ANZA Seismic Network- From Monitoring to Science

NASA Astrophysics Data System (ADS)

Vernon, F.; Eakin, J.; Martynov, V.; Newman, R.; Offield, G.; Hindley, A.; Astiz, L.

2007-05-01

The ANZA Seismic Network (http:eqinfo.ucsd.edu) utilizes broadband and strong motion sensors with 24-bit dataloggers combined with real-time telemetry to monitor local and regional seismicity in southernmost California. The ANZA network provides real-time data to the IRIS DMC, California Integrated Seismic Network (CISN), other regional networks, and the Advanced National Seismic System (ANSS), in addition to providing near real-time information and monitoring to the greater San Diego community. Twelve high dynamic range broadband and strong motion sensors adjacent to the San Jacinto Fault zone contribute data for earthquake source studies and continue the monitoring of the seismic activity of the San Jacinto fault initiated 24 years ago. Five additional stations are located in the San Diego region with one more station on San Clemente Island. The ANZA network uses the advance wireless networking capabilities of the NSF High Performance Wireless Research and Education Network (http:hpwren.ucsd.edu) to provide the communication infrastructure for the real-time telemetry of Anza seismic stations. The ANZA network uses the Antelope data acquisition software. The combination of high quality hardware, communications, and software allow for an annual network uptime in excess of 99.5% with a median annual station real-time data return rate of 99.3%. Approximately 90,000 events, dominantly local sources but including regional and teleseismic events, comprise the ANZA network waveform database. All waveform data and event data are managed using the Datascope relational database. The ANZA network data has been used in a variety of scientific research including detailed structure of the San Jacinto Fault Zone, earthquake source physics, spatial and temporal studies of aftershocks, array studies of teleseismic body waves, and array studies on the source of microseisms. To augment the location, detection, and high frequency observations of the seismic source spectrum from local

Application of Neutral Networks to Seismic Signal Discrimination

DTIC Science & Technology

1993-05-15

AD-A276 626 PL-TR-93-2154 Application of Neural Networks to Seismic Signal Discrimination James A. Cercone V. Shane Foster W. Mike Clark Larry... Networks to Seismic Signal Discrimination PE 61101E PR 1DMO TA DA WU AA .AUTHOR(S) Stephen Goodman John Martin C James A. Cercone Don J. Smith G...of Technology Applications of Neural Networks to Seismic Classification project. The first year of research focused on identification and collection

Automatic Seismic-Event Classification with Convolutional Neural Networks.

NASA Astrophysics Data System (ADS)

Bueno Rodriguez, A.; Titos Luzón, M.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

2017-12-01

Active volcanoes exhibit a wide range of seismic signals, providing vast amounts of unlabelled volcano-seismic data that can be analyzed through the lens of artificial intelligence. However, obtaining high-quality labelled data is time-consuming and expensive. Deep neural networks can process data in their raw form, compute high-level features and provide a better representation of the input data distribution. These systems can be deployed to classify seismic data at scale, enhance current early-warning systems and build extensive seismic catalogs. In this research, we aim to classify spectrograms from seven different seismic events registered at "Volcán de Fuego" (Colima, Mexico), during four eruptive periods. Our approach is based on convolutional neural networks (CNNs), a sub-type of deep neural networks that can exploit grid structure from the data. Volcano-seismic signals can be mapped into a grid-like structure using the spectrogram: a representation of the temporal evolution in terms of time and frequency. Spectrograms were computed from the data using Hamming windows with 4 seconds length, 2.5 seconds overlapping and 128 points FFT resolution. Results are compared to deep neural networks, random forest and SVMs. Experiments show that CNNs can exploit temporal and frequency information, attaining a classification accuracy of 93%, similar to deep networks 91% but outperforming SVM and random forest. These results empirically show that CNNs are powerful models to classify a wide range of volcano-seismic signals, and achieve good generalization. Furthermore, volcano-seismic spectrograms contains useful discriminative information for the CNN, as higher layers of the network combine high-level features computed for each frequency band, helping to detect simultaneous events in time. Being at the intersection of deep learning and geophysics, this research enables future studies of how CNNs can be used in volcano monitoring to accurately determine the detection and

The Budget Guide to Seismic Network Management

NASA Astrophysics Data System (ADS)

Hagerty, M. T.; Ebel, J. E.

2007-05-01

Regardless of their size, there are certain tasks that all seismic networks must perform, including data collection and processing, earthquake location, information dissemination, and quality control. Small seismic networks are unlikely to possess the resources -- manpower and money -- required to do much in-house development. Fortunately, there are a lot of free or inexpensive software solutions available that are able to perform many of the required tasks. Often the available solutions are all-in-one turnkey packages designed and developed for much larger seismic networks, and the cost of adapting them to a smaller network must be weighed against the ease with which other, non-seismic software can be adapted to the same task. We describe here the software and hardware choices we have made for the New England Seismic Network (NESN), a sparse regional seismic network responsible for monitoring and reporting all seismicity within the New England region in the northeastern U.S. We have chosen to use a cost-effective approach to monitoring using free, off-the-shelf solutions where available (e.g., Earthworm, HYP2000) and modifying freeware solutions when it is easier than trying to adapt a large, complicated package. We have selected for use software that is: free, likely to receive continued support from the seismic or, preferably, larger internet community, and modular. Modularity is key to our design because it ensures that if one component of our processing system becomes obsolete, we can insert a suitable replacement with few modifications to the other modules. Our automated event detection, identification and location system is based on a wavelet transform analysis of station data that arrive continuously via TCP/IP transmission over the internet. Our system for interactive analyst review of seismic events and remote system monitoring utilizes a combination of Earthworm modules, Perl cgi-bin scripts, Java, and native Unix commands and can now be carried out via

Improved Seismic Acquisition System and Data Processing for the Italian National Seismic Network

NASA Astrophysics Data System (ADS)

Badiali, L.; Marcocci, C.; Mele, F.; Piscini, A.

2001-12-01

A new system for acquiring and processing digital signals has been developed in the last few years at the Istituto Nazionale di Geofisica e Vulcanologia (INGV). The system makes extensive use of the internet communication protocol standards such as TCP and UDP which are used as the transport highway inside the Italian network, and possibly in a near future outside, to share or redirect data among processes. The Italian National Seismic Network has been working for about 18 years equipped with vertical short period seismometers and transmitting through analog lines, to the computer center in Rome. We are now concentrating our efforts on speeding the migration towards a fully digital network based on about 150 stations equipped with either broad band or 5 seconds sensors connected to the data center partly through wired digital communication and partly through satellite digital communication. The overall process is layered through intranet and/or internet. Every layer gathers data in a simple format and provides data in a processed format, ready to be distributed towards the next layer. The lowest level acquires seismic data (raw waveforms) coming from the remote stations. It handshakes, checks and sends data in LAN or WAN according to a distribution list where other machines with their programs are waiting for. At the next level there are the picking procedures, or "pickers", on a per instrument basis, looking for phases. A picker spreads phases, again through the LAN or WAN and according to a distribution list, to one or more waiting locating machines tuned to generate a seismic event. The event locating procedure itself, the higher level in this stack, can exchange information with other similar procedures. Such a layered and distributed structure with nearby targets allows other seismic networks to join the processing and data collection of the same ongoing event, creating a virtual network larger than the original one. At present we plan to cooperate with other

Community Seismic Network (CSN)

NASA Astrophysics Data System (ADS)

Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Chandy, M.; Krause, A.

2010-12-01

In collaboration with computer science and earthquake engineering, we are developing a dense network of low-cost accelerometers that send their data via the Internet to a cloud-based center. The goal is to make block-by-block measurements of ground shaking in urban areas, which will provide emergency response information in the case of large earthquakes, and an unprecedented high-frequency seismic array to study structure and the earthquake process with moderate shaking. When deployed in high-rise buildings they can be used to monitor the state of health of the structure. The sensors are capable of a resolution of approximately 80 micro-g, connect via USB ports to desktop computers, and cost about $100 each. The network will adapt to its environment by using network-wide machine learning to adjust the picking sensitivity. We are also looking into using other motion sensing devices such as cell phones. For a pilot project, we plan to deploy more than 1000 sensors in the greater Pasadena area. The system is easily adaptable to other seismically vulnerable urban areas.

Introduction of digital object identifiers (DOI) for seismic networks

NASA Astrophysics Data System (ADS)

Evans, Peter; Strollo, Angelo; Clark, Adam; Ahern, Tim; Newman, Rob; Clinton, John; Pequegnat, Catherine; Pedersen, Helle

2015-04-01

Proper attribution for scientific source data is important in promoting transparency and recognising the role of data providers in science. Data sets such as those produced by seismic networks now need to be citable and permanently locatable for research users. Recently the EIDA and IRIS-DMC communities have worked together on development of methods for generation, maintenance and promotion of persistent identifiers for seismic networks. This resulted in a 2014 Recommendation by the International Federation of Digital Seismograph Networks (FDSN) on the use of Digital Object Identifiers (DOI) for seismic networks. These can be cited equivalently to scientific papers, and tools such as DataCite allow the tracking of citations to these datasets. The GEOFON, IRIS and RESIF data centres have now begun to roll-out of these seismic network DOIs. This has involved working with principal investigators to prepare metadata consistent with the FDSN recommendation, preparation of landing pages, and changes to the web sites to promote DOIs where available. This has involved preparing improved descriptions of the data (metadata) and clarifying how individuals and institutions should best be recognised for their contributions to making the data available. We illustrate this process for a few representative networks. We will be in contact with additional network operators to help them establish DOIs for their networks in future.

Romanian Educational Seismic Network Project

NASA Astrophysics Data System (ADS)

Tataru, Dragos; Ionescu, Constantin; Zaharia, Bogdan; Grecu, Bogdan; Tibu, Speranta; Popa, Mihaela; Borleanu, Felix; Toma, Dragos; Brisan, Nicoleta; Georgescu, Emil-Sever; Dobre, Daniela; Dragomir, Claudiu-Sorin

2013-04-01

Romania is one of the most active seismic countries in Europe, with more than 500 earthquakes occurring every year. The seismic hazard of Romania is relatively high and thus understanding the earthquake phenomena and their effects at the earth surface represents an important step toward the education of population in earthquake affected regions of the country and aims to raise the awareness about the earthquake risk and possible mitigation actions. In this direction, the first national educational project in the field of seismology has recently started in Romania: the ROmanian EDUcational SEISmic NETwork (ROEDUSEIS-NET) project. It involves four partners: the National Institute for Earth Physics as coordinator, the National Institute for Research and Development in Construction, Urban Planning and Sustainable Spatial Development " URBAN - INCERC" Bucharest, the Babeş-Bolyai University (Faculty of Environmental Sciences and Engineering) and the software firm "BETA Software". The project has many educational, scientific and social goals. The main educational objectives are: training students and teachers in the analysis and interpretation of seismological data, preparing of several comprehensive educational materials, designing and testing didactic activities using informatics and web-oriented tools. The scientific objective is to introduce into schools the use of advanced instruments and experimental methods that are usually restricted to research laboratories, with the main product being the creation of an earthquake waveform archive. Thus a large amount of such data will be used by students and teachers for educational purposes. For the social objectives, the project represents an effective instrument for informing and creating an awareness of the seismic risk, for experimentation into the efficacy of scientific communication, and for an increase in the direct involvement of schools and the general public. A network of nine seismic stations with SEP seismometers

Southern Appalachian Regional Seismic Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M.

1994-08-01

The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even withmore » its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.« less

Puerto Rico Strong Motion Seismic Network

NASA Astrophysics Data System (ADS)

Huerta-Lopez, C. I.; Martínez-Cruzado, J. A.; Martínez-Pagan, J.; Santana-Torres, E. X.; Torres-O, D. M.

2014-12-01

The Puerto Rico Strong Motion Seismic Network is currently in charge of the operation of: (i) free-field (ff) strong motion stations, (ii) instrumented structures (STR) (Dams, Bridges, Buildings), and (iii) the data acquisition/monitoring and analysis of earthquakes considered strong from the point of view of their intensity and magnitude. All these instruments are deployed in the Puerto Rico Island (PRI), US-, and British-Virgin Islands (BVI), and Dominican Republic (DR). The Puerto Rico Island and the Caribbean region have high potential to be affected by earthquakes that could be catastrophic for the area. The Puerto Rico Strong Motion Seismic Network (actually Puerto Rico Strong Motion Program, PRSMP) has grown since 1970's from 7 ff strong motion stations and one instrumented building with analog accelerographs to 111 ff strong motion stations and 16 instrumented buildings with digital accelerographs: PRI: 88 ff, 16 STR., DR: 13 ff, BVI: 5 ff, 2 STR collecting data via IP (internet), DU (telephone), and stand alone stations The current stage of the PRSMP seismic network, the analysis of moderate earthquakes that were recorded and/or occurred on the island, results of the intensity distribution of selected earthquakes, as well as results of dynamic parameter identification of some of the instrumented structures are here presented.

Optimizing Seismic Monitoring Networks for EGS and Conventional Geothermal Projects

NASA Astrophysics Data System (ADS)

Kraft, Toni; Herrmann, Marcus; Bethmann, Falko; Stefan, Wiemer

2013-04-01

In the past several years, geological energy technologies receive growing attention and have been initiated in or close to urban areas. Some of these technologies involve injecting fluids into the subsurface (e.g., oil and gas development, waste disposal, and geothermal energy development) and have been found or suspected to cause small to moderate sized earthquakes. These earthquakes, which may have gone unnoticed in the past when they occurred in remote sparsely populated areas, are now posing a considerable risk for the public acceptance of these technologies in urban areas. The permanent termination of the EGS project in Basel, Switzerland after a number of induced ML~3 (minor) earthquakes in 2006 is one prominent example. It is therefore essential for the future development and success of these geological energy technologies to develop strategies for managing induced seismicity and keeping the size of induced earthquakes at a level that is acceptable to all stakeholders. Most guidelines and recommendations on induced seismicity published since the 1970ies conclude that an indispensable component of such a strategy is the establishment of seismic monitoring in an early stage of a project. This is because an appropriate seismic monitoring is the only way to detect and locate induced microearthquakes with sufficient certainty to develop an understanding of the seismic and geomechanical response of the reservoir to the geotechnical operation. In addition, seismic monitoring lays the foundation for the establishment of advanced traffic light systems and is therefore an important confidence building measure towards the local population and authorities. We have developed an optimization algorithm for seismic monitoring networks in urban areas that allows to design and evaluate seismic network geometries for arbitrary geotechnical operation layouts. The algorithm is based on the D-optimal experimental design that aims to minimize the error ellipsoid of the linearized

Sensing network for electromagnetic fields generated by seismic activities

NASA Astrophysics Data System (ADS)

Gershenzon, Naum I.; Bambakidis, Gust; Ternovskiy, Igor V.

2014-06-01

The sensors network is becoming prolific and play now increasingly more important role in acquiring and processing information. Cyber-Physical Systems are focusing on investigation of integrated systems that includes sensing, networking, and computations. The physics of the seismic measurement and electromagnetic field measurement requires special consideration how to design electromagnetic field measurement networks for both research and detection earthquakes and explosions along with the seismic measurement networks. In addition, the electromagnetic sensor network itself could be designed and deployed, as a research tool with great deal of flexibility, the placement of the measuring nodes must be design based on systematic analysis of the seismic-electromagnetic interaction. In this article, we review the observations of the co-seismic electromagnetic field generated by earthquakes and man-made sources such as vibrations and explosions. The theoretical investigation allows the distribution of sensor nodes to be optimized and could be used to support existing geological networks. The placement of sensor nodes have to be determined based on physics of electromagnetic field distribution above the ground level. The results of theoretical investigations of seismo-electromagnetic phenomena are considered in Section I. First, we compare the relative contribution of various types of mechano-electromagnetic mechanisms and then analyze in detail the calculation of electromagnetic fields generated by piezomagnetic and electrokinetic effects.

Site characterization of the national seismic network of Italy

NASA Astrophysics Data System (ADS)

Bordoni, Paola; Pacor, Francesca; Cultrera, Giovanna; Casale, Paolo; Cara, Fabrizio; Di Giulio, Giuseppe; Famiani, Daniela; Ladina, Chiara; PIschiutta, Marta; Quintiliani, Matteo

2017-04-01

The national seismic network of Italy (Rete Sismica Nazionale, RSN) run by Istituto Nazionale di Geofisica e Vulcanologia (INGV) consists of more than 400 seismic stations connected in real time to the institute data center in order to locate earthquakes for civil defense purposes. A critical issue in the performance of a network is the characterization of site condition at the recording stations. Recently INGV has started addressing this subject through the revision of all available geological and geophysical data, the acquisition of new information by means of ad-hoc field measurements and the analysis of seismic waveforms. The main effort is towards building a database, integrated with the other INGV infrastructures, designed to archive homogeneous parameters through the seismic network useful for a complete site characterization, including housing, geological, seismological and geotechnical features as well as the site class according to the European and Italian building codes. Here we present the ongoing INGV activities.

OGS improvements in 2012 in running the Northeastern Italy Seismic Network: the Ferrara VBB borehole seismic station

NASA Astrophysics Data System (ADS)

Pesaresi, Damiano; Romanelli, Marco; Barnaba, Carla; Bragato, Pier Luigi; Durì, Giorgio

2013-04-01

The Centro di Ricerche Sismologiche (CRS, Seismological Research Center) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data center in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of about 100 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of Northeastern Italy. The southwestern edge of the OGS seismic network stands on the Po alluvial basin: earthquake localization and characterization in this area is affected by the presence of soft alluvial deposits. OGS ha already experience in running a local seismic network in high noise conditions making use of borehole installations in the case of the micro-seismicity monitoring of a local gas storage site for a private company. Following the ML=5.9 earthquake that struck the Emilia region around Ferrara in Northern Italy on May 20, 2012 at 02:03:53 UTC, a cooperation of Istituto Nazionale di Geofisica e Vulcanologia, OGS, the Comune di Ferrara and the University of Ferrara lead to the reinstallation of a previously existing very broad band (VBB) borehole seismic station in Ferrara. The aim of the OGS intervention was on one hand to extend its real time seismic monitoring capabilities toward South-West, including Ferrara and its surroundings, and on the other hand to evaluate the seismic response at the site. We will describe improvements in running the Northeastern Italy Seismic Network, including details of the Ferrara VBB

Recent Progress of Seismic Observation Networks in Japan

NASA Astrophysics Data System (ADS)

Okada, Y.

2013-04-01

Before the occurrence of disastrous Kobe earthquake in 1995, the number of high sensitivity seismograph stations operated in Japan was nearly 550 and was concentrated in the Kanto and Tokai districts, central Japan. In the wake of the Kobe earthquake, Japanese government has newly established the Headquarters for Earthquake Research Promotion and started the reconstruction of seismic networks to evenly cover the whole Japan. The basic network is composed of three seismographs, i.e. high sensitivity seismograph (Hi-net), broadband seismograph (F-net), and strong motion seismograph (K-NET). A large majority of Hi-net stations are also equipped with a pair of strong motion sensors at the bottom of borehole and the ground surface (KiK-net). A plenty of high quality data obtained from these networks are circulated at once and is producing several new seismological findings as well as providing the basis for the Earthquake Early Warning system. In March 11, 2011, "Off the Pacific coast of Tohoku Earthquake" was generated with magnitude 9.0, which records the largest in the history of seismic observation in Japan. The greatest disaster on record was brought by huge tsunami with nearly 20 thousand killed or missing people. We are again noticed that seismic observation system is quite poor in the oceanic region compared to the richness of it in the inland region. In 2012, NIED has started the construction of ocean bottom seismic and tsunami observation network along the Japan Trench. It is planned to layout 154 stations with an average spacing of 30km, each of which is equipped with an accelerometer for seismic observation and a water pressure gauge for tsunami observation. We are expecting that more rapid and accurate warning of earthquake and tsunami becomes possible by this observing network.

Detection capability of the IMS seismic network based on ambient seismic noise measurements

NASA Astrophysics Data System (ADS)

Gaebler, Peter J.; Ceranna, Lars

2016-04-01

All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection threshold can be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

Network Optimization for Induced Seismicity Monitoring in Urban Areas

NASA Astrophysics Data System (ADS)

Kraft, T.; Husen, S.; Wiemer, S.

2012-12-01

With the global challenge to satisfy an increasing demand for energy, geological energy technologies receive growing attention and have been initiated in or close to urban areas in the past several years. Some of these technologies involve injecting fluids into the subsurface (e.g., oil and gas development, waste disposal, and geothermal energy development) and have been found or suspected to cause small to moderate sized earthquakes. These earthquakes, which may have gone unnoticed in the past when they occurred in remote sparsely populated areas, are now posing a considerable risk for the public acceptance of these technologies in urban areas. The permanent termination of the EGS project in Basel, Switzerland after a number of induced ML~3 (minor) earthquakes in 2006 is one prominent example. It is therefore essential to the future development and success of these geological energy technologies to develop strategies for managing induced seismicity and keeping the size of induced earthquake at a level that is acceptable to all stakeholders. Most guidelines and recommendations on induced seismicity published since the 1970ies conclude that an indispensable component of such a strategy is the establishment of seismic monitoring in an early stage of a project. This is because an appropriate seismic monitoring is the only way to detect and locate induced microearthquakes with sufficient certainty to develop an understanding of the seismic and geomechanical response of the reservoir to the geotechnical operation. In addition, seismic monitoring lays the foundation for the establishment of advanced traffic light systems and is therefore an important confidence building measure towards the local population and authorities. We have developed an optimization algorithm for seismic monitoring networks in urban areas that allows to design and evaluate seismic network geometries for arbitrary geotechnical operation layouts. The algorithm is based on the D-optimal experimental

Cloud Computing Services for Seismic Networks

NASA Astrophysics Data System (ADS)

Olson, Michael

This thesis describes a compositional framework for developing situation awareness applications: applications that provide ongoing information about a user's changing environment. The thesis describes how the framework is used to develop a situation awareness application for earthquakes. The applications are implemented as Cloud computing services connected to sensors and actuators. The architecture and design of the Cloud services are described and measurements of performance metrics are provided. The thesis includes results of experiments on earthquake monitoring conducted over a year. The applications developed by the framework are (1) the CSN---the Community Seismic Network---which uses relatively low-cost sensors deployed by members of the community, and (2) SAF---the Situation Awareness Framework---which integrates data from multiple sources, including the CSN, CISN---the California Integrated Seismic Network, a network consisting of high-quality seismometers deployed carefully by professionals in the CISN organization and spread across Southern California---and prototypes of multi-sensor platforms that include carbon monoxide, methane, dust and radiation sensors.

The Quake-Catcher Network: An Innovative Community-Based Seismic Network

NASA Astrophysics Data System (ADS)

Saltzman, J.; Cochran, E. S.; Lawrence, J. F.; Christensen, C. M.

2009-12-01

The Quake-Catcher Network (QCN) is a volunteer computing seismic network that engages citizen scientists, teachers, and museums to participate in the detection of earthquakes. In less than two years, the network has grown to over 1000 participants globally and continues to expand. QCN utilizes Micro-Electro-Mechanical System (MEMS) accelerometers, in laptops and external to desktop computers, to detect moderate to large earthquakes. One goal of the network is to involve K-12 classrooms and museums by providing sensors and software to introduce participants to seismology and community-based scientific data collection. The Quake-Catcher Network provides a unique opportunity to engage participants directly in the scientific process, through hands-on activities that link activities and outcomes to their daily lives. Partnerships with teachers and museum staff are critical to growth of the Quake Catcher Network. Each participating institution receives a MEMS accelerometer to connect, via USB, to a computer that can be used for hands-on activities and to record earthquakes through a distributed computing system. We developed interactive software (QCNLive) that allows participants to view sensor readings in real time. Participants can also record earthquakes and download earthquake data that was collected by their sensor or other QCN sensors. The Quake-Catcher Network combines research and outreach to improve seismic networks and increase awareness and participation in science-based research in K-12 schools.

OGS improvements in 2012 in running the North-eastern Italy Seismic Network: the Ferrara VBB borehole seismic station

NASA Astrophysics Data System (ADS)

Pesaresi, D.; Romanelli, M.; Barnaba, C.; Bragato, P. L.; Durì, G.

2014-07-01

The Centro di Ricerche Sismologiche (CRS, Seismological Research Centre) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the North-eastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data centre in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of about 100 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of North-eastern Italy. The south-western edge of the OGS seismic network (Fig. 1) stands on the Po alluvial basin: earthquake localization and characterization in this area is affected by the presence of soft alluvial deposits. OGS ha already experience in running a local seismic network in high noise conditions making use of borehole installations in the case of the micro-seismicity monitoring of a local gas storage site for a private company. Following the ML = 5.9 earthquake that struck the Emilia region around Ferrara in Northern Italy on 20 May 2012 at 02:03:53 UTC, a cooperation of Istituto Nazionale di Geofisica e Vulcanologia, OGS, the Comune di Ferrara and the University of Ferrara lead to the reinstallation of a previously existing very broad band (VBB) borehole seismic station in Ferrara. The aim of the OGS intervention was on one hand to extend its real time seismic monitoring capabilities toward South-West, including Ferrara and its surroundings, and on the other hand to evaluate the seismic response at the site. We will describe improvements in running the North-eastern Italy Seismic Network, including details of

Specification goals for a Mars seismic network

NASA Technical Reports Server (NTRS)

Davis, Paul M.

1990-01-01

A seismic network on Mars should have enough stations (e.g., 24) to characterize the seismicity of the planet for comparison with a diversity of structural features; be comprised of low noise stations, preferably underground, 3 to 4 orders of magnitude more sensitive than those used on Viking; record over a sufficient band-width (DC-30 Hz) to detect micro-earthquakes to normal modes; and record for a sufficient duration (10 years) and data rate (10(exp 8) Mb/day/station) to obtain a data set comparable to that from the Apollo mission to the Moon so that locations of major internal boundaries can be inferred, such as those in the Earth, i.e., crust - lithosphere - asthenosphere - upper - lower phase transitions - outer - inner core. The proposed Mars Global Network Mission provides an opportunity to sense the dynamics and probe the interior of the planet. The seismic objectives, the availability of the instrumentation and trade-offs to meet them are discussed.

The Great Maule earthquake: seismicity prior to and after the main shock from amphibious seismic networks

NASA Astrophysics Data System (ADS)

Lieser, K.; Arroyo, I. G.; Grevemeyer, I.; Flueh, E. R.; Lange, D.; Tilmann, F. J.

2013-12-01

The Chilean subduction zone is among the seismically most active plate boundaries in the world and its coastal ranges suffer from a magnitude 8 or larger megathrust earthquake every 10-20 years. The Constitución-Concepción or Maule segment in central Chile between ~35.5°S and 37°S was considered to be a mature seismic gap, rupturing last in 1835 and being seismically quiet without any magnitude 4.5 or larger earthquakes reported in global catalogues. It is located to the north of the nucleation area of the 1960 magnitude 9.5 Valdivia earthquake and to the south of the 1928 magnitude 8 Talca earthquake. On 27 February 2010 this segment ruptured in a Mw=8.8 earthquake, nucleating near 36°S and affecting a 500-600 km long segment of the margin between 34°S and 38.5°S. Aftershocks occurred along a roughly 600 km long portion of the central Chilean margin, most of them offshore. Therefore, a network of 30 ocean-bottom-seismometers was deployed in the northern portion of the rupture area for a three month period, recording local offshore aftershocks between 20 September 2010 and 25 December 2010. In addition, data of a network consisting of 33 landstations of the GeoForschungsZentrum Potsdam were included into the network, providing an ideal coverage of both the rupture plane and areas affected by post-seismic slip as deduced from geodetic data. Aftershock locations are based on automatically detected P wave onsets and a 2.5D velocity model of the combined on- and offshore network. Aftershock seismicity analysis in the northern part of the survey area reveals a well resolved seismically active splay fault in the accretionary prism of the Chilean forearc. Our findings imply that in the northernmost part of the rupture zone, co-seismic slip most likely propagated along the splay fault and not the subduction thrust fault. In addition, the updip limit of aftershocks along the plate interface can be verified to about 40 km landwards from the deformation front. Prior to

Seismic signal auto-detecing from different features by using Convolutional Neural Network

NASA Astrophysics Data System (ADS)

Huang, Y.; Zhou, Y.; Yue, H.; Zhou, S.

2017-12-01

We try Convolutional Neural Network to detect some features of seismic data and compare their efficience. The features include whether a signal is seismic signal or noise and the arrival time of P and S phase and each feature correspond to a Convolutional Neural Network. We first use traditional STA/LTA to recongnize some events and then use templete matching to find more events as training set for the Neural Network. To make the training set more various, we add some noise to the seismic data and make some synthetic seismic data and noise. The 3-component raw signal and time-frequancy ananlyze are used as the input data for our neural network. Our Training is performed on GPUs to achieve efficient convergence. Our method improved the precision in comparison with STA/LTA and template matching. We will move to recurrent neural network to see if this kind network is better in detect P and S phase.

Studies of infrasound propagation using the USArray seismic network (Invited)

NASA Astrophysics Data System (ADS)

Hedlin, M. A.; Degroot-Hedlin, C. D.; Walker, K. T.

2010-12-01

Although there are currently ~ 100 infrasound arrays worldwide, more than ever before, the station density is still insufficient to provide validation for detailed propagation modeling. Much structure in the atmosphere is short-lived and occurs at spatial scales much smaller than the average distance between infrasound stations. Relatively large infrasound signals can be observed on seismic channels due to coupling at the Earth's surface. Recent research, using data from the 70-km spaced 400-station USArray and other seismic network deployments, has shown the value of dense seismic network data for filling in the gaps between infrasound arrays. The dense sampling of the infrasound wavefield has allowed us to observe complete travel-time branches of infrasound signals and shed more light on the nature of infrasound propagation. We present early results from our studies of impulsive atmospheric sources, such as series of UTTR rocket motor detonations in Utah. The Utah blasts have been well recorded by USArray seismic stations and infrasound arrays in Nevada and Washington State. Recordings of seismic signals from a series of six events in 2007 are used to pinpoint the shot times to < 1 second. Variations in the acoustic branches and signal arrival times at the arrays are used to probe variations in atmospheric structure. Although we currently use coupled signals we anticipate studying dense acoustic network recordings as the USArray is currently being upgraded with infrasound microphones. These new sensors will allow us to make semi-continental scale network recordings of infrasound signals free of concerns about how the signals observed on seismic channels were modified when being coupled to seismic.

Seismic Velocity Measurements at Expanded Seismic Network Sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woolery, Edward W; Wang, Zhenming

2005-01-01

Structures at the Paducah Gaseous Diffusion Plant (PGDP), as well as at other locations in the northern Jackson Purchase of western Kentucky may be subjected to large far-field earthquake ground motions from the New Madrid seismic zone, as well as those from small and moderate-sized local events. The resultant ground motion a particular structure is exposed from such event will be a consequence of the earthquake magnitude, the structures' proximity to the event, and the dynamic and geometrical characteristics of the thick soils upon which they are, of necessity, constructed. This investigation evaluated the latter. Downhole and surface (i.e., refractionmore » and reflection) seismic velocity data were collected at the Kentucky Seismic and Strong-Motion Network expansion sites in the vicinity of the Paducah Gaseous Diffusion Plant (PGDP) to define the dynamic properties of the deep sediment overburden that can produce modifying effects on earthquake waves. These effects are manifested as modifications of the earthquake waves' amplitude, frequency, and duration. Each of these three ground motion manifestations is also fundamental to the assessment of secondary earthquake engineering hazards such as liquefaction.« less

The Mexican Seismic Network (Red Sísmica Mexicana)

NASA Astrophysics Data System (ADS)

Valdes-Gonzales, C. M.; Arreola-Manzano, J.; Castelan-Pescina, G.; Alonso-Rivera, P.; Saldivar-Rangel, M. A.; Rodriguez-Arteaga, O. O.; Lopez-Lena-Villasana, R.

