S32A-01 INVITED
Maintenance and Logistics Support for the International Monitoring System Network of the CTBTO
The global network of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), once completed, will consist of 321 monitoring facilities of four different technologies: hydroacoustic, seismic, infrasonic, and radionuclide. As of today, about 65% of the installations are completed and contribute data to the products issued by the International Data Centre (IDC) of the CTBTO. In order to accomplish the task to reliably collect evidence for any potential nuclear test explosion anywhere on the planet, all stations are required to perform to very high data availability requirements (at least 98% data availability over a 12-month period). To enable reaching this requirement, a three-layer concept has been developed to allow efficient support of the IMS stations: Operations, Maintenance and Logistics, and Engineering. Within this concept Maintenance and Logistics provide second level support of the stations, whereby problems arising at the station are assigned through the IMS ticket system to Maintenance if they cannot be resolved on the Operations level. Maintenance will then activate the required resources to appropriately address and ultimately resolve the problem. These resources may be equipment support contracts, other third party contracts, or the dispatch of a maintenance team. Engineering Support will be activated if the problem requires redesign of the station or after catastrophic failures when a total rebuild of a station may be necessary. In this model, Logistics Support is responsible for parts replenishment and support contract management. Logistics Support also collects and analyzes relevant failure mode and effect information, develops supportability models, and has the responsibility for document management, obsolescence, risk & quality, and configuration management, which are key elements for efficient station support. Maintenance Support in addition is responsible for maintenance strategies, for planning and oversight of the execution of preventive maintenance programs by the Station Operators, and for review of operational troubleshooting procedures used in first level support. Particular challenges for the efficient and successful Maintenance and Logistics Support of the IMS network lie in the specific political boundary conditions regulating its implementation, in the fact that all IMS facilities and their equipment are owned by the respective host countries, and in finding the appropriate balance between outsourcing services and retaining essential in-house expertise.
S32A-02 INVITED
IMS NETWORK OPERATIONS
The Comprehensive Nuclear Test-Ban Treaty CTBT, which prohibits all nuclear test explosions, was opened for signature in UN New York on 24 September 1996. Up to this date, the Treaty has been signed by 177 States and ratified by 138 of which 34 belong to a group of 44 States whose ratification is necessary for the Treaty to enter into force (EiF). A Preparatory Commission was created to prepare the Treaty's EiF. Further information on the CTBT can be found in www.ctbto.org. One key element being established for verifying the compliance with the Treaty is the International Monitoring System. The IMS is a world scale network comprised with instruments of four different monitoring technologies (Hydroacoustic, Infrasound, Seismic and Radionuclide). These are 321 monitoring stations and 16 radionuclide laboratories that monitor the earth for evidence of nuclear explosions in all environments. While the IMS network is approximately 60% complete, the commission has taken the necessary steps to enter the operational phase, based on industrial standards for Operations and Maintenance. A general overview of the operational processes, procedures and tools will be presented.
S32A-03
Special Challenges in the Operation of International Monitoring System Stations
The Comprehensive Nuclear Test Ban Treaty (CTBT) is a global treaty that bans nuclear test explosions in any environment. The treaty was opened for signature on 24 September 1996. To date, 177 countries have signed the treaty and 138 have ratified it. Among those having ratified are 34 of 44 required for the treaty to enter into force. The three pillars that support the treaty are the International Monitoring System (IMS) to detect test explosions, the International Data Centre (IDC) to produce and distribute both automatic and analyst reviewed data products, and On Site Inspection (OSI) to clarify whether a detected event was, in fact, a nuclear test explosion. The IMS is a globally distributed network of four technologies. Three wave-form technologies are designed to detect the waves produced by nuclear test explosions underground, in the air, and underwater. A radionuclide particulate network and noble gas experiment are designed detect radioactive isotopes generated by nuclear explosions. The diverse nature of the network presents a number of special challenges to the Network and Data System Operations Section of the IDC (NDSO), the group responsible for the effective operation of the IMS. One challenge faced by NDSO is the diversity of the equipment and software suppliers. There are currently many companies supplying equipment and technology for the 321 station IMS. This poses problems of consistency in operator training and in the applications of standard operating procedures. One solution to this problem was the development of the Standard Station Interface (SSI). The extensive geographical distribution of the stations presents another, challenge to effective IMS operations. The IMS includes stations in such remote locations as Soccorro Island, Tristan de Cunha, and the Antarctic and Sub-antarctic regions. Each of these locations presents its own set of challenges in terms of environment, logistics, and availability of qualified personnel.
