PRIMARILY STUDY ON FEATURES OF SURFACE RUPTURES INDUCED BY THE 2016 MW7.8 KARKOURA EARTHQUAKE,NEW ZEALAND

The surface ruptures produced by the 2016 M_W7.8 Karkoura earthquake, New Zealand are distributed in a belt with~170km long and~35km wide, trending generally in the NE-SW direction. There are at least 12 faults on which meter-scale displacements are identified and they were formed across two distinct seismotectonic provinces with fundamental different characteristics(Hamling et al., 2017; Litchfield et al., 2017). Although the trending directions of the seismic surface ruptures vary greatly at different locations, the ruptured faults can be generally divided into two groups with the NE to NEE direction and the NNW to N direction, respectively. The faults in the NNW-near NS direction are nearly parallel with 40~50km apart and featured by reverse movement with the maximum displacement of 5~6m. The faults in the NE-NNE direction, with the maximum of 25~30km apart are not continuous and featured by the dextral strike slip with the largest displacement of 10~12m. Even if some faults along the NE-NEE direction are end to end connected, their strikes differ by about 30°. The combination styles of the strike-slip fault surface ruptures along the NE-NEE direction can be merged into 3 categories, including en-echelon, bifurcation and parallel patterns. The scales of the fault surface ruptures with the same structural style could be obviously different in different areas, which results in significant changes in the widths of deformation zone, from tens of meters to hundreds of meters. En-echelon distributed surface rupture(section)can appear as a combination belt of meter-scale to dozens of meter-scale shear fracture with bulge and compressional shear fractures, and also can be characterized by the combination of the left-step en-echelon tensile shear fractures with a length of more than one hundred meters. The step-overs between surface rupture sections are clearly different in sizes, which can be dozens of meters, hundreds of meters to several kilometers. The spacing between parallel surface ruptures can be several meters, dozens of meters to several kilometers. Besides, as one of the prominent characteristics, the seismic surface ruptures caused by the Karkoura earthquake broke through the known distribution pattern of active faults. The surface ruptures can occur either on the previously thought inactive or unmapped faults, or break through the distribution range of previously realized active faults in the striking or lateral direction. The basic features about the distribution and widths of the surface ruptures induced by the 2016 M_W7.8 Karkoura earthquake, New Zealand presented in this paper might be helpful for understanding some seismic problems such as complex corresponding relationship between the active faults and the deep seismogenic structure, and the necessary measurements for engineering crossing active faults.     

Mineral fibres and environmental monitoring:A comparison of different analytical strategies in New Caledonia

Covered by ultrabasic units for more than a third of its surface,the New Caledonia(South West Pacific)is one of the largest world producers of Ni-ore from lateritic deposits.Almost all outcrops of geological units and open mines contain serpentine and amphibole,also as asbestos varieties.In this geological context,in which weathering processes had a great contribution in the production and dispersion of mineral fibres into the environment,the development of a routinely analytical strategy,able to discriminate an asbestiform fibre from a non-harmful particle,is a pivotal requisite.However,the acquisition of all these parameters is necessary for determining the risk associated to fibres exposition.A multidisciplinary routinely approach,based on the use of complementary simply-to-use but reliable analytical methods is the only possible strategy.In addition,the instrumental apparatus must be easily transportable on the field,directly on the mining site.The employment of specialized tools such as Polarized Light Microscopy associated to Dispersion Staining method(PLM/DS)and portable Raman spectroscopy for identification of environmental asbestos,are proved extremely effective in the improvement of the performance and rapidity of data acquisition and interpretation.Both PLM/DS and handheld Raman devices confirmed to be discriminant in the detection and characterization of asbestos fibres for both serpentine and amphibole.Furthermore,these techniques proved extremely effective even in the presence of strongly fibrous and altered samples.     