2014-12-01

The Mexican Seismic Network (Red Sísmica Mexicana) was created to give sufficient information and opportune to make decisions in order to mitigate seismic and tsunami risk. This was a Mexican government initiative headed by CENAPRED (National Disaster Prevention Center) who made an effort to integrated academic institutions and civil agencies to work together through a collaboration agreement. This network is supported by Universidad National Autónoma de México (UNAM) and its seismic networks (Broad Band and Strong Motion), the Centro de Instrumentación y Registro Sismico (CIRES) with its Earthquake Early Warning System that covers the Guerrero Gap and Oaxaca earthquakes, The Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) with the support of its expertise in tsunami observation and the Secretaria de Marina (SEMAR) to monitor the sea level and operate the Mexican Tsunami Warning Center. The institutions involved in this scope have the compromise to interchange and share the data and advice to the Civil Protection authorities.

Automatic Classification of volcano-seismic events based on Deep Neural Networks.

NASA Astrophysics Data System (ADS)

Titos Luzón, M.; Bueno Rodriguez, A.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

2017-12-01

Seismic monitoring of active volcanoes is a popular remote sensing technique to detect seismic activity, often associated to energy exchanges between the volcano and the environment. As a result, seismographs register a wide range of volcano-seismic signals that reflect the nature and underlying physics of volcanic processes. Machine learning and signal processing techniques provide an appropriate framework to analyze such data. In this research, we propose a new classification framework for seismic events based on deep neural networks. Deep neural networks are composed by multiple processing layers, and can discover intrinsic patterns from the data itself. Internal parameters can be initialized using a greedy unsupervised pre-training stage, leading to an efficient training of fully connected architectures. We aim to determine the robustness of these architectures as classifiers of seven different types of seismic events recorded at "Volcán de Fuego" (Colima, Mexico). Two deep neural networks with different pre-training strategies are studied: stacked denoising autoencoder and deep belief networks. Results are compared to existing machine learning algorithms (SVM, Random Forest, Multilayer Perceptron). We used 5 LPC coefficients over three non-overlapping segments as training features in order to characterize temporal evolution, avoid redundancy and encode the signal, regardless of its duration. Experimental results show that deep architectures can classify seismic events with higher accuracy than classical algorithms, attaining up to 92% recognition accuracy. Pre-training initialization helps these models to detect events that occur simultaneously in time (such explosions and rockfalls), increase robustness against noisy inputs, and provide better generalization. These results demonstrate deep neural networks are robust classifiers, and can be deployed in real-environments to monitor the seismicity of restless volcanoes.

MyShake: Initial Observations from a Global Smartphone Seismic Network

NASA Astrophysics Data System (ADS)

Kong, Q.; Allen, R. M.; Schreier, L.

2016-12-01

MyShake is a global smartphone seismic network that harnesses the power of crowdsourcing. It has two component: an android application running on the personal smartphones to detect earthquake-like motion, and a network detection algorithm to aggregate results from multiple smartphones to detect earthquakes. The MyShake application was released to the public on Feb 12th 2016. Within the first 5 months, there are more than 200 earthquakes recorded by the smartphones all over the world, including events in Chile, Argentina, Mexico, Morocco, Greece, Nepal, New Zealand, Taiwan, Japan, and across North America. In this presentation, we will show the waveforms we recorded from the smartphones for different earthquakes, and the evidences for using this data as a supplementary to the current earthquake early warning system. We will also show the performance of MyShake system during the some earthquakes in US. In short, MyShake smartphone seismic network can be a nice complementary system to the current traditional seismic network, at the same time, it can be a standalone system in places where few seismic stations were installed to reduce the earthquake hazards.

Caltech/USGS Southern California Seismic Network: Recent Developments

NASA Astrophysics Data System (ADS)

Bhadha, R.; Chen, S.; Crummey, J.; Hauksson, E.; Solanki, K.; Thomas, V. I.; Watkins, M.; Yip, R.; Yu, E.; Given, D.; Peats, R.; Schwarz, S.

2010-12-01

The SCSN is the modern digital ground motion seismic network in Southern California and performs the following tasks: 1) Operates remote seismic stations and the central data processing systems in Pasadena; 2) Generates and reports real-time products including location, magnitude, ShakeMap, and others; 3) Responds to FEMA, CalEMA, media, and public inquiries about earthquakes; 4) Manages the production, archival, and distribution of waveforms, phase picks, and other data at the SCEDC; 5) Contributes to development and maintenance of the ANSS Quake Monitoring System (AQMS) software to add new features and improve robustness; 6) Supports the deployment of AQMS to other ANSS member regional seismic networks. The public regularly accesses the CISN, SCSN, and SCEDC web pages for up-to-date quake info and more than 230,000 users subscribe to the Electronic Notification System (ENS) which sends rapid notifications via email and cell phones. We distribute our products via Internet (EIDS), email, and paging, to USGS in Reston and Golden, FEMA, CalEMA, local governments, partner members, and other subscribers. We have developed CISN Display and provide ShakeCast for customers who require real-time earthquake information. The SCSN also exchanges waveform, phase pick, and amplitude data in real-time with several other partner networks, including Menlo Park, UCB, UNR, Anza network, the Tsunami Warning Centers, IRIS, and the NEIC. We operate a number of 24/7 on-call rotations to provide quick response to verify seismic events as well as addressing systems and telemetry issues. As part of our goals to improve quality, robustness, and coverage, some of our recent efforts include: 1) Converting the digital stations in the network to Q330 dataloggers; 2) Developing command and control capabilities such as automated mass re-centering; 3) Migration from serial to Ethernet communications; 4) Clustering of data acquisition servers for fail-over to improve data availability; 5) Use of

Scientific Rationale and Requirements for a Global Seismic Network on Mars

NASA Technical Reports Server (NTRS)

Solomon, Sean C.; Anderson, Don L.; Banerdt, W. Bruce; Butler, Rhett G.; Davis, Paul M.; Duennebier, Frederick K.; Nakamura, Yosio; Okal, Emile A.; Phillips, Roger J.

1991-01-01

Following a brief overview of the mission concepts for a Mars Global Network Mission as of the time of the workshop, we present the principal scientific objectives to be achieved by a Mars seismic network. We review the lessons for extraterrestrial seismology gained from experience to date on the Moon and on Mars. An important unknown on Mars is the expected rate of seismicity, but theoretical expectations and extrapolation from lunar experience both support the view that seismicity rates, wave propagation characteristics, and signal-to-noise ratios are favorable to the collection of a scientifically rich dataset during the multiyear operation of a global seismic experiment. We discuss how particular types of seismic waves will provide the most useful information to address each of the scientific objectives, and this discussion provides the basis for a strategy for station siting. Finally, we define the necessary technical requirements for the seismic stations.

The improved broadband Real-Time Seismic Network in Romania

NASA Astrophysics Data System (ADS)

Neagoe, C.; Ionescu, C.

2009-04-01

Starting with 2002 the National Institute for Earth Physics (NIEP) has developed its real-time digital seismic network. This network consists of 96 seismic stations of which 48 broad band and short period stations and two seismic arrays are transmitted in real-time. The real time seismic stations are equipped with Quanterra Q330 and K2 digitizers, broadband seismometers (STS2, CMG40T, CMG 3ESP, CMG3T) and strong motions sensors Kinemetrics episensors (+/- 2g). SeedLink and AntelopeTM (installed on MARMOT) program packages are used for real-time (RT) data acquisition and exchange. The communication from digital seismic stations to the National Data Center in Bucharest is assured by 5 providers (GPRS, VPN, satellite communication, radio lease line and internet), which will assure the back-up communications lines. The processing centre runs BRTT's AntelopeTM 4.10 data acquisition and processing software on 2 workstations for real-time processing and post processing. The Antelope Real-Time System is also providing automatic event detection, arrival picking, event location and magnitude calculation. It provides graphical display and reporting within near-real-time after a local or regional event occurred. Also at the data center was implemented a system to collect macroseismic information using the internet on which macro seismic intensity maps are generated. In the near future at the data center will be install Seiscomp 3 data acquisition processing software on a workstation. The software will run in parallel with Antelope software as a back-up. The present network will be expanded in the near future. In the first half of 2009 NIEP will install 8 additional broad band stations in Romanian territory, which also will be transmitted to the data center in real time. The Romanian Seismic Network is permanently exchanging real -time waveform data with IRIS, ORFEUS and different European countries through internet. In Romania, magnitude and location of an earthquake are now

Internet-Based Solutions for a Secure and Efficient Seismic Network

NASA Astrophysics Data System (ADS)

Bhadha, R.; Black, M.; Bruton, C.; Hauksson, E.; Stubailo, I.; Watkins, M.; Alvarez, M.; Thomas, V.

2017-12-01

The Southern California Seismic Network (SCSN), operated by Caltech and USGS, leverages modern Internet-based computing technologies to provide timely earthquake early warning for damage reduction, event notification, ShakeMap, and other data products. Here we present recent and ongoing innovations in telemetry, security, cloud computing, virtualization, and data analysis that have allowed us to develop a network that runs securely and efficiently.Earthquake early warning systems must process seismic data within seconds of being recorded, and SCSN maintains a robust and resilient network of more than 350 digital strong motion and broadband seismic stations to achieve this goal. We have continued to improve the path diversity and fault tolerance within our network, and have also developed new tools for latency monitoring and archiving.Cyberattacks are in the news almost daily, and with most of our seismic data streams running over the Internet, it is only a matter of time before SCSN is targeted. To ensure system integrity and availability across our network, we have implemented strong security, including encryption and Virtual Private Networks (VPNs).SCSN operates its own data center at Caltech, but we have also installed real-time servers on Amazon Web Services (AWS), to provide an additional level of redundancy, and eventually to allow full off-site operations continuity for our network. Our AWS systems receive data from Caltech-based import servers and directly from field locations, and are able to process the seismic data, calculate earthquake locations and magnitudes, and distribute earthquake alerts, directly from the cloud.We have also begun a virtualization project at our Caltech data center, allowing us to serve data from Virtual Machines (VMs), making efficient use of high-performance hardware and increasing flexibility and scalability of our data processing systems.Finally, we have developed new monitoring of station average noise levels at most stations

Circuit-Detour Design and Implementation - Enhancing the Southern California's Seismic Network Reliability through Redundant Network Paths

NASA Astrophysics Data System (ADS)

Watkins, M.; Busby, R.; Rico, H.; Johnson, M.; Hauksson, E.

2003-12-01

We provide enhanced network robustness by apportioning redundant data communications paths for seismic stations in the field. By providing for more than one telemetry route, either physical or logical, network operators can improve availability of seismic data while experiencing occasional network outages, and also during the loss of key gateway interfaces such as a router or central processor. This is especially important for seismic stations in sparsely populated regions where a loss of a single site may result in a significant gap in the network's monitoring capability. A number of challenges arise in the application of a circuit-detour mechanism. One requirement is that it fits well within the existing framework of our real-time system processing. It is also necessary to craft a system that is not needlessly complex to maintain or implement, particularly during a crisis. The method that we use for circuit-detours does not require the reconfiguration of dataloggers or communications equipment in the field. Remote network configurations remain static, changes are only required at the central site. We have implemented standardized procedures to detour circuits on similar transport mediums, such as virtual circuits on the same leased line; as well as physically different communications pathways, such as a microwave link backed up by a leased line. The lessons learned from these improvements in reliability, and optimization efforts could be applied to other real-time seismic networks. A fundamental tenant of most seismic networks is that they are reliable and have a high percentage of real-time data availability. A reasonable way to achieve these expectations is to provide alternate means of delivering data to the central processing sites, with a simple method for utilizing these alternate paths.

Building an educational seismic network in Romanian schools

NASA Astrophysics Data System (ADS)

Zaharia, Bogdan; Tataru, Dragos; Grecu, Bogdan; Ionescu, Constantin; Bican-Brisan, Nicoleta; Neagoe, Cristian

2014-05-01

Understanding the earthquake phenomena and their effects is an important step toward the education of population and aims to raise the awareness about the earthquake risk and possible mitigation actions. In this sense, The Romanian Educational Seismic Network project represents an efficient communication tool, allowing teaching and learning about the earthquakes and seismic wave impact through experimental practices and educational activities. The seismic network consist of nine SEP seismometers installed in high-schools from the most important seismic areas (Vrancea, Banat, Făgăraş, Dobrogea), vulnerable cities (Bucharest, Iasi) or high populated places (Cluj, Sibiu, Timisoara, Zalău) and is coordinated by the National Institute of Earth Physics from Bucharest. Once installed, the seismic network is the starting point of activities for students through an e-learning platform. Some objectives are aimed: - To train students and teachers how to make analysis and interpretation of seismological data; - To make science more interesting for students; - To improve the participation rates in physical sciences for students; - To raise awareness of geoscience as a scientific discipline for pre-university students; - To promote the installation and effective use of educational seismographs and seismic data; - To reinforce and develop relationships between participating schools and research institutes; - To create an earthquake database this will be used by students and teachers for educational purposes. Different types of practical activities using educational seismometer, designed by researchers for students, are described in educational materials and in the web platform project. Also we encourage the teachers from the participating schools to share their experiences and produce new didactic tools for the classroom. This collaborative work could illustrate the conjugated efforts of researchers and teachers for a better education and awareness of the risk culture

The performance of the stations of the Romanian seismic network in monitoring the local seismic activity

NASA Astrophysics Data System (ADS)

Ardeleanu, Luminita Angela; Neagoe, Cristian

2014-05-01

The seismic survey of the territory of Romania is mainly performed by the national seismic network operated by the National Institute for Earth Physics of Bucharest. After successive developments and upgrades, the network consists at present of 123 permanent stations equipped with high quality digital instruments (Kinemetrics K2, Quantera Q330, Quantera Q330HR, PS6-24 and Basalt digitizers) - 102 real time and 20 off-line stations - which cover the whole territory of the country. All permanent stations are supplied with 3 component accelerometers (episenzor type), while the real time stations are in addition provided with broadband (CMG3ESP, CMG40T, KS2000, KS54000, KS2000, CMG3T, STS2) or short period (SH-1, S13, Mark l4c, Ranger, GS21, L22_VEL) velocity sensors. Several communication systems are currently used for the real time data transmission: an analog line in UHF band, a line through GPRS (General Packet Radio Service), a dedicated line through satellite, and a dedicated line provided by the Romanian Special Telecommunication Service. During the period January 1, 2006 - June 30, 2013, 5936 shallow depth seismic events - earthquakes and quarry blasts - with local magnitude ML ≥ 1.2 were localized on the Romanian territory, or in its immediate vicinity, using the records of the national seismic network; 1467 subcrustal earthquakes (depth ≥ 60 km) with magnitude ML ≥ 1.9 were also localized in the Vrancea region, at the bend of the Eastern Carpathians. The goal of the present study is to evaluate the individual contribution of the real time seismic stations to the monitoring of the local seismicity. The performance of each station is estimated by taking into consideration the fraction of events that are localised using the station records, compared to the total number of events of the catalogue, occurred during the time of station operation. Taking into account the nonuniform space distribution of earthquakes, the location of the site and the recovery

Monitoring Instrument Performance in Regional Broadband Seismic Network Using Ambient Seismic Noise

NASA Astrophysics Data System (ADS)

Ye, F.; Lyu, S.; Lin, J.

2017-12-01

In the past ten years, the number of seismic stations has increased significantly, and regional seismic networks with advanced technology have been gradually developed all over the world. The resulting broadband data help to improve the seismological research. It is important to monitor the performance of broadband instruments in a new network in a long period of time to ensure the accuracy of seismic records. Here, we propose a method that uses ambient noise data in the period range 5-25 s to monitor instrument performance and check data quality in situ. The method is based on an analysis of amplitude and phase index parameters calculated from pairwise cross-correlations of three stations, which provides multiple references for reliable error estimates. Index parameters calculated daily during a two-year observation period are evaluated to identify stations with instrument response errors in near real time. During data processing, initial instrument responses are used in place of available instrument responses to simulate instrument response errors, which are then used to verify our results. We also examine feasibility of the tailing noise using data from stations selected from USArray in different locations and analyze the possible instrumental errors resulting in time-shifts used to verify the method. Additionally, we show an application that effects of instrument response errors that experience pole-zeros variations on monitoring temporal variations in crustal properties appear statistically significant velocity perturbation larger than the standard deviation. The results indicate that monitoring seismic instrument performance helps eliminate data pollution before analysis begins.

Emergency seismic and CGPS networks: a first employment for the L'Aquila Mw 6.3 earthquake

NASA Astrophysics Data System (ADS)

Abruzzese, L.; Avallone, A.; Cecere, G.; Cattaneo, M.; Cardinale, V.; Castagnozzi, A.; Cogliano, R.; Criscuoli, F.; D'Agostino, N.; D'Ambrosio, C.; de Luca, G.; D'Anastasio, E.; Falco, L.; Flammia, V.; Migliari, F.; Minichiello, F.; Memmolo, A.; Monachesi, G.; Moschillo, R.; Pignone, M.; Pucillo, S.; Selvaggi, G.; Zarrilli, L.; Delladio, A.; Govoni, A.; Franceschi, D.; de Martin, M.; Moretti, M.

2009-12-01

During the last 2 years, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) developed an important real-time temporary seismic network infrastructure in order to densify the Italian National Seismic Network in epicentral areas thus enhancing the localization of the micro-seismicity after main earthquake events. This real-time temporary seismic network is constituted by various mobile and autonomous seismic stations that in group of three are telemetered to a Very Small Aperture Terminal (VSAT). This system uses a dedicated bandwidth on UHF, Wi-Fi and satellite frequency that allows the data flow in real-time at INGV centre in Rome (and Grottaminarda as backup center). The deployment of the seismic network is managed in a geographical information systems (GIS) by particular scenarios that visualizes, for the epicentral area, information about instrumental seismicity, seismic risk, macroseismic felts and territorial data. Starting from digital terrain model, the surface spatial analysis (Viewshed, Observer Point) allows the geographic arrangement of the stations and relative scenarios. The April, 6th, 2009 Mw 6.3 L'Aquila destructive earthquake represented the first real-case to test the entire emergency seismic network infrastructure. Less than 6 hours after the earthquake occurrence, a first accelerometer station was already sending data at INGV seismic monitoring headquarters. A total number of 9 seismic stations have been installed within 3 days after the earthquake. Furthermore, 5 permanent GPS stations have been installed in the epicentral area within 1 to 9 days after the main shock to detect the post-seismic deformation induced by the earthquake. We will show and describe the details of the Emergency Seismic Network infrastructure, and the first results from the collected data.

Determination of trajectories of fireballs using seismic network data

NASA Astrophysics Data System (ADS)

Ishihara, Y.

2006-12-01

Fireballs, Bolides, which are caused by high velocity passages of meteoroids through the atmosphere, generate shockwaves. Meteor shockwave provide us very important information (arrival time and amplitude) to study meteor physics. The shockwave arrival time data enable us to determine trajectories of the fireballs. On the other hand, the shockwave amplitude tells us size and ablation history of the meteoroid. Infrasound observation is one of the ways of detecting bolide shockwaves. However, we have no infrasound observational networks extends for large area with enough spatial distribution for determination of trajectories and estimate ablation histories. We have only a few infrasound arrays that have three or four elements, in the Japanese islands. Last decade, digital seismic networks are greatly improved for the purpose of monitoring micro earthquakes. Those seismic networks are quite sensitive for detecting micro ground vibration, and then those networks could detect not only seismic wave generated by earthquakes, but also ground oscillations generated by coupling of meteor shockwave with the ground near station. Last years, I analyses this kind of ground motion data recorded by seismic network, as meteor shockwave signals. For example, we estimate some great fireball's aerial path from arrival times of shockwaves (e.g., Ishihara et. al., 2003 Earth Planets, and Space, 2004 Geophysical Research. Letters.; Pujol et al., 2006 Planetary and Space Science), and we estimate sizes and ablation history of some great fireball and a meteorite fall (Ishihara et al., 2004 Meteoroids2004). In Japan, some great fireball falls occurred during 2004 to 2005. In this presentation, I show the trajectories of these fireballs determined from shockwave analysis. Some fireballs trajectories are also determined from photographic records. The trajectories determined from shockwave and that from photos show good agreement.

Location Performance and Detection Threshold of the Spanish National Seismic Network

NASA Astrophysics Data System (ADS)

D'Alessandro, Antonino; Badal, José; D'Anna, Giuseppe; Papanastassiou, Dimitris; Baskoutas, Ioannis; Özel, Nurcan M.

2013-11-01

Spain is a low-to-moderate seismicity area with relatively low seismic hazard. However, several strong shallow earthquakes have shaken the country causing casualties and extensive damage. Regional seismicity is monitored and surveyed by means of the Spanish National Seismic Network, maintenance and control of which are entrusted to the Instituto Geográfico Nacional. This array currently comprises 120 seismic stations distributed throughout Spanish territory (mainland and islands). Basically, we are interested in checking the noise conditions, reliability, and seismic detection capability of the Spanish network by analyzing the background noise level affecting the array stations, errors in hypocentral location, and detection threshold, which provides knowledge about network performance. It also enables testing of the suitability of the velocity model used in the routine process of earthquake location. To perform this study we use a method that relies on P and S wave travel times, which are computed by simulation of seismic rays from virtual seismic sources placed at the nodes of a regular grid covering the study area. Given the characteristics of the seismicity of Spain, we drew maps for M L magnitudes 2.0, 2.5, and 3.0, at a focal depth of 10 km and a confidence level 95 %. The results relate to the number of stations involved in the hypocentral location process, how these stations are distributed spatially, and the uncertainties of focal data (errors in origin time, longitude, latitude, and depth). To assess the extent to which principal seismogenic areas are well monitored by the network, we estimated the average error in the location of a seismic source from the semiaxes of the ellipsoid of confidence by calculating the radius of the equivalent sphere. Finally, the detection threshold was determined as the magnitude of the smallest seismic event detected at least by four stations. The northwest of the peninsula, the Pyrenees, especially the westernmost segment

Ghana's experience in the establishment of a national digital seismic network observatory

NASA Astrophysics Data System (ADS)

Ahulu, Sylvanus; Danuor, Sylvester Kojo

2015-07-01

The Government of Ghana has established a National Digital Seismic Network Observatory in Ghana with the aim of monitoring events such as earthquakes, blasts from mining and quarrying, nuclear tests, etc. The Digital Observatory was commissioned on 19 December 2012, and was dedicated to Geosciences in Ghana. Previously Ghana did not have any operational, digital seismic network acquisition system with the capability of monitoring and analysing data for planning and research purposes. The Ghana Geological Survey has been monitoring seismic events with an analogue system which was not efficient and does not deliver real-time data. Hence, the importance of setting up the National Digital Seismic Network System which would enable the Geological Survey to constantly monitor, manage and coordinate both natural and man-made seismic activities in the country and around the globe, to some extent on real-time basis. The Network System is made up of six remote digital stations that transmit data via satellite to the central observatory. Sensors used are 3× Trillium Compact and 3× Trillium 120PA with Trident digitizers. The department has also acquired strong motion equipment: Titan accelerometers with Taurus digitizers from Nanometrics. Three of each of these instruments have been installed at the Akosombo and Kpong hydrodams, and also at the Weija water supply dam. These instruments are used to monitor dams. The peak ground acceleration (PGA) values established from the analysed data from the accelerometers will be used to retrofit or carry out maintenance work of the dam structures to avoid collapse. Apart from these, the observatory also assesses and analyses seismic waveforms relevant to its needs from the Global Seismographic Network (GSN) system operated by the US Geological Survey. The Ghana Geological Survey, through its Seismic Network Observatory makes data available to its stakeholder institutions for earthquake disaster mitigation; reports on all aspects of

Alaska Volcano Observatory Seismic Network Data Availability

NASA Astrophysics Data System (ADS)

Dixon, J. P.; Haney, M. M.; McNutt, S. R.; Power, J. A.; Prejean, S. G.; Searcy, C. K.; Stihler, S. D.; West, M. E.

2009-12-01

The Alaska Volcano Observatory (AVO) established in 1988 as a cooperative program of the U.S. Geological Survey, the Geophysical Institute at the University of Alaska Fairbanks, and the Alaska Division of Geological and Geophysical Surveys, monitors active volcanoes in Alaska. Thirty-three volcanoes are currently monitored by a seismograph network consisting of 193 stations, of which 40 are three-component stations. The current state of AVO’s seismic network, and data processing and availability are summarized in the annual AVO seismological bulletin, Catalog of Earthquake Hypocenters at Alaska Volcanoes, published as a USGS Data Series (most recent at http://pubs.usgs.gov/ds/467). Despite a rich seismic data set for 12 VEI 2 or greater eruptions, and over 80,000 located earthquakes in the last 21 years, the volcanic seismicity in the Aleutian Arc remains understudied. Initially, AVO seismic data were only provided via a data supplement as part of the annual bulletin, or upon request. Over the last few years, AVO has made seismic data more available with the objective of increasing volcano seismic research on the Aleutian Arc. The complete AVO earthquake catalog data are now available through the annual AVO bulletin and have been submitted monthly to the on-line Advanced National Seismic System (ANSS) composite catalog since 2008. Segmented waveform data for all catalog earthquakes are available upon request and efforts are underway to make this archive web accessible as well. Continuous data were first archived using a tape backup, but the availability of low cost digital storage media made a waveform backup of continuous data a reality. Currently the continuous AVO waveform data can be found in several forms. Since late 2002, AVO has burned all continuous waveform data to DVDs, as well as storing these data in Antelope databases at the Geophysical Institute. Beginning in 2005, data have been available through a Winston Wave Server housed at the USGS in

The LUSI Seismic Experiment: Deployment of a Seismic Network around LUSI, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Karyono, Karyono; Mazzini, Adriano; Lupi, Matteo; Syafri, Ildrem; Haryanto, Iyan; Masturyono, Masturyono; Hadi, Soffian; Rohadi, Suprianto; Suardi, Iman; Rudiyanto, Ariska; Pranata, Bayu

2015-04-01

The spectacular Lusi eruption started in northeast Java, Indonesia the 29 of May 2006 following a M6.3 earthquake striking the island. Initially, several gas and mud eruption sites appeared along the reactivated strike-slip Watukosek fault system and within weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. Lusi is located few kilometres to the NE of the Arjuno-Welirang volcanic complex. Lusi sits upon the Watukosek fault system. From this volcanic complex originates the Watukosek fault system that was reactivated by the M6.3 earthquake in 2006 and is still periodically reactivated by the frequent seismicity. To date Lusi is still active and erupting gas, water, mud and clasts. Gas and water data show that the Lusi plumbing system is connected with the neighbouring Arjuno-Welirang volcanic complex. This makes the Lusi eruption a "sedimentary hosted geothermal system". To verify and characterise the occurrence of seismic activity and how this perturbs the connected Watukosek fault, the Arjuno-Welirang volcanic system and the ongoing Lusi eruption, we deployed 30 seismic stations (short-period and broadband) in this region of the East Java basin. The seismic stations are more densely distributed around LUSI and the Watukosek fault zone that stretches between Lusi and the Arjuno Welirang (AW) complex. Fewer stations are positioned around the volcanic arc. Our study sheds light on the seismic activity along the Watukosek fault system and describes the waveforms associated to the geysering activity of Lusi. The initial network aims to locate small event that may not be captured by the Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG) seismic network and it will be crucial to design the second phase of the seismic experiment that will consist of a local earthquake tomography of the Lusi-Arjuno Welirang region and temporal variations of vp/vs ratios. Such variations will then be ideally related to

UMTS rapid response real-time seismic networks: implementation and strategies at INGV

NASA Astrophysics Data System (ADS)

Govoni, Aladino; Margheriti, Lucia; Moretti, Milena; Lauciani, Valentino; Sensale, Gianpaolo; Bucci, Augusto; Criscuoli, Fabio

2015-04-01

The benefits of portable real-time seismic networks are several and well known. During the management of a temporary experiment from the real-time data it is possible to detect and fix rapidly problems with power supply, time synchronization, disk failures and, most important, seismic signal quality degradation due to unexpected noise sources or sensor alignment/tampering. This usually minimizes field maintenance trips and maximizes both the quantity and the quality of the acquired data. When the area of the temporary experiment is not well monitored by the local permanent network, the real-time data from the temporary experiment can be fed to the permanent network monitoring system improving greatly both the real-time hypocentral locations and the final revised bulletin. All these benefits apply also in case of seismic crises when rapid deployment stations can significantly contribute to the aftershock analysis. Nowadays data transmission using meshed radio networks or satellite systems is not a big technological problem for a permanent seismic network where each site is optimized for the device power consumption and is usually installed by properly specialized technicians that can configure transmission devices and align antennas. This is not usually practical for temporary networks and especially for rapid response networks where the installation time is the main concern. These difficulties are substantially lowered using the now widespread UMTS technology for data transmission. A small (but sometimes power hungry) properly configured device with an omnidirectional antenna must be added to the station assembly. All setups are usually configured before deployment and this allows for an easy installation also by untrained personnel. We describe here the implementation of a UMTS based portable seismic network for both temporary experiments and rapid response applications developed at INGV. The first field experimentation of this approach dates back to the 2009 L

New strong motion network in Georgia: basis for specifying seismic hazard

NASA Astrophysics Data System (ADS)

Kvavadze, N.; Tsereteli, N. S.

