Megathrust Stress Drop as Trigger of Aftershock Seismicity: Insights From the 2011 Tohoku Earthquake, Japan

Numerous normal-faulting aftershocks in subduction forearcs commonly follow large megathrust earthquakes. Postseismic normal faulting has been explained by stress changes induced by the stress drop along the megathrust. However, details of forearc stress changes and aftershock triggering mechanisms remain poorly understood. Here, we use numerical force-balance models combined with Coulomb failure analysis to show that the megathrust stress drop supports normal faulting, but that forearc-wide aftershock triggering is feasible within a narrow range of megathrust stress drop values and preseismic stress states only. We determine this range for the 2011 Tohoku earthquake (Japan) and show that the associated stress changes explain the aftershock seismicity in unprecedented detail and are consistent with the stress released by forearc seismicity before and after the earthquake

Kinematics and Convergent Tectonics of the Northwestern South American Plate During the Cenozoic

The interaction of the northern Nazca and southwestern Caribbean oceanic plates with northwestern South America (NWSA) and the collision of the Panama-Choco arc (PCA) have significant implications on the evolution of the northern Andes. Based on a quantitative kinematic reconstruction of the Caribbean and Farallon/Farallon-derived plates, we reconstructed the subducting geometries beneath NWSA and the PCA accretion to the continent. The persistent northeastward migration of the Caribbean plate relative to NWSA in Cenozoic time caused the continuous northward advance of the Farallon-Caribbean plate boundary, which in turn resulted in its progressive concave trench bending against NWSA. The increasing complexity during the Paleogene included the onset of Caribbean shallow subduction, the PCA approaching the continent, and the forced shallow Farallon subduction that ended in the fragmentation of the Farallon Plate into the Nazca and Cocos plates and the Coiba and Malpelo microplates by the late Oligocene. The convergence tectonics after late Oligocene comprised the accretional process of the PCA to NWSA, which evolved from subduction erosion of the forearc to collisional tectonics by the middle Miocene, as well as changes of convergence angle and slab dip of the Farallon-derived plates, and the attachment of the Coiba and Malpelo microplates to the Nazca plate around 9 Ma, resulting in a change of convergence directions. During the Pliocene, the Nazca slab broke at 5.5°N, shaping the modern configuration. Overall, the proposed reconstruction is supported by geophysical data and is well correlated with the magmatic and deformation history of the northern Andes

Forming a Mogi Doughnut in the Years Prior to and Immediately Before the 2014 M8.1 Iquique, Northern Chile, Earthquake

Asperities are patches where the fault surfaces stick until they break in earthquakes. Locating asperities and understanding their causes in subduction zones is challenging because they are generally located offshore. We use seismicity, interseismic and coseismic slip, and the residual gravity field to map the asperity responsible for the 2014M8.1 Iquique, Chile, earthquake. For several years prior to the mainshock, seismicity occurred exclusively downdip of the asperity. Two weeks before the mainshock, a series of foreshocks first broke the upper plate then the updip rim of the asperity. This seismicity formed a ring around the slip patch (asperity) that later ruptured in the mainshock. The asperity correlated both with high interseismic locking and a circular gravity low, suggesting that it is controlled by geologic structure. Most features of the spatiotemporal seismicity pattern can be explained by a mechanical model in which a single asperity is stressed by relative plate motion

Kinematic 3D Retro-Deformation of Fault Blocks Picked from 3D Seismics

Movement on fault planes causes a large amount of smaller-scale deformation, ductile or brittle, in the area surrounding the fault. Much of this deformation is below the resolution of reflection seismics (i.e. sub-seismic, <10m displacement), but it is important to determine this deformation, since it can make up a large portion of the total bulk strain, for instance in a developing sedimentary basin. Calculation of the amount of sub-seismic strain around a fault by 3-D geometrical kinematic retro-deformation can also be used to predict the orientation and magnitude of these smaller-scale structures. However, firstly a 3-D model of the fault and its faulted horizons must be constructed at a high enough resolution to be able to preserve fault and horizon morphology with a grid spacing of less than 10 m. Secondly, the kinematics of the fault need to be determined, and thirdly a suitable deformation algorithm chosen to fit the deformation style. Then by restoring the faulted horizons to their pre-deformation state (a ‘regional’), the moved horizons can be interrogated as to the strain they underwent. Since strain is commutative, the deformation demonstrated during this retro-deformation is equivalent to that during the natural, forward deformation...conferenc

Мотивация целевых групп при выводе продукта на рынок

Сделан вывод о том, что при разработке системы мотивации необходимо проводить сегментацию клиентов и персонала по группам преобладающих потребностей, как это делается с рынками в маркетинге. А также выделены целевые группы, влияющие на процесс вывода нового продукта на рынок, и особенности их мотивации

Visual hallucinations associated with varenicline: a case report

<p>Abstract</p> <p>Introduction</p> <p>Varenicline is widely used for smoking cessation. It has shown efficacy over placebo and bupropion in manufacturer-sponsored trials. Those with mental illness were excluded from these trials. There are case reports of exacerbation of mental illness and development of psychiatric symptoms with varenicline use.</p> <p>Case presentation</p> <p>A 61-year-old male Caucasian being treated for post-traumatic stress disorder, depression not otherwise specified and alcohol dependence, was prescribed varenicline while he was in a post-traumatic stress disorder/alcohol dual diagnosis treatment program. He developed visual hallucinations, which became worse with titration of the medication. These symptoms resolved upon discontinuation of varenicline.</p> <p>Conclusion</p> <p>Patients with mental illness have a higher incidence of nicotine dependence, and attempts should be made for smoking cessation. Varenicline has not been widely tested in this population. There are reports of exacerbation of mental illness, and probable causation of psychiatric symptoms in the mentally ill. Providers should be aware of this possibility and advise their patients appropriately.</p

Olfactory and gustatory sensory changes to tobacco smoke in pregnant smokers

Models of smoking behavior change include addiction, social, and behavioral concepts. The purpose of this study was to explore the prevalence of two biologic factors, olfactory and gustatory responses to tobacco smoke, as potentially powerful contributors to smoking behavior change among pregnant women. Data were obtained from 209 pregnant smokers. The majority of women reported olfactory (62%) and gustatory (53%) aversions to tobacco. Aversions first appeared during the first trimester of pregnancy. Women who experienced olfactory aversions were more likely also to experience gustatory aversions. Olfactory aversions were associated with women smoking less. Aversions to tobacco smoke are common among pregnant smokers, are associated with women smoking less, and could help explain pregnant women’s smoking patterns