S32A-04
Operating a global seismic network - perspectives from the USGS GSN
The Global Seismographic Network (GSN) is a permanent digital network of state-of-the-art seismological and geophysical sensors connected by a global telecommunications network, serving as a multi-use scientific facility used for seismic monitoring for response applications, basic and applied research in solid earthquake geophysics, and earth science education. A joint program of the U.S. Geological Survey (USGS), the National Science Foundation, and Incorporated Research Institutions in Seismology (IRIS), the GSN provides near- uniform, worldwide monitoring of the Earth through 144 modern, globally distributed seismic stations. The USGS currently operates 90 GSN or GSN-affiliate stations. As a US government program, the USGS GSN is evaluated on several performance measures including data availability, data latency, and cost effectiveness. The USGS-component of the GSN, like the GSN as a whole, is in transition from a period of rapid growth to steady- state operations. The program faces challenges of aging equipment and increased operating costs at the same time that national and international earthquake and tsunami monitoring agencies place an increased reliance on GSN data. Data acquisition of the USGS GSN is based on the Quanterra Q680 datalogger, a workhorse system that is approaching twenty years in the field, often in harsh environments. An IRIS instrumentation committee recently selected the Quanterra Q330 HR as the "next generation" GSN data acquisition system, and the USGS will begin deploying the new equipment in the middle of 2007. These new systems will address many of the issues associated with the ageing Q680 while providing a platform for interoperability across the GSN.. In order to address the challenge of increasing operational costs, the USGS employs several tools. First, the USGS benefits from the contributions of local host institutions. The station operators are the first line of defense when a station experiences problems, changing boards, swapping cables, and re-centering sensors. In order to facilitate this effort, the USGS maintains supplies of on-site spares at a number of stations, primarily at those with difficult shipping or travel logistics. In addition, the USGS is moving toward the GSN standard of installing a secondary broadband sensor at each site, to serve as a backup in case of failure of the primary broadband sensor. The recent transition to real-time telemetry has been an enormous boon for station operations as well as for earthquake and tsunami monitoring. For example, the USGS examines waveforms daily for data dropouts (gaps), out-of-nominal range data values, and overall noise levels. Higher level quality control focuses on problems in sensitivity, timing, polarity, orientation, and general instrument behavior. The quality control operations are essential for quickly identifying problems with stations, allowing for remedial or preventive maintenance that preserves data continuity and quality and minimizes catastrophic failure of the station or significant loss of data. The USGS tracks network performance using a variety of tools. Through Web pages with plots of waveforms (heliplots), data latency, and data availability, quick views of station status are available. The USGS has recently implemented other monitoring tools, such as SeisNetWatch, for evaluating station state of health.
S32A-05
European Scale Developments of the Seismological Waveform Data Exchange Infrastructure.
Seismological stations in Europe and its surroundings are operated, maintained and funded by more then 100 different observatories and networks. Currently more then 700 (semi)permanent broadband seismograph stations are operating within the region. This does not include semi-permanent and short-time deployments by universities and research institutes. Coordinating and implementing (real-time) data exchange is a major challenge and is done within the framework of ORFEUS (Observatories and Research Facilities for EUropean Seismology: www.orfeus-eu.org). ORFEUS is confronted both with technical challenges; data formats, large variety of instrumentation, unequal maintenance standards and communication links, and political challenges. It is therefore impressive that in a joint effort of (currently) more then 40 networks the Virtual European Broadband Seismic Network (VEBSN; www.orfeus- eu.org/meredian/vebsn.htm) was created, starting 2003. Currently close to 200 stations are contributing to the VEBSN and its numbers are steadily increasing. The VEBSN backbone, but not its only backbone, is the SeedLink data exchange protocol developed by GFZ. A de-facto standardization of this protocol in Europe enables each network to upgrade its national network with stations across its borders and consequently provide a significant improved national service. The VEBSN is currently also upgraded to operate as the core network for European scale early warnings for regional large earthquakes. The VEBSN also enables Europe to implement, operate and maintain an efficient waveform data archive. European scale funding realities have prioritized the formation of a distributed archive, the European Integrated Waveform Data Archive (EIDA). The core of which is currently being realized within the framework of the EC-project NERIES (http:neries.knmi.nl) as a joint effort of the ORFEUS data center at the KNMI in The Netherlands, GFZ in Germany, INGV in Italy and IPGP in France. The EIDA will be the European regional FDSN waveform data archive. In this presentation we will provide a description of the VEBSN, its status and current developments and a short overview of the waveform data archiving project.