2017-12-01

Risk created by hazardous natural events is closely related to sustainable development of the society. Global observations have confirmed tendency of growing losses resulting from natural disasters, one of the most dangerous and destructive if which are earthquakes. Georgia is located in seismically active region. So, it is imperative to evaluate probabilistic seismic hazard and seismic risk with proper accuracy. National network of Georgia includes 35 station all of which are seismometers. There are significant gaps in strong motion recordings, which essential for seismic hazard assessment. To gather more accelerometer recordings, we have built a strong motion network distributed on the territory of Georgia. The network includes 6 stations for now, with Basalt 4x datalogger and strong motion sensor Episensor ES-T. For each site, Vs30 and soil resonance frequencies have been measured. Since all but one station (Tabakhmelam near Tbilisi), are located far from power and internet lines special system was created for instrument operation. Solar power is used to supply the system with electricity and GSM/LTE modems for internet access. VPN tunnel was set up using Raspberry pi, for two-way communication with stations. Tabakhmela station is located on grounds of Ionosphere Observatory, TSU and is used as a hub for the network. This location also includes a broadband seismometer and VLF electromagnetic waves observation antenna, for possible earthquake precursor studies. On server, located in Tabakhmela, the continues data is collected from all the stations, for later use. The recordings later will be used in different seismological and engineering problems, namely selecting and creating GMPE model for Caucasus, for probabilistic seismic hazard and seismic risk evaluation. These stations are a start and in the future expansion of strong motion network is planned. Along with this, electromagnetic wave observations will continue and additional antennas will be implemented

Improving the Detectability of the Catalan Seismic Network for Local Seismic Activity Monitoring

NASA Astrophysics Data System (ADS)

Jara, Jose Antonio; Frontera, Tànit; Batlló, Josep; Goula, Xavier

2016-04-01

The seismic survey of the territory of Catalonia is mainly performed by the regional seismic network operated by the Cartographic and Geologic Institute of Catalonia (ICGC). After successive deployments and upgrades, the current network consists of 16 permanent stations equipped with 3 component broadband seismometers (STS2, STS2.5, CMG3ESP and CMG3T), 24 bits digitizers (Nanometrics Trident) and VSAT telemetry. Data are continuously sent in real-time via Hispasat 1D satellite to the ICGC datacenter in Barcelona. Additionally, data from other 10 stations of neighboring areas (Spain, France and Andorra) are continuously received since 2011 via Internet or VSAT, contributing both to detect and to locate events affecting the region. More than 300 local events with Ml ≥ 0.7 have been yearly detected and located in the region. Nevertheless, small magnitude earthquakes, especially those located in the south and south-west of Catalonia may still go undetected by the automatic detection system (DAS), based on Earthworm (USGS). Thus, in order to improve the detection and characterization of these missed events, one or two new stations should be installed. Before making the decision about where to install these new stations, the performance of each existing station is evaluated taking into account the fraction of detected events using the station records, compared to the total number of events in the catalogue, occurred during the station operation time from January 1, 2011 to December 31, 2014. These evaluations allow us to build an Event Detection Probability Map (EDPM), a required tool to simulate EDPMs resulting from different network topology scenarios depending on where these new stations are sited, and becoming essential for the decision-making process to increase and optimize the event detection probability of the seismic network.

The Global Detection Capability of the IMS Seismic Network in 2013 Inferred from Ambient Seismic Noise Measurements

NASA Astrophysics Data System (ADS)

Gaebler, P. J.; Ceranna, L.

2016-12-01

All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection thresholdcan be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

Urban MEMS based seismic network for post-earthquakes rapid disaster assessment

NASA Astrophysics Data System (ADS)

D'Alessandro, A.; Luzio, D.; D'Anna, G.

2014-09-01

In this paper, we introduce a project for the realization of the first European real-time urban seismic network based on Micro Electro-Mechanical Systems (MEMS) technology. MEMS accelerometers are a highly enabling technology, and nowadays, the sensitivity and the dynamic range of these sensors are such as to allow the recording of earthquakes of moderate magnitude even at a distance of several tens of kilometers. Moreover, thanks to their low cost and smaller size, MEMS accelerometers can be easily installed in urban areas in order to achieve an urban seismic network constituted by high density of observation points. The network is being implemented in the Acireale Municipality (Sicily, Italy), an area among those with the highest hazard, vulnerability and exposure to the earthquake of the Italian territory. The main objective of the implemented urban network will be to achieve an effective system for post-earthquake rapid disaster assessment. The earthquake recorded, also that with moderate magnitude will be used for the effective seismic microzonation of the area covered by the network. The implemented system will be also used to realize a site-specific earthquakes early warning system.

The Central and Eastern U.S. Seismic Network: Legacy of USArray

NASA Astrophysics Data System (ADS)

Eakins, J. A.; Astiz, L.; Benz, H.; Busby, R. W.; Hafner, K.; Reyes, J. C.; Sharer, G.; Vernon, F.; Woodward, R.

2014-12-01

As the USArray Transportable Array entered the central and eastern United States, several Federal agencies (National Science Foundation, U.S. Geological Survey, U.S. Nuclear Regulatory Commission, and Department of Energy) recognized the unique opportunity to retain TA stations beyond the original timeline. The mission of the CEUSN is to produce data that enables researchers and Federal agencies alike to better understand the basic geologic questions, background earthquake rates and distribution, seismic hazard potential, and associated societal risks of this region. The selected long-term sub-array from Transportable Array (TA) stations includes nearly 200 sites, complemented by 100 broadband stations from the existing regional seismic networks to form the Central and Eastern United States Network (CEUSN). Multiple criteria for site selection were weighed by an inter-agency TA Station Selection (TASS) Working Group: seismic noise characteristics, data availability in real time, proximity to nuclear power plants, and homogeneous distribution throughout the region. The Array Network Facility (ANF) started collecting data for CEUSN network stations since late 2013, with all stations collected since May 2014. Regional seismic data streams are collected in real-time from the IRIS Data Management Center (DMC). TA stations selected to be part of CEUSN, retain the broadband sensor to which a 100 sps channel is added, the infrasound and environmental channels, and, at some stations, accelerometers are deployed. The upgraded sites become part of the N4 network for which ANF provides metadata and can issue remote commands to the station equipment. Stations still operated by TA, but planned for CEUSN, are included in the virtual network so all stations are currently available now. By the end of 2015, the remaining TA stations will be upgraded. Data quality control procedures developed for TA stations at ANF and at the DMC are currently performed on N4 data. However

How a Country-Wide Seismological Network Can Improve Understanding of Seismicity and Seismic Hazard -- The Example of Bhutan

NASA Astrophysics Data System (ADS)

Hetényi, G.; Diehl, T.; Singer, J.; Kissling, E. H.; Clinton, J. F.; Wiemer, S.

2015-12-01

The Eastern Himalayas are home to a seemingly complex seismo-tectonic evolution. The rate of instrumental seismicity is lower than the average along the orogen, there is no record of large historical events, but both paleoseismology and GPS studies point to potentially large (M>8) earthquakes. Due to the lack of a permanent seismic monitoring system in the area, our current level of understanding is inappropriate to create a reliable quantitative seismic hazard model for the region. Existing maps are based on questionable hypotheses and show major inconsistencies when compared to each other. Here we present results on national and regional scales from a 38-station broadband seismological network we operated for almost 2 years in the Kingdom of Bhutan. A thorough, state-of-the-art analysis of local and regional earthquakes builds a comprehensive catalogue that reveals significantly (2-to-3 orders of magnitude) more events than detected from global networks. The seismotectonic analysis reveals new patterns of seismic activity as well as striking differences over relatively short distances within the Himalayas, only partly explained by surface observations such as geology. We compare a priori and a posteriori (BMC) magnitude of completeness maps and show that our network was able to detect all felt events during its operation. Some of these events could be felt at surprisingly large distances. Based on our experiment and experience, we draft the pillars on which a permanent seismological observatory for Bhutan could be constructed. Such a continuous monitoring system of seismic activity could then lead to a reliable quantitative seismic hazard model for Bhutan and surrounding regions, and serve as a base to improve building codes and general preparedness.

Automatic classification of seismic events within a regional seismograph network

NASA Astrophysics Data System (ADS)

Tiira, Timo; Kortström, Jari; Uski, Marja

2015-04-01

A fully automatic method for seismic event classification within a sparse regional seismograph network is presented. The tool is based on a supervised pattern recognition technique, Support Vector Machine (SVM), trained here to distinguish weak local earthquakes from a bulk of human-made or spurious seismic events. The classification rules rely on differences in signal energy distribution between natural and artificial seismic sources. Seismic records are divided into four windows, P, P coda, S, and S coda. For each signal window STA is computed in 20 narrow frequency bands between 1 and 41 Hz. The 80 discrimination parameters are used as a training data for the SVM. The SVM models are calculated for 19 on-line seismic stations in Finland. The event data are compiled mainly from fully automatic event solutions that are manually classified after automatic location process. The station-specific SVM training events include 11-302 positive (earthquake) and 227-1048 negative (non-earthquake) examples. The best voting rules for combining results from different stations are determined during an independent testing period. Finally, the network processing rules are applied to an independent evaluation period comprising 4681 fully automatic event determinations, of which 98 % have been manually identified as explosions or noise and 2 % as earthquakes. The SVM method correctly identifies 94 % of the non-earthquakes and all the earthquakes. The results imply that the SVM tool can identify and filter out blasts and spurious events from fully automatic event solutions with a high level of confidence. The tool helps to reduce work-load in manual seismic analysis by leaving only ~5 % of the automatic event determinations, i.e. the probable earthquakes for more detailed seismological analysis. The approach presented is easy to adjust to requirements of a denser or wider high-frequency network, once enough training examples for building a station-specific data set are available.

Seismic waveform inversion using neural networks

NASA Astrophysics Data System (ADS)

De Wit, R. W.; Trampert, J.

2012-12-01

Full waveform tomography aims to extract all available information on Earth structure and seismic sources from seismograms. The strongly non-linear nature of this inverse problem is often addressed through simplifying assumptions for the physical theory or data selection, thus potentially neglecting valuable information. Furthermore, the assessment of the quality of the inferred model is often lacking. This calls for the development of methods that fully appreciate the non-linear nature of the inverse problem, whilst providing a quantification of the uncertainties in the final model. We propose to invert seismic waveforms in a fully non-linear way by using artificial neural networks. Neural networks can be viewed as powerful and flexible non-linear filters. They are very common in speech, handwriting and pattern recognition. Mixture Density Networks (MDN) allow us to obtain marginal posterior probability density functions (pdfs) of all model parameters, conditioned on the data. An MDN can approximate an arbitrary conditional pdf as a linear combination of Gaussian kernels. Seismograms serve as input, Earth structure parameters are the so-called targets and network training aims to learn the relationship between input and targets. The network is trained on a large synthetic data set, which we construct by drawing many random Earth models from a prior model pdf and solving the forward problem for each of these models, thus generating synthetic seismograms. As a first step, we aim to construct a 1D Earth model. Training sets are constructed using the Mineos package, which computes synthetic seismograms in a spherically symmetric non-rotating Earth by summing normal modes. We train a network on the body waveforms present in these seismograms. Once the network has been trained, it can be presented with new unseen input data, in our case the body waves in real seismograms. We thus obtain the posterior pdf which represents our final state of knowledge given the

Review of Natural Phenomena Hazard (NPH) Assessments for the DOE Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snow, Robert L.; Ross, Steven B.

2011-09-15

The purpose of this review is to assess the need for updating Natural Phenomena Hazard (NPH) assessments for the DOE's Hanford Site, as required by DOE Order 420.1B Chapter IV, Natural Phenomena Hazards Mitigation, based on significant changes in state-of-the-art NPH assessment methodology or site-specific information. This review is an update and expansion to the September 2010 review of PNNL-19751, Review of Natural Phenomena Hazard (NPH) Assessments for the Hanford 200 Areas (Non-Seismic).

The Caucasus Seismic Network (CNET): Seismic Structure of the Greater and Lesser Caucasus

NASA Astrophysics Data System (ADS)

Sandvol, E. A.; Mackey, K. G.; Nabelek, J.; Yetermishli, G.; Godoladze, T.; Babayan, H.; Malovichko, A.

2017-12-01

The Greater Caucasus are a portion of the Alpine-Himalayan mountain belt that has undergone rapid uplift in the past 5 million years, thus serving as a unique natural laboratory to study the early stages of orogenesis. Relatively lower resolution seismic velocity models of this region show contradictory lateral variability. Furthermore, recent waveform modeling of seismograms has clearly demonstrated the presence of deep earthquakes (with a maximum hypocentral depth of 175 km) below the Greater Caucasus. The region has been largely unexplored in terms of the detailed uppermost mantle and crustal seismic structure due in part to the disparate data sets that have not yet been merged as well as key portions being sparsely instrumented. We have established collaborative agreements across the region. Building on these agreements we recently deployed a major multi-national seismic array across the Greater Caucasus to address fundamental questions about the nature of continental deformation in this poorly understood region. Our seismic array has two components: (1) a grid of stations spanning the entire Caucasus and (2) two seismic transects consisting of stations spaced at distances of less than 10 km that cross the Greater Caucasus. In addition to the temporary stations, we are working to integrate data from the national networks to produce high resolution images of the seismic structure. Using data from over 106 new seismic stations in Azerbaijan, Armenia, Russia, and Georgia, we hope to gain a better understanding of the recent uplift ( 5 Ma) of the Greater Caucasus and the nature of seismogenic deformation in the region.

Study of earthquakes using a borehole seismic network at Koyna, India

NASA Astrophysics Data System (ADS)

Gupta, Harsh; Satyanarayana, Hari VS; Shashidhar, Dodla; Mallika, Kothamasu; Ranjan Mahato, Chitta; Shankar Maity, Bhavani

2017-04-01

Koyna, located near the west coast of India, is a classical site of artificial water reservoir triggered earthquakes. Triggered earthquakes started soon after the impoundment of the Koyna Dam in 1962. The activity has continued till now including the largest triggered earthquake of M 6.3 in 1967; 22 earthquakes of M ≥ 5 and several thousands smaller earthquakes. The latest significant earthquake of ML 3.7 occurred on 24th November 2016. In spite of having a network of 23 broad band 3-component seismic stations in the near vicinity of the Koyna earthquake zone, locations of earthquakes had errors of 1 km. The main reason was the presence of 1 km thick very heterogeneous Deccan Traps cover that introduced noise and locations could not be improved. To improve the accuracy of location of earthquakes, a unique network of eight borehole seismic stations surrounding the seismicity was designed. Six of these have been installed at depths varying from 981 m to 1522 m during 2015 and 2016, well below the Deccan Traps cover. During 2016 a total of 2100 earthquakes were located. There has been a significant improvement in the location of earthquakes and the absolute errors of location have come down to ± 300 m. All earthquakes of ML ≥ 0.5 are now located, compared to ML ≥1.0 earlier. Based on seismicity and logistics, a block of 2 km x 2 km area has been chosen for the 3 km deep pilot borehole. The installation of the borehole seismic network has further elucidated the correspondence between rate of water loading/unloading the reservoir and triggered seismicity.

The Irpinia Seismic Network (ISN): a new Monitoring Infrastructure for Seismic Alert Management in Campania Region, Southern Italy

NASA Astrophysics Data System (ADS)

Iannaccone, G.; Satriano, C.; Weber, E.; Cantore, L.; Corciulo, M.; Romano, L.; Martino, C.; Dicrosta, M.; Zollo, A.

2005-12-01

The Irpinia Seismic Network is an high dynamics, high density seismographic network under development in the Southern Apenninic chain. It is deployed in the area stroken by several destructive earthquakes during last centuries. In its final configuration the network will consist of more than fourty high dynamic seismic stations subdivided in physical subnetworks inter-connected by a robust data transmission system. The system is being designed with two primary targets: -Monitoring and analysis of background seismic activity produced by the active fault system which is the cause for large earthquakes in the past, included the 1980, Irpinia earthquake (Ms=6.9) - Development and experimentation of a prototype system for seismic early and post-event warning to be used for protecting public infrastructures and buildings of strategic relevance of the Regione Campania The seismic network will be completed in two stages: 1 - Deployment of 30 seismic stations along the Campania-Lucania Apenninic chain (to date almost completed) 2 - Setting up radio communication system for data transmission. Installation of 12 additional seismic stations (end of year 2006) To ensure an high dynamic recording range each site is equipped with two type of sensors: 30 force-balance accelerometer (model Guralp CMG5-T) and a velocimeter. In particular, 25 sites with short period three components instrument (model Geotech S13-J) and 5 with broad-band sensor (Nanometrics Trillium, with frequency response in the 0.033-50 Hz band). The used data logger is the Osiris-6 model produced by Agecodagis whose main features are: six channels, O/N 24 bit A/D converter, ARM processor with embedded Linux and open source software, two PCMCIA slots (used for two 5GB microdrive or one disk and wi-fi card), Ethernet, wi-fi and serial communication, low power cosumption (~1 W). Power is ensured by two 120 W solar panels and two 130 Ah gel batteries. Each recording site is equipped with a control/alarm system through

Urban MEMS based seismic network for post-earthquakes rapid disaster assessment

NASA Astrophysics Data System (ADS)

D'Alessandro, Antonino; Luzio, Dario; D'Anna, Giuseppe

2014-05-01

Life losses following disastrous earthquake depends mainly by the building vulnerability, intensity of shaking and timeliness of rescue operations. In recent decades, the increase in population and industrial density has significantly increased the exposure to earthquakes of urban areas. The potential impact of a strong earthquake on a town center can be reduced by timely and correct actions of the emergency management centers. A real time urban seismic network can drastically reduce casualties immediately following a strong earthquake, by timely providing information about the distribution of the ground shaking level. Emergency management centers, with functions in the immediate post-earthquake period, could be use this information to allocate and prioritize resources to minimize loss of human life. However, due to the high charges of the seismological instrumentation, the realization of an urban seismic network, which may allow reducing the rate of fatalities, has not been achieved. Recent technological developments in MEMS (Micro Electro-Mechanical Systems) technology could allow today the realization of a high-density urban seismic network for post-earthquakes rapid disaster assessment, suitable for the earthquake effects mitigation. In the 1990s, MEMS accelerometers revolutionized the automotive-airbag system industry and are today widely used in laptops, games controllers and mobile phones. Due to their great commercial successes, the research into and development of MEMS accelerometers are actively pursued around the world. Nowadays, the sensitivity and dynamics of these sensors are such to allow accurate recording of earthquakes with moderate to strong magnitude. Due to their low cost and small size, the MEMS accelerometers may be employed for the realization of high-density seismic networks. The MEMS accelerometers could be installed inside sensitive places (high vulnerability and exposure), such as schools, hospitals, public buildings and places of

Studies Of Infrasonic Propagation Using Dense Seismic Networks

NASA Astrophysics Data System (ADS)

Hedlin, M. A.; deGroot-Hedlin, C. D.; Drob, D. P.

2011-12-01

Although there are approximately 100 infrasonic arrays worldwide, more than ever before, the station density is still insufficient to provide validation for detailed propagation modeling. Relatively large infrasonic signals can be observed on seismic channels due to coupling at the Earth's surface. Recent research, using data from the 70-km spaced 400-station USArray and other seismic network deployments, has shown the value of dense seismic network data for filling in the gaps between infrasonic arrays. The dense sampling of the infrasonic wavefield has allowed us to observe complete travel-time branches of infrasound and address important research problems in infrasonic propagation. We present our analysis of infrasound created by a series of rocket motor detonations that occurred at the UTTR facility in Utah in 2007. These data were well recorded by the USArray seismometers. We use the precisely located blasts to assess the utility of G2S mesoscale models and methods to synthesize infrasonic propagation. We model the travel times of the branches using a ray-based approach and the complete wavefield using a FDTD algorithm. Although results from both rays and FDTD approaches predict the travel times to within several seconds, only about 40% of signals are predicted using rays largely due to penetration of sound into shadow zones. FDTD predicts some sound penetration into the shadow zone, but the observed shadow zones, as defined by the seismic data, have considerably narrower spatial extent than either method predicts, perhaps due to un-modeled small-scale structure in the atmosphere.

Earthquake Monitoring: SeisComp3 at the Swiss National Seismic Network

NASA Astrophysics Data System (ADS)

Clinton, J. F.; Diehl, T.; Cauzzi, C.; Kaestli, P.

2011-12-01

The Swiss Seismological Service (SED) has an ongoing responsibility to improve the seismicity monitoring capability for Switzerland. This is a crucial issue for a country with low background seismicity but where a large M6+ earthquake is expected in the next decades. With over 30 stations with spacing of ~25km, the SED operates one of the densest broadband networks in the world, which is complimented by ~ 50 realtime strong motion stations. The strong motion network is expected to grow with an additional ~80 stations over the next few years. Furthermore, the backbone of the network is complemented by broadband data from surrounding countries and temporary sub-networks for local monitoring of microseismicity (e.g. at geothermal sites). The variety of seismic monitoring responsibilities as well as the anticipated densifications of our network demands highly flexible processing software. We are transitioning all software to the SeisComP3 (SC3) framework. SC3 is a fully featured automated real-time earthquake monitoring software developed by GeoForschungZentrum Potsdam in collaboration with commercial partner, gempa GmbH. It is in its core open source, and becoming a community standard software for earthquake detection and waveform processing for regional and global networks across the globe. SC3 was originally developed for regional and global rapid monitoring of potentially tsunamagenic earthquakes. In order to fulfill the requirements of a local network recording moderate seismicity, SED has tuned configurations and added several modules. In this contribution, we present our SC3 implementation strategy, focusing on the detection and identification of seismicity on different scales. We operate several parallel processing "pipelines" to detect and locate local, regional and global seismicity. Additional pipelines with lower detection thresholds can be defined to monitor seismicity within dense subnets of the network. To be consistent with existing processing

Community Seismic Network (CSN)

NASA Astrophysics Data System (ADS)

Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Cheng, M.; Guy, R.; Chandy, M.; Krause, A.; Bunn, J.; Olson, M.; Faulkner, M.

2011-12-01

The CSN is a network of low-cost accelerometers deployed in the Pasadena, CA region. It is a prototype network with the goal of demonstrating the importance of dense measurements in determining the rapid lateral variations in ground motion due to earthquakes. The main product of the CSN is a map of peak ground produced within seconds of significant local earthquakes that can be used as a proxy for damage. Examples of this are shown using data from a temporary network in Long Beach, CA. Dense measurements in buildings are also being used to determine the state of health of structures. In addition to fixed sensors, portable sensors such as smart phones are also used in the network. The CSN has necessitated several changes in the standard design of a seismic network. The first is that the data collection and processing is done in the "cloud" (Google cloud in this case) for robustness and the ability to handle large impulsive loads (earthquakes). Second, the database is highly de-normalized (i.e. station locations are part of waveform and event-detection meta data) because of the mobile nature of the sensors. Third, since the sensors are hosted and/or owned by individuals, the privacy of the data is very important. The location of fixed sensors is displayed on maps as sensor counts in block-wide cells, and mobile sensors are shown in a similar way, with the additional requirement to inhibit tracking that at least two must be present in a particular cell before any are shown. The raw waveform data are only released to users outside of the network after a felt earthquake.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohay, Alan C.; Clayton, Ray E.; Sweeney, Mark D.

The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the eventmore » of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. During FY 2010, the Hanford Seismic Network recorded 873 triggers on the seismometer system, which included 259 seismic events in the southeast Washington area and an additional 324 regional and teleseismic events. There were 210 events determined to be local earthquakes relevant to the Hanford Site. One hundred and fifty-five earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of Richland just west of the Columbia River. The Wooded Island events recorded this fiscal year were a continuation of the swarm events observed during fiscal year 2009 and reported in previous quarterly and annual reports (Rohay et al. 2009a, 2009b, 2009c, 2010a, 2010b, and 2010c). Most events were considered minor (coda-length magnitude [Mc] less than 1.0) with the largest event recorded on February 4, 2010 (3.0Mc). The estimated depths of the Wooded Island events are shallow (averaging approximately 1.5 km deep) placing the swarm within the Columbia River Basalt Group. Based upon the last two quarters (Q3 and Q4) data, activity at the Wooded

The Self-Organising Seismic Early Warning Information Network

NASA Astrophysics Data System (ADS)

Kühnlenz, F.; Eveslage, I.; Fischer, J.; Fleming, K. M.; Lichtblau, B.; Milkereit, C.; Picozzi, M.

2009-12-01

The Self-Organising Seismic Early Warning Information Network (SOSEWIN) represents a new approach for Earthquake Early Warning Systems (EEWS), consisting in taking advantage of novel wireless communications technologies without the need of a planned, centralised infrastructure. It also sets out to overcome problems of insufficient node density, which typically affects present existing early warning systems, by having the SOSEWIN seismological sensing units being comprised of low-cost components (generally bought "off-the-shelf"), with each unit initially costing 100's of Euros, in contrast to 1,000's to 10,000's for standard seismological stations. The reduced sensitivity of the new sensing units arising from the use of lower-cost components will be compensated by the network's density, which in the future is expected to number 100's to 1000's over areas served currently by the order of 10's of standard stations. The robustness, independence of infrastructure, spontaneous extensibility due to a self-healing/self-organizing character in the case of removing/failing or adding sensors makes SOSEWIN potentially useful for various use cases, e.g. monitoring of building structures or seismic microzonation. Nevertheless its main purpose is the earthquake early warning, for which reason the ground motion is continuously monitored by conventional accelerometers (3-component) and processed within a station. Based on this, the network itself decides whether an event is detected through cooperating stations. SEEDLink is used to store and provide access to the sensor data. Experiences and selected experiment results with the SOSEWIN-prototype installation in the Ataköy district of Istanbul (Turkey) are presented. SOSEWIN considers also the needs of earthquake task forces, which want to set-up a temporary seismic network rapidly and with light-weighted stations to record after-shocks. The wireless and self-organising character of this sensor network is of great value to do this

Earthquake Monitoring with the MyShake Global Smartphone Seismic Network

NASA Astrophysics Data System (ADS)

Inbal, A.; Kong, Q.; Allen, R. M.; Savran, W. H.

2017-12-01

Smartphone arrays have the potential for significantly improving seismic monitoring in sparsely instrumented urban areas. This approach benefits from the dense spatial coverage of users, as well as from communication and computational capabilities built into smartphones, which facilitate big seismic data transfer and analysis. Advantages in data acquisition with smartphones trade-off with factors such as the low-quality sensors installed in phones, high noise levels, and strong network heterogeneity, all of which limit effective seismic monitoring. Here we utilize network and array-processing schemes to asses event detectability with the MyShake global smartphone network. We examine the benefits of using this network in either triggered or continuous modes of operation. A global database of ground motions measured on stationary phones triggered by M2-6 events is used to establish detection probabilities. We find that the probability of detecting an M=3 event with a single phone located <10 km from the epicenter exceeds 70%. Due to the sensor's self-noise, smaller magnitude events at short epicentral distances are very difficult to detect. To increase the signal-to-noise ratio, we employ array back-projection techniques on continuous data recorded by thousands of phones. In this class of methods, the array is used as a spatial filter that suppresses signals emitted from shallow noise sources. Filtered traces are stacked to further enhance seismic signals from deep sources. We benchmark our technique against traditional location algorithms using recordings from California, a region with large MyShake user database. We find that locations derived from back-projection images of M 3 events recorded by >20 nearby phones closely match the regional catalog locations. We use simulated broadband seismic data to examine how location uncertainties vary with user distribution and noise levels. To this end, we have developed an empirical noise model for the metropolitan Los

Detecting earthquakes over a seismic network using single-station similarity measures

NASA Astrophysics Data System (ADS)

Bergen, Karianne J.; Beroza, Gregory C.

2018-06-01

New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected moveout. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to 2 weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalogue (including 95 per cent of the catalogue events), and less than 1 per cent of these candidate events are false detections.

Detecting Earthquakes over a Seismic Network using Single-Station Similarity Measures

NASA Astrophysics Data System (ADS)

Bergen, Karianne J.; Beroza, Gregory C.

2018-03-01

New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected move-out. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to two weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalog (including 95% of the catalog events), and less than 1% of these candidate events are false detections.

Modernization of the Caltech/USGS Southern California Seismic Network

NASA Astrophysics Data System (ADS)

Bhadha, R.; Devora, A.; Hauksson, E.; Johnson, D.; Thomas, V.; Watkins, M.; Yip, R.; Yu, E.; Given, D.; Cone, G.; Koesterer, C.

2009-12-01

The USGS/ANSS/ARRA program is providing Government Furnished Equipment (GFE), and two year funding for upgrading the Caltech/USGS Southern California Seismic Network (SCSN). The SCSN is the modern digital ground motion seismic network in southern California that monitors seismicity and provides real-time earthquake information products such as rapid notifications, moment tensors, and ShakeMap. The SCSN has evolved through the years and now consists of several well-integrated components such as Short-Period analog, TERRAscope, digital stations, and real-time strong motion stations, or about 300 stations. In addition, the SCSN records data from about 100 stations provided by partner networks. To strengthen the ability of SCSN to meet the ANSS performance standards, we will install GFE and carry out the following upgrades and improvements of the various components of the SCSN: 1) Upgrade of dataloggers at seven TERRAscope stations; 2) Upgrade of dataloggers at 131 digital stations and upgrade broadband sensors at 25 stations; 3) Upgrade of SCSN metadata capabilities; 4) Upgrade of telemetry capabilities for both seismic and GPS data; and 5) Upgrade balers at stations with existing Q330 dataloggers. These upgrades will enable the SCSN to meet the ANSS Performance Standards more consistently than before. The new equipment will improve station uptimes and reduce maintenance costs. The new equipment will also provide improved waveform data quality and consequently superior data products. The data gaps due to various outages will be minimized, and ‘late’ data will be readily available through retrieval from on-site storage. Compared to the outdated equipment, the new equipment will speed up data delivery by about 10 sec, which is fast enough for earthquake early warning applications. The new equipment also has about a factor of ten lower consumption of power. We will also upgrade the SCSN data acquisition and data center facilities, which will improve the SCSN

The Canarian Seismic Monitoring Network: design, development and first result

NASA Astrophysics Data System (ADS)

D'Auria, Luca; Barrancos, José; Padilla, Germán D.; García-Hernández, Rubén; Pérez, Aaron; Pérez, Nemesio M.

2017-04-01

Tenerife is an active volcanic island which experienced several eruptions of moderate intensity in historical times, and few explosive eruptions in the Holocene. The increasing population density and the consistent number of tourists are constantly raising the volcanic risk. In June 2016 Instituto Volcanologico de Canarias started the deployment of a seismological volcano monitoring network consisting of 15 broadband seismic stations. The network began its full operativity in November 2016. The aim of the network are both volcano monitoring and scientific research. Currently data are continuously recorded and processed in real-time. Seismograms, hypocentral parameters, statistical informations about the seismicity and other data are published on a web page. We show the technical characteristics of the network and an estimate of its detection threshold and earthquake location performances. Furthermore we present other near-real time procedures on the data: analysis of the ambient noise for determining the shallow velocity model and temporal velocity variations, detection of earthquake multiplets through massive data mining of the seismograms and automatic relocation of events through double-difference location.

The Jalisco Seismic Telemetric Network (RESJAL)

NASA Astrophysics Data System (ADS)

Nunez-Cornu, F. J.; Nunez-Cornu, F. J.; Reyes-Davila, G.; Reyes-Davila, G.; Suarez-Plascencia, C.; Suarez-Plascencia, C.; Gonzalez-Ledezma, M.; Garcia-Puga, J.

2001-12-01

The region of Jalisco is one of the most active seismic regions in Mexico, the main tectonic units in this region are the Jalisco Block and the Rivera Plate. The greatest earthquake (M=8.2) occurred in Mexico in the Twenty-Century (1932) took place in the coast of Jalisco, this was followed by another one (Ms =7.8) fifteen days later. In 1995 an earthquake magnitude 8.0 took place in the coast of Jalisco, but its rupture area was only the southern half of the rupture area proposed for the 1932 earthquakes, these facts suggest the existence of an important seismic Gap in the north coast of Jalisco which includes the area of Bahía de Banderas. However, not only subduction earthquakes occurred in this region there are also large inland earthquakes, such as the December 27, 1568 and February 11, 1872 events. There are also three active volcanoes Sanganguey, Ceboruco and the most active volcano in Mexico, the Colima volcano. In spite of these facts and the risk associated to these processes, there were only one seismological permanent station in Chamela on the coast of Jalisco and an analog telemetric network (RESCO) located on the Colima Volcano and the south part of the Colima Rift Zone (CRZ). By these reasons, the Unidad Estatal de Protección Civil de Jalisco (Jalisco Civil Defense) began a project to install a Digital Telemetric Network in the region in several phases, this project is carrying out jointly with SisVOc UdeG.; due to the size of the area and the topography of the region it is very difficult to get direct telemetric links, by these reasons the network is designed in cells with nodes, where the nodes are the different Campus of the University of Guadalajara located in the region, all Campus are linked by a computer network. First phase started in August 2001, it includes the installation of six stations, each station with a Kinemetrics Everest 24 bit datalogger, GPS time, and a Lennartz LE3Dlite 1Hz sensor, using KNI NMS to control and data acquisition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohay, Alan C.; Sweeney, Mark D.; Hartshorn, Donald C.

