Join us at the SSA 2018! Booth 10/11
We have lined up a great program this year for the SSA with oral and poster presentations as well as new product introductions. Please visit us at our booth #10/11.
The best digitizer just got better!
The new Centaur Digital Recorder (CTR4 series models) introduces a number of capabilities including calibration output enhancements that support broader sensor calibration capability. These new models support a current source mode in addition to voltage source mode and improved calibration output signal accuracy of ±1%. The voltage mode maximum output range has been doubled to 20 Vpp.
Direct bury or Vault, you don't have to choose.
Trillium Horizon, the latest addition to the Trillium 120 product line, is one of our most versatile seismometers to date. This seismometer matches the portability and deployability of our Trillium Compact line with the performance of our vault seismometers. This dual-purpose instrument can be direct buried at shallow depth or set on a pier, meaning the Trillium Horizon gives you the most versatility for your investment.
Oral Presentations Abstracts
Presenting author: Emrah Yenier, May 16, 9:00 am, Jasmine Room
Earthquake early warning (EEW) systems are an important piece of seismic loss mitigation programs. They provide an advance notification of an on-going event before the arrival of damaging seismic waves to a target site. This notification can be used by various clients (e.g., government agencies, system control centers, emergency response teams, and public) to reduce the social and economic impacts of major earthquakes. EEW systems should be able to automatically distinguish seismic radiations from noise and estimate shaking intensity of not yet arrived waves from very first arrivals for maximized notification time. The accuracy of estimated source parameters and shaking intensities are as important as the advance warning time for achieving effective and trustworthy systems. In this study, existing EEW algorithms are tested in pseudo real time in order to identify their strengths and limitations from a perspective of warning recipients. The evolutionary accuracies of estimated location, magnitude and ground-motion amplitudes are compared. The trade-offs between prediction accuracies and warning lead time are examined, and potential improvements with integration of machine learning techniques are explored.
Presenting author: Emrah Yenier, May 16, 2:45 pm, Tuttle Room
Accurate and complete seismic event catalogs generated in real-time provide valuable insight into induced seismic risk management and public safety strategies among others. However, due to the vast amount of seismic data being collected, the construction of such catalogs is labor intensive. Hence an automated process is sought to reduce the workload involved in catalog production. Conventionally events are detected by applying an autopicker to seismic data streams and grouping picks into sets corresponding to potential events; picks are generated when a threshold is surpassed on a characteristic function (CF) for a given channel. In the scenario of a small magnitude event it is likely only a few channels have visible arrivals and the threshold must be set low to increase the chances of detecting these signals. However, reducing the threshold also increases the number of false positives produced. This mixture of true and false picks in any given solution can introduce significant errors into the corresponding event location. In order to maintain the system sensitivity ie. number of true positives (earthquakes) while reducing the effect of false positives (sets of noise picks) we apply a technique we call Feature Weighted Beamforming (FWB). Features are computed from 3C seismograms utilising; spectral content, covariance between channels, and common CFs (STA/LTA, Kurtosis). Models relating the features to phase likelihood and station-event azimuth are formed using machine learning techniques. Likelihood values are referenced to P-S phase pairs which are stacked on a 4D grid representing event location and origin time. Preliminary results show a significant reduction in the distance between automatic solutions and their corresponding manually reviewed counterparts as compared to conventional picking techniques, as well as a significant reduction in the number of false positive detections.
Poster Presentation Abstract
Presenting Author: Tim Parker, May 17, Riverfront South Room
The surge of using geophoned autonomous nodes for scientific projects is advancing passive imaging and monitoring techniques for scientific research, oil and gas projects, hydrology, civil engineering and new applications for short term dense seismic monitoring. The concept of a small, minimal configuration, low power, simple deployments without worry of environmental conditions can be applied to temporary broadband sensor system deployments using the next generation of direct bury broadband sensors. We explore some preliminary scientific deployment scenarios that can be used for broadband studies or as an example of a much smaller logistics next generation Earthscope array type station with little if any difference in noise performance and a potentially order of magnitude less cost. The concept of research grade latency can be applied for telemetry to recover quasi realtime data or very low cost system state of health.
Lightning Talk Abstract
The Canadian Cordillera Array (CCArray) is an initiative to install a Cordilleran-scale open-data network with the goal of holistically examining the Earth system from the core to the magnetosphere. Building on the scientific momentum of previous Earth systems research and data acquisition initiatives in North America (e.g. Lithoprobe (1984 to 2004) and EarthScope (2004 to ~2018 or later)), the vision for CCArray is to install a network of multidisciplinary telemetered observatories. The core CCArray network is envisaged to include broadband seismometers (including ocean bottom seismometers in the Beaufort Sea and offshore British Columbia) and Global Navigation Satellite System (GNSS) receivers. Additional instrumentation and measurements at selected locations could include meteorological and atmospheric gas sensors, borehole temperature and moisture sensors, riometers and magnetometers, relative and absolute gravity measurements. Education-outreach- communication programs will be integral to CCArray. While some instruments may only be in place for up to three years, some techniques, such as GNSS monitoring of crustal motions, require longer operational times. The intention is to continue operation of some stations to densify long-term monitoring across Canada. CCArray represents the initial component of an envisaged future pan-Canadian Earth observation network called Earth-system Observing Network – Réseau d’Observation du Système TerrestrE (EON-ROSE).
Early Warning for Large Earthquakes and Tsunamis: Challenges, Case Studies and Innovations
Co-chaired by Emrah Yenier, May 16, 8:30 am, 10:45 am, Jasmine room
The Future of Telemetered Seismic Arrays, Where the Operation of the Network Ends and the Science Begins
Co-chaired by Tim Parker, May 16, 2:15 pm, 4:15 pm, Tuttle Room