63 research outputs found

    Surface Faulting and Ground Deformation: Considerations on Their Lower Detectable Limit and on FDHA for Nuclear Installations

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    We performed a review of a representative data set on coseismic surface deformation, derived from both interferometric synthetic aperture radar imaging and from a traditional field survey of surface faulting. This analysis indicates a minimum threshold value of Mw 5.4\u20135.5 for earthquake-induced ground deformation and faulting, with an inherently lower limit of detection that makes it hard to recognize surface deformation caused by Mw < 4.5\u20135.0 events. Significant exceptions are represented by shallow (i.e., less than circa 5 km) events that occur in volcano-tectonic settings, where surface deformation and dislocation are also clearly detectable for Mw circa 4.0. Furthermore, a statistically significant regression between the areal extent of surface deformation and maximum slip at surface is proposed. This correlation is discussed in relation to fault displacement hazard analysis for nuclear power plants. In particular, the deformation area is used to find a potential solution for the second and third criterion for defining a capable fault

    Surface faulting during the August 24, 2016, central Italy earthquake (Mw 6.0): Preliminary results

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    We present some preliminary results on the mapping of coseismically-induced ground ruptures following the Aug. 24, 2016, Central Italy earthquake (Mw 6.0). The seismogenic source, as highlighted by InSAR and seismological data, ruptured across two adjacent structures: the Mt. Vettore and Laga faults. We collected field data on ground breaks along the whole deformed area and two different scenarios of on-fault coseismic displacement arise from these observations. To the north, along the Mt. Vettore fault, surface faulting can be mapped quite continuously along a well-defined fault strand while such features are almost absent to the south, along the Laga fault, where flysch-like marly units are present. A major lithological control affects the surface expression of faulting, resulting in a complex deformation pattern

    Failed back surgeries and minnesota multiphasic personality inventory (MMPI) profiles

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    MMPI profiles were evaluated for 105 prospective surgical patients who had previously undergone surgery or other procedures for treatment of back pain. Patients were classified into groups having undergone zero, one, two, three, or four or more previous surgeries. While all groups demonstrated a characteristic somatogenic profile, none of the MMPI validity or clinical scales significantly differentiated the groups and there was no relationship between increased number of surgeries and MMPI scale characteristics. These results support the nonoptimistic prognostication of the somatogenic MMPI profile for surgical intervention for back pain but show no clear relationship of MMPI profile characteristics to degree of experience of previously failed surgery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44850/1/10880_2005_Article_BF01999744.pd

    A database of the coseismic effects following the 30 October 2016 Norcia earthquake in Central Italy

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    We provide a database of the coseismic geological surface effects following the Mw 6.5 Norcia earthquake that hit central Italy on 30 October 2016. This was one of the strongest seismic events to occur in Europe in the past thirty years, causing complex surface ruptures over an area of >400 km 2. The database originated from the collaboration of several European teams (Open EMERGEO Working Group; about 130 researchers) coordinated by the Istituto Nazionale di Geofisica e Vulcanologia. The observations were collected by performing detailed field surveys in the epicentral region in order to describe the geometry and kinematics of surface faulting, and subsequently of landslides and other secondary coseismic effects. The resulting database consists of homogeneous georeferenced records identifying 7323 observation points, each of which contains 18 numeric and string fields of relevant information. This database will impact future earthquake studies focused on modelling of the seismic processes in active extensional settings, updating probabilistic estimates of slip distribution, and assessing the hazard of surface faulting

    Coulomb pre-stress and fault bends are ignored yet vital factors for earthquake triggering and hazard

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    Successive locations of individual large earthquakes (Mw>5.5) over years to centuries can be difficult to explain with simple Coulomb Stress Transfer (CST) because it is common for seismicity to circumvent nearest-neighbour along-strike faults where coseismic CST is greatest. We demonstrate that Coulomb pre-stress (the cumulative CST from multiple earthquakes and interseismic loading on non-planar faults) may explain this, evidenced by study of a 667-year historical record of earthquakes in central Italy. Heterogeneity in Coulomb pre-stresses across the fault system is >±50 bars, whereas coseismic CST is <±2 bars, so the latter will rarely overwhelm the former, explaining why historical earthquakes rarely rupture nearest neighbor faults. However, earthquakes do tend to occur where the cumulative coseismic and interseismic CST is positive, although there are notable examples where earthquake propagate across negatively stressed portions of faults. Hence Coulomb pre-stress calculated for non-planar faults is an ignored yet vital factor for earthquake triggering

    The risk factors and predictive factors for anastomotic leakage after resection for colorectal cancer: reappraisal of the literature

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    Anastomotic leakage is a serious complication that can occur after colorectal surgery. Several risk factors for anastomotic leakage have been reported based on the findings of prospective and retrospective studies, including patient characteristics, the use of neoadjuvant therapy, the tumor location, intraoperative events, etc. However, as these risk factors affect each other, the statistical results have differed in each study. In addition, differences in surgical methods, including laparoscopy versus laparotomy or stapling anastomosis versus handsewn anastomosis, may influence the incidence of anastomotic leakage. This mini-review summarizes the results of reported papers to clarify the current evidence of risk factors for anastomotic leakage
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