The Hanford Seismic Assessment Program (HSAP) provides an uninterrupted collection of high-quality raw and processed seismic data from the Hanford Seismic Network for the U.S. Department of Energy and its contractors. The HSAP is responsible for locating and identifying sources of seismic activity and monitoring changes in the historical pattern of seismic activity at the Hanford Site. The data are compiled, archived, and published for use by the Hanford Site for waste management, natural phenomena hazards assessments, and engineering design and construction. In addition, the HSAP works with the Hanford Site Emergency Services Organization to provide assistance in the eventmore » of a significant earthquake on the Hanford Site. The Hanford Seismic Network and the Eastern Washington Regional Network consist of 44 individual sensor sites and 15 radio relay sites maintained by the Hanford Seismic Assessment Team. The Hanford Seismic Network recorded 23 local earthquakes during the third quarter of FY 2010. Sixteen earthquakes were located at shallow depths (less than 4 km), five earthquakes at intermediate depths (between 4 and 9 km), most likely in the pre-basalt sediments, and two earthquakes were located at depths greater than 9 km, within the basement. Geographically, twelve earthquakes were located in known swarm areas, 3 earthquakes occurred near a geologic structure (Saddle Mountain anticline), and eight earthquakes were classified as random events. The highest magnitude event (3.0 Mc) was recorded on May 8, 2010 at depth 3.0 km with epicenter located near the Saddle Mountain anticline. Later in the quarter (May 24 and June 28) two additional earthquakes were also recorded nearly at the same location. These events are not considered unusual in that earthquakes have been previously recorded at this location, for example, in October 2006 (Rohay et al; 2007). Six earthquakes were detected in the vicinity of Wooded Island, located about eight miles north of

IMPLEMENTATION OF THE SEISMIC DESIGN CRITERIA OF DOE-STD-1189-2008 APPENDIX A [FULL PAPER

DOE Office of Scientific and Technical Information (OSTI.GOV)

OMBERG SK

2008-05-14

This paper describes the approach taken by two Fluor Hanford projects for implementing of the seismic design criteria from DOE-STD-1189-2008, Appendix A. The existing seismic design criteria and the new seismic design criteria is described, and an assessment of the primary differences provided. The gaps within the new system of seismic design criteria, which necessitate conduct of portions of work to the existing technical standards pending availability of applicable industry standards, is discussed. Two Hanford Site projects currently in the Control Decision (CD)-1 phase of design have developed an approach to implementation of the new criteria. Calculations have been performedmore » to determine the seismic design category for one project, based on information available in early CD-1. The potential effects of DOE-STD-1189-2008, Appendix A seismic design criteria on the process of project alternatives analysis is discussed. Present of this work is expected to benefit others in the DOE Complex that may be implementing DOE-STD-1189-2008.« less

Leveraging EarthScope USArray with the Central and Eastern United States Seismic Network

NASA Astrophysics Data System (ADS)

Busby, R.; Sumy, D. F.; Woodward, R.; Frassetto, A.; Brudzinski, M.

2015-12-01

Recent earthquakes, such as the 2011 M5.8 Mineral, Virginia earthquake, raised awareness of the comparative lack of knowledge about seismicity, site response to ground shaking, and the basic geologic underpinnings in this densely populated region. With this in mind, the National Science Foundation, United States Geological Survey, United States Nuclear Regulatory Commission, and Department of Energy supported the creation of the Central and Eastern United States Seismic Network (CEUSN). These agencies, along with the IRIS Consortium who operates the network, recognized the unique opportunity to retain EarthScope Transportable Array (TA) seismic stations in this region beyond the standard deployment duration of two years per site. The CEUSN project supports 159 broadband TA stations, more than 30 with strong motion sensors added, that are scheduled to operate through 2017. Stations were prioritized in regions of elevated seismic hazard that have not been traditionally heavily monitored, such as the Charlevoix and Central Virginia Seismic Zones, and in regions proximal to nuclear power plants and other critical facilities. The stations (network code N4) transmit data in real time, with broadband and strong motion sensors sampling at 100 samples per second. More broadly the CEUSN concept also recognizes the existing backbone coverage of permanently operating seismometers in the CEUS, and forms a network of over 300 broadband stations. This multi-agency collaboration is motivated by the opportunity to use one facility to address multiple missions and needs in a way that is rarely possible, and to produce data that enables both researchers and federal agencies to better understand seismic hazard potential and associated seismic risks. In June 2015, the CEUSN Working Group (www.usarray.org/ceusn_working_group) was formed to review and provide advice to IRIS Management on the performance of the CEUSN as it relates to the target scientific goals and objectives. Map shows

The Self-Organising Seismic Early Warning Information Network: Scenarios

NASA Astrophysics Data System (ADS)

Kühnlenz, F.; Fischer, J.; Eveslage, I.

2009-04-01

SAFER and EDIM working groups, the Department of Computer Science, Humboldt-Universität zu Berlin, Berlin, Germany, and Section 2.1 Earthquake Risk and Early Warning, GFZ German Research Centre for Geosciences, Germany Contact: Frank Kühnlenz, kuehnlenz@informatik.hu-berlin.de The Self-Organising Seismic Early Warning Information Network (SOSEWIN) represents a new approach for Earthquake Early Warning Systems (EEWS), consisting in taking advantage of novel wireless communications technologies without the need of a planned, centralised infrastructure. It also sets out to overcome problems of insufficient node density, which typically affects present existing early warning systems, by having the SOSEWIN seismological sensing units being comprised of low-cost components (generally bought "off-the-shelf"), with each unit initially costing 100's of Euros, in contrast to 1,000's to 10,000's for standard seismological stations. The reduced sensitivity of the new sensing units arising from the use of lower-cost components will be compensated by the network's density, which in the future is expected to number 100's to 1000's over areas served currently by the order of 10's of standard stations. The robustness, independence of infrastructure, spontaneous extensibility due to a self-healing/self-organizing character in the case of removing/failing or adding sensors makes SOSEWIN potentially useful for various use cases, e.g. monitoring of building structures or seismic microzonation. Nevertheless its main purpose is the earthquake early warning, for which reason the ground motion is continuously monitored by conventional accelerometers (3-component). It uses SEEDLink to store and provide access to the sensor data. SOSEWIN considers also the needs of earthquake task forces, which want to set-up a temporary seismic network rapidly and with light-weighted stations to record after-shocks. The wireless and self-organising character of this sensor network should be of great value

A decade of passive seismic monitoring experiments with local networks in four Italian regions

NASA Astrophysics Data System (ADS)

Chiaraluce, L.; Valoroso, L.; Anselmi, M.; Bagh, S.; Chiarabba, C.

2009-10-01

We report on four seismic monitoring experiments that in the past ten years we carried out with dense local networks in seismically active Italian areas where for at least a year, tens of three component seismic stations were set up to record microseismicity. The areas observed are Alpago-Cansiglio, located in the Venetian Alps, Città di Castello in the Northern Apennines, Marsica in the Central Apennines and Val d'Agri located in the Southern Apennines. We produced homogeneous catalogues regarding earthquake locations and local magnitudes to investigate seismicity patterns during an inter-seismic period. The four regions are characterised by different kinematics, strain rates and historical/recent seismicity. We investigate earthquake distribution in space, time and size obtaining reference seismic rates and parameters of the Gutenberg and Richter law. We declustered the catalogues to look for coherent signs in the background seismic activity. Despite a difference in the catalogues magnitudes of completeness due both to the diverse detection threshold of the local networks and different seismic release, we detect and observe two common main behaviours: a) The Alpago-Cansiglio and Marsica regions are characterised by a relatively lower rate of seismic release associated to the episodic occurrence of seismic sequences with the largest event being 3 < ML < 4. In these areas the seismicity is not localised around the main faults. b) The Città di Castello and Val d'Agri regions have a relatively high rate of seismicity release almost continuously with time, and the increase in earthquake production is not clearly related to seismic sequences. In these areas the seismicity nucleates around defined fault systems and is usually lower than ML < 3. We suggest that the presence of over-pressured fluids in the Città di Castello and Val d'Agri uppermost crustal volume may favour and mould the higher rate of microseismic release.

Unravelling Responses for the Canadian National Seismic Network

NASA Astrophysics Data System (ADS)

Mulder, T. L.

2009-12-01

There are a number of attendant difficulties any network must deal with that range from defining the transfer function to instrument naming conventions to choices of final local file format representation. These choices ultimately result in the ease of conversion to other data formats and therefore directly impact useability. In particular, the ease of data exhange and use of established software that is dependent on standard data types is impacted. This becomes particularly critical with large (terabyte) dataset processing and when integrating external datasets into analysis procedures. Transfer functions, often referred to as instrument responses, are a key component in describing instrumentation. The transfer function describes the complete response of the seismic system. The seismic system is designed to be a linear system that can be decomposed into discrete components. Analogue or digital convolution can be represented as multiplication in the frequency domain. The two basic elements of a seismic system are the sensor and datalogger. The analogue sensor can be represented mathmatically as poles and zeroes. The datalogger can be further broken down into its discrete analogue and digital components: the preamp, A/D converter, and fir filters. The Canadian seismic network (CNSN) digitizers have an additional complication. To save telemetry band-width, the 32 bit signal from the digitizer has a transmission gain removed. The transmission gain (txgain) represents the number of the least significant bits truncated from the sample (2^txgain) after which the data is compressed and transmitted. While telemetry band-width is not the issue it was, now that many sites have ip connectivity, this user programmable transmission gain is still in use and can vary from station to station. The processes receiving the transmitted data do not restore the pre-transmission scaling, consequently the archived waveform files can vary in bit weight over time from station to station

How wind turbines affect the performance of seismic monitoring stations and networks

NASA Astrophysics Data System (ADS)

Neuffer, Tobias; Kremers, Simon

2017-12-01

In recent years, several minor seismic events were observed in the apparently aseismic region of the natural gas fields in Northern Germany. A seismic network was installed in the region consisting of borehole stations with sensor depths up to 200 m and surface stations to monitor induced seismicity. After installation of the network in 2012, an increasing number of wind turbines was established in proximity (<5 km) to several stations, thereby influencing the local noise conditions. This study demonstrates the impact of wind turbines on seismic noise level in a frequency range of 1-10 Hz at the monitoring sites with correlation to wind speed, based on the calculation of power spectral density functions and I95 values of waveforms over a time period of 4 yr. It could be shown that higher wind speeds increase the power spectral density amplitudes at distinct frequencies in the considered frequency band, depending on height as well as number and type of influencing wind turbines. The azimuthal direction of incoming Rayleigh waves at a surface station was determined to identify the noise sources. The analysis of the perturbed wave field showed that Rayleigh waves with backazimuths pointing to wind turbines in operation are dominating the wave field in a frequency band of 3-4 Hz. Additional peaks in a frequency range of 1-4 Hz could be attributed to turbine tower eigenfrequencies of various turbine manufactures with the hub height as defining parameter. Moreover, the influence of varying noise levels at a station on the ability to automatically detect seismic events was investigated. The increased noise level in correlation to higher wind speeds at the monitoring sites deteriorates the station's recording quality inhibiting the automatic detection of small seismic events. As a result, functionality and task fulfilment of the seismic monitoring network is more and more limited by the increasing number of nearby wind turbines.

Making Initial Earthquake Catalogs from a Temporary Seismic Network for Monitoring Aftershocks

NASA Astrophysics Data System (ADS)

Park, J.; Kang, T. S.; Kim, K. H.; Rhie, J.; Kim, Y.

2017-12-01

The ML 5.1 foreshock and the ML 5.8 mainshock earthquakes occurred consecutively in Gyeongju, the southeastern part of the Korean Peninsula, on September 12, 2016. A temporary seismic network was installed quickly to observe aftershocks followed this mainshock event in the vicinity of the epicenter. The network was consisting of 27 stations equipped with broadband sensors initially and it has been operated in off-line system which required a periodic manual backup of the recorded data. We detected P-triggers and associated events by using SeisComP3 to make an initial catalogue of aftershock events rapidly. If necessary, manual picking was performed to obtain precise P- and S-arrival times from a module, scolv, included in SeisComP3. For cross-checking of reliable identification of seismic phases, a seismic python package, PhasePApy, was applied in parallel with SeisComP3. Then we get the precise relocated coordinates and depth of the aftershock events using the velellipse algorithm. The resulting dataset comprises of an initial aftershock catalog. The catalog will provide the means to address some important questions and issues on seismogenesis in this intraplate seismicity region including the 2016 Gyeongju earthquake sequence and to improve seismic hazard estimation of the region.

Strong Motion Network of Medellín and Aburrá Valley: technical advances, seismicity records and micro-earthquake monitoring

NASA Astrophysics Data System (ADS)

Posada, G.; Trujillo, J. C., Sr.; Hoyos, C.; Monsalve, G.

2017-12-01

The tectonics setting of Colombia is determined by the interaction of Nazca, Caribbean and South American plates, together with the Panama-Choco block collision, which makes a seismically active region. Regional seismic monitoring is carried out by the National Seismological Network of Colombia and the Accelerometer National Network of Colombia. Both networks calculate locations, magnitudes, depths and accelerations, and other seismic parameters. The Medellín - Aburra Valley is located in the Northern segment of the Central Cordillera of Colombia, and according to the Colombian technical seismic norm (NSR-10), is a region of intermediate hazard, because of the proximity to seismic sources of the Valley. Seismic monitoring in the Aburra Valley began in 1996 with an accelerometer network which consisted of 38 instruments. Currently, the network consists of 26 stations and is run by the Early Warning System of Medellin and Aburra Valley (SIATA). The technical advances have allowed the real-time communication since a year ago, currently with 10 stations; post-earthquake data is processed through operationally near-real-time, obtaining quick results in terms of location, acceleration, spectrum response and Fourier analysis; this information is displayed at the SIATA web site. The strong motion database is composed by 280 earthquakes; this information is the basis for the estimation of seismic hazards and risk for the region. A basic statistical analysis of the main information was carried out, including the total recorded events per station, natural frequency, maximum accelerations, depths and magnitudes, which allowed us to identify the main seismic sources, and some seismic site parameters. With the idea of a more complete seismic monitoring and in order to identify seismic sources beneath the Valley, we are in the process of installing 10 low-cost shake seismometers for micro-earthquake monitoring. There is no historical record of earthquakes with a magnitude

Utah's Regional/Urban ANSS Seismic Network---Strategies and Tools for Quality Performance

NASA Astrophysics Data System (ADS)

Burlacu, R.; Arabasz, W. J.; Pankow, K. L.; Pechmann, J. C.; Drobeck, D. L.; Moeinvaziri, A.; Roberson, P. M.; Rusho, J. A.

2007-05-01

The University of Utah's regional/urban seismic network (224 stations recorded: 39 broadband, 87 strong-motion, 98 short-period) has become a model for locally implementing the Advanced National Seismic System (ANSS) because of successes in integrating weak- and strong-motion recording and in developing an effective real-time earthquake information system. Early achievements included implementing ShakeMap, ShakeCast, point-to- multipoint digital telemetry, and an Earthworm Oracle database, as well as in-situ calibration of all broadband and strong-motion stations and submission of all data and metadata into the IRIS DMC. Regarding quality performance, our experience as a medium-size regional network affirms the fundamental importance of basics such as the following: for data acquisition, deliberate attention to high-quality field installations, signal quality, and computer operations; for operational efficiency, a consistent focus on professional project management and human resources; and for customer service, healthy partnerships---including constant interactions with emergency managers, engineers, public policy-makers, and other stakeholders as part of an effective state earthquake program. (Operational cost efficiencies almost invariably involve trade-offs between personnel costs and the quality of hardware and software.) Software tools that we currently rely on for quality performance include those developed by UUSS (e.g., SAC and shell scripts for estimating local magnitudes) and software developed by other organizations such as: USGS (Earthworm), University of Washington (interactive analysis software), ISTI (SeisNetWatch), and IRIS (PDCC, BUD tools). Although there are many pieces, there is little integration. One of the main challenges we face is the availability of a complete and coherent set of tools for automatic and post-processing to assist in achieving the goals/requirements set forth by ANSS. Taking our own network---and ANSS---to the next level

Autonomous telemetry system by using mobile networks for a long-term seismic observation

NASA Astrophysics Data System (ADS)

Hirahara, S.; Uchida, N.; Nakajima, J.

2012-04-01

When a large earthquake occurs, it is important to know the detailed distribution of aftershocks immediately after the main shock for the estimation of the fault plane. The large amount of seismic data is also required to determine the three-dimensional seismic velocity structure around the focal area. We have developed an autonomous telemetry system using mobile networks, which is specialized for aftershock observations. Because the newly developed system enables a quick installation and real-time data transmission by using mobile networks, we can construct a dense online seismic network even in mountain areas where conventional wired networks are not available. This system is equipped with solar panels that charge lead-acid battery, and enables a long-term seismic observation without maintenance. Furthermore, this system enables a continuous observation at low costs with flat-rate or prepaid Internet access. We have tried to expand coverage areas of mobile communication and back up Internet access by configuring plural mobile carriers. A micro server embedded with Linux consists of automatic control programs of the Internet connection and data transmission. A status monitoring and remote maintenance are available via the Internet. In case of a communication failure, an internal storage can back up data for two years. The power consumption of communication device ranges from 2.5 to 4.0 W. With a 50 Ah lead-acid battery, this system continues to record data for four days if the battery charging by solar panels is temporarily unavailable.

The Italian National Seismic Network

NASA Astrophysics Data System (ADS)

Michelini, Alberto

2016-04-01

The Italian National Seismic Network is composed by about 400 stations, mainly broadband, installed in the Country and in the surrounding regions. About 110 stations feature also collocated strong motion instruments. The Centro Nazionale Terremoti, (National Earthquake Center), CNT, has installed and operates most of these stations, although a considerable number of stations contributing to the INGV surveillance has been installed and is maintained by other INGV sections (Napoli, Catania, Bologna, Milano) or even other Italian or European Institutions. The important technological upgrades carried out in the last years has allowed for significant improvements of the seismic monitoring of Italy and of the Euro-Mediterranean Countries. The adopted data transmission systems include satellite, wireless connections and wired lines. The Seedlink protocol has been adopted for data transmission. INGV is a primary node of EIDA (European Integrated Data Archive) for archiving and distributing, continuous, quality checked data. The data acquisition system was designed to accomplish, in near-real-time, automatic earthquake detection and hypocenter and magnitude determination (moment tensors, shake maps, etc.). Database archiving of all parametric results are closely linked to the existing procedures of the INGV seismic monitoring environment. Overall, the Italian earthquake surveillance service provides, in quasi real-time, hypocenter parameters which are then revised routinely by the analysts of the Bollettino Sismico Nazionale. The results are published on the web page http://cnt.rm.ingv.it/ and are publicly available to both the scientific community and the the general public. This presentation will describe the various activities and resulting products of the Centro Nazionale Terremoti. spanning from data acquisition to archiving, distribution and specialised products.

xQuake: A Modern Approach to Seismic Network Analytics

NASA Astrophysics Data System (ADS)

Johnson, C. E.; Aikin, K. E.

2017-12-01

While seismic networks have expanded over the past few decades, and social needs for accurate and timely information has increased dramatically, approaches to the operational needs of both global and regional seismic observatories have been slow to adopt new technologies. This presentation presents the xQuake system that provides a fresh approach to seismic network analytics based on complexity theory and an adaptive architecture of streaming connected microservices as diverse data (picks, beams, and other data) flow into a final, curated catalog of events. The foundation for xQuake is the xGraph (executable graph) framework that is essentially a self-organizing graph database. An xGraph instance provides both the analytics as well as the data storage capabilities at the same time. Much of the analytics, such as synthetic annealing in the detection process and an evolutionary programing approach for event evolution, draws from the recent GLASS 3.0 seismic associator developed by and for the USGS National Earthquake Information Center (NEIC). In some respects xQuake is reminiscent of the Earthworm system, in that it comprises processes interacting through store and forward rings; not surprising as the first author was the lead architect of the original Earthworm project when it was known as "Rings and Things". While Earthworm components can easily be integrated into the xGraph processing framework, the architecture and analytics are more current (e.g. using a Kafka Broker for store and forward rings). The xQuake system is being released under an unrestricted open source license to encourage and enable sthe eismic community support in further development of its capabilities.

The AlpArray Seismic Network: current status and next steps

NASA Astrophysics Data System (ADS)

Hetényi, György; Molinari, Irene; Clinton, John; Kissling, Edi

2016-04-01

The AlpArray initiative (http://www.alparray.ethz.ch) is a large-scale European collaboration to study the entire Alpine orogen at high resolution and in 3D with a large variety of geoscientific methods. The core element of the initiative is an extensive and dense broadband seismological network, the AlpArray Seismic Network (AASN), which complements the permanent seismological stations to ensure homogeneous coverage of the greater Alpine area. The some 260 temporary stations of the AlpArray Seismic Network are operated as a joint effort by a number of institutions from Austria, Bosnia-Herzegovina, Croatia, Czech Republic, France, Germany, Hungary, Italy, Slovakia and Switzerland. The first stations were installed in Spring 2015 and the full AASN is planned to be operational by early Summer 2016. In this poster we present the actual status of the deployment, the effort undertaken by the contributing groups, station performance, typical noise levels, best practices in installation as well as in data management, often encountered challenges, and planned next steps including the deployment of ocean bottom seismometers in the Ligurian Sea.

Development of real time monitor system displaying seismic waveform data observed at seafloor seismic network, DONET, for disaster management information

NASA Astrophysics Data System (ADS)

Horikawa, H.; Takaesu, M.; Sueki, K.; Takahashi, N.; Sonoda, A.; Miura, S.; Tsuboi, S.

2014-12-01

Mega-thrust earthquakes are anticipated to occur in the Nankai Trough in southwest Japan. In the source areas, we have deployed seafloor seismic network, DONET (Dense Ocean-floor Network System for Earthquake and Tsunamis), in 2010 in order to monitor seismicity, crustal deformations, and tsunamis. DONET system consists of totally 20 stations, which is composed of six kinds of sensors, including strong-motion seismometers　and quartz pressure gauges. Those stations are densely distributed with an average spatial interval of 15-20 km and cover near the trench axis to coastal areas. Observed data are transferred to a land station through a fiber-optical cable and then to JAMSTEC (Japan Agency for Marine-Earth Science and Technology) data management center through a private network in real time. After 2011 off the Pacific coast of Tohoku Earthquake, each local government close to Nankai Trough try to plan disaster prevention scheme. JAMSTEC will disseminate DONET data combined with research accomplishment so that they will be widely recognized as important earthquake information. In order to open DONET data observed for research to local government, we have developed a web application system, REIS　(Real-time Earthquake Information System). REIS is providing seismic waveform data to some local governments close to Nankai Trough as a pilot study. As soon as operation of DONET is ready, REIS will start full-scale operation. REIS can display seismic waveform data of DONET in real-time, users can select strong motion and pressure data, and configure the options of trace view arrangement, time scale, and amplitude. In addition to real-time monitoring, REIS can display past seismic waveform data and show earthquake epicenters on the map. In this presentation, we briefly introduce DONET system and then show our web　application system. We also discuss our future plans for further developments of REIS.

UMTS rapid response real-time seismic networks: implementation and strategies at INGV

NASA Astrophysics Data System (ADS)

Govoni, A.; Margheriti, L.; Moretti, M.; Lauciani, V.; Sensale, G.; Bucci, A.; Criscuoli, F.

2015-12-01

Universal Mobile Telecommunications System (UMTS) and its evolutions are nowadays the most affordable and widespread data communication infrastructure available almost world wide. Moreover the always growing cellular phone market is pushing the development of new devices with higher performances and lower power consumption. All these characteristics make UMTS really useful for the implementation of an "easy to deploy" temporary real-time seismic station. Despite these remarkable features, there are many drawbacks that must be properly taken in account to effectively transmit the seismic data: Internet security, signal and service availability, power consumption. - Internet security: exposing seismological data services and seismic stations to the Internet is dangerous, attack prone and can lead to downtimes in the services, so we setup a dedicated Virtual Private Network (VPN) service to protect all the connected devices. - Signal and service availability: while for temporary experiment a carefull planning and an accurate site selection can minimize the problem, this is not always the case with rapid response networks. Moreover, as with any other leased line, the availability of the UMTS service during a seismic crisis is basically unpredictable. Nowadays in Italy during a major national emergency a Committee of the Italian Civil Defense ensures unified management and coordination of emergency activities. Inside it the telecom companies are committed to give support to the crisis management improving the standards in their communication networks. - Power consumption: it is at least of the order of that of the seismic station and, being related to data flow and signal quality is largely unpredictable. While the most secure option consists in adding a second independent solar power supply to the seismic station, this is not always a very convenient solution since it doubles the cost and doubles the equipment on site. We found that an acceptable trade-off is to add an

Martian seismicity

NASA Technical Reports Server (NTRS)

Phillips, Roger J.; Grimm, Robert E.

1991-01-01

The design and ultimate success of network seismology experiments on Mars depends on the present level of Martian seismicity. Volcanic and tectonic landforms observed from imaging experiments show that Mars must have been a seismically active planet in the past and there is no reason to discount the notion that Mars is seismically active today but at a lower level of activity. Models are explored for present day Mars seismicity. Depending on the sensitivity and geometry of a seismic network and the attenuation and scattering properties of the interior, it appears that a reasonable number of Martian seismic events would be detected over the period of a decade. The thermoelastic cooling mechanism as estimated is surely a lower bound, and a more refined estimate would take into account specifically the regional cooling of Tharsis and lead to a higher frequency of seismic events.

A dense microseismic monitoring network in Korea for uncovering relationship between seismic activity and neotectonic features

NASA Astrophysics Data System (ADS)

Kang, T.; Lee, J. M.; Kim, W.; Jo, B. G.; Chung, T.; Choi, S.

2012-12-01

A few tens of surface traces indicating movements in Quaternary were found in the southeastern part of the Korean Peninsula. Following both the geological and engineering definitions, those features are classified into "active", in geology, or "capable", in engineering, faults. On the other hand, the present-day seismicity of the region over a couple of thousand years is indistinguishable on the whole with the rest of the Korean Peninsula. It is therefore of great interest whether the present seismic activity is related to the neotectonic features or not. Either of conclusions is not intuitive in terms of the present state of seismic monitoring network in the region. Thus much interest in monitoring seismicity to provide an improved observation resolution and to lower the event-detection threshold has increased with many observations of the Quaternary faults. We installed a remote, wireless seismograph network which is composed of 20 stations with an average spacing of 10 km. Each station is equipped with a three-component Trillium Compact seismometer and Taurus digitizer. Instrumentation and analysis advancements are now offering better tools for this monitoring. This network is scheduled to be in operation over about one and a half year. In spite of the relatively short observation period, we expect that the high density of the network enables us to monitor seismic events with much lower magnitude threshold compared to the preexisting seismic network in the region. Following the Gutenberg-Richter relationship, the number of events with low magnitude is logarithmically larger than that with high magnitude. Following this rule, we can expect that many of microseismic events may reveal behavior of their causative faults, if any. We report the results of observation which has been performed over a year up to now.

Peru Subduction Zone Seismic Experiment (PeruSZE): Preliminary Results From a Seismic Network Between Mollendo and Lake Titicaca, Peru.

NASA Astrophysics Data System (ADS)

Guy, R.; Stubailo, I.; Skinner, S.; Phillips, K.; Foote, E.; Lukac, M.; Aguilar, V.; Tavera, H.; Audin, L.; Husker, A.; Clayton, R.; Davis, P. M.

2008-12-01

This work describes preliminary results from a 50 station broadband seismic network recently installed from the coast to the high Andes in Peru. UCLA's Center for Embedded Network Sensing (CENS) and Caltech's Tectonic Observatory are collaborating with the IRD (French L'Institut de Recherche pour le Developpement) and the Institute of Geophysics, in Lima Peru in a broadband seismic experiment that will study the transition from steep to shallow slab subduction. The currently installed line has stations located above the steep subduction zone at a spacing of about 6 km. In 2009 we plan to install a line of 50 stations north from this line along the crest of the Andes, crossing the transition from steep to shallow subduction. A further line from the end of that line back to the coast, completing a U shaped array, is in the planning phase. The network is wirelessly linked using multi-hop network software designed by computer scientists in CENS in which data is transmitted from station to station, and collected at Internet drops, from where it is transmitted over the Internet to CENS each night. The instrument installation in Peru is almost finished and we have been receiving data daily from 10 stations (out of total 50) since June 2008. The rest are recording on-site while the RF network is being completed. The software system provides dynamic link quality based routing, reliable data delivery, and a disruption tolerant shell interface for managing the system from UCLA without the need to travel to Peru. The near real-time data delivery also allows immediate detection of any problems at the sites. We are building a seismic data and GPS quality control toolset that would greatly minimize the station's downtime by alerting the users of any possible problems.

Design and Implementation of the National Seismic Monitoring Network in the Kingdom of Bhutan

NASA Astrophysics Data System (ADS)

Ohmi, S.; Inoue, H.; Chophel, J.; Pelgay, P.; Drukpa, D.

2017-12-01

Bhutan-Himalayan district is located along the plate collision zone between Indian and Eurasian plates, which is one of the most seismically active region in the world. Recent earthquakes such as M7.8 Gorkha Nepal earthquake in April 25, 2015 and M6.7 Imphal, India earthquake in January 3, 2016 are examples of felt earthquakes in Bhutan. However, there is no permanent seismic monitoring system ever established in Bhutan, whose territory is in the center of the Bhutan-Himalayan region. We started establishing permanent seismic monitoring network of minimum requirements and intensity meter network over the nation. The former is composed of six (6) observation stations in Bhutan with short period weak motion and strong motion seismometers as well as three (3) broad-band seismometers, and the latter is composed of twenty intensity meters located in every provincial government office. Obtained data are transmitted to the central processing system in the DGM office in Thimphu in real time. In this project, DGM will construct seismic vault with their own budget which is approved as the World Bank project, and Japan team assists the DGM for site survey of observation site, designing the observation vault, and designing the data telemetry system as well as providing instruments for the observation such as seismometers and digitizers. We already started the operation of the six (6) weak motion stations as well as twenty (20) intensity meter stations. Additionally, the RIMES (Regional Integrated Multi-hazard Early Warning System for Africa and Asia) is also providing eight (8) weak motion stations and we are keeping close communication to operate them as one single seismic monitoring network composed of fourteen (14) stations. This network will be definitely utilized for not only for seismic disaster mitigation of the country but also for studying the seismotectonics in the Bhutan-Himalayan region which is not yet precisely revealed due to the lack of observation data in the

Seismic and Geodetic Monitoring of the Nicoya, Costa Rica, Seismic Gap

NASA Astrophysics Data System (ADS)

Protti, M.; Gonzalez, V.; Schwartz, S.; Dixon, T.; Kato, T.; Kaneda, Y.; Simila, G.; Sampson, D.