Choice chamber experiments to test the attraction of postflexion Rhabdosargus holubi larvae to water of estuarine and riverine origin

Although the recruitment of larvae and juveniles of marine fishes into estuaries has been well documented, little is known about the factors governing the immigration of estuary-associated marine fishes into estuaries. Fishes have a well-developed sense of smell and it has been suggested by several workers that olfactory cues of freshwater or estuarine origin serve as stimuli, attracting larvae and juveniles of estuary-associated species into estuaries. Attraction of postflexion Rhabdosargus holubi larvae to estuary and river water from the Kowie estuarine system, South Africa, was measured using a rectangular choice chamber. In experiments, conducted during peak recruitment periods, larvae selected estuary and river water with a significantly higher frequency than sea water. This study, the first to assess the possible role of olfaction in the recruitment process of an estuary-associated marine fish species, demonstrates that larvae are able to recognise water from different origins, probably based on odour.     

Multiwavelength Study of two Unidentified γ-ray Sources

Most counterparts of the identified low-latitude γ-ray sources are isolated neutron stars (INSs). Since INSs are characterized by an extremely high value of f _X/f _opt, a systematic X-ray/optical coverage of the fields of unidentified low-latitude γ-ray sources is the best way to unveil INS counterparts of unidentified sources. Since the low-latitude sources are heavily affected by the interstellar absorption in both the X-ray and optical bands, we decided to apply the above strategy to two middle-latitude EGRET sources, which could belong to a local galactic population: 3EG J0616-3310 and 3EG J1249-8330. Here we report on the global X-ray characterization of about 300 objects, on their candidate optical counterparts and on the preliminary results of their identification.     

Semi-analytical solution for viscous Stokes flow in two eccentrically nested spheres

Applying the infinite Prandtl number approximation, a semi-analytical solution for computing 2-D axisymmetric viscous Stokes flow in a model consisting of two eccentrically nested spheres of different viscosities is derived. Since numerical codes based on spectral or finite techniques for modelling mantle flow in a spherical geometry in the presence of lateral viscosity variation are becoming more and more popular, reliable examples for testing and validating such codes are extremely useful. The eccentrically nested sphere solution was used to test a numerical algorithm based on a mixed spherical-harmonic finite-element formulation of the Stokes problem, and good agreement was obtained.     

Notes on fossil remains from the Early Cretaceous Lohan Cura Formation, Neuquén Province, Argentina

In this contribution, we describe an association of fossil remains collected in the locality of Cerro de Los Leones, approximately 8 km southwest of the town of Picún Leufú, Neuquén Province, Argentina, from different levels of the Albian Cullín Grande Member, Lohan Cura Formation. The fossils include pelecypodan (Neocorbicula dinosauriorum, Neocorbicula pehuenchensis, and genus indet.) and gastropodan (Physa wichmanni) molluscs, a mesoeucrocodylian, possible pterosaurs, theropods, and sauropods. The sedimentary environment at Cerro de los Leones is characterized by fluvial deposits corresponding to a sandy meandering fluvial system. The most fossiliferous levels (located in the lower part of the exposed sequence) were developed in a distal flood plain and flood basin areas. Sedimentological and paleopedological features suggest semi-arid conditions during the deposition of the Cullín Grande Member. Despite the fragmentary nature of the specimens described here, the new information provided from the Albian assemblages of the Lohan Cura Formation at the Cerro de Los Leones locality provides a broader panorama of the composition of terrestrial faunas during the Early Cretaceous in Patagonia.     

Palaeoenvironmental records from fossil corals: The effects of submarine diagenesis on temperature and climate estimates

