The configuration of the seismic zone and the downgoing slab in southern Peru

Using data from temporary networks of portable seismographs in southern Peru, we located 888 shallow and intermediate depth events near a proposed discontinuity in the seismic zone there. These events reveal a prominent contortion, instead of a discontinuity, that trends approximately N80°E, parallel to the direction of relative plate motion. North of about 15°S, the seismic zone beneath Peru is nearly horizontal, but south of about 15.5°S, it dips at about 25°. Volcanoes lie above the more steeply dipping zone where earthquakes occur between 120 and 140 km, and the volcanic line in southern Peru stops abruptly at the contortion

A blind hierarchical coherent search for gravitational-wave signals from coalescing compact binaries in a network of interferometric detectors

We describe a hierarchical data analysis pipeline for coherently searching for gravitational wave (GW) signals from non-spinning compact binary coalescences (CBCs) in the data of multiple earth-based detectors. It assumes no prior information on the sky position of the source or the time of occurrence of its transient signals and, hence, is termed "blind". The pipeline computes the coherent network search statistic that is optimal in stationary, Gaussian noise, and allows for the computation of a suite of alternative statistics and signal-based discriminators that can improve its performance in real data. Unlike the coincident multi-detector search statistics employed so far, the coherent statistics are different in the sense that they check for the consistency of the signal amplitudes and phases in the different detectors with their different orientations and with the signal arrival times in them. The first stage of the hierarchical pipeline constructs coincidences of triggers from the multiple interferometers, by requiring their proximity in time and component masses. The second stage follows up on these coincident triggers by computing the coherent statistics. The performance of the hierarchical coherent pipeline on Gaussian data is shown to be better than the pipeline with just the first (coincidence) stage.Comment: 12 pages, 3 figures, accepted for publication in Classical and Quantum Gravit

Muon-spin rotation and magnetization studies of chemical and hydrostatic pressure effects in EuFe_{2}(As_{1-x}P_{x})_{2}

The magnetic phase diagram of EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was investigated by means of magnetization and muon-spin rotation studies as a function of chemical (isovalent substitution of As by P) and hydrostatic pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe spins with respect to P content and hydrostatic pressure are determined and discussed. The present investigations reveal that the magnetic coupling between the Eu and the Fe sublattices strongly depends on chemical and hydrostatic pressure. It is found that chemical and hydrostatic pressure have a similar effect on the Eu and Fe magnetic order.Comment: 11 pages, 10 figure

Preliminary paleomagnetic characterization and anisotropy of magnetic susceptibility (AMS) of ancient terraces of the Ebro river

En este trabajo se realiza el estudio paleomagnético preliminar del nivel de terraza más antiguo (198-220 m) del río Ebro, en el sector central de la Cuenca del Ebro. Igualmente se ha realizado un análisis conjunto de la anisotropía de susceptibilidad magnética (AMS) y los datos de paleocorrientes en la zona. Las desmagnetizaciones muestran direcciones con una clara polaridad inversa de alta temperatura (300-675°C), con una componente adicional normal viscosa <100ºC, indicando que la edad del depósito es anterior al límite Brunhes-Matuyama (773.000 años). La ASM muestra un comportamiento más complejo controlado por la mineralogía magnética. Las fábricas con susceptibilidad paramagnética dominante mostraron foliación magnética paralela al plano de estratificación indicando su posible utilidad en el estudio de paleocorrientesIn this work we carry out a preliminary paleomagnetic analysis focused in the oldest fluvial terrace (198-220 m) of the Ebro River, in the central sector of the Ebro Basin. We have also conducted a combined analysis of anisotropy of magnetic susceptibility (ASM) and paleocurrent data in the area. The paleomagnetic record shows a clear high temperature (300-675° C) reverse polarity with an additional viscous normal component <100º C, indicating that the materials were deposited during the Matuyama chron (reverse polarity) which implies an age > 773.000 years. The ASM shows a more complex behaviour controlled by the magnetic mineralogy. Dominant paramagnetic fabrics show magnetic foliation parallel to the bedding indicating their potential utility in the study of paleocurrent

Estudio ecotoxicológico del arroyo Las Conchitas (Buenos Aires) : 1. Toxicidad en aga y sedimentos.2.Parámetros fisico-químicos y relevamiento de la biota

Fil: Herkovits, Jorge. Instituto de Ciencias Ambientales y Salud, Fundación PROSAMAFil: Rodrígues Capítulo, Alberto. Instituto de Limnología Raúl Ringuelet, CONICET-UNLPFil: Boyle, Terence. US Geological Survey, Colorado State UniversityFil: Servant, Roberto. Comisión Nacional de Energía AtómicaFil: Pérez-Coll, Cristina. Instituto de Ciencias Ambientales y Salud, Fundación PROSAMAFil: Gómez, Nora. Instituto de Limnología Raúl Ringuelet, CONICET-UNLPFil: Muñoz, Lorena. Instituto de Ciencias Ambientales y Salud, Fundación PROSAMAFil: Domínguez, Olga. Instituto de Ciencias Ambientales y Salud, Fundación PROSAMAFil: Cortelezzi, Agustina. Instituto de Limnología Raúl Ringuelet, CONICET-UNLPFil: Licursi, Magdalena. Instituto de Limnología Raúl Ringuelet, CONICET-UNLPFil: Vanrell, Tomás. Municipalidad de BerazateguiFil: López, Ariel. Municipalidad de Florencio VarelaFil: Varela, L.. Municipalidad de BerazateguiFil: Castañaga, L.. Instituto de Ciencias Ambientales y Salud, Fundación PROSAMAFil: Puszczyk, Eduardo. Municipalidad de Florencio VarelaFil: Cordero, Miriam. Municipalidad de Florencio Varel

Inventory and review of the Mio–Pleistocene São Jorge flora (Madeira Island, Portugal): palaeoecological and biogeographical implications

The occurrence of plant fossils on Madeira Island has been known since the mid-nineteenth century. Charles Lyell and George Hartung discovered a leaf bed rich in Lauraceae and fern fossils at S~ao Jorge in 1854. The determinations were controversial but a full review was never performed. Here we propose possible geological settings for the fossiliferous outcrop, and present an inventory and a systematic review of the surviving specimens of the S~ao Jorge macroflora. The S~ao Jorge leaf bed no longer outcrops due to a landslide in 1865. It was possible to establish the two alternative volcano stratigraphical settings in the sedimentary intercalations from the Middle Volcanic Complex, ranging in age from 7 to 1.8 Ma. The descriptions of Heer (1857), Bunbury (1859) and Hartung & Mayer (1864) are reviewed based on 82 surviving specimens. From the initial 37 taxa, we recognize only 20: Osmunda sp., Pteridium aquilinum, Asplenium cf. onopteris, aff. Asplenium, cf. Polystichum, cf. Davallia, Woodwardia radicans, Filicopsida gen. et sp. indet. 1 and 2, Ocotea foetens, Salix sp., Erica arborea, cf. Vaccinium, Rubus sp, cf. Myrtus, Magnoliopsida gen. et sp. indet. 1 to 3, Liliopsida gen. et sp. indet. 1. Magnoliopsida gen. et sp. indet. 4 is based on one previously undescribed flower or fruit. The floristic composition of the S~ao Jorge fossils resembles the current floristic association of temperate stink laurel (Ocotea foetens) forest, suggesting a warm and humid palaeoclimate and indicating that laurel forests were present in Macaronesia at least since the Gelasian, a time when the palaeotropical geofloral elements were almost extinct in Europe.info:eu-repo/semantics/publishedVersio