2007-05-01

The Nicoya segment of the Middle America Trench has been recognized as a mature seismic gap with potential to generate a large earthquake in the near future (it ruptured with large earthquakes in 1853, 1900 and 1950). Low level of background seismicity and fast crustal deformation of the forearc are indicatives of strong coupling along the plate interface. Given its high seismic potential, the available data and especially the fact that the Nicoya peninsula extends over large part of the rupture area, this gap was selected as one of the two sites for a MARGINS-SEIZE experiment. With the goal of documenting the evolution of loading and stress release along this seismic gap, an international effort involving several institutions from Costa Rica, the United States and Japan is being carried out for over a decade in the region. This effort involves the installation of temporary and permanent seismic and geodetic networks. The seismic network includes short period, broad band and strong motion instruments. The seismic monitoring has provided valuable information on the geometry and characteristics of the plate interface. The geodetic network includes temporary and permanent GPS stations as well as surface and borehole tiltmeters. The geodetic networks have helped quantify the extend and degree of coupling. A continuously recording, three- station GPS network on the Nicoya Peninsula, Costa Rica, recorded what we believe is the first slow slip event observed along the plate interface of the Costa Rica subduction zone. We will present results from these monitoring networks. Collaborative international efforts are focused on expanding these seismic and geodetic networks to provide improved resolution of future creep events, to enhanced understanding of the mechanical behavior of the Nicoya subduction segment of the Middle American Trench and possibly capture the next large earthquake and its potential precursor deformation.

MyShake: A smartphone seismic network for earthquake early warning and beyond.

PubMed

Kong, Qingkai; Allen, Richard M; Schreier, Louis; Kwon, Young-Woo

2016-02-01

Large magnitude earthquakes in urban environments continue to kill and injure tens to hundreds of thousands of people, inflicting lasting societal and economic disasters. Earthquake early warning (EEW) provides seconds to minutes of warning, allowing people to move to safe zones and automated slowdown and shutdown of transit and other machinery. The handful of EEW systems operating around the world use traditional seismic and geodetic networks that exist only in a few nations. Smartphones are much more prevalent than traditional networks and contain accelerometers that can also be used to detect earthquakes. We report on the development of a new type of seismic system, MyShake, that harnesses personal/private smartphone sensors to collect data and analyze earthquakes. We show that smartphones can record magnitude 5 earthquakes at distances of 10 km or less and develop an on-phone detection capability to separate earthquakes from other everyday shakes. Our proof-of-concept system then collects earthquake data at a central site where a network detection algorithm confirms that an earthquake is under way and estimates the location and magnitude in real time. This information can then be used to issue an alert of forthcoming ground shaking. MyShake could be used to enhance EEW in regions with traditional networks and could provide the only EEW capability in regions without. In addition, the seismic waveforms recorded could be used to deliver rapid microseism maps, study impacts on buildings, and possibly image shallow earth structure and earthquake rupture kinematics.

MyShake: Initial observations from a global smartphone seismic network

NASA Astrophysics Data System (ADS)

Kong, Qingkai; Allen, Richard M.; Schreier, Louis

2016-09-01

MyShake is a global smartphone seismic network that harnesses the power of crowdsourcing. In the first 6 months since the release of the MyShake app, there were almost 200,000 downloads. On a typical day about 8000 phones provide acceleration waveform data to the MyShake archive. The on-phone app can detect and trigger on P waves and is capable of recording magnitude 2.5 and larger events. More than 200 seismic events have been recorded so far, including events in Chile, Argentina, Mexico, Morocco, Nepal, New Zealand, Taiwan, Japan, and across North America. The largest number of waveforms from a single earthquake to date comes from the M5.2 Borrego Springs earthquake in Southern California, for which MyShake collected 103 useful three-component waveforms. The network continues to grow with new downloads from the Google Play store everyday and expands rapidly when public interest in earthquakes peaks such as during an earthquake sequence.

The AlpArray Seismic Network: A Large-Scale European Experiment to Image the Alpine Orogen

NASA Astrophysics Data System (ADS)

Hetényi, György; Molinari, Irene; Clinton, John; Bokelmann, Götz; Bondár, István; Crawford, Wayne C.; Dessa, Jean-Xavier; Doubre, Cécile; Friederich, Wolfgang; Fuchs, Florian; Giardini, Domenico; Gráczer, Zoltán; Handy, Mark R.; Herak, Marijan; Jia, Yan; Kissling, Edi; Kopp, Heidrun; Korn, Michael; Margheriti, Lucia; Meier, Thomas; Mucciarelli, Marco; Paul, Anne; Pesaresi, Damiano; Piromallo, Claudia; Plenefisch, Thomas; Plomerová, Jaroslava; Ritter, Joachim; Rümpker, Georg; Šipka, Vesna; Spallarossa, Daniele; Thomas, Christine; Tilmann, Frederik; Wassermann, Joachim; Weber, Michael; Wéber, Zoltán; Wesztergom, Viktor; Živčić, Mladen

2018-04-01

The AlpArray programme is a multinational, European consortium to advance our understanding of orogenesis and its relationship to mantle dynamics, plate reorganizations, surface processes and seismic hazard in the Alps-Apennines-Carpathians-Dinarides orogenic system. The AlpArray Seismic Network has been deployed with contributions from 36 institutions from 11 countries to map physical properties of the lithosphere and asthenosphere in 3D and thus to obtain new, high-resolution geophysical images of structures from the surface down to the base of the mantle transition zone. With over 600 broadband stations operated for 2 years, this seismic experiment is one of the largest simultaneously operated seismological networks in the academic domain, employing hexagonal coverage with station spacing at less than 52 km. This dense and regularly spaced experiment is made possible by the coordinated coeval deployment of temporary stations from numerous national pools, including ocean-bottom seismometers, which were funded by different national agencies. They combine with permanent networks, which also required the cooperation of many different operators. Together these stations ultimately fill coverage gaps. Following a short overview of previous large-scale seismological experiments in the Alpine region, we here present the goals, construction, deployment, characteristics and data management of the AlpArray Seismic Network, which will provide data that is expected to be unprecedented in quality to image the complex Alpine mountains at depth.

Adding seismic broadband analysis to characterize Andean backarc seismicity in Argentina

NASA Astrophysics Data System (ADS)

Alvarado, P.; Giuliano, A.; Beck, S.; Zandt, G.

2007-05-01

Characterization of the highly seismically active Andean backarc is crucial for assessment of earthquake hazards in western Argentina. Moderate-to-large crustal earthquakes have caused several deaths, damage and drastic economic consequences in Argentinean history. We have studied the Andean backarc crust between 30°S and 36°S using seismic broadband data available from a previous ("the CHARGE") IRIS-PASSCAL experiment. We collected more than 12 terabytes of continuous seismic data from 22 broadband instruments deployed across Chile and Argentina during 1.5 years. Using free software we modeled full regional broadband waveforms and obtained seismic moment tensor inversions of crustal earthquakes testing for the best focal depth for each event. We also mapped differences in the Andean backarc crustal structure and found a clear correlation with different types of crustal seismicity (i.e. focal depths, focal mechanisms, magnitudes and frequencies of occurrence) and previously mapped terrane boundaries. We now plan to use the same methodology to study other regions in Argentina using near-real time broadband data available from the national seismic (INPRES) network and global seismic networks operating in the region. We will re-design the national seismic network to optimize short-period and broadband seismic station coverage for different network purposes. This work is an international effort that involves researchers and students from universities and national government agencies with the goal of providing more information about earthquake hazards in western Argentina.

The California Integrated Seismic Network

NASA Astrophysics Data System (ADS)

Hellweg, M.; Given, D.; Hauksson, E.; Neuhauser, D.; Oppenheimer, D.; Shakal, A.

2007-05-01

The mission of the California Integrated Seismic Network (CISN) is to operate a reliable, modern system to monitor earthquakes throughout the state; to generate and distribute information in real-time for emergency response, for the benefit of public safety, and for loss mitigation; and to collect and archive data for seismological and earthquake engineering research. To meet these needs, the CISN operates data processing and archiving centers, as well as more than 3000 seismic stations. Furthermore, the CISN is actively developing and enhancing its infrastructure, including its automated processing and archival systems. The CISN integrates seismic and strong motion networks operated by the University of California Berkeley (UCB), the California Institute of Technology (Caltech), and the United States Geological Survey (USGS) offices in Menlo Park and Pasadena, as well as the USGS National Strong Motion Program (NSMP), and the California Geological Survey (CGS). The CISN operates two earthquake management centers (the NCEMC and SCEMC) where statewide, real-time earthquake monitoring takes place, and an engineering data center (EDC) for processing strong motion data and making it available in near real-time to the engineering community. These centers employ redundant hardware to minimize disruptions to the earthquake detection and processing systems. At the same time, dual feeds of data from a subset of broadband and strong motion stations are telemetered in real- time directly to both the NCEMC and the SCEMC to ensure the availability of statewide data in the event of a catastrophic failure at one of these two centers. The CISN uses a backbone T1 ring (with automatic backup over the internet) to interconnect the centers and the California Office of Emergency Services. The T1 ring enables real-time exchange of selected waveforms, derived ground motion data, phase arrivals, earthquake parameters, and ShakeMaps. With the goal of operating similar and redundant

GeoNetGIS: a Geodetic Network Geographical Information System to manage GPS networks in seismic and volcanic areas

NASA Astrophysics Data System (ADS)

Cristofoletti, P.; Esposito, A.; Anzidei, M.

2003-04-01

This paper presents the methodologies and issues involved in the use of GIS techniques to manage geodetic information derived from networks in seismic and volcanic areas. Organization and manipulation of different geodetical, geological and seismic database, give us a new challenge in interpretation of information that has several dimensions, including spatial and temporal variations, also the flexibility and brand range of tools available in GeoNetGIS, make it an attractive platform for earthquake risk assessment. During the last decade the use of geodetic networks based on the Global Positioning System, devoted to geophysical applications, especially for crustal deformation monitoring in seismic and volcanic areas, increased dramatically. The large amount of data provided by these networks, combined with different and independent observations, such as epicentre distribution of recent and historical earthquakes, geological and structural data, photo interpretation of aerial and satellite images, can aid for the detection and parameterization of seismogenic sources. In particular we applied our geodetic oriented GIS to a new GPS network recently set up and surveyed in the Central Apennine region: the CA-GeoNet. GeoNetGIS is designed to analyze in three and four dimensions GPS sources and to improve crustal deformation analysis and interpretation related with tectonic structures and seismicity. It manages many database (DBMS) consisting of different classes, such as Geodesy, Topography, Seismicity, Geology, Geography and Raster Images, administrated according to Thematic Layers. GeoNetGIS represents a powerful research tool allowing to join the analysis of all data layers to integrate the different data base which aid for the identification of the activity of known faults or structures and suggesting the new evidences of active tectonics. A new approach to data integration given by GeoNetGIS capabilities, allow us to create and deliver a wide range of maps, digital

Continuous Seismic Threshold Monitoring

DTIC Science & Technology

1992-05-31

Continuous threshold monitoring is a technique for using a seismic network to monitor a geographical area continuously in time. The method provides...area. Two approaches are presented. Site-specific monitoring: By focusing a seismic network on a specific target site, continuous threshold monitoring...recorded events at the site. We define the threshold trace for the network as the continuous time trace of computed upper magnitude limits of seismic

VORBrouter: A dynamic data routing system for Real-Time Seismic networks

NASA Astrophysics Data System (ADS)

Hansen, T.; Vernon, F.; Lindquist, K.; Orcutt, J.

2004-12-01

For anyone who has managed a moderately complex buffered real-time data transport system, the need for reliable adaptive data transport is clear. The ROADNet VORBrouter system, an extension to the ROADNet data catalog system [AGU-2003, Dynamic Dataflow Topology Monitoring for Real-time Seismic Networks], allows dynamic routing of real-time seismic data from sensor to end-user. Traditional networks consist of a series of data buffer computers with data transport interconnections configured by hand. This allows for arbitrarily complex data networks, which can often exceed full comprehension by network administrators, sometimes resulting in data loops or accidental data cutoff. In order to manage data transport systems in the event of a network failure, a network administrator must be called upon to change the data transport paths and to recover the missing data. Using VORBrouter, administrators can sleep at night while still providing 7/24 uninterupted data streams at realistic cost. This software package uses information from the ROADNet data catalog system to route packets around failed link outages and to new consumers in real-time. Dynamic data routing protocols operating on top of the Antelope Data buffering layer allow authorized users to request data sets from their local buffer and to have them delivered from anywhere within the network of buffers. The VORBrouter software also allows for dynamic routing around network outages, and the elimination of duplicate data paths within the network, while maintaining the nearly lossless data transport features exhibited by the underlying Antelope system. We present the design of the VORBrouter system, its features, limitations and some future research directions.

Forecasting of Energy Expenditure of Induced Seismicity with Use of Artificial Neural Network

NASA Astrophysics Data System (ADS)

Cichy, Tomasz; Banka, Piotr

2017-12-01

Coal mining in many Polish mines in the Upper Silesian Coal Basin is accompanied by high levels of induced seismicity. In mining plants, the methods of shock monitoring are improved, allowing for more accurate localization of the occurring phenomena and determining their seismic energy. Equally important is the development of ways of forecasting seismic hazards that may occur while implementing mine design projects. These methods, depending on the length of time for which the forecasts are made, can be divided into: longterm, medium-term, short-term and so-called alarm. Long-term forecasts are particularly useful for the design of seam exploitations. The paper presents a method of predicting changes in energy expenditure of shock using a properly trained artificial neural network. This method allows to make long-term forecasts at the stage of the mine’s exploitation design, thus enabling the mining work plans to be reviewed to minimize the potential for tremors. The information given at the input of the neural network is indicative of the specific energy changes of the elastic deformation occurring in the selected, thick, resistant rock layers (tremor-prone layers). Energy changes, taking place in one or more tremor-prone layers are considered. These indicators describe only the specific energy changes of the elastic deformation accumulating in the rock as a consequence of the mining operation, but does not determine the amount of energy released during the destruction of a given volume of rock. In this process, the potential energy of elastic strain transforms into other, non-measurable energy types, including the seismic energy of recorded tremors. In this way, potential energy changes affect the observed induced seismicity. The parameters used are characterized by increases (declines) of specific energy with separation to occur before the hypothetical destruction of the rock and after it. Additional input information is an index characterizing the rate of

MyShake: A smartphone seismic network for earthquake early warning and beyond

PubMed Central

Kong, Qingkai; Allen, Richard M.; Schreier, Louis; Kwon, Young-Woo

2016-01-01

Large magnitude earthquakes in urban environments continue to kill and injure tens to hundreds of thousands of people, inflicting lasting societal and economic disasters. Earthquake early warning (EEW) provides seconds to minutes of warning, allowing people to move to safe zones and automated slowdown and shutdown of transit and other machinery. The handful of EEW systems operating around the world use traditional seismic and geodetic networks that exist only in a few nations. Smartphones are much more prevalent than traditional networks and contain accelerometers that can also be used to detect earthquakes. We report on the development of a new type of seismic system, MyShake, that harnesses personal/private smartphone sensors to collect data and analyze earthquakes. We show that smartphones can record magnitude 5 earthquakes at distances of 10 km or less and develop an on-phone detection capability to separate earthquakes from other everyday shakes. Our proof-of-concept system then collects earthquake data at a central site where a network detection algorithm confirms that an earthquake is under way and estimates the location and magnitude in real time. This information can then be used to issue an alert of forthcoming ground shaking. MyShake could be used to enhance EEW in regions with traditional networks and could provide the only EEW capability in regions without. In addition, the seismic waveforms recorded could be used to deliver rapid microseism maps, study impacts on buildings, and possibly image shallow earth structure and earthquake rupture kinematics. PMID:26933682

ULF radio monitoring network in a seismic area

NASA Astrophysics Data System (ADS)

Toader, Victorin; Moldovan, Iren-Adelina; Ionescu, Constantin; Marmureanu, Alexandru

2017-04-01

ULF monitoring is a part of a multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains). Four radio receivers (100 kHz - microwave) placed on faults in a high seismic area characterized by deep earthquakes detect fairly weak radio waves. The radio power is recorded in correlation with many other parameters related to near surface low atmosphere phenomena (seismicity, solar radiation, air ionization, electromagnetic activity, radon, CO2 concentration, atmospheric pressure, telluric currents, infrasound, seismo-acoustic emission, meteorological information). We follow variations in the earth's surface propagate radio waves avoiding reflection on ionosphere. For this reason the distance between stations is less than 60 km and the main source of emission is near (Bod broadcasting transmitter for long- and medium-wave radio, next to Brasov city). In the same time tectonic stress affects the radio propagation in air and it could generates ULF waves in ground (LAI coupling). To reduce the uncertainty is necessary to monitor a location for extended periods of time to outline local and seasonal fluctuations. Solar flares do not affect seismic activity but they produce disturbances in telecommunications networks and power grids. Our ULF monitoring correlated with two local magnetometers does not indicate this so far with our receivers. Our analysis was made during magnetic storms with Kp 7 and 8 according to NOAA satellites. To correlate the results we implemented an application that monitors the satellite EUTELSAT latency compared to WiMAX land communication in the same place. ULF band radio monitoring showed that our receiver is dependent on temperature and that it is necessary to introduce a band pass filter in data analysis. ULF data acquisition is performed by Kinemetrics and National Instruments digitizers with a sampling rate of 100 Hz in Miniseed format and then converted into text files with 1 Hz rate for analysis in very low

Using Antelope and Seiscomp in the framework of the Romanian Seismic Network

NASA Astrophysics Data System (ADS)

Marius Craiu, George; Craiu, Andreea; Marmureanu, Alexandru; Neagoe, Cristian

2014-05-01

The National Institute for Earth Physics (NIEP) operates a real-time seismic network designed to monitor the seismic activity on the Romania territory, dominated by the Vrancea intermediate-depth (60-200 km) earthquakes. The NIEP real-time network currently consists of 102 stations and two seismic arrays equipped with different high quality digitizers (Kinemetrics K2, Quanterra Q330, Quanterra Q330HR, PS6-26, Basalt), broadband and short period seismometers (CMG3ESP, CMG40T, KS2000, KS54000, KS2000, CMG3T, STS2, SH-1, S13, Mark l4c, Ranger, Gs21, Mark 22) and acceleration sensors (Episensor Kinemetrics). The primary goal of the real-time seismic network is to provide earthquake parameters from more broad-band stations with a high dynamic range, for more rapid and accurate computation of the locations and magnitudes of earthquakes. The Seedlink and AntelopeTM program packages are completely automated Antelope seismological system is run at the Data Center in Măgurele. The Antelope data acquisition and processing software is running for real-time processing and post processing. The Antelope real-time system provides automatic event detection, arrival picking, event location, and magnitude calculation. It also provides graphical displays and automatic location within near real time after a local, regional or teleseismic event has occurred SeisComP 3 is another automated system that is run at the NIEP and which provides the following features: data acquisition, data quality control, real-time data exchange and processing, network status monitoring, issuing event alerts, waveform archiving and data distribution, automatic event detection and location, easy access to relevant information about stations, waveforms, and recent earthquakes. The main goal of this paper is to compare both of these data acquisitions systems in order to improve their detection capabilities, location accuracy, magnitude and depth determination and reduce the RMS and other location errors.

A seismic network to investigate the sedimentary hosted hydrothermal Lusi system

NASA Astrophysics Data System (ADS)

Javad Fallahi, Mohammad; Mazzini, Adriano; Lupi, Matteo; Obermann, Anne; Karyono, Karyono

2016-04-01

The 29th of May 2006 marked the beginning of the sedimentary hosted hydrothermal Lusi system. During the last 10 years we witnessed numerous alterations of the Lusi system behavior that coincide with the frequent seismic and volcanic activity occurring in the region. In order to monitor the effect that the seismicity and the activity of the volcanic arc have on Lusi, we deployed a ad hoc seismic network. This temporary network consist of 10 broadband and 21 short period stations and is currently operating around the Arjuno-Welirang volcanic complex, along the Watukosek fault system and around Lusi, in the East Java basin since January 2015. We exploit this dataset to investigate surface wave and shear wave velocity structure of the upper-crust beneath the Arjuno-Welirang-Lusi complex in the framework of the Lusi Lab project (ERC grant n° 308126). Rayleigh and Love waves travelling between each station-pair are extracted by cross-correlating long time series of ambient noise data recorded at the stations. Group and phase velocity dispersion curves are obtained by time-frequency analysis of cross-correlation functions, and are tomographically inverted to provide 2D velocity maps corresponding to different sampling depths. 3D shear wave velocity structure is then acquired by inverting the group velocity maps.

Modeling propagation of infrasound signals observed by a dense seismic network.

PubMed

Chunchuzov, I; Kulichkov, S; Popov, O; Hedlin, M

2014-01-01

The long-range propagation of infrasound from a surface explosion with an explosive yield of about 17.6 t TNT that occurred on June 16, 2008 at the Utah Test and Training Range (UTTR) in the western United States is simulated using an atmospheric model that includes fine-scale layered structure of the wind velocity and temperature fields. Synthetic signal parameters (waveforms, amplitudes, and travel times) are calculated using parabolic equation and ray-tracing methods for a number of ranges between 100 and 800 km from the source. The simulation shows the evolution of several branches of stratospheric and thermospheric signals with increasing range from the source. Infrasound signals calculated using a G2S (ground-to-space) atmospheric model perturbed by small-scale layered wind velocity and temperature fluctuations are shown to agree well with recordings made by the dense High Lava Plains seismic network located at an azimuth of 300° from UTTR. The waveforms of calculated infrasound arrivals are compared with those of seismic recordings. This study illustrates the utility of dense seismic networks for mapping an infrasound field with high spatial resolution. The parabolic equation calculations capture both the effect of scattering of infrasound into geometric acoustic shadow zones and significant temporal broadening of the arrivals.

Seismic Attenuation and Stiffness Modulus Dispersion in Porous Rocks Containing Stochastic Fracture Networks

NASA Astrophysics Data System (ADS)

Hunziker, Jürg; Favino, Marco; Caspari, Eva; Quintal, Beatriz; Rubino, J. Germán.; Krause, Rolf; Holliger, Klaus

2018-01-01

Understanding seismic attenuation and modulus dispersion mechanisms in fractured rocks can result in significant advances for the indirect characterization of such environments. In this paper, we study attenuation and modulus dispersion of seismic waves caused by fluid pressure diffusion (FPD) in stochastic 2-D fracture networks, allowing for a state-of-the-art representation of natural fracture networks by a power law length distribution. To this end, we apply numerical upscaling experiments consisting of compression and shear tests to our samples of fractured rocks. The resulting P and S wave attenuation and modulus dispersion behavior is analyzed with respect to the density, the length distribution, and the connectivity of the fractures. We focus our analysis on two manifestations of FPD arising in fractured rocks, namely, fracture-to-background FPD at lower frequencies and fracture-to-fracture FPD at higher frequencies. Our results indicate that FPD is sensitive not only to the fracture density but also to the geometrical characteristics of the fracture length distributions. In particular, our study suggests that information about the local connectivity of a fracture network could be retrieved from seismic data. Conversely, information about the global connectivity, which is directly linked to the effective hydraulic conductivity of the probed volume, remains rather difficult to infer.

Seismic activity offshore Martinique and Dominica islands (Central Lesser Antilles subduction zone) from temporary onshore and offshore seismic networks

NASA Astrophysics Data System (ADS)

Ruiz, M.; Galve, A.; Monfret, T.; Sapin, M.; Charvis, P.; Laigle, M.; Evain, M.; Hirn, A.; Flueh, E.; Gallart, J.; Diaz, J.; Lebrun, J. F.

2013-09-01

This work focuses on the analysis of a unique set of seismological data recorded by two temporary networks of seismometers deployed onshore and offshore in the Central Lesser Antilles Island Arc from Martinique to Guadeloupe islands. During the whole recording period, extending from January to the end of August 2007, more than 1300 local seismic events were detected in this area. A subset of 769 earthquakes was located precisely by using HypoEllipse. We also computed focal mechanisms using P-wave polarities of the best azimuthally constrained earthquakes. We detected earthquakes beneath the Caribbean forearc and in the Atlantic oceanic plate as well. At depth seismicity delineates the Wadati-Benioff Zone down to 170 km depth. The main seismic activity is concentrated in the lower crust and in the mantle wedge, close to the island arc beneath an inner forearc domain in comparison to an outer forearc domain where little seismicity is observed. We propose that the difference of the seismicity beneath the inner and the outer forearc is related to a difference of crustal structure between the inner forearc interpreted as a dense, thick and rigid crustal block and the lighter and more flexible outer forearc. Seismicity is enhanced beneath the inner forearc because it likely increases the vertical stress applied to the subducting plate.

Sismos a l'Ecole : a Seismic Educational Network (FRANCE) linked with Research

NASA Astrophysics Data System (ADS)

Berenguer, J.; Le Puth, J.; Courboulex, F.; Zodmi, B.; Boneff, M.

2007-12-01

Ahead of the quick evolution of our society, in which scientific information has to be accurately understood by a great majority, the promotion of a responsible behaviour coming from educated and trained citizens has become a priority. One of the roles of school is to enable children to understand sciences, these same sciences that were long ago the prerogative of scientific laboratories. The educational network SISMOS à l\\'"Ecole is an example of a project structured on the knowledge of seismic risks through a scientific and technological approach. It develops a teaching method leading to an approach towards the knowledge of natural disasters. The original and innovating feature of this educational network is to enable students to set up a seismograph in their school. The recorded signals - coming from a regional or a worldwide seismic activity - feed an on- line database, which is in fact a real research centre for seismic resources as well as a starting point for educational and scientific activities. The network, that numbers about thirty stations set up in France, in its overseas departments and territories, and in a couple of French schools abroad, is based upon an experience initiated in the French Riviera ten years ago or so. The achievement of the program has from then on gone beyond the simple purpose of conveying seismic data that research and monitoring centres could have recorded. Thanks to the use of scientific measures, students become involved and get into complex notions revolving around geophysics and geosciences. Developing simple tools, setting up concrete experiments combined with an investigate reasoning makes it easier to build up a quality scientific culture as well as an education of citizens to risks.

Seismicity of the rocky mountains and Rio Grande Rift from the EarthScope Transportable Array and CREST temporary seismic networks, 2008-2010

NASA Astrophysics Data System (ADS)

Nakai, J. S.; Sheehan, A. F.; Bilek, S. L.

2017-03-01

We developed a catalog of small magnitude (ML -0.1 to 4.7) seismicity across Colorado and New Mexico from the EarthScope USArray Transportable Array and CREST (Colorado Rocky Mountains Experiment and Seismic Transects) seismic networks from 2008 to 2010 to characterize active deformation in the Rio Grande Rift. We recorded over 900 earthquakes in the Rio Grande Rift region, not including induced earthquakes and mine blasts, and find that the rift is actively deforming both broadly and in distinct regions. Seismic events that are likely induced, mostly in the Raton Basin, make up 66% of the catalog (1837 earthquakes). Neogene faults in the northern rift in north central Colorado are seismically active in the North Park Basin and northwestern Colorado. The central rift from the San Luis Basin (southern Colorado) to south of the Socorro Magma Body is the most seismically active rift region, and seismicity delineates the deformation in the Colorado Plateau transition zone, which is spatially correlated with volcanic vents, dikes, and faults within the western Jemez Lineament. The eastern Jemez Lineament is nearly aseismic and surrounded by a halo of seismicity culminating in boundaries defined by recent moderate (Mw 3.9 and Mw 3.3) earthquakes. The southern rift is characterized by diffuse seismicity in Texas and Mexico. This study provides an updated seismic catalog built with uniformity in seismometer coverage and low epicentral uncertainties ( 2 km) that allows for regional evaluation of seismicity. During this time period, clusters of seismicity and moderate magnitude earthquakes characterize deformation in a low-strain rate extensional environment.

Teaching hands-on geophysics: examples from the Rū seismic network in New Zealand

NASA Astrophysics Data System (ADS)

van Wijk, Kasper; Simpson, Jonathan; Adam, Ludmila

2017-03-01

Education in physics and geosciences can be effectively illustrated by the analysis of earthquakes and the subsequent propagation of seismic waves in the Earth. Educational seismology has matured to a level where both the hard- and software are robust and user friendly. This has resulted in successful implementation of educational networks around the world. Seismic data recorded by students are of such quality that these can be used in classic earthquake location exercises, for example. But even ocean waves weakly coupled into the Earth’s crust can now be recorded on educational seismometers. These signals are not just noise, but form the basis of more recent developments in seismology, such as seismic interferometry, where seismic waves generated by ocean waves—instead of earthquakes—can be used to infer information about the Earth’s interior. Here, we introduce an earthquake location exercise and an analysis of ambient seismic noise, and present examples. Data are provided, and all needed software is freely available.

A networks-based discrete dynamic systems approach to volcanic seismicity

NASA Astrophysics Data System (ADS)

Suteanu, Mirela

2013-04-01

The detection and relevant description of pattern change concerning earthquake events is an important, but challenging task. In this paper, earthquake events related to volcanic activity are considered manifestations of a dynamic system evolving over time. The system dynamics is seen as a succession of events with point-like appearance both in time and in space. Each event is characterized by a position in three-dimensional space, a moment of occurrence, and an event size (magnitude). A weighted directed network is constructed to capture the effects of earthquakes on subsequent events. Each seismic event represents a node. Relations among events represent edges. Edge directions are given by the temporal succession of the events. Edges are also characterized by weights reflecting the strengths of the relation between the nodes. Weights are calculated as a function of (i) the time interval separating the two events, (ii) the spatial distance between the events, (iii) the magnitude of the earliest event among the two. Different ways of addressing weight components are explored, and their implications for the properties of the produced networks are analyzed. The resulting networks are then characterized in terms of degree- and weight distributions. Subsequently, the distribution of system transitions is determined for all the edges connecting related events in the network. Two- and three-dimensional diagrams are constructed to reflect transition distributions for each set of events. Networks are thus generated for successive temporal windows of different size, and the evolution of (a) network properties and (b) system transition distributions are followed over time and compared to the timeline of documented geologic processes. Applications concerning volcanic seismicity on the Big Island of Hawaii show that this approach is capable of revealing novel aspects of change occurring in the volcanic system on different scales in time and in space.

Explosion Source Location Study Using Collocated Acoustic and Seismic Networks in Israel

NASA Astrophysics Data System (ADS)

Pinsky, V.; Gitterman, Y.; Arrowsmith, S.; Ben-Horin, Y.