S32A-06
Development of Automated Signal and Meta-data Quality Assessment at the USGS ANSS NOC
Real-time earthquake processing systems at the Advanced National Seismic System (ANSS) National Operations Center (NOC) rely on high-quality broadband seismic data to compute accurate earthquake locations, moment-tensor solutions, finite-fault models, Shakemaps and impact assessments. The NEIC receives real- time seismic data from the ANSS backbone, the Global Seismographic Network, ANSS regional network operators, foreign regional and national networks, the tsunami warning centers and the International Monitoring System. For many contributed stations, calibration information is not well known. In addition, equipment upgrades or changes may occur, making it difficult to maintain accurate metadata. The high-degree of real-time integration of seismic data necessitates the development of automated QC tools and procedures that identify changes in instrument response, quality of waveforms and other systematic changes in station performance that might affect NEIC computations and products. We present new tools and methods that will allow NEIC and other network operations to evaluate seismic station performance and characteristics both in the time and frequency domain using probability density functions (PDF) of power spectral densities (PSD) (McNamara and Buland, 2004). The method involves determining station standard noise conditions and characterizing deviations from the standard using the probabilistic distribution hourly PSDs. We define the standard station noise conditions to lie within the 10th and 90th percentile of the PSD distribution. The computed PSDs are stored in a database, allowing a user to access specific time periods of PSDs (PDF subsets) and time series segments through a client-interface or programmatic database calls. This allows the user to visually define the spectral characteristics of known system transients. In order to identify instrument response changes or systems transients we compare short-term spectral envelopes (1 hour to 1 day) against the long-term station noise envelopes. Operationally, the software is useful for characterizing the current and past performance of existing broadband stations, for conducting tests on potential new seismic station locations, for detecting problems with the recording system or sensors, and for evaluating the overall quality of data and meta-data. Currently, PQLX is operational at the USGS for station performance monitoring and metadata quality control.
S32A-07
The IRIS DMC: Perspectives on Real-Time Data Management and Open Access From a Large Seismological Archive: Challenges, Tools, and Quality Assurance
The IRIS Data Management Center, located in Seattle, WA, is the largest openly accessible geophysical archive in
the world, and has a unique perspective on data management and operational practices that gets the most out of
your network. Networks scale broad domains in time and space, from finite needs to monitor bridges and dams
to national and international networks like the GSN and the FDSN that establish a baseline for global monitoring
and research, the requirements that go into creating a well-tuned DMC archive treat these the same, building a
collaborative network of networks that generations of users rely on and adds value to the data.
Funded by the National Science Foundation through the Division of Earth Sciences, IRIS is operated through
member universities and in cooperation with the USGS, and the DMS facility is a bridge between a globally
distributed collaboration of seismic networks and an equally distributed network of users that demand a high
standard for data quality, completeness, and ease of access. I will describe the role that a perpetual archive has
in the life cycle of data, and how hosting real-time data performs a dual role of being a hub for continuous data
from approximately 59 real-time networks, and distributing these (along with other data from the 40-year library of
available time-series data) to researchers, while simultaneously providing shared data back to networks in real-
time that benefits monitoring activities. I will describe aspects of our quality-assurance framework that are both
passively and actively performed on 1100 seismic stations, generating over 6,000 channels of regularly sampled
data arriving daily, that data providers can use as aids in operating their network, and users can likewise use
when requesting suitable data for research purposes. The goal of the DMC is to eliminate bottlenecks in data
discovery and shortening the steps leading to analysis.
This includes many challenges, including keeping metadata current, tools for evaluating and viewing them, along
with measuring and creating databases of other performance metrics and how monitoring them closer to real-
time helps reduce operation costs, creates a richer repository, and eliminates problems over generations of duty
cycles of data usage. I will describe a new resource, called the Nominal Response Library, which hopes to
provide accurate and representative examples of sensor and data logger configurations that are hosted at the
DMC and constitute a high-graded subset for crafting your own metadata. Finally, I want to encourage all network
operators who do not currently submit SEED format data to an archive to consider these benefits, and briefly
discuss how robust transfer mechanisms that include Earthworm, LISS, Antelope, NRTS and SeisComp, to
name a few, can assist you in contributing your network data and help create this enabling virtual network of
networks. In this era of high performance Internet capacity, the process that enables others to share your data
and allows you to utilize external sources of data is nearly seamless with your current mission of network
operation.
http:www.iris.edu
S32A-08
Real-Time Data Processing Systems and Products at the Alaska Earthquake Information Center
The Alaska Earthquake Information Center (AEIC) receives data from over 400 seismic sites located within the state boundaries and the surrounding regions and serves as a regional data center. In 2007, the AEIC reported ~20,000 seismic events, with the largest event of M6.6 in Andreanof Islands. The real-time earthquake detection and data processing systems at AEIC are based on the Antelope system from BRTT, Inc. This modular and extensible processing platform allows an integrated system complete from data acquisition to catalog production. Multiple additional modules constructed with the Antelope toolbox have been developed to fit particular needs of the AEIC. The real-time earthquake locations and magnitudes are determined within 2-5 minutes of the event occurrence. AEIC maintains a 24/7 seismologist-on-duty schedule. Earthquake alarms are based on the real- time earthquake detections. Significant events are reviewed by the seismologist on duty within 30 minutes of the occurrence with information releases issued for significant events. This information is disseminated immediately via the AEIC website, ANSS website via QDDS submissions, through e-mail, cell phone and pager notifications, via fax broadcasts and recorded voice-mail messages. In addition, automatic regional moment tensors are determined for events with M>=4.0. This information is posted on the public website. ShakeMaps are being calculated in real-time with the information currently accessible via a password-protected website. AEIC is designing an alarm system targeted for the critical lifeline operations in Alaska. AEIC maintains an extensive computer network to provide adequate support for data processing and archival. For real-time processing, AEIC operates two identical, interoperable computer systems in parallel.