86,661 research outputs found
Neotectónica de la cuenca del Tuy, Venezuela: Observaciones complementarias
No full textNuevos datos obtenidos en un afloramiento previamente estudiado (estacion N°24) por AUDEMARD (1984) han permitido confirmar y reforzar las dos fases de deformación establecidas por dicho autor, presentes en los sedimentos pliocuatemarios de la cuenca del Tuy: una primera fase distensiva con a3 de orientación NE-SW y una segunda transpresiva caracterizada por a1 sub horizontal y de orientación NNW-SSE. Abstract: New complementary geological observations obtained from an outcrop {station N° 24) already evaluated by AUDEMARD {1984) have permitted to confirm the existence of two local tectonic phases in the Tuy basin, previously advanced by this author. Tite Plio-Quaternary sedimentary sequence of the Tuy basin has undergone two tectonic phases: the first phase is extensional characterized by a NE-SW minimum horizontal stress, whereas the latest phase is transpressive with a maximum horizontal stress oriented NNW-SSE
Geological Criteria for Evaluating Seismicity Revisited: Forty Years of Paleoseismic Investigations and the Natural Record of Past Earthquakes
No full textThe identification of individual past earthquakes and their characterization in time and space, as well as in magnitude, can be approached in many different ways with a large variety of methods and techniques, using a wide spectrum of objects and
features. We revise the stratigraphic and geomorphic evidence currently used in the study of paleoseismicity, after more than three decades since the work by Allen (1975),
which was arguably the first critical overview in the field of earthquake geology. Natural objects or geomarkers suitable for paleoseismic analyses are essentially preserved
in the sediments, and in a broader sense, in the geologic record. Therefore, the study of these features requires the involvement of geoscientists, but very frequently it is a
multidisciplinary effort. The constructed environment and heritage, which typically are the focus of archaeoseismology and macroseismology, here are left aside. The geomarkers
suitable to paleoseismic assessment can be grouped based on their physical relation to the earthquake’s causative fault. If directly associated with the fault surface
rupture, these objects are known as direct or on-fault features (primary effects in the Environmental Seismic Intensity [ESI] 2007 scale). Conversely, those indicators not in direct contact with the fault plane are known as indirect or off-fault evidence
(secondary effects in the ESI 2007 scale). This second class of evidence can be subdivided into three types or subclasses: type A, which encompasses seismically induced effects, including soft-sediment deformation (soil liquefaction, mud diapirism), mass
movements (including slumps), broken (disturbed) speleothems, fallen precarious rocks, shattered basement rocks, and marks of degassing (pockmarks, mud volcanoes); type B, which consists of remobilized and redeposited sediments (turbidites, homogenites, and tsunamites) and transported rock fragments (erratic blocks); and type C, entailing regional markers of uplift or subsidence (such as reef tracts, microatolls, terrace risers, river channels, and in some cases progressive unconformities).
The first subclass of objects (type A) is generated by seismic shaking. The second subclass (type B) relates either to water bodies set in motion by the earthquake (for the sediments and erratic blocks) or to earthquake shaking; in a general way, they all relate to wave propagation through different materials. The third subclass (type C) is mostly related to the tectonic deformation itself and can range from local (next to the causative fault) to regional scale.
The natural exposure of the paleoseismic objects—which necessarily conditions the paleoseismic approach employed—is largely controlled by the geodynamic setting.
For instance, oceanic subduction zones are mostly submarine, while collisional settings tend to occur in continental environments. Divergent and wrenching margins may occur anywhere, in any marine, transitional, or continental environment.
Despite the fact that most past subduction earthquakes have to be assessed through indirect evidence, paleoseismic analyses of this category of events have made dramatic progress recently, owing to the increasingly catastrophic impact that they have on human society
Recent advances in landslide investigation: Issues and perspectives.