2013-12-01

We explore a joined analysis of seismic and infrasonic signals for improvement in automatic monitoring of small local/regional events, such as construction and quarry blasts, military chemical explosions, sonic booms, etc. using collocated seismic and infrasonic networks recently build in Israel (ISIN) in the frame of the project sponsored by the Bi-national USA-Israel Science Foundation (BSF). The general target is to create an automatic system, which will provide detection, location and identification of explosions in real-time or close-to-real time manner. At the moment the network comprises 15 stations hosting a microphone and seismometer (or accelerometer), operated by the Geophysical Institute of Israel (GII), plus two infrasonic arrays, operated by the National Data Center, Soreq: IOB in the South (Negev desert) and IMA in the North of Israel (Upper Galilee),collocated with the IMS seismic array MMAI. The study utilizes a ground-truth data-base of numerous Rotem phosphate quarry blasts, a number of controlled explosions for demolition of outdated ammunitions and experimental surface explosions for a structure protection research, at the Sayarim Military Range. A special event, comprising four military explosions in a neighboring country, that provided both strong seismic (up to 400 km) and infrasound waves (up to 300 km), is also analyzed. For all of these events the ground-truth coordinates and/or the results of seismic location by the Israel Seismic Network (ISN) have been provided. For automatic event detection and phase picking we tested the new recursive picker, based on Statistically optimal detector. The results were compared to the manual picks. Several location techniques have been tested using the ground-truth event recordings and the preliminary results obtained have been compared to the ground-truth locations: 1) a number of events have been located as intersection of azimuths estimated using the wide-band F-K analysis technique applied to the

Quantifying capability of a local seismic network in terms of locations and focal mechanism solutions of weak earthquakes

NASA Astrophysics Data System (ADS)

Fojtíková, Lucia; Kristeková, Miriam; Málek, Jiří; Sokos, Efthimios; Csicsay, Kristián; Zahradník, Jiří

2016-01-01

Extension of permanent seismic networks is usually governed by a number of technical, economic, logistic, and other factors. Planned upgrade of the network can be justified by theoretical assessment of the network capability in terms of reliable estimation of the key earthquake parameters (e.g., location and focal mechanisms). It could be useful not only for scientific purposes but also as a concrete proof during the process of acquisition of the funding needed for upgrade and operation of the network. Moreover, the theoretical assessment can also identify the configuration where no improvement can be achieved with additional stations, establishing a tradeoff between the improvement and additional expenses. This paper presents suggestion of a combination of suitable methods and their application to the Little Carpathians local seismic network (Slovakia, Central Europe) monitoring epicentral zone important from the point of seismic hazard. Three configurations of the network are considered: 13 stations existing before 2011, 3 stations already added in 2011, and 7 new planned stations. Theoretical errors of the relative location are estimated by a new method, specifically developed in this paper. The resolvability of focal mechanisms determined by waveform inversion is analyzed by a recent approach based on 6D moment-tensor error ellipsoids. We consider potential seismic events situated anywhere in the studied region, thus enabling "mapping" of the expected errors. Results clearly demonstrate that the network extension remarkably decreases the errors, mainly in the planned 23-station configuration. The already made three-station extension of the network in 2011 allowed for a few real data examples. Free software made available by the authors enables similar application in any other existing or planned networks.

NON-INVASIVE DETERMINATION OF THE LOCATION AND DISTRBUTION OF FREE-PHASE DENSE NONAQUEOUS PHASE LIQUIDS (DNAPL) BY SEISMIC REFLECTION TECHNIQUES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael G. Waddell; William J. Domoracki; Jerome Eyer

2003-01-01

The Earth Sciences and Resources Institute, University of South Carolina is conducting a proof of concept study to determine the location and distribution of subsurface DNAPL carbon tetrachloride (CCl{sub 4}) contamination at the 216-Z-9 crib, 200 West area, DOE Hanford Site, Washington by use of two-dimensional high-resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are noninvasive means of site characterization and direct free-phase DNAPL detection. This final report covers the results of Tasks 1,more » 2, and 3. Task (1) contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task (2) is the design and acquisition of 2-D seismic reflection data to image areas of probable high concentration of DNAPL. Task (3) is the processing and interpretation of the 2-D data. During the commission of these tasks four seismic reflection profiles were collected. Subsurface velocity information was obtained by vertical seismic profile surveys in three wells. The interpretation of these data is in two parts. Part one is the construction and interpretation of structural contour maps of the contact between the Hanford Fine unit and the underlying Plio/Pleistocene unit and of the contact between the Plio/Pleistocene unit and the underlying caliche layer. These two contacts were determined to be the most likely surfaces to contain the highest concentration CCl{sub 4}. Part two of the interpretation uses the results of the AVO modeling to locate any seismic amplitude anomalies that

Hanford Site National Environmental Policy Act (NEPA) Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, Joanne P.; Burk, Kenneth W.; Chamness, Mickie A.

2007-09-27

specific information covering statutory and regulatory requirements for use in an environmental assessment or environmental impact statement. When preparing environmental assessments and EISs, authors should consult Recommendations for the Preparation of Environmental Assessments and Environmental Impact Statements published by the DOE Office of NEPA Oversight (DOE 2004). Additional direction and guidance on the preparation of DOE NEPA documents can be found at http://tis.eh.doe.gov/nepa/guidance.html. Individuals seeking baseline data on the Hanford Site and its past activities may also use the information contained in this document to evaluate projected activities and their impacts. Pacific Northwest National Laboratory (PNNL) staff prepared individual sections of this document, with input from other Hanford Site contractors with the best available information through May 2007. More detailed data are available from reference sources cited or from the authors. For this 2007 revision, the following sections of the document were reviewed by the authors and updated with the best available information through May 2005: Climate and Meteorology Air Quality Geology – Seismicity section only Hydrology – Flow charts for the Columbia and Yakima rivers only Ecology – Threatened and Endangered Species subsection only Socioeconomics Occupational Safety All of Chapter 6.« less

A study of infrasonic anisotropy and multipathing in the atmosphere using seismic networks.

PubMed

Hedlin, Michael A H; Walker, Kristoffer T

2013-02-13

We discuss the use of reverse time migration (RTM) with dense seismic networks for the detection and location of sources of atmospheric infrasound. Seismometers measure the response of the Earth's surface to infrasound through acoustic-to-seismic coupling. RTM has recently been applied to data from the USArray network to create a catalogue of infrasonic sources in the western US. Specifically, several hundred sources were detected in 2007-2008, many of which were not observed by regional infrasonic arrays. The influence of the east-west stratospheric zonal winds is clearly seen in the seismic data with most detections made downwind of the source. We study this large-scale anisotropy of infrasonic propagation, using a winter and summer source in Idaho. The bandpass-filtered (1-5 Hz) seismic waveforms reveal in detail the two-dimensional spread of the infrasonic wavefield across the Earth's surface within approximately 800 km of the source. Using three-dimensional ray tracing, we find that the stratospheric winds above 30 km altitude in the ground-to-space (G2S) atmospheric model explain well the observed anisotropy pattern. We also analyse infrasound from well-constrained explosions in northern Utah with a denser IRIS PASSCAL seismic network. The standard G2S model correctly predicts the anisotropy of the stratospheric duct, but it incorrectly predicts the dimensions of the shadow zones in the downwind direction. We show that the inclusion of finer-scale structure owing to internal gravity waves infills the shadow zones and predicts the observed time durations of the signals. From the success of this method in predicting the observations, we propose that multipathing owing to fine scale, layer-cake structure is the primary mechanism governing propagation for frequencies above approximately 1 Hz and infer that stochastic approaches incorporating internal gravity waves are a useful improvement to the standard G2S model for infrasonic propagation modelling.

Crowd-Sourcing Seismic Data for Education and Research Opportunities with the Quake-Catcher Network

NASA Astrophysics Data System (ADS)

Sumy, D. F.; DeGroot, R. M.; Benthien, M. L.; Cochran, E. S.; Taber, J. J.

2016-12-01

The Quake Catcher Network (QCN; quakecatcher.net) uses low cost micro-electro-mechanical system (MEMS) sensors hosted by volunteers to collect seismic data. Volunteers use accelerometers internal to laptop computers, phones, tablets or small (the size of a matchbox) MEMS sensors plugged into desktop computers using a USB connector to collect scientifically useful data. Data are collected and sent to a central server using the Berkeley Open Infrastructure for Network Computing (BOINC) distributed computing software. Since 2008, sensors installed in museums, schools, offices, and residences have collected thousands of earthquake records, including the 2010 M8.8 Maule, Chile, the 2010 M7.1 Darfield, New Zealand, and 2015 M7.8 Gorkha, Nepal earthquakes. In 2016, the QCN in the United States transitioned to the Incorporated Research Institutions for Seismology (IRIS) Consortium and the Southern California Earthquake Center (SCEC), which are facilities funded through the National Science Foundation and the United States Geological Survey, respectively. The transition has allowed for an influx of new ideas and new education related efforts, which include focused installations in several school districts in southern California, on Native American reservations in North Dakota, and in the most seismically active state in the contiguous U.S. - Oklahoma. We present and describe these recent educational opportunities, and highlight how QCN has engaged a wide sector of the public in scientific data collection, particularly through the QCN-EPIcenter Network and NASA Mars InSight teacher programs. QCN provides the public with information and insight into how seismic data are collected, and how researchers use these data to better understand and characterize seismic activity. Lastly, we describe how students use data recorded by QCN sensors installed in their classrooms to explore and investigate felt earthquakes, and look towards the bright future of the network.

Seismic Monitoring for the United Arab Emirates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodgers, A; Nakanishi, K

2005-04-11

There is potential for earthquakes in the United Arab Emirates and in the Zagros mountains to cause structural damage and pose a threat to safety of people. Damaging effects from earthquakes can be mitigated by knowledge of the location and size of earthquakes, effects on construction, and monitoring these effects over time. Although a general idea of seismicity in the UAE may be determined with data from global seismic networks, these global networks do not have the sensitivity to record smaller seismic events and do not have the necessary accuracy to locate the events. A National Seismic Monitoring Observatory ismore » needed for the UAE that consists of a modern seismic network and a multidisciplinary staff that can analyze and interpret the data from the network. A seismic network is essential to locate earthquakes, determine event magnitudes, identify active faults and measure ground motions from earthquakes. Such a network can provide the data necessary for a reliable seismic hazard assessment in the UAE. The National Seismic Monitoring Observatory would ideally be situated at a university that would provide access to the wide range of disciplines needed in operating the network and providing expertise in analysis and interpretation.« less

Evidence of magma intrusion at Fourpeaked volcano, Alaska in 2006-2007 from a rapid-response seismic network and volcanic gases

USGS Publications Warehouse

Gardine, M.; West, M.; Werner, C.; Doukas, M.

2011-01-01

On September 17th, 2006, Fourpeaked volcano had a widely-observed phreatic eruption. At the time, Fourpeaked was an unmonitored volcano with no known Holocene activity, based on limited field work. Airborne gas sampling began within days of the eruption and a modest seismic network was installed in stages. Vigorous steaming continued for months; however, there were no further eruptions similar in scale to the September 17 event. This eruption was followed by several months of sustained seismicity punctuated by vigorous swarms, and SO2 emissions exceeding a thousand tons/day. Based on observations during and after the phreatic eruption, and assuming no recent pre-historical eruptive activity at Fourpeaked, we propose that the activity was caused by a minor injection of new magma at or near 5km depth beneath Fourpeaked, which remained active over several months as this magma equilibrated into the crust. By early 2007 declining seismicity and SO2 emission signaled the end of unrest. Because the Fourpeaked seismic network was installed in stages and the seismicity was punctuated by discrete swarms, we use Fourpeaked to illustrate quantitatively the efficacy and shortcomings of rapid response seismic networks for tracking volcanic earthquakes.

Hanford`s innovations for science education

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, D.

1996-12-31

In recognition of declining science literacy in the United States and a projected shortfall of scientists, engineers and technologists to address environmental problems nationally and internationally during the 21st century, Westinghouse Hanford Company has launched several innovative science education projects at the US Department of Energy Hanford Site. The Hanford Site is very rich in resources that can be brought to bear on the problem: world-class technical experts, state of the art facilities and equipment, and the largest environmental laboratory in the world. During the past two years, several innovative science education initiatives have been conceived and pursued at themore » secondary education level including the International Academy for the Environment (residential high school with an environmental theme), Environmental BATTmobile Program (mobile middle school science education program), and Multicultural Experiences in Math and Science (education program based on cultural contributions to math and science). Hanford scientists, engineers and administrators have worked with the education community (K-12 and college-university) to develop innovative approaches to science education.« less

Supervised machine learning on a network scale: application to seismic event classification and detection

NASA Astrophysics Data System (ADS)

Reynen, Andrew; Audet, Pascal

2017-09-01

A new method using a machine learning technique is applied to event classification and detection at seismic networks. This method is applicable to a variety of network sizes and settings. The algorithm makes use of a small catalogue of known observations across the entire network. Two attributes, the polarization and frequency content, are used as input to regression. These attributes are extracted at predicted arrival times for P and S waves using only an approximate velocity model, as attributes are calculated over large time spans. This method of waveform characterization is shown to be able to distinguish between blasts and earthquakes with 99 per cent accuracy using a network of 13 stations located in Southern California. The combination of machine learning with generalized waveform features is further applied to event detection in Oklahoma, United States. The event detection algorithm makes use of a pair of unique seismic phases to locate events, with a precision directly related to the sampling rate of the generalized waveform features. Over a week of data from 30 stations in Oklahoma, United States are used to automatically detect 25 times more events than the catalogue of the local geological survey, with a false detection rate of less than 2 per cent. This method provides a highly confident way of detecting and locating events. Furthermore, a large number of seismic events can be automatically detected with low false alarm, allowing for a larger automatic event catalogue with a high degree of trust.

Contribution of the Surface and Down-Hole Seismic Networks to the Location of Earthquakes at the Soultz-sous-Forêts Geothermal Site (France)

NASA Astrophysics Data System (ADS)

Kinnaert, X.; Gaucher, E.; Kohl, T.; Achauer, U.

2018-03-01

Seismicity induced in geo-reservoirs can be a valuable observation to image fractured reservoirs, to characterize hydrological properties, or to mitigate seismic hazard. However, this requires accurate location of the seismicity, which is nowadays an important seismological task in reservoir engineering. The earthquake location (determination of the hypocentres) depends on the model used to represent the medium in which the seismic waves propagate and on the seismic monitoring network. In this work, location uncertainties and location inaccuracies are modeled to investigate the impact of several parameters on the determination of the hypocentres: the picking uncertainty, the numerical precision of picked arrival times, a velocity perturbation and the seismic network configuration. The method is applied to the geothermal site of Soultz-sous-Forêts, which is located in the Upper Rhine Graben (France) and which was subject to detailed scientific investigations. We focus on a massive water injection performed in the year 2000 to enhance the productivity of the well GPK2 in the granitic basement, at approximately 5 km depth, and which induced more than 7000 earthquakes recorded by down-hole and surface seismic networks. We compare the location errors obtained from the joint or the separate use of the down-hole and surface networks. Besides the quantification of location uncertainties caused by picking uncertainties, the impact of the numerical precision of the picked arrival times as provided in a reference catalogue is investigated. The velocity model is also modified to mimic possible effects of a massive water injection and to evaluate its impact on earthquake hypocentres. It is shown that the use of the down-hole network in addition to the surface network provides smaller location uncertainties but can also lead to larger inaccuracies. Hence, location uncertainties would not be well representative of the location errors and interpretation of the seismicity

Community Seismic Network (CSN)

NASA Astrophysics Data System (ADS)

Clayton, R. W.; Heaton, T. H.; Kohler, M. D.; Cheng, M.; Guy, R.; Chandy, M.; Krause, A.; Bunn, J.; Olson, M.; Faulkner, M.; Liu, A.; Strand, L.

2012-12-01

We report on developments in sensor connectivity, architecture, and data fusion algorithms executed in Cloud computing systems in the Community Seismic Network (CSN), a network of low-cost sensors housed in homes and offices by volunteers in the Pasadena, CA area. The network has over 200 sensors continuously reporting anomalies in local acceleration through the Internet to a Cloud computing service (the Google App Engine) that continually fuses sensor data to rapidly detect shaking from earthquakes. The Cloud computing system consists of data centers geographically distributed across the continent and is likely to be resilient even during earthquakes and other local disasters. The region of Southern California is partitioned in a multi-grid style into sets of telescoping cells called geocells. Data streams from sensors within a geocell are fused to detect anomalous shaking across the geocell. Temporal spatial patterns across geocells are used to detect anomalies across regions. The challenge is to detect earthquakes rapidly with an extremely low false positive rate. We report on two data fusion algorithms, one that tessellates the surface so as to fuse data from a large region around Pasadena and the other, which uses a standard tessellation of equal-sized cells. Since September 2011, the network has successfully detected earthquakes of magnitude 2.5 or higher within 40 Km of Pasadena. In addition to the standard USB device, which connects to the host's computer, we have developed a stand-alone sensor that directly connects to the internet via Ethernet or wifi. This bypasses security concerns that some companies have with the USB-connected devices, and allows for 24/7 monitoring at sites that would otherwise shut down their computers after working hours. In buildings we use the sensors to model the behavior of the structures during weak events in order to understand how they will perform during strong events. Visualization models of instrumented buildings ranging

Recent developments in seismic seabed oil reservoir monitoring applications using fibre-optic sensing networks

NASA Astrophysics Data System (ADS)

De Freitas, J. M.

2011-05-01

This review looks at recent developments in seismic seabed oil reservoir monitoring techniques using fibre-optic sensing networks. After a brief introduction covering the background and scope of the review, the following section focuses on state-of-the-art fibre-optic hydrophones and accelerometers used for seismic applications. Related metrology aspects of the sensor such as measurement of sensitivity, noise and cross-axis performance are addressed. The third section focuses on interrogation systems. Two main phase-based competing systems have emerged over the past two decades for seismic applications, with a third technique showing much promise; these have been compared in terms of general performance.

The Community Seismic Network: Enabling Observations Through Citizen Science Participation

NASA Astrophysics Data System (ADS)

Kohler, M. D.; Clayton, R. W.; Heaton, T. H.; Bunn, J.; Guy, R.; Massari, A.; Chandy, K. M.

2017-12-01

The Community Seismic Network is a dense accelerometer array deployed in the greater Los Angeles area and represents the future of densely instrumented urban cities where localized vibration measurements are collected continuously throughout the free-field and built environment. The hardware takes advantage of developments in the semiconductor industry in the form of inexpensive MEMS accelerometers that are each coupled with a single board computer. The data processing and archival architecture borrows from developments in cloud computing and network connectedness. The ability to deploy densely in the free field and in upper stories of mid/high-rise buildings is enabled by community hosts for sensor locations. To this end, CSN has partnered with the Los Angeles Unified School District (LAUSD), the NASA-Jet Propulsion Laboratory (JPL), and commercial and civic building owners to host sensors. At these sites, site amplification estimates from RMS noise measurements illustrate the lateral variation in amplification over length scales of 100 m or less, that correlate with gradients in the local geology such as sedimentary basins that abut crystalline rock foothills. This is complemented by high-resolution, shallow seismic velocity models obtained using an H/V method. In addition, noise statistics are used to determine the reliability of sites for ShakeMap and earthquake early warning data. The LAUSD and JPL deployments are examples of how situational awareness and centralized warning products such as ShakeMap and ShakeCast are enabled by citizen science participation. Several buildings have been instrumented with at least one triaxial accelerometer per floor, providing measurements for real-time structural health monitoring through local, customized displays. For real-time and post-event evaluation, the free-field and built environment CSN data and products illustrate the feasibility of order-of-magnitude higher spatial resolution mapping compared to what is currently

A new algorithm to detect earthquakes outside the seismic network: preliminary results

NASA Astrophysics Data System (ADS)

Giudicepietro, Flora; Esposito, Antonietta Maria; Ricciolino, Patrizia

2017-04-01

In this text we are going to present a new technique for detecting earthquakes outside the seismic network, which are often the cause of fault of automatic analysis system. Our goal is to develop a robust method that provides the discrimination result as quickly as possible. We discriminate local earthquakes from regional earthquakes, both recorded at SGG station, equipped with short period sensors, operated by Osservatorio Vesuviano (INGV) in the Southern Apennines (Italy). The technique uses a Multi Layer Perceptron (MLP) neural network with an architecture composed by an input layer, a hidden layer and a single node output layer. We pre-processed the data using the Linear Predictive Coding (LPC) technique to extract the spectral features of the signals in a compact form. We performed several experiments by shortening the signal window length. In particular, we used windows of 4, 2 and 1 seconds containing the onset of the local and the regional earthquakes. We used a dataset of 103 local earthquakes and 79 regional earthquakes, most of which occurred in Greece, Albania and Crete. We split the dataset into a training set, for the network training, and a testing set to evaluate the network's capacity of discrimination. In order to assess the network stability, we repeated this procedure six times, randomly changing the data composition of the training and testing set and the initial weights of the net. We estimated the performance of this method by calculating the average of correct detection percentages obtained for each of the six permutations. The average performances are 99.02%, 98.04% and 98.53%, which concern respectively the experiments carried out on 4, 2 and 1 seconds signal windows. The results show that our method is able to recognize the earthquakes outside the seismic network using only the first second of the seismic records, with a suitable percentage of correct detection. Therefore, this algorithm can be profitably used to make earthquake automatic

Detection and localization capability of an urban seismic sinkhole monitoring network

NASA Astrophysics Data System (ADS)

Becker, Dirk; Dahm, Torsten; Schneider, Fabian

2017-04-01

Microseismic events linked to underground processes in sinkhole areas might serve as precursors to larger mass dislocation or rupture events which can cause felt ground shaking or even structural damage. To identify these weak and shallow events, a sensitive local seismic monitoring network is needed. In case of an urban environment the performance of local monitoring networks is severely compromised by the high anthropogenic noise level. We study the detection and localization capability of such a network, which is already partly installed in the urban area of the city of Hamburg, Germany, within the joint project SIMULTAN (http://www.gfz-potsdam.de/en/section/near-surface-geophysics/projects/simultan/). SIMULTAN aims to monitor a known sinkhole structure and gain a better understanding of the underlying processes. The current network consists of six surface stations installed in the basement of private houses and underground structures of a research facility (DESY - Deutsches Elektronen Synchrotron). During the started monitoring campaign since 2015, no microseismic events could be unambiguously attributed to the sinkholes. To estimate the detection and location capability of the network, we calculate synthetic waveforms based on the location and mechanism of former events in the area. These waveforms are combined with the recorded urban seismic noise at the station sites. As detection algorithms a simple STA/LTA trigger and a more sophisticated phase detector are used. While the STA/LTA detector delivers stable results and is able to detect events with a moment magnitude as low as 0.35 at a distance of 1.3km from the source even under the present high noise conditions the phase detector is more sensitive but also less stable. It should be stressed that due to the local near surface conditions of the wave propagation the detections are generally performed on S- or surface waves and not on P-waves, which have a significantly lower amplitude. Due to the often

The Los Alamos Seismic Network (LASN): Improved Network Instrumentation, Local Earthquake Catalog Updates, and Peculiar Types of Data

NASA Astrophysics Data System (ADS)

Roberts, P. M.; Ten Cate, J. A.; House, L. S.; Greene, M. K.; Morton, E.; Kelley, R. E.

2013-12-01

The Los Alamos Seismic Network (LASN) has operated for 41 years, and provided the data to locate more than 2,500 earthquakes in north-central New Mexico. The network was installed for seismic verification research, as well as to monitor and locate earthquakes near Los Alamos National Laboratory (LANL). LASN stations are the only monitoring stations in New Mexico north of Albuquerque. The original network once included 22 stations in northern Mew Mexico. With limited funding in the early 1980's, the network was downsized to 7 stations within an area of about 15 km (N-S) by 15 km (E-W), centered on Los Alamos. Over the last four years, eight additional stations have been installed, which have considerably expanded the spatial coverage of the network. Currently, 7 stations have broadband, three-component seismometers with digital telemetry, and the remaining 8 have traditional 1 Hz short-period seismometers with either analog telemetry or on-site digital recording. A vertical array of accelerometers was also installed in a wellbore on LANL property. This borehole array has 3-component digital strong-motion sensors. Recently we began upgrading the local strong-motion accelerometer (SMA) network as well, with the addition of high-resolution digitizers and high-sensitivity force-balance accelerometers (FBA). We will present an updated description of the current LASN station, instrumentation and telemetry configurations, as well as the data acquisition and event-detection software structure used to record events in Earthworm. Although more than 2,000 earthquakes were detected and located in north-central New Mexico during the first 11 years of LASN's operation (1973 to 1984), currently only 1-2 earthquakes per month are detected and located within about 150 km of Los Alamos. Over 850 of these nearby earthquakes have been located from 1973 to present. We recently updated the LASN earthquake catalog for north-central New Mexico up through 2012 and most of 2013. Locations

Detection of rainfall-induced landslides on regional seismic networks

NASA Astrophysics Data System (ADS)

Manconi, Andrea; Coviello, Velio; Gariano, Stefano Luigi; Picozzi, Matteo

2017-04-01

Seismic techniques are increasingly adopted to detect signals induced by mass movements and to quantitatively evaluate geo-hydrological hazards at different spatial and temporal scales. By analyzing landslide-induced seismicity, it is possible obtaining significant information on the source of the mass wasting, as well as on its dynamics. However, currently only few studies have performed a systematic back analysis on comprehensive catalogues of events to evaluate the performance of proposed algorithms. In this work, we analyze a catalogue of 1058 landslides induced by rainfall in Italy. Among these phenomena, there are 234 rock falls, 55 debris flows, 54 mud flows, and 715 unspecified shallow landslides. This is a subset of a larger catalogue collected by the Italian research institute for geo-hydrological protection (CNR IRPI) during the period 2000-2014 (Brunetti et al., 2015). For each record, the following information are available: the type of landslide; the geographical location of the landslide (coordinates, site, municipality, province, and 3 classes of geographic accuracy); the temporal information on the landslide occurrence (day, month, year, time, date, and 3 classes of temporal accuracy); the rainfall conditions (rainfall duration and cumulated event rainfall) that have resulted in the landslide. We consider here only rainfall-induced landslides for which exact date and time were known from chronicle information. The analysis of coeval seismic data acquired by regional seismic networks show clear signals in at least 3 stations for 64 events (6% of the total dataset). Among them, 20 are associated to local earthquakes and 2 to teleseisms; 10 are anomalous signals characterized by irregular and impulsive waveforms in both time and frequency domains; 33 signals are likely associated to the landslide occurrence, as they have a cigar-shaped waveform characterized by emerging onsets, duration of several tens of seconds, and low frequencies (1-10 Hz). For

Earthquake location determination using data from DOMERAPI and BMKG seismic networks: A preliminary result of DOMERAPI project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramdhan, Mohamad; Agency for Meteorology, Climatology and Geophysics of Indonesia; Nugraha, Andri Dian

DOMERAPI project has been conducted to comprehensively study the internal structure of Merapi volcano, especially about deep structural features beneath the volcano. DOMERAPI earthquake monitoring network consists of 46 broad-band seismometers installed around the Merapi volcano. Earthquake hypocenter determination is a very important step for further studies, such as hypocenter relocation and seismic tomographic imaging. Ray paths from earthquake events occurring outside the Merapi region can be utilized to delineate the deep magma structure. Earthquakes occurring outside the DOMERAPI seismic network will produce an azimuthal gap greater than 180{sup 0}. Owing to this situation the stations from BMKG seismic networkmore » can be used jointly to minimize the azimuthal gap. We identified earthquake events manually and carefully, and then picked arrival times of P and S waves. The data from the DOMERAPI seismic network were combined with the BMKG data catalogue to determine earthquake events outside the Merapi region. For future work, we will also use the BPPTKG (Center for Research and Development of Geological Disaster Technology) data catalogue in order to study shallow structures beneath the Merapi volcano. The application of all data catalogues will provide good information as input for further advanced studies and volcano hazards mitigation.« less

50 years of Global Seismic Observations

NASA Astrophysics Data System (ADS)

Anderson, K. R.; Butler, R.; Berger, J.; Davis, P.; Derr, J.; Gee, L.; Hutt, C. R.; Leith, W. S.; Park, J. J.

2007-12-01

Seismological recordings have been made on Earth for hundreds of years in some form or another, however, global monitoring of earthquakes only began in the 1890's when John Milne created 40 seismic observatories to measure the waves from these events. Shortly after the International Geophysical Year (IGY), a concerted effort was made to establish and maintain a more modern standardized seismic network on the global scale. In the early 1960's, the World-Wide Standardized Seismograph Network (WWSSN) was established through funding from the Advanced Research Projects Agency (ARPA) and was installed and maintained by the USGS's Albuquerque Seismological Laboratory (then a part of the US Coast and Geodetic Survey). This network of identical seismic instruments consisted of 120 stations in 60 countries. Although the network was motivated by nuclear test monitoring, the WWSSN facilitated numerous advances in observational seismology. From the IGY to the present, the network has been upgraded (High-Gain Long-Period Seismograph Network, Seismic Research Observatories, Digital WWSSN, Global Telemetered Seismograph Network, etc.) and expanded (International Deployment of Accelerometers, US National Seismic Network, China Digital Seismograph Network, Joint Seismic Project, etc.), bringing the modern day Global Seismographic Network (GSN) to a current state of approximately 150 stations. The GSN consists of state-of-the-art very broadband seismic transducers, continuous power and communications, and ancillary sensors including geodetic, geomagnetic, microbarographic, meteorological and other related instrumentation. Beyond the GSN, the system of global network observatories includes contributions from other international partners (e.g., GEOSCOPE, GEOFON, MEDNET, F-Net, CTBTO), forming an even larger backbone of permanent seismological observatories as a part of the International Federation of Digital Seismograph Networks. 50 years of seismic network operations have provided

EGU2013 SM1.4/GI1.6 session: "Improving seismic networks performances: from site selection to data integration"

NASA Astrophysics Data System (ADS)

Pesaresi, D.; Busby, R.

2013-08-01

The number and quality of seismic stations and networks in Europe continually improves, nevertheless there is always scope to optimize their performance. In this session we welcomed contributions from all aspects of seismic network installation, operation and management. This includes site selection; equipment testing and installation; planning and implementing communication paths; policies for redundancy in data acquisition, processing and archiving; and integration of different datasets including GPS and OBS.

Alaska Seismic Network Upgrade and Expansion

NASA Astrophysics Data System (ADS)

Sandru, J. M.; Hansen, R. A.; Estes, S. A.; Fowler, M.

2009-12-01

such as ANSS, Alaska Volcano Observatory, Bradley Lake Dam, Red Dog Mine, The Plate Boundary Observatory (PBO), Alaska Tsunami Warning Center, and City and State Emergency Managers has helped link vast networks together so that the overall data transition can be varied. This lessens the likelihood of having a single point of failure for an entire network. Robust communication is key to retrieving seismic data. AEIC has gone through growing pains learning how to harden our network and encompassing the many types of telemetry that can be utilized in today's world. Redundant telemetry paths are a goal that is key to retrieving data, however at times this is not feasible with the vast size and terrain in Alaska. We will demonstrate what has worked for us and what our network consists of.

Site Assessment of a New State-Wide Seismic Network in Texas (TexNet)

NASA Astrophysics Data System (ADS)

Savvaidis, A.; Young, B.; Mukherjee, T.; Hennings, P.; Rathje, E.; Zalachoris, G.; Young, M.; Walter, J. I.; DeShon, H. R.; Frohlich, C.

