2012 Haida Gwaii Mw 7.7 Earthquake Response - Ocean Bottom Seismometer Relocation and Geophone Orientation Analysis and Quality Control of Wide-Angle P-wave Refraction Data

Canada's second largest instrumentally recorded earthquake occurred on October 27th, 2012, off the west coast of Moresby Island, Haida Gwaii. Analysis of seismic waveforms and the pattern of aftershocks indicate that it was a thrust earthquake with a magnitude of Mw = 7.7. To accurately locate earthquakes, recording stations need to be positioned such that they surround the epicenter and the sound speed at which seismic waves travel through the earth's crust must be known. The land stations on Haida Gwaii are all to the east of the aftershock sequence, thus making these offshore earthquake locations uncertain and making depths for those events almost impossible to calculate accurately. Only sparse information from seismic refraction work conducted in the early 1980ies on the offshore velocity structure around the epicenter is known. Therefore, a series of 14 ocean bottom seismometers (OBS) were deployed for the duration of 1 month between December 6, 2012 and January 5, 2013 to record a portion of the aftershock sequence. An active source seismic program was conducted in January 2013 prior to the OBS recovery to acquire information on the sediment- and crustal structures to aid in the earthquake location analyses. However, the initial refraction data were not recorded on any of the 14 OBS as the batteries on all of the OBS stations had drained by the time of the survey. An extra set of six OBS was re-deployed and a total of four single-channel seismic profiles were acquired across these six OBS stations for a smaller-scale detailed refraction velocity experiment. Using the active source seismic data, each of the six OBS of the second deployment were re-located on the ocean floor, which is a critical pre-requisite for any velocity analysis. The OBS instruments drifted on average by 200m to the NW of the deployment drop-position. New offset information for the relocated OBS stations were calculated, and used for an initial exemplary but non-ray-tracing based 1D refraction velocity analysis on selected OBS stations to demonstrate the general utility of the OBS refraction data. Additional particle motion analyses were conducted for five of the six OBS stations of the second refraction survey to define the geophone orientation. One of these six stations (OBS-5) appeared to have identical horizontal components and therefore could not be used for a geophone-orientation determination. Long-range refraction seismic arrivals from the active-source experiment with a single 520 cubic inch G-gun were identified on some of the Haida Gwaii land-stations with offset ranges of up to 58 km. This information can potentially be used for a deep-crustal refraction velocity analysis. At this stage, only basic information on these land-station data is documented for potential future analyses

EON-ROSE and the Canadian Cordillera Array – Building Bridges to Span Earth System Science in Canada

EON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) is a new initiative for a pan-Canadian research collaboration to holistically examine Earth systems from the ionosphere into the core. The Canadian Cordillera Array (CC Array) is the pilot phase, and will extend across the Cordillera from the Beaufort Sea to the U.S. border. The vision for EON-ROSE is to install a network of telemetered observatories to monitor solid Earth, environmental and atmospheric processes. EON-ROSE is an inclusive, combined effort of Canadian universities, federal, provincial and territorial government agencies, industry, and international collaborators. Brainstorming sessions and several workshops have been held since May 2016. The first station will be installed at Kluane Lake Research Station in southwestern Yukon during the summer of 2018. The purpose of this report is to provide a framework for continued discussion and development.RÉSUMÉEON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) est une nouvelle initiative de collaboration de recherche pancanadienne visant à étudier de manière holistique les systèmes terrestres, depuis l’ionosphère jusqu’au noyau. Le Réseau canadien de la cordillère (CC Array) en est la phase pilote, laquelle couvrira toute la Cordillère, de la mer de Beaufort jusqu’à la frontière étasunienne. L’objectif d’EON-ROSE est d’installer un réseau d’observatoires télémétriques pour suivre en continu les processusterrestres, environnementaux et atmosphériques. EON-ROSE est un effort combiné et inclusif des universités canadiennes, des organismes gouvernementaux fédéraux, provinciaux et territoriaux, de l’industrie et de collaborateurs internationaux. Des séances de remue-méninges et plusieurs ateliers ont été tenus depuis mai 2016. La première station sera installée à la station de recherche du lac Kluane, dans le sud-ouest du Yukon, au cours de l’été 2018. Le but du présent rapport est de fournir un cadre de discussion et de développement continu

Fasting plasma glucose (FPG) and the risk of impaired glucose tolerance in obese children and adolescents.