The geochemistry of coral skeletons may reflect seawater conditions at the time of deposition and the analysis of fossil skeletons offers a method to reconstruct past climate. However the precipitation of cements in the primary coral skeleton during diagenesis may significantly affect bulk skeletal geochemistry. We used secondary ion mass spectrometry (SIMS) to measure Sr, Mg, B, U and Ba concentrations in primary coral aragonite and aragonite and calcite cements in fossil Porites corals from submerged reefs around the Hawaiian Islands. Cement and primary coral geochemistry were significantly different in all corals. We estimate the effects of cement inclusion on climate estimates from drilled coral samples, which combine cements and primary coral aragonite. Secondary 1% calcite or ∼2% aragonite cement contamination significantly affects Sr/Ca SST estimates by +1 °C and −0.4 to −0.9 °C, respectively. Cement inclusion also significantly affects Mg/Ca, B/Ca and U/Ca SST estimates in some corals. X-ray diffraction (XRD) will not detect secondary aragonite cements and significant calcite contamination may be below the limit of detection (∼1%) of the technique. Thorough petrographic examination of fossils is therefore essential to confirm that they are pristine before bulk drilled samples are analysed. To confirm that the geochemistry of the original coral structures is not affected by the precipitation of cements in adjacent pore spaces we analysed the primary coral aragonite in cemented and uncemented areas of the skeleton. Sr/Ca, B/Ca and U/Ca of primary coral aragonite is not affected by the presence of cements in adjacent interskeletal pore spaces i.e. the coral structures maintain their original composition and selective SIMS analysis of these structures offers a route to the reconstruction of accurate SSTs from altered coral skeletons. However, Mg/Ca and Ba/Ca of primary coral aragonite are significantly higher in parts of skeletons infilled with high Mg calcite cement. We hypothesise this reflects cement infilling of intraskeletal pore spaces in the primary coral structure.     

Role of Humification Processes in Recycling Organic Wastes of Various Nature and Sources as Soil Amendments

Recycling the large amounts of organic wastes produced by agriculture, forestry, urban and industrial activities as soil, organic amendments are the most popular and efficient option for avoiding their dispersion in the environment and restoring, maintaining, and/or improving the content of soil organic matter. Chemical stability and biological maturity are two important factors for the successful use of organic wastes in agriculture with limited risk for the surrounding environment. Stabilization and maturation of raw organic wastes inherently imply the achievement of an extensive humification, that is, a wide conversion of easily degradable organic matter to refractory organic compounds that resemble native soil humic substances (HS). Soil HS are the most important components of soil organic matter responsible of several soil functions and processes. As a consequence, the amount and quality of HS‐like fractions in any organic amendment are believed to be of primary importance for its agronomic efficacy, environmental safety and economic value. The first part of this review focuses on the chemical and physico‐chemical changes occurring in the humic substances (HS) ‐like fractions of organic wastes of various nature and sources subjected to common treatment processes aimed at producing environmentally‐safe soil amendments with beneficial agronomic properties. The second part discusses the composition, structure, and chemical reactivity of the HS‐like components in organic amendments of various origins and nature, and their effects on native soil HS. The review concludes by highlighting the need for innovative research targeted mainly to achieve a better fundamental understanding of the molecular structure and reactivity of soil HS and HS‐like fractions in organic amendments, the mechanisms of HS formation and transformations in the natural environment and during the treatment processes of raw organic wastes, the interactions with metals and organic xenobiotics, and the direct physiological effects that HS may exert on plants.     

Flood hydrograph attenuation induced by a reservoir system: analysis with a distributed rainfall‐runoff model

Spatially distributed hydrologic models can be effectively utilized for flood event simulation over basins where a complex system of reservoirs affecting the natural flow regime is present. Flood peak attenuation through mountain reservoirs can, in fact, mitigate the impact of major floods in flood‐prone areas of the lower river valley. Assessment of this effect for a complex reservoir system is performed with a spatially distributed hydrologic model where the surface runoff formation and the hydraulic routing through each reservoir and the river system are performed at a fine spatial and time resolution. The Toce River basin is presented as a case study, because of the presence of 14 active hydroelectric dams that affect the natural flow regime. A recent extreme flood event is simulated using a multi‐realization kriging method for modelling the spatial distribution of rainfall. A sensitivity analysis of the key elements of the distributed hydrologic model is also performed. The flood hydrograph attenuation is assessed. Several possible reservoir storage conditions are used to characterize the initial condition of each reservoir. The results demonstrate how a distributed hydrologic model can contribute to defining strategies for reservoir management in flood mitigation. Copyright © 2004 John Wiley & Sons, Ltd.