2016-12-01

Earthquake activity has recently increased in the southern mid-continent of the U.S., including Texas. To monitor seismicity activity in the state of Texas, a new seismicity monitoring program known as TexNet, was funded by the Texas State Legislature in 2015. TexNet consists of 22 new permanent broadband (120s post-hole) seismic stations that will complement the 17 stations currently operating in the State. These permanent stations will provide the baseline seismicity of the state. In addition, 36 portable stations (incorporating both a 20s post-hole seismometer and a post-hole accelerometer) will be used to densify the network in specific areas, of the State, depending on measured seismicity level, proximity to infrastructure, or other scientific investigations. One goal for TexNet is to provide authenticated data needed to evaluate the location, and frequency of earthquakes. To minimize the uncertainties in earthquake locations and increase detectability of the network, an extensive site assessment survey was conducted. The initial station positions were chosen based on Earthscope, Transportable Array (TA) site positions, while ensuring that the stations were relatively evenly-spaced across the State. We then analyzed the noise and earthquake data from the TA seismometers, and added new locations based on geology, topography, and absence of nearby human activities. A 30-min noise test was conducted at each site to identify the site amplification using HVSR information. A 24-hr survey then followed, where the noise level during day and night was identified, analyzed using power spectral density and compared to the NHNM and NLNM (Peterson, 1993; USGS Open File Report, 322). Based on these survey results nearby alternative sites were evaluated to improve final site position. Full deployment and data streaming is expected by December 2016, and will be discussed during this presentation.

MyShake - Smartphone seismic network powered by citizen scientists

NASA Astrophysics Data System (ADS)

Kong, Q.; Allen, R. M.; Schreier, L.; Strauss, J. A.

2017-12-01

MyShake is a global smartphone seismic network that harnesses the power of crowdsourcing. It is driven by the citizen scientists that run MyShake on their personal smartphones. It has two components: an android application running on the smartphones to detect earthquake-like motion, and a network detection algorithm to aggregate results from multiple smartphones to confirm when an earthquake occurs. The MyShake application was released to the public on Feb 12th 2016. Within the first year, more than 250,000 people downloaded MyShake app around the world. There are more than 500 earthquakes recorded by the smartphones in this period, including events in Chile, Argentina, Mexico, Morocco, Greece, Nepal, New Zealand, Taiwan, Japan, and across North America. Currently, we are working on earthquake early warning with MyShake network and the shaking data provided by MyShake is a unique dataset that can be used for the research community.

Linkages of fracture network geometry and hydro-mechanical properties to spatio-temporal variations of seismicity in Koyna-Warna Seismic Zone

NASA Astrophysics Data System (ADS)

Selles, A.; Mikhailov, V. O.; Arora, K.; Ponomarev, A.; Gopinadh, D.; Smirnov, V.; Srinu, Y.; Satyavani, N.; Chadha, R. K.; Davulluri, S.; Rao, N. P.

2017-12-01

Well logging data and core samples from the deep boreholes in the Koyna-Warna Seismic Zone (KWSZ) provided a glimpse of the 3-D fracture network responsible for triggered earthquakes in the region. The space-time pattern of earthquakes during the last five decades show strong linkage of favourably oriented fractures system deciphered from airborne LiDAR and borehole structural logging to the seismicity. We used SAR interferometry data on surface displacements to estimate activity of the inferred faults. The failure in rocks at depths is largely governed by overlying lithostatic and pore fluid pressure in the rock matrix which are subject to change in space and time. While lithostatic pressure tends to increase with depth pore pressure is prone to fluctuations due to any change in the hydrological regime. Based on the earthquake catalogue data, the seasonal variations in seismic activity associated with annual fluctuations in the reservoir water level were analyzed over the time span of the entire history of seismological observations in this region. The regularities in the time changes in the structure of seasonal variations are revealed. An increase in pore fluid pressure can result in rock fracture and oscillating pore fluid pressures due to a reservoir loading and unloading cycles can cause iterative and cumulative damage, ultimately resulting in brittle failure under relatively low effective mean stress conditions. These regularities were verified by laboratory physical modeling. Based on our observations of main trends of spatio-temporal variations in seismicity as well as the spatial distribution of fracture network a conceptual model is presented to explain the triggered earthquakes in the KWSZ. The work was supported under the joint Russian-Indian project of the Russian Science Foundation (RSF) and the Department of Science and Technology (DST) of India (RSF project no. 16-47-02003 and DST project INT/RUS/RSF/P-13).

An Application of the SSHAC Level 3 Process to the Probabilistic Seismic Hazard Analysis for Nuclear Facilities at the Hanford Site, Eastern Washington, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coppersmith , Kevin J.; Bommer, Julian J.; Bryce, Robert W.

Under the sponsorship of the US Department of Energy (DOE) and the electric utility Energy Northwest, the Pacific Northwest National Laboratory (PNNL) is conducting a probabilistic seismic hazard analysis (PSHA) within the framework of a SSHAC Level 3 procedure (Senior Seismic Hazard Analysis Committee; Budnitz et al., 1997). Specifically, the project is being conducted following the guidelines and requirements specified in NUREG-2117 (USNRC, 2012b) and consistent with approach given in the American Nuclear Standard ANSI/ANS-2.29-2008 Probabilistic Seismic Hazard Analysis. The collaboration between DOE and Energy Northwest is spawned by the needs of both organizations for an accepted PSHA with highmore » levels of regulatory assurance that can be used for the design and safety evaluation of nuclear facilities. DOE committed to this study after performing a ten-year review of the existing PSHA, as required by DOE Order 420.1C. The study will also be used by Energy Northwest as a basis for fulfilling the NRC’s 10CFR50.54(f) requirement that the western US nuclear power plants conduct PSHAs in conformance with SSHAC Level 3 procedures. The study was planned and is being carried out in conjunction with a project Work Plan, which identifies the purpose of the study, the roles and responsibilities of all participants, tasks and their associated schedules, Quality Assurance (QA) requirements, and project deliverables. New data collection and analysis activities are being conducted as a means of reducing the uncertainties in key inputs to the PSHA. It is anticipated that the results of the study will provide inputs to the site response analyses at multiple nuclear facility sites within the Hanford Site and at the Columbia Generating Station.« less

The Berkeley Digital Seismic Network

NASA Astrophysics Data System (ADS)

Romanowicz, B.; Dreger, D.; Neuhauser, D.; Karavas, W.; Hellweg, M.; Uhrhammer, R.; Lombard, P.; Friday, J.; Lellinger, R.; Gardner, J.; McKenzie, M. R.; Bresloff, C.

2007-05-01

Since it began monitoring earthquakes in northern California 120 years ago, the Berkeley Seismological Laboratory (BSL) has been striving to produce the highest quality and most complete seismic data possible in the most modern way. This goal has influenced choices in instrumentation, installation and telemetry, as well as the investment in expertise and manpower. Since the transition to broadband (BB) instrumentation in the mid- 1980s and to a fully digitally telemetered network in the early 1990s, we have continued these efforts. Each of our 25 BB installations includes three component BB seismometers (STS-1s or STS-2) and digital accelerometers to capture the full range of ground motion from distant teleseisms to large, nearby earthquakes (almost 250 dB). The ground motion is recorded on-site by 24 bit dataloggers. Additional environmental parameters, such as temperature and pressure, are also monitored continuously. Many stations record also C-GPS data that is transmitted continuously to the BSL via shared real-time telemetry. The BDSN's first stations were installed in abandoned mines. In the last 15 years, we developed installations using buried shipping containers to reduce environmental noise and provide security and easy access to the equipment. Data are transmitted in real-time at several sampling rates to one or more processing centers, using frame relay, radio, microwave, and/or satellite. Each site has 7-30 days of onsite data storage to guard against data loss during telemetry outages. Each station is supplied with backup batteries to provide power for 3 days. The BDSN real-time data acquisition, earthquake analysis and archiving computers are housed in a building built to "emergency grade" seismic standards, with air conditioning and power backed up by a UPS and a large generator. Data latency and power are monitored by automated processes that alert staff via pager and email. Data completeness and timing quality are automatically assessed on a daily

Exploiting IoT Technologies and Open Source Components for Smart Seismic Network Instrumentation

NASA Astrophysics Data System (ADS)

Germenis, N. G.; Koulamas, C. A.; Foundas, P. N.

2017-12-01

The data collection infrastructure of any seismic network poses a number of requirements and trade-offs related to accuracy, reliability, power autonomy and installation & operational costs. Having the right hardware design at the edge of this infrastructure, embedded software running inside the instruments is the heart of pre-processing and communication services implementation and their integration with the central storage and processing facilities of the seismic network. This work demonstrates the feasibility and benefits of exploiting software components from heterogeneous sources in order to realize a smart seismic data logger, achieving higher reliability, faster integration and less development and testing costs of critical functionality that is in turn responsible for the cost and power efficient operation of the device. The instrument's software builds on top of widely used open source components around the Linux kernel with real-time extensions, the core Debian Linux distribution, the earthworm and seiscomp tooling frameworks, as well as components from the Internet of Things (IoT) world, such as the CoAP and MQTT protocols for the signaling planes, besides the widely used de-facto standards of the application domain at the data plane, such as the SeedLink protocol. By using an innovative integration of features based on lower level GPL components of the seiscomp suite with higher level processing earthworm components, coupled with IoT protocol extensions to the latter, the instrument can implement smart functionality such as network controlled, event triggered data transmission in parallel with edge archiving and on demand, short term historical data retrieval.

Toward the azimuthal characteristics of ionospheric and seismic effects of "Chelyabinsk" meteorite fall according to the data from coherent radar, GPS, and seismic networks

NASA Astrophysics Data System (ADS)

Berngardt, O. I.; Perevalova, N. P.; Dobrynina, A. A.; Kutelev, K. A.; Shestakov, N. V.; Bakhtiarov, V. F.; Kusonsky, O. A.; Zagretdinov, R. V.; Zherebtsov, G. A.

2015-12-01

We present the results of a study of the azimuthal characteristics of ionospheric and seismic effects of the meteorite `Chelyabinsk,' based on the data from the network of GPS receivers, coherent decameter radar EKB, and network of seismic stations, located near the meteorite fall trajectory. It is shown that 6-14 min after the bolide explosion, GPS network observed the cone-shaped wavefront of traveling ionospheric disturbances (TIDs) that is interpreted as a ballistic acoustic wave. The typical TIDs propagation velocity were observed 661 ± 256 m/s, which corresponds to the expected acoustic wave speed for 240 km height. Fourteen minutes after the bolide explosion, at distances of 200 km, we observed the emergence and propagation of a TID with annular wavefront that is interpreted as gravitational mode of internal atmospheric waves. The propagation velocity of this TID was 337 ± 89 m/s which corresponds to the propagation velocity of these waves in similar situations. At EKB radar, we observed TIDs in the sector of azimuthal angles close to the perpendicular to the meteorite trajectory. The observed TID velocity (400 m/s) and azimuthal properties correlate well with the model of ballistic wave propagating at 120-140 km altitude. It is shown that the azimuthal distribution of the amplitude of vertical seismic oscillations with periods 3-60 s can be described qualitatively by the model of vertical strike-slip rupture, propagating at 1 km/s along the meteorite fall trajectory to distance of about 40 km. These parameters correspond to the direction and velocity of propagation of the ballistic wave peak by the ground. It is shown that the model of ballistic wave caused by supersonic motion and burning of the meteorite in the upper atmosphere can satisfactorily explain the various azimuthal ionospheric effects, observed by the coherent decameter radar EKB, GPS receivers network, and the azimuthal characteristics of seismic waves at large distances.

RAPID DETERMINATION OF FOCAL DEPTH USING A GLOBAL NETWORK OF SMALL-APERTURE SEISMIC ARRAYS

NASA Astrophysics Data System (ADS)

Seats, K.; Koper, K.; Benz, H.

2009-12-01

The National Earthquake Information Center (NEIC) of the United States Geological Survey (USGS) operates 24 hours a day, 365 days a year with the mission of locating and characterizing seismic events around the world. A key component of this task is quickly determining the focal depth of each seismic event, which has a first-order effect on estimates of ground shaking used in the impact assessment applications of emergency response activities. Current methods of depth estimation used at the NEIC include arrival time inversion both with and without depth phases, a Bayesian depth constraint based on historical seismicity (1973-present), and moment tensor inversion primarily using P- and S-wave waveforms. In this study, we explore the possibility of automated modeling of waveforms from vertical-component arrays of the International Monitoring System (IMS) to improve rapid depth estimation at NEIC. Because these arrays are small-aperture, they are effective at increasing signal to noise ratios for frequencies of 1 Hz and higher. Currently, NEIC receives continuous real-time data from 23 IMS arrays. Following work done by previous researchers, we developed a technique that acts as an array of arrays. For a given epicentral location we calculate fourth root beams for each IMS array in the distance range of 30 to 95 degrees at the expected slowness vector of the first arrival. Because the IMS arrays are small-aperture, these beams highlight energy that has slowness similar to the first arrival, such as depth phases. The beams are rectified by taking the envelope and then automatically aligned on the largest peak within 5 seconds of the expected arrival time. The station beams are then combined into network beams assuming a range of depths varying from 10 km to 700 km in increments of 1 km. The network beams are computed assuming both pP and sP propagation, and a measure of beam power is output as a function of depth for both propagation models, as well as their sum. We

Automated classification of seismic sources in a large database: a comparison of Random Forests and Deep Neural Networks.

NASA Astrophysics Data System (ADS)

Hibert, Clement; Stumpf, André; Provost, Floriane; Malet, Jean-Philippe

2017-04-01

In the past decades, the increasing quality of seismic sensors and capability to transfer remotely large quantity of data led to a fast densification of local, regional and global seismic networks for near real-time monitoring of crustal and surface processes. This technological advance permits the use of seismology to document geological and natural/anthropogenic processes (volcanoes, ice-calving, landslides, snow and rock avalanches, geothermal fields), but also led to an ever-growing quantity of seismic data. This wealth of seismic data makes the construction of complete seismicity catalogs, which include earthquakes but also other sources of seismic waves, more challenging and very time-consuming as this critical pre-processing stage is classically done by human operators and because hundreds of thousands of seismic signals have to be processed. To overcome this issue, the development of automatic methods for the processing of continuous seismic data appears to be a necessity. The classification algorithm should satisfy the need of a method that is robust, precise and versatile enough to be deployed to monitor the seismicity in very different contexts. In this study, we evaluate the ability of machine learning algorithms for the analysis of seismic sources at the Piton de la Fournaise volcano being Random Forest and Deep Neural Network classifiers. We gather a catalog of more than 20,000 events, belonging to 8 classes of seismic sources. We define 60 attributes, based on the waveform, the frequency content and the polarization of the seismic waves, to parameterize the seismic signals recorded. We show that both algorithms provide similar positive classification rates, with values exceeding 90% of the events. When trained with a sufficient number of events, the rate of positive identification can reach 99%. These very high rates of positive identification open the perspective of an operational implementation of these algorithms for near-real time monitoring of

Reassessment of the Seismicity and seismic hazards of Libya

NASA Astrophysics Data System (ADS)

Ben Suleman, A.; Elmeladi, A.

2009-04-01

The tectonic evolution of Libya, located at the northern extreme of the African continent, has yielded a complex crustal structure that is composed of a series of basins and uplifts. The present day deformation of Libya is the result of the Eurasia-Africa continental collision. At the end of the year 2005, The Libyan National Seismological Network was established to monitor local, regional and teleseismic activities, as well as to provide high quality data for research projects both locally and on the regional and global scale. This study aims to discuss the seismicity of Libya by using the new data from the Libyan national seismological network and to focus on the seismic hazards. At first glance the seismic activity map shows dominant trends of seismicity with most of the seismic activity concentrated along the northern coastal areas. Four major seismic trends were quite noticeable. A first trend is a NW-SE direction coinciding with the eastern boarder of the Hun Graben. A second trend is also a NW-SE direction in the offshore area and might be a continuation of this trend. The other two trends were located in the western Gulf of Sirt and Cyrenaica platform. The rest of seismicity is diffuse either offshore or in land, with no good correlation with well-mapped faults. Detailed investigations of the Libyan seismicity indicates that the Libya has experienced earthquakes of varying magnitudes and that there is definitely a certain amount of seismic risk involved in engineering projects, particularly in the northern regions. Detailed investigation of the distribution of the Libyan earthquakes in space and time along with all other geological considerations suggested the classification of the country into four seismic zones with the Hun graben zone being the most seismically active zone.

Reevaluation of the Seismicity and seismic hazards of Northeastern Libya

NASA Astrophysics Data System (ADS)

Ben Suleman, abdunnur; Aousetta, Fawzi

2014-05-01

Libya, located at the northern margin of the African continent, underwent many episodes of orogenic activities. These episodes of orogenic activities affected and shaped the geological setting of the country. This study represents a detailed investigation that aims to focus on the seismicity and its implications on earthquake hazards of Northeastern Libya. At the end of year 2005 the Libyan National Seismological Network starts functioning with 15 stations. The Seismicity of the area under investigation was reevaluated using data recorded by the recently established network. The Al-Maraj earthquake occurred in May 22nd 2005was analyzed. This earthquake was located in a known seismically active area. This area was the sight of the well known 1963 earthquake that kills over 200 people. Earthquakes were plotted and resulting maps were interpreted and discussed. The level of seismic activity is higher in some areas, such as the city of Al-Maraj. The offshore areas north of Al-Maraj seem to have higher seismic activity. It is highly recommended that the recent earthquake activity is considered in the seismic hazard assessments for the northeastern part of Libya.

Deployment of broadband seismic and infrasonic networks on Tungurahua and Cotopaxi Volcanoes, Ecuador

NASA Astrophysics Data System (ADS)

Kumagai, H.; Yepes, H.; Vaca, M.; Caceres, V.; Nagai, T.; Yokoe, K.; Imai, T.; Miyakawa, K.; Yamashina, T.; Arrais, S.; Vasconez, F.; Pinajota, E.; Cisneros, C.; Ramos, C.; Paredes, M.; Gomezjurado, L.; Garcia-Aristizabal, A.; Molina, I.; Ramon, P.; Segovia, M.; Palacios, P.; Enriquez, W.; Inoue, I.; Nakano, M.; Inoue, H.

2006-12-01

Tungurahua and Cotopaxi are andesitic active volcanoes in Ecuadorian Andes. Tungurahua continues its eruptive activity since 1999, in which explosive eruptions accompanying pyroclastic flows occurred in July- August, 2006. Cotopaxi is one of the world's highest glacier-clad active volcanoes, and its seismic activity remains high since 2001. To enhance the monitoring capability of these volcanoes, we have installed broadband seismometers (Guralp CMG-40T: 60 s-50 Hz) and infrasonic sensors (ACO TYPE7144/4144: 10 s- 100 Hz) on these volcanoes through the technical cooperation program of Japan International Cooperation Agency (JICA). Three and five stations are currently installed at Tungurahua and Cotopaxi, respectively, and additional two stations will be installed at Tungurahua. Both seismic and infrasonic waveform data at each station are digitized by a Geotech Smart24D datalogger with a sampling frequency of 50 Hz, and transmitted by a digital telemetry system using 2.4 GHz Wireless LAN to the central office in Quito. The Tungurahua's eruptive activity accompanying pyroclastic flows in July-August 2006 was monitored in real-time by the network. The observed waveforms show a wide variety of signatures in response to various eruption styles: intermittent tremor during Strombolian eruptions, five-hour-long continuous strong tremor during heightened eruptions, very-long-period (VLP) seismic signals (10-50 s) associated with pyroclastic flows, and impulsive seismic and infrasonic events of explosions. At Cotopaxi Volcano, VLP signals (2 s) accompanying long- period signals (1-2 Hz) were detected by our network. Similar events occurred in 2002, and are interpreted as gas-release process from magma in an intruded dike beneath Cotopaxi (Molina et al, submitted to JGR). The present observation of the same type of events suggests that the intruded dike is still active beneath Cotopaxi. These signals detected by our networks are highly useful to understand volcanic processes

Romanian Complex Data Center for Dense Seismic network

NASA Astrophysics Data System (ADS)

Neagoe, Cristian; Ionescu, Constantin; Marius Manea, Liviu

2010-05-01

Since 2002 the National Institute for Earth Physics (NIEP) developed its own real-time digital seismic network: consisting of 96 seismic stations of which 35 are broadband sensors and 24 stations equipped with short period sensors and two arrays earthquakes that transmit data in real time at the National Data Center (NDC) and Eforie Nord (EFOR) Seismic Observatory. EFOR is the back-up for the NDC and also a monitoring center for Black Sea tsunamis. Seismic stations are equipped with Quanterra Q330 and K2 digitizers, broadband seismometers (STS2, CMG40T, CMG 3ESP, CMG3T) and acceleration sensors Episensor Kinemetrics (+ / - 2G). SeedLink who is a part of Seiscomp2.5 and Antelope are software packages used for acquisition in real time (RT) and for data exchange. Communication of digital seismic stations to the National Data Center in Bucharest and Seismic Observatory Eforie Nord is assured by 5 providers (GPRS, VPN, satellite radio and Internet communication). For acquisition and data processing at the two centers of reception and processing is used AntelopeTM 4.11 running on 2 workstations: one for real-time and other for offline processing and also a Seiscomp 3 server that works as back-up for Antelope 4.11 Both acquisition and analysis of seismic data systems produced information about local and global parameters of earthquakes, in addition Antelope is used for manual processing (association events, the calculation of magnitude, creating a database, sending seismic bulletins, calculation of PGA and PGV , etc.), generating ShakeMap products and interacts with global data centers. In order to make all this information easily available across the Web and also lay the grounds for a more modular and flexible development environment the National Data Center developed tools to enable centralizing of data from software such as Antelope which is using a dedicated database system ( Datascope, a database system based on text files ) to a more general-purpose database, My

Georgia-Armenia Transboarder seismicity studies

NASA Astrophysics Data System (ADS)

Godoladze, T.; Tvaradze, N.; Javakishvili, Z.; Elashvili, M.; Durgaryan, R.; Arakelyan, A.; Gevorgyan, M.

2012-12-01

In the presented study we performed Comprehensive seismic analyses for the Armenian-Georgian transboarder active seismic fault starting on Armenian territory, cutting the state boarder and having possibly northern termination on Adjara-Triealeti frontal structure in Georgia. In the scope of International projects: ISTC A-1418 "Open network of scientific Centers for mitigation risk of natural hazards in the Southern Caucasus and Central Asia" and NATO SfP- 983284 Project "Caucasus Seismic Emergency Response" in Akhalkalaki (Georgia) seismic center, Regional Summer school trainings and intensive filed investigations were conducted. Main goal was multidisciplinary study of the Javakheti fault structure and better understanding seismicity of the area. Young scientists from Turkey, Armenia, Azerbaijan and Georgia were participated in the deployment of temporal seismic network in order to monitor seisimity on the Javakheti highland and particularly delineate fault scarf and identify active seismic structures. In the scope of international collaboration the common seismic database has been created in the southern Caucasus and collected data from the field works is available now online. Javakheti highland, which is located in the central part of the Caucasus, belongs to the structure of the lesser Caucasus and represents a history of neotectonic volcanism existed in the area. Jasvakheti highland is seismicalu active region devastating from several severe earthquakes(1088, 1283, 1899…). Hypocenters located during analogue network were highly scattered and did not describe real pattern of seismicity of the highland. We relocated hypocenters of the region and improved local velocity model. The hypocenters derived from recently deployed local seismic network in the Javakheti highland, clearly identified seismically active structures. Fault plane solutions of analogue data of the Soviet times have been carefully analyzed and examined. Moment tensor inversion were preformed

Southern California Seismic Network: New Design and Implementation of Redundant and Reliable Real-time Data Acquisition Systems

NASA Astrophysics Data System (ADS)

Saleh, T.; Rico, H.; Solanki, K.; Hauksson, E.; Friberg, P.

2005-12-01

The Southern California Seismic Network (SCSN) handles more than 2500 high-data rate channels from more than 380 seismic stations distributed across southern California. These data are imported real-time from dataloggers, earthworm hubs, and partner networks. The SCSN also exports data to eight different partner networks. Both the imported and exported data are critical for emergency response and scientific research. Previous data acquisition systems were complex and difficult to operate, because they grew in an ad hoc fashion to meet the increasing needs for distributing real-time waveform data. To maximize reliability and redundancy, we apply best practices methods from computer science for implementing the software and hardware configurations for import, export, and acquisition of real-time seismic data. Our approach makes use of failover software designs, methods for dividing labor diligently amongst the network nodes, and state of the art networking redundancy technologies. To facilitate maintenance and daily operations we seek to provide some separation between major functions such as data import, export, acquisition, archiving, real-time processing, and alarming. As an example, we make waveform import and export functions independent by operating them on separate servers. Similarly, two independent servers provide waveform export, allowing data recipients to implement their own redundancy. The data import is handled differently by using one primary server and a live backup server. These data import servers, run fail-over software that allows automatic role switching in case of failure from primary to shadow. Similar to the classic earthworm design, all the acquired waveform data are broadcast onto a private network, which allows multiple machines to acquire and process the data. As we separate data import and export away from acquisition, we are also working on new approaches to separate real-time processing and rapid reliable archiving of real-time data

Crowd-Sourcing Seismic Data: Lessons Learned from the Quake-Catcher Network

NASA Astrophysics Data System (ADS)

Cochran, E. S.; Sumy, D. F.; DeGroot, R. M.; Clayton, R. W.

2015-12-01

The Quake Catcher Network (QCN; qcn.caltech.edu) uses low cost micro-electro-mechanical system (MEMS) sensors hosted by volunteers to collect seismic data. Volunteers use accelerometers internal to laptop computers, phones, tablets or small (the size of a matchbox) MEMS sensors plugged into desktop computers using a USB connector to collect scientifically useful data. Data are collected and sent to a central server using the Berkeley Open Infrastructure for Network Computing (BOINC) distributed computing software. Since 2008, when the first citizen scientists joined the QCN project, sensors installed in museums, schools, offices, and residences have collected thousands of earthquake records. We present and describe the rapid installations of very dense sensor networks that have been undertaken following several large earthquakes including the 2010 M8.8 Maule Chile, the 2010 M7.1 Darfield, New Zealand, and the 2015 M7.8 Gorkha, Nepal earthquake. These large data sets allowed seismologists to develop new rapid earthquake detection capabilities and closely examine source, path, and site properties that impact ground shaking at a site. We show how QCN has engaged a wide sector of the public in scientific data collection, providing the public with insights into how seismic data are collected and used. Furthermore, we describe how students use data recorded by QCN sensors installed in their classrooms to explore and investigate earthquakes that they felt, as part of 'teachable moment' exercises.

Site Assessment of a New State-Wide Seismic Network in Texas (TexNet), USA.

NASA Astrophysics Data System (ADS)

Savvaidis, Alexandros; Young, Bissett; Hennings, Peter; Rathje, Ellen; Zalachoris, George; Young, Michael H.; Walter, Jacob I.; DeShon, Heather R.; Frohlich, Cliff

2017-04-01

Earthquake activity has recently increased in the southern mid-continent of the U.S., including Texas. To monitor seismicity activity in the state of Texas, a new seismicity monitoring program known as TexNet, was funded by the Texas State Legislature in 2015. TexNet consists of 22 new permanent broadband (120s post-hole) seismic stations that will complement the 17 stations currently operating in the State. These permanent stations will provide the baseline seismicity of the state. In addition, 36 portable stations (incorporating both a 20s post-hole seismometer and a post-hole accelerometer) will be used to densify the network in specific areas, of the State, depending on measured seismicity level, proximity to infrastructure, or other scientific investigations. One goal for TexNet is to provide authenticated data needed to evaluate the location, and frequency of earthquakes. To minimize the uncertainties in earthquake locations and increase detectability of the network, an extensive site assessment survey was conducted. The initial station positions were chosen based on Earthscope, Transportable Array (TA) site positions, while ensuring that the stations were relatively evenly-spaced across the State. We then analyzed the noise and earthquake data from the TA seismometers, and added new locations based on geology, topography, and absence of nearby human activities. A 30-min noise test was conducted at each site to identify the site amplification using HVSR information. A 24-hr survey then followed, where the noise level during day and night was identified, analyzed using power spectral density and compared to the NHNM and NLNM (Peterson, 1993; USGS Open File Report, 322). Based on these survey results nearby alternative sites were evaluated to improve final site position. Deployment and data streaming started on September 2016, and will be discussed during this presentation.

Hiding earthquakes from scrupulous monitoring eyes of dense local seismic networks

NASA Astrophysics Data System (ADS)

Bogiatzis, P.; Ishii, M.; Kiser, E.

2012-12-01

Accurate and complete cataloguing of aftershocks is essential for a variety of purposes, including the estimation of the mainshock rupture area, the identification of seismic gaps, and seismic hazard assessment. However, immediately following large earthquakes, the seismograms recorded by local networks are noisy, with energy arriving from hundreds of aftershocks, in addition to different seismic phases interfering with one another. This causes deterioration in the performance of detection and location of earthquakes using conventional methods such as the S-P approach. This is demonstrated by results of back-projection analysis of teleseismic data showing that a significant number of events are undetected by the Japan Meteorological Agency, within the first twenty-four hours after the Mw9.0 Tohoku-oki, Japan earthquake. The spatial distribution of the hidden events is not arbitrary. Most of these earthquakes are located close to the trench, while some are located at the outer rise. Furthermore, there is a relatively sharp trench-parallel boundary separating the detected and undetected events. We investigate the cause of these hidden earthquakes using forward modeling. The calculation of raypaths for various source locations and takeoff angles with the "shooting" method suggests that this phenomenon is a consequence of the complexities associated with subducting slab. Laterally varying velocity structure defocuses the seismic energy from shallow earthquakes located near the trench and makes the observation of P and S arrivals difficult at stations situated on mainland Japan. Full waveform simulations confirm these results. Our forward calculations also show that the probability of detection is sensitive to the depth of the event. Shallower events near the trench are more difficult to detect than deeper earthquakes that are located inside the subducting plate for which the shadow-zone effect diminishes. The modeling effort is expanded to include three

Using Network Theory to Understand Seismic Noise in Dense Arrays

NASA Astrophysics Data System (ADS)

Riahi, N.; Gerstoft, P.

2015-12-01

Dense seismic arrays offer an opportunity to study anthropogenic seismic noise sources with unprecedented detail. Man-made sources typically have high frequency, low intensity, and propagate as surface waves. As a result attenuation restricts their measurable footprint to a small subset of sensors. Medium heterogeneities can further introduce wave front perturbations that limit processing based on travel time. We demonstrate a non-parametric technique that can reliably identify very local events within the array as a function of frequency and time without using travel-times. The approach estimates the non-zero support of the array covariance matrix and then uses network analysis tools to identify clusters of sensors that are sensing a common source. We verify the method on simulated data and then apply it to the Long Beach (CA) geophone array. The method exposes a helicopter traversing the array, oil production facilities with different characteristics, and the fact that noise sources near roads tend to be around 10-20 Hz.

Seismic databases of The Caucasus

NASA Astrophysics Data System (ADS)

Gunia, I.; Sokhadze, G.; Mikava, D.; Tvaradze, N.; Godoladze, T.