A timely diagnosis of impaired glucose tolerance (IGT) is desirable in obesity. The oral glucose tolerance test (OGTT), the gold standard to diagnose this condition, may not be realistically performed in all patients due to discomfort, labor, and cost. The aim of this study was to assess whether one or more biochemical indexes measured in fasting conditions could be used to identify obese children at risk of IGT. A cohort of 563 white obese children and adolescents (M/F: 315/248; aged 4-17 years) was recruited and underwent anthropometric evaluation and OGTT. Anthropometric parameters, fasting plasma glucose (FPG), fasting serum insulin (FSI), and homeostasis model assessment of insulin resistance (HOMA(IR)) were tested in pursuit of a possible threshold to be used as a predictor of IGT. Thirty-seven children (6.9%) had IGT and one child (0.1%) had type 2 diabetes (T2D). FPG, FSI, and HOMA(IR) were all significantly higher in children with IGT than in children without IGT. Receiver-operating characteristic (ROC) curve analyses run for gender and puberty-adjusted FPG, FSI, and HOMA(IR) were all significant: area under the curve (95% confidence interval) equaled 0.68 (0.59-0.76), 0.66 (0.56-0.76), and 0.68 (0.59-0.78), respectively. The three parameters did not show significantly different sensitivity/specificity in the pooled population or in the gender/puberty subgroups. Thresholds varied among gender/puberty subgroups for FSI and HOMA(IR), but not for FPG, which showed a fixed threshold of 86 mg/dl. A gender/puberty independent cutoff of FPG may be considered a screening tool to narrow clinical indication to OGTT in obese white children and adolescent

Development of structural debris flow fragility curves (debris flow buildings resistance) using momentum flux rate as a hazard parameter

Societal risks associated with debris flow hazards are significant and likely to escalate due to global population growth trends and the compounding effects of climate change. Quantitative risk assessment methods (QRA) provide a means of anticipating the likely impacts and consequences of settlement in areas susceptible to landslide activity and are increasingly being used to inform land use decisions that seek to increase disaster resilience through mitigation and/or adaptation. Current QRA methods for debris flow hazards are based primarily on empirical vulnerability functions that relate hazard intensity (depth, velocity, etc.) to expected levels of loss for a given asset of concern, i.e. most of current methods are dedicated to loss-intensity relations. Though grounded in observed cause-effect relationships, empirical vulnerability functions are not designed to predict the capacity of a building to withstand the physical impacts of a debris flow event, or the related uncertainties associated with modelling building performance as a function of variable debris flow parameters. This paper describes a methodology for developing functions that relate hazard intensity to probability of structural damage, i.e., fragility functions, rather than vulnerability functions, based on the combined hydrodynamic forces of a debris flow event (hazard level) and the inherent structural resistance of building typologies that are common in rural mountainous settings (building performance). Hazard level includes a hydrodynamic force variable (FDF), which accounts for the combined effects of debris flow depth and velocity, i.e. momentum flux (hv2), material density (?) and related flow characteristics including drag (Cd) and impact coefficient (Kd). Building performance is measured in terms of yield strength (Ay), ultimate lateral capacity (AU) and weight to breadth ratios (W/B) defined for a portfolio building types that are common in mountain settlements. Collectively, these model parameters are combined using probabilistic methods to produce building-specific fragility functions that describe the probability of reaching or exceeding successive thresholds of structural damage over a range of hazard intensity values, expressed in terms of momentum flux. Validation of the proposed fragility model is based on a comparison between model outputs and observed cause-effect relationships for recent debris flow events in South Korea and in Colombia. Debris flow impact momentum fluxes, capable of resulting in complete damage to unreinforced masonry buildings (URM) in those regions are estimated to be on the order of 24 m3/s2, consistent with field-based observations. Results of our study offer additional capabilities for assessing risks associated with urban growth and development in areas exposed to debris flow hazards. © 2018 Elsevier B.V