel reinforcement and concrete resulting from the structural design of each frame. A comparison of initial construction costs of a building with dissipators and a conventional building shows that the former is 3·5 per cent more expensive.     

MAJOR AND TRACE ELEMENT DETERMINATIONS ON NIST GLASS STANDARD REFERENCE MATERIALS 611, 612, 614 AND 1834 BY INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY

We report on the major and trace element composition and homogeneity of NIST (National Institute of Standards and Technology) glass standard reference materials 611, 612, 614, and 1834 for use as microanalytical trace element standards in laser ablation-inductively coupled plasma-mass spectrometry. The four analyzed NIST glasses were not designed as microanalytical standards, but their availability and careful preparation made them obvious candidates. Our data indicate that NIST 1834 is inhomogeneous on a scale of 100 mg with respect to several trace elements. Within analytical uncertainty, NIST 611, 612, and 614 are apparently homogeneous.     

TRACE ELEMENT DETERMINATIONS FOR USGS BASALT BHVO-1 AND NIST STANDARD REFERENCE MATERIALS 278, 688 AND 694 BY INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY

Results are presented for 26 to 30 trace elements determined in four rock reference materials of geochemical interest: USGS Basalt BHVO-1, Rhyolite Obsidian NIST 278, Basalt NIST688, and Phosphate Rock NIST694. Determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). Good agreement was obtained among solution standard comparison and standard addition analytical techniques, and among samples prepared with different dissolution methods. Generally good agreement was obtained between determined trace element values and values reported in the literature.