No full textThis is the "Guest editorial" of a Special Issue of the journal Geomorphology which includes 14 papers dealing with landslides selected from two conferences of the International Association of Geomorphologists (IAG): the Regional Conference held in Brasov, Romania, in September 2008 and the Seventh International Conference celebrated in Melbourne, Australia, in July 2009. The Regional Conference, under the theme "Landslides, floods and global environmental change in mountain regions", was organized in a classic landslide area, the Carpathian Mountains.The articles covers a wide geographical and thematic canvas, with a special flavour from Eastern Europe derived from the IAG Regional Conference held in Romania. The study areas include all the major continents with the exception of North America. Eight papers from Europe (Andorra, Czech Republic, Estonia, Poland, Romania, Spain, Switzerland) deal with a wide diversity of topics; magnitude and frequency relationships in the Pyrenees, paleoenvironmental record of landslide activity in the Carpathians, slope instability in glacialacustrine clays in the Estonian coastal plain, landslide characterization in the Bohemian Massif, susceptibility mapping in Romania, mapping and assessment of debris-flow sediment sources in the Swiss Alps, and shallow slides and trenching applied to large landslides in a reservoir in the Pyrenees. Two papers deal with a catastrophic rock slide-avalanche in Japan. There is a paper on the interaction between large dam-forming landslides and fluvial activity in the deepest valley in the world located in Nepal. An article from Venezuela documents very large landslides associated with the Boconó Fault in the Andes. A paper reviews blanket peat landslides in subantartic islands. Finally, one paper discusses the relative role played by climate change and human activity on landslide activity, with numerous examples from New Zealand.The Guest Editorial, beside outlining the main content of each papers, highlights the recent advances in landslide investigation
Future trends in paleoseismology: Integrated study of the seismic landscape as a vital tool in seismic hazard analyses
No full textThis paper forms the Introduction to this Special Issue of Tectonophysics, devoted to selected scientific research
presented during events sponsored by the INQUA Subcommission on Paleoseismicity in the past few years. In this
note, we summarize the contents of the contributed papers and use the issues they raise to review the state-of-the-art in
paleoseismology from a Quaternary geology perspective. In our opinion, the evolution of paleoseismological studies in
the past decade clearly demonstrates that in order to properly understand the seismic potential of a region, and to
assess the associated hazards, broad-based/multidisciplinary studies are necessary to take full advantage from the
geological evidence of past earthquakes. A major challenge in future paleoseismic research is to build detailed
empirical relations between various categories of coseismic effects in the natural environment and earthquake magnitude/
intensity. These relations should be compiled in a way that is fully representative of the wide variety of natural
environments on Earth, in terms of climatic settings, Quaternary tectonic evolution, rheological parameters of the
seismogenic crust, and stress environment. For instance, available data indicate that between earthquake magnitude and
surface faulting parameters different scaling laws exist, and they are a function of the local geodynamic setting
(including style of faulting, typical focal depths, heat flow). In this regard, we discuss in some detail the concept of
seismic landscape, which provides the necessary background for developing paleoseismological research strategies. The
large amount of paleoseismological data collected in recent years shows that each earthquake source creates a signature
on the geology and the geomorphology of an area that is unequivocally related with the order of magnitude of its
earthquake potential. This signature is defined as the seismic landscape of the area (e.g., Serva, L., Vittori, E., Ferreli,
L., Michetti, A.M., 1997. Geology and seismic hazard. In: Grellet, B., Mohammadioun, B., Hays, W. (Eds.),
Proceedings of the Second France–United States Workshop on Earthquake Hazard Assessment in Intraplate Regions:
Central and Eastern United States and Western Europe, October 16, 1995, Nice, France, 20–24, Ouest Editions, Nantes,
France; Michetti, A.M., Hancock, P.L., 1997. Paleoseismology: understanding past earthquakes using quaternary geology Journal of Geodynamics 24 (1–4), 3–10). We then illustrate how this relatively new framework is helpful in understanding
the seismic behavior of faults capable of producing surface faulting and provides a comprehensive approach for the use of
paleoseismicity data in earthquake hazard characterization
Paleoseismology, integrated study of the Quaternary geological record for earthquake deformation and faulting
No full textTectonophysics 408 (2005) v– vi, Special Issue
Paleoseismology:
Integrated study of the Quaternary geological record
for earthquake deformation and faulting, doi:10.1016/S0040-1951(05)00465-
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
DNA probes as potential tools for the detection of marteilia refringens
No full textSince its first description, the paramyxean parasite Marteilia refringens has been recognized as a significant pathogen of bivalve mollusks. The existence of a complex life cycle was postulated by many authors. Here we report the development of DNA-based detection assays as powerful tools to elucidate the Marteilia refringens life cycle. After alignment of the Marteilia refringens ribosomal DNA small subunit sequence with those of various eukaryotic organisms, polymerase chain reaction primers were designed. Specific primers were used to amplify DNA extracted from purified Marteilia refringens and infected hosts. The specificity of amplified fragments was confirmed by Southern blotting with an oligoprobe. For in situ hybridization, four probes were tested for specific detection of 18S rRNA isolated from Marteilia refringens and other eukaryotic cells by Northern blotting. The most specific probe, Smart 2, was successfully used to detect Marteilia refringens by in situ hybridization in infected oysters and mussels.Source type: Electronic(1
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
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