2012-12-01

The Caucasus is one of the active segments of the Alpine-Himalayan collision belt. The region needs continues seismic monitoring systems for better understanding of tectonic processes going in the region. Seismic Monitoring Center of Georgia (Ilia State University) is operating the digital seismic network of the country and is also collecting and exchanging data with neighboring countries. The main focus of our study was to create seismic database which is well organized, easily reachable and is convenient for scientists to use. The seismological database includes the information about more than 100 000 earthquakes from the whole Caucasus. We have to mention that it includes data from analog and digital seismic networks. The first analog seismic station in Georgia was installed in 1899 in the Caucasus in Tbilisi city. The number of analog seismic stations was increasing during next decades and in 1980s about 100 analog stations were operated all over the region. From 1992 due to political and economical situation the number of stations has been decreased and in 2002 just two analog equipments was operated. New digital seismic network was developed in Georgia since 2003. The number of digital seismic stations was increasing and in current days there are more than 25 digital stations operating in the country. The database includes the detailed information about all equipments installed on seismic stations. Database is available online. That will make convenient interface for seismic data exchange data between Caucasus neighboring countries. It also makes easier both the seismic data processing and transferring them to the database and decreases the operator's mistakes during the routine work. The database was created using the followings: php, MySql, Javascript, Ajax, GMT, Gmap, Hypoinverse.

Seismic Noise Analysis and Reduction through Utilization of Collocated Seismic and Atmospheric Sensors at the GRO Chile Seismic Network

NASA Astrophysics Data System (ADS)

Farrell, M. E.; Russo, R. M.

2013-12-01

The installation of Earthscope Transportable Array-style geophysical observatories in Chile expands open data seismic recording capabilities in the southern hemisphere by nearly 30%, and has nearly tripled the number of seismic stations providing freely-available data in southern South America. Through the use of collocated seismic and atmospheric sensors at these stations we are able to analyze how local atmospheric conditions generate seismic noise, which can degrade data in seismic frequency bands at stations in the ';roaring forties' (S latitudes). Seismic vaults that are climate-controlled and insulated from the local environment are now employed throughout the world in an attempt to isolate seismometers from as many noise sources as possible. However, this is an expensive solution that is neither practical nor possible for all seismic deployments; and also, the increasing number and scope of temporary seismic deployments has resulted in the collection and archiving of terabytes of seismic data that is affected to some degree by natural seismic noise sources such as wind and atmospheric pressure changes. Changing air pressure can result in a depression and subsequent rebound of Earth's surface - which generates low frequency noise in seismic frequency bands - and even moderate winds can apply enough force to ground-coupled structures or to the surface above the seismometers themselves, resulting in significant noise. The 10 stations of the permanent Geophysical Reporting Observatories (GRO Chile), jointly installed during 2011-12 by IRIS and the Chilean Servicio Sismológico, include instrumentation in addition to the standard three seismic components. These stations, spaced approximately 300 km apart along the length of the country, continuously record a variety of atmospheric data including infrasound, air pressure, wind speed, and wind direction. The collocated seismic and atmospheric sensors at each station allow us to analyze both datasets together, to

Socio-economic effect of seismic retrofit implemented on bridges in the Los Angeles highway network.

DOT National Transportation Integrated Search

2008-12-01

This research studied socio-economic effect of the seismic retrofit implemented on bridges in Los Angeles Area : Freeway Network. Firstly, advanced FE (Finite Element) modeling and nonlinear time history analysis are carried out to : evaluate the sei...

RMT focal plane sensitivity to seismic network geometry and faulting style

USGS Publications Warehouse

Johnson, Kendra L.; Hayes, Gavin; Herrmann, Robert B.; Benz, Harley M.; McNamara, Daniel E.; Bergman, Eric A.

2016-01-01

Modern tectonic studies often use regional moment tensors (RMTs) to interpret the seismotectonic framework of an earthquake or earthquake sequence; however, despite extensive use, little existing work addresses RMT parameter uncertainty. Here, we quantify how network geometry and faulting style affect RMT sensitivity. We examine how data-model fits change with fault plane geometry (strike and dip) for varying station configurations. We calculate the relative data fit for incrementally varying geometries about a best-fitting solution, applying our workflow to real and synthetic seismograms for both real and hypothetical station distributions and earthquakes. Initially, we conduct purely observational tests, computing RMTs from synthetic seismograms for hypothetical earthquakes and a series of well-behaved network geometries. We then incorporate real data and station distributions from the International Maule Aftershock Deployment (IMAD), which recorded aftershocks of the 2010 MW 8.8 Maule earthquake, and a set of regional stations capturing the ongoing earthquake sequence in Oklahoma and southern Kansas. We consider RMTs computed under three scenarios: (1) real seismic records selected for high data quality; (2) synthetic seismic records with noise computed for the observed source-station pairings and (3) synthetic seismic records with noise computed for all possible station-source pairings. To assess RMT sensitivity for each test, we observe the ‘fit falloff’, which portrays how relative fit changes when strike or dip varies incrementally; we then derive the ranges of acceptable strikes and dips by identifying the span of solutions with relative fits larger than 90 per cent of the best fit. For the azimuthally incomplete IMAD network, Scenario 3 best constrains fault geometry, with average ranges of 45° and 31° for strike and dip, respectively. In Oklahoma, Scenario 3 best constrains fault dip with an average range of 46°; however, strike is best constrained

Hanford Site National Environmental Policy Act (NEPA) Characterization Report, Revision 17

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neitzel, Duane A.; Bunn, Amoret L.; Cannon, Sandra D.

2005-09-30

. Information in Chapter 6 of this document can be adapted and supplemented with specific information for a chapter covering statutory and regulatory requirements in an environmental assessment or environmental impact statement. When preparing environmental assessments and EISs, authors should also be cognizant of the document titled Recommendations for the Preparation of Environmental Assessments and Environmental Impact Statements published by the DOE Office of NEPA Oversight (DOE 2004). Additional guidance on preparing DOE NEPA documents can be found at http://tis.eh.doe.gov/nepa/guidance.html. Any interested individual seeking baseline data on the Hanford Site and its past activities may also use the information contained in this document to evaluate projected activities and their impacts. For this 2005 revision, the following sections of the document were reviewed by the authors and updated with the best available information through May 2005: Climate and Meteorology Air Quality Geology – Seismicity section only Hydrology – Flow charts for the Columbia and Yakima rivers only Ecology – Threatened and Endangered Species subsection only Socioeconomics Occupational Safety All of Chapter 6.« less

Thirty years of seismic network recording in South Australia: Selected results

NASA Astrophysics Data System (ADS)

Greenhalgh, S. A.; Love, D.; Sinadinovski, C.

1994-11-01

The year 1993 marks 30 years of seismic network recording of earthquakes in South Australia. The network currently comprises 17 short-period instruments, of which six use digital recording and five employ triaxial sensors. Approximately 350 earthquakes are located within the State each year using a computerized seismic analysis system developed by the Phillip Institute of Technology. A duration-based magnitude scale, equivalent to the Richter M(sub L) scale, has been developed for most stations. The pre-network (historical) record of earthquake activity in South Australia dates back to 1837. Epicenters are available for just 45 earthquakes. Of these, ten are of magnitude five or greater. The instrumental data over the last 30 years show a similar trend in epicentral pattern to the historical earthquakes, with the major zones being the Flinders Ranges, Eyre Peninsula and the Southeast. There have been 40 earthquakes of magnitude four or greater since 1963, the largest earthquake being of magnitude six in the Musgrave Ranges during 1986. Mine and quarry blasts within the State have been useful in calibration of the network, both in terms of hypocentral location and amplitude studies. The explosions have also furnished valuable information on the crustal velocity distribution. Epicentral co-ordinates of mine blasts are generally good to within 3-5 km. The explosions yield Richter magnitudes of one (charge size 1 or 2 tons) to 2.5 (charge size 50 tons). The crustal S waves, used in earthquake magnitude determinations, exhibit an amplitude-distance decay coefficient of 1.2. The P-wave velocity function of the crust increases non-linearly with depth, from about 5.0 km /s near the surface to 6.4 km /s at 20 km depth, where the gradient reduces, with the velocity reaching a value of about 7.4 km /s at a depth of 40 km.

Seismic Hazard Analysis on a Complex, Interconnected Fault Network

NASA Astrophysics Data System (ADS)

Page, M. T.; Field, E. H.; Milner, K. R.

2017-12-01

In California, seismic hazard models have evolved from simple, segmented prescriptive models to much more complex representations of multi-fault and multi-segment earthquakes on an interconnected fault network. During the development of the 3rd Uniform California Earthquake Rupture Forecast (UCERF3), the prevalence of multi-fault ruptures in the modeling was controversial. Yet recent earthquakes, for example, the Kaikora earthquake - as well as new research on the potential of multi-fault ruptures (e.g., Nissen et al., 2016; Sahakian et al. 2017) - have validated this approach. For large crustal earthquakes, multi-fault ruptures may be the norm rather than the exception. As datasets improve and we can view the rupture process at a finer scale, the interconnected, fractal nature of faults is revealed even by individual earthquakes. What is the proper way to model earthquakes on a fractal fault network? We show multiple lines of evidence that connectivity even in modern models such as UCERF3 may be underestimated, although clustering in UCERF3 mitigates some modeling simplifications. We need a methodology that can be applied equally well where the fault network is well-mapped and where it is not - an extendable methodology that allows us to "fill in" gaps in the fault network and in our knowledge.

Multi-parameter observations in the Ibero-Moghrebian region: the Western Mediterranean seismic network (WM) and ROA GPS geodynamic network

NASA Astrophysics Data System (ADS)

Pazos, Antonio; Martín Davila, José; Buforn, Elisa; Gárate Pasquín, Jorge; Catalán Morollón, Manuel; Hanka, Winfried; Udías, Agustín.; Benzzeghoud, Mourad; Harnafi, Mimoun

2010-05-01

The plate boundary between Eurasia and Africa plates crosses the called "Ibero-Maghrebian" region from the San Vicente Cape (SW Portugal) to Tunisia including the South of Iberia, Alboran Sea, and northern Morocco and Algeria. In this area, the convergence, with a low rate, is accommodated over a wide and diffuse deformation zone, characterized by a significant and widespread moderate seismic activity [Buforn et al., 1995], and the occurrence of large earthquakes is separated by long time intervals. Since more than hundred years ago San Fernando Naval Observatory (ROA), in collaboration with other Institutes, has deployed different geophysical and geodetic equipment in the Southern Spain - North-western Africa area in order to study this broad deformation zone. Currently a Broad Band seismic net (Western Mediterranean, WM net) is deployed, in collaboration with other institutions, around the Gulf of Cádiz and the Alboran sea, with stations in the South of Iberia and in North Africa (at Spanish places and Morocco), together with the seismic stations a permanent geodetic GPS net is co-installed at the same sites. Also, other geophysical instruments have been installed: a Satellite Laser Ranging (SLR) station at San Fernando Observatory Headquarter, a Geomagnetic Observatory in Cádiz bay area and some meteorological stations. These networks have been recently improved with the deployment of a new submarine and on-land geophysical observatory in the Alboran island (ALBO Observatory), where a permanent GPS, a meteorological station were installed on land and a permanent submarine observatory in 50 meters depth was also deploy in last October (with a broad band seismic sensor, a 3 C accelerometer and a DPG). This work shows the present status and the future plans of these networks and some results.

Monitoring of seismic time-series with advanced parallel computational tools and complex networks

NASA Astrophysics Data System (ADS)

Kechaidou, M.; Sirakoulis, G. Ch.; Scordilis, E. M.

2012-04-01

Earthquakes have been in the focus of human and research interest for several centuries due to their catastrophic effect to the everyday life as they occur almost all over the world demonstrating a hard to be modelled unpredictable behaviour. On the other hand, their monitoring with more or less technological updated instruments has been almost continuous and thanks to this fact several mathematical models have been presented and proposed so far to describe possible connections and patterns found in the resulting seismological time-series. Especially, in Greece, one of the most seismically active territories on earth, detailed instrumental seismological data are available from the beginning of the past century providing the researchers with valuable and differential knowledge about the seismicity levels all over the country. Considering available powerful parallel computational tools, such as Cellular Automata, these data can be further successfully analysed and, most important, modelled to provide possible connections between different parameters of the under study seismic time-series. More specifically, Cellular Automata have been proven very effective to compose and model nonlinear complex systems resulting in the advancement of several corresponding models as possible analogues of earthquake fault dynamics. In this work preliminary results of modelling of the seismic time-series with the help of Cellular Automata so as to compose and develop the corresponding complex networks are presented. The proposed methodology will be able to reveal under condition hidden relations as found in the examined time-series and to distinguish the intrinsic time-series characteristics in an effort to transform the examined time-series to complex networks and graphically represent their evolvement in the time-space. Consequently, based on the presented results, the proposed model will eventually serve as a possible efficient flexible computational tool to provide a generic

Seismic monitoring at Cascade Volcanic Centers, 2004?status and recommendations

USGS Publications Warehouse

Moran, Seth C.

2004-01-01

The purpose of this report is to assess the current (May, 2004) status of seismic monitoring networks at the 13 major Cascade volcanic centers. Included in this assessment are descriptions of each network, analyses of the ability of each network to detect and to locate seismic activity, identification of specific weaknesses in each network, and a prioritized list of those networks that are most in need of additional seismic stations. At the outset it should be recognized that no Cascade volcanic center currently has an adequate seismic network relative to modern-day networks at Usu Volcano (Japan) or Etna and Stromboli volcanoes (Italy). For a system the size of Three Sisters, for example, a modern-day, cutting-edge seismic network would ideally consist of a minimum of 10 to 12 short-period three-component seismometers (for determining particle motions, reliable S-wave picks, moment tensor inversions, fault-plane solutions, and other important seismic parameters) and 7 to 10 broadband sensors (which, amongst other considerations, enable detection and location of very long period (VLP) and other low-frequency events, moment tensor inversions, and, because of their wide dynamic range, on-scale recording of large-amplitude events). Such a dense, multi component seismic network would give the ability to, for example, detect in near-real-time earthquake migrations over a distance of ~0.5km or less, locate tremor sources, determine the nature of a seismic source (that is, pure shear, implosive, explosive), provide on-scale recordings of very small and very large-amplitude seismic signals, and detect localized changes in seismic stress tensor orientations caused by movement of magma bodies. However, given that programmatic resources are currently limited, installation of such networks at this time is unrealistic. Instead, this report focuses on identifying what additional stations are needed to guarantee that anomalous seismicity associated with volcanic unrest will be

OGS improvements in the year 2011 in running the Northeastern Italy Seismic Network

NASA Astrophysics Data System (ADS)

Bragato, P. L.; Pesaresi, D.; Saraò, A.; Di Bartolomeo, P.; Durı, G.

2012-04-01

The Centro di Ricerche Sismologiche (CRS, Seismological Research Center) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 15 very sensitive broad band and 21 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data center in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of about 100 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of Northeastern Italy. Since 2002 OGS-CRS is using the Antelope software suite on several workstations plus a SUN Cluster as the main tool for collecting, analyzing, archiving and exchanging seismic data, initially in the framework of the EU Interreg IIIA project "Trans-national seismological networks in the South-Eastern Alps". SeisComP is also used as a real time data exchange server tool. In order to improve the seismological monitoring of the Northeastern Italy area, at OGS-CRS we tuned existing programs and created ad hoc ones like: a customized web server named PickServer to manually relocate earthquakes, a script for automatic moment tensor determination, scripts for web publishing of earthquake parametric data, waveforms, state of health parameters and shaking maps, noise characterization by means of automatic spectra analysis, and last but not least scripts for email/SMS/fax alerting. The OGS-CRS Real Time Seismological website (RTS, http://rts.crs.inogs.it/) operative since several years was initially developed in the framework of the Italian DPC-INGV S3 Project: the RTS website shows classic earthquake locations

Monitoring groundwater and river interaction along the Hanford reach of the Columbia River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, M.D.

1994-04-01

As an adjunct to efficient Hanford Site characterization and remediation of groundwater contamination, an automatic monitor network has been used to measure Columbia River and adjacent groundwater levels in several areas of the Hanford Site since 1991. Water levels, temperatures, and electrical conductivity measured by the automatic monitor network provided an initial database with which to calibrate models and from which to infer ground and river water interactions for site characterization and remediation activities. Measurements of the dynamic river/aquifer system have been simultaneous at 1-hr intervals, with a quality suitable for hydrologic modeling and for computer model calibration and testing.more » This report describes the equipment, procedures, and results from measurements done in 1993.« less

Goat Moths (Lepidoptera: Cossidae) of the Hanford Site and Hanford National Monument, Washington State

USDA-ARS?s Scientific Manuscript database

Three species of goat moths are recorded at the Hanford Nuclear Site and Hanford National Monument in south central Washington State. They are: Comadia bertholdi (Grote), 1880, Givira cornelia (Neumoegen & Dyar), 1893, and Prionoxystus robiniae (Peck), 1818. The general habitat of the Hanford area...

A wireless sensor network for monitoring volcano-seismic signals

NASA Astrophysics Data System (ADS)

Lopes Pereira, R.; Trindade, J.; Gonçalves, F.; Suresh, L.; Barbosa, D.; Vazão, T.

2014-12-01

Monitoring of volcanic activity is important for learning about the properties of each volcano and for providing early warning systems to the population. Monitoring equipment can be expensive, and thus the degree of monitoring varies from volcano to volcano and from country to country, with many volcanoes not being monitored at all. This paper describes the development of a wireless sensor network (WSN) capable of collecting geophysical measurements on remote active volcanoes. Our main goals were to create a flexible, easy-to-deploy and easy-to-maintain, adaptable, low-cost WSN for temporary or permanent monitoring of seismic tremor. The WSN enables the easy installation of a sensor array in an area of tens of thousands of m2, allowing the location of the magma movements causing the seismic tremor to be calculated. This WSN can be used by recording data locally for later analysis or by continuously transmitting it in real time to a remote laboratory for real-time analyses. We present a set of tests that validate different aspects of our WSN, including a deployment on a suspended bridge for measuring its vibration.

Sources of high frequency seismic noise: insights from a dense network of ~250 stations in northern Alsace (France)

NASA Astrophysics Data System (ADS)

Vergne, Jerome; Blachet, Antoine; Lehujeur, Maximilien

2015-04-01

Monitoring local or regional seismic activity requires stations having a low level of background seismic noise at frequencies higher than few tenths of Hertz. Network operators are well aware that the seismic quality of a site depends on several aspects, among them its geological setting and the proximity of roads, railways, industries or trees. Often, the impact of each noise source is only qualitatively known which precludes estimating the quality of potential future sites before they are tested or installed. Here, we want to take advantage of a very dense temporary network deployed in Northern Alsace (France) to assess the effect of various kinds of potential sources on the level of seismic noise observed in the frequency range 0.2-50 Hz. In September 2014, more than 250 seismic stations (FairfieldNodal@ Zland nodes with 10Hz vertical geophone) have been installed every 1.5 km over a ~25km diameter disc centred on the deep geothermal sites of Soultz-sous-Forêts and Rittershoffen. This region exhibits variable degrees of human imprints from quite remote areas to sectors with high traffic roads and big villages. It also encompasses both the deep sedimentary basin of the Rhine graben and the piedmont of the Vosges massif with exposed bedrock. For each site we processed the continuous data to estimate probability density functions of the power spectral densities. At frequencies higher than 1 Hz most sites show a clear temporal modulation of seismic noise related to human activity with the well-known variations between day and night and between weekdays and weekends. Moreover we observe a clear evolution of the spatial distribution of seismic noise levels with frequency. Basically, between 0.5 and 4 Hz the geological setting modulates the level of seismic noise. At higher frequencies, the amplitude of seismic noise appears mostly related to the distance to nearby roads. Based on road maps and traffic estimation, a forward approach is performed to model the induced

Predicting the performance of local seismic networks using Matlab and Google Earth.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chael, Eric Paul

2009-11-01

We have used Matlab and Google Earth to construct a prototype application for modeling the performance of local seismic networks for monitoring small, contained explosions. Published equations based on refraction experiments provide estimates of peak ground velocities as a function of event distance and charge weight. Matlab routines implement these relations to calculate the amplitudes across a network of stations from sources distributed over a geographic grid. The amplitudes are then compared to ambient noise levels at the stations, and scaled to determine the smallest yield that could be detected at each source location by a specified minimum number ofmore » stations. We use Google Earth as the primary user interface, both for positioning the stations of a hypothetical local network, and for displaying the resulting detection threshold contours.« less

Modern Adaptive Analytics Approach to Lowering Seismic Network Detection Thresholds

NASA Astrophysics Data System (ADS)

Johnson, C. E.

2017-12-01

Modern seismic networks present a number of challenges, but perhaps most notably are those related to 1) extreme variation in station density, 2) temporal variation in station availability, and 3) the need to achieve detectability for much smaller events of strategic importance. The first of these has been reasonably addressed in the development of modern seismic associators, such as GLASS 3.0 by the USGS/NEIC, though some work still remains to be done in this area. However, the latter two challenges demand special attention. Station availability is impacted by weather, equipment failure or the adding or removing of stations, and while thresholds have been pushed to increasingly smaller magnitudes, new algorithms are needed to achieve even lower thresholds. Station availability can be addressed by a modern, adaptive architecture that maintains specified performance envelopes using adaptive analytics coupled with complexity theory. Finally, detection thresholds can be lowered using a novel approach that tightly couples waveform analytics with the event detection and association processes based on a principled repicking algorithm that uses particle realignment for enhanced phase discrimination.

Studying Fin Whales with Seafloor Seismic Networks

NASA Astrophysics Data System (ADS)

Wilcock, W. S.; Soule, D. C.; Weirathmueller, M.; Thomson, R.

2011-12-01

Baleen whales are found throughout the world's oceans and their welfare captivates the general public. Depending on the species, baleen whales vocalize at frequencies ranging from ~10 Hz to several kilohertz. Passive acoustic studies of whale calls are used to investigate behavior and habitat usage, monitor the recovery of populations from whaling and assess the impacts of anthropogenic sounds. Since airguns are a significant source of sound in the oceans, the research goals of academic seismologists can lead to conflicts with those who advocate for whale conservation while being unwilling to consider the societal benefits of marine geophysical studies. In contrast, studies that monitor earthquakes with ocean bottom seismometers (OBSs) provide an opportunity to enhance studies of baleen whales and improve relationships with environmental advocates. The bandwidth of the typical high-frequency or intermediate-band ocean bottom seismometer overlaps the call frequency of the two largest baleen whale species; blue whales generate sequences of 10- to 20-s-long calls centered at ~16 Hz and fin whales produce long sequences of downswept 1-s-long chirps centered at ~20 Hz. Several studies have demonstrated the potential of OBS networks to monitor calling patterns and determine tracks for fin and blue whales. We will summarize the results from a study to track fin whales near the Endeavour hydrothermal vent fields on the Juan de Fuca Ridge and investigate a potential correlation between the density of whales and enhanced zooplankton found throughout the water column overlying the vent fields. From 2003-2006 an 8-station local seismic network that was designed to monitor hydrothermal earthquakes also recorded ~300,000 fin whale vocalizations, mostly in the fall and winter. Automatic picking and localization techniques that are analogous to those used to analyze earthquakes are employed to determine whale tracks. The tracks are then used to interpret calling patterns in the

Towards marine seismological Network: real time small aperture seismic array

NASA Astrophysics Data System (ADS)

Ilinskiy, Dmitry

2017-04-01

Most powerful and dangerous seismic events are generated in underwater subduction zones. Existing seismological networks are based on land seismological stations. Increased demands for accuracy of location, magnitude, rupture process of coming earthquakes and at the same time reduction of data processing time require information from seabed seismic stations located near the earthquake generation area. Marine stations provide important contribution for clarification of the tectonic settings in most active subduction zones of the world. Early warning system for subduction zone area is based on marine seabed array which located near the area of most hazardous seismic zone in the region. Fast track processing for location of the earthquake hypocenter and energy takes place in buoy surface unit. Information about detected and located earthquake reaches the onshore seismological center earlier than the first break waves from the same earthquake will reach the nearest onshore seismological station. Implementation of small aperture array is based on existed and shown a good proven performance and costs effective solutions such as weather moored buoy and self-pop up autonomous seabed seismic nodes. Permanent seabed system for real-time operation has to be installed in deep sea waters far from the coast. Seabed array consists of several self-popup seismological stations which continuously acquire the data, detect the events of certain energy class and send detected event parameters to the surface buoy via acoustic link. Surface buoy unit determine the earthquake location by receiving the event parameters from seabed units and send such information in semi-real time to the onshore seismological center via narrow band satellite link. Upon the request from the cost the system could send wave form of events of certain energy class, bottom seismic station battery status and other environmental parameters. When the battery life of particular seabed unit is close to became empty

Acoustic⁻Seismic Mixed Feature Extraction Based on Wavelet Transform for Vehicle Classification in Wireless Sensor Networks.

PubMed

Zhang, Heng; Pan, Zhongming; Zhang, Wenna

2018-06-07

An acoustic⁻seismic mixed feature extraction method based on the wavelet coefficient energy ratio (WCER) of the target signal is proposed in this study for classifying vehicle targets in wireless sensor networks. The signal was decomposed into a set of wavelet coefficients using the à trous algorithm, which is a concise method used to implement the wavelet transform of a discrete signal sequence. After the wavelet coefficients of the target acoustic and seismic signals were obtained, the energy ratio of each layer coefficient was calculated as the feature vector of the target signals. Subsequently, the acoustic and seismic features were merged into an acoustic⁻seismic mixed feature to improve the target classification accuracy after the acoustic and seismic WCER features of the target signal were simplified using the hierarchical clustering method. We selected the support vector machine method for classification and utilized the data acquired from a real-world experiment to validate the proposed method. The calculated results show that the WCER feature extraction method can effectively extract the target features from target signals. Feature simplification can reduce the time consumption of feature extraction and classification, with no effect on the target classification accuracy. The use of acoustic⁻seismic mixed features effectively improved target classification accuracy by approximately 12% compared with either acoustic signal or seismic signal alone.

Final Hanford Comprehensive Land-Use Plan Environmental Impact Statement, Hanford Site, Richland, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

N /A

This Final ''Hanford Comprehensive Land-Use Plan Environmental Impact Statement'' (HCP EIS) is being used by the Department of Energy (DOE) and its nine cooperating and consulting agencies to develop a comprehensive land-use plan (CLUP) for the Hanford Site. The DOE will use the Final HCP EIS as a basis for a Record of Decision (ROD) on a CLUP for the Hanford Site. While development of the CLUP will be complete with release of the HCP EIS ROD, full implementation of the CLUP is expected to take at least 50 years. Implementation of the CLUP would begin a more detailed planningmore » process for land-use and facility-use decisions at the Hanford Site. The DOE would use the CLUP to screen proposals. Eventually, management of Hanford Site areas would move toward the CLUP land-use goals. This CLUP process could take more than 50 years to fully achieve the land-use goals.« less

Exploring methods of cGPS transient detections for the Chilean cGPS network in conjunction with displacement predictions from seismic catalogues: To what extent can we detect seismic and aseismic motion in the cGPS network?

NASA Astrophysics Data System (ADS)

Bedford, J. R.; Moreno, M.; Oncken, O.; Li, S.; Schurr, B.; Metzger, S.; Baez, J. C.; Deng, Z.; Melnick, D.

2016-12-01

Various algorithms for the detection of transient deformation in cGPS networks are under currently being developed to relieve us of by-eye detection, which is an error prone and time-expensive activity. Such algorithms aim to separate the time series into secular, seasonal, and transient components. Additional white and coloured noise, as well as common-mode (network correlated) noise, may remain in the separated transient component of the signal, depending on the processing flow before the separation step. The a-priori knowledge of regional seismicity can assist in the recognition of steps in the data, which are generally corrected for if they are above the noise-floor. Sometimes, the cumulative displacement caused by small earthquakes can create a seemingly continuous transient signal in the cGPS leading to confusion as to whether to attribute this transient motion as seismic or aseismic. Here we demonstrate the efficacy of various transient detection algorithms for subsets of the Chilean cGPS network and present the optimal processing flow for teasing out the transients. We present a step-detection and removal algorithm and estimate the seismic efficiency of any detected transient signals by forward modelling the surface displacements of the earthquakes and comparing to the recovered transient signals. A major challenge in separating signals in the Chilean cGPS network is the overlapping of postseismic effects at adjacent segments: For example, a Mw 9 earthquake will produce a postseismic viscoelastic relaxation that is sustained over decades and several hundreds of kilometres. Additionally, it has been observed in Chile and Japan that following moderately large earthquakes (e.g. Mw > 8) the secular velocities of adjacent segments in the subduction margin suddenly change and remain changed: this effect may be related to a change in speed of slab subduction rather than viscoelastic relaxation, and therefore the signal separation algorithms that assume a time

The AlpArray Seismic Network: status and operation

NASA Astrophysics Data System (ADS)

Hetényi, György; Molinari, Irene; Clinton, John; Kissling, Edi

2017-04-01

The AlpArray initiative (http://www.alparray.ethz.ch) is a large-scale European collaboration to study the entire Alpine orogen at high resolution and in 3D with a large variety of geoscientific methods. The core element of the initiative is an extensive and dense broadband seismological network, the AlpArray Seismic Network (AASN). Over 300 temporary stations complement the permanent seismological stations to ensure homogeneous coverage of the greater Alpine area. The AASN has officially started operation in January 2016 and is now complete on land. It is operated in a joint effort by a number of institutions from Austria, Bosnia-Herzegovina, Croatia, Czech Republic, France, Germany, Hungary, Italy, Slovakia and Switzerland. In the Ligurian Sea, a 32-station OBS campaign is planned from June 2017 until March 2018. This will complete the coverage of the greater Alpine area at an unprecedented resolution. In this poster we present the actual status of the deployment, the effort undertaken by the contributing groups, station performance, best practices, data management as well as often encountered challenges, and provide a meeting and discussion point during the conference.

High school students as a seismic network analysts

NASA Astrophysics Data System (ADS)

Filatov, P.; Fedorenko, Yu.; Beketova, E.; Husebye, E.

2003-04-01

Many research organizations have a large amount of collected seismological data. Some data centers keep data closed from scientists, others have a specific interfaces for access, what is not acceptable for education. For SeisSchool Network in Norway we have developed an universal interface for research and study. The main principles of our interface are: bullet Accessibility - it should provides data access for everybody any where via Internet without restrictions of hardware platform, operational system, Internet browser or bandwidth of connection. bullet Informativity - it should visualize data, have examples of processing routines (filters, envelopes) including phase picking and event location. Also it provides access to various seismology information. bullet Scalability - provide storage for various types of seismic data and a multitude of services for many user levels. This interface (http://pcg1.ifjf.uib.no) helps analysts in basic research and together with information of our Web site we introduces students to theory and practice of seismology. Based on our Web interface group of students won a Norwegian Young Scientists award. In this presentation we demonstrate advantages of our interface, on-line data processing and how to monitoring our network in near real time.

Earthquakes in the Classroom, Las Vegas, NV: The Nevada Educational Seismic Network (NESN)

NASA Astrophysics Data System (ADS)

Hopkins, J.; Snelson, C. M.; Zaragoza, S. A.; Smith, K.; Depolo, D.

2002-12-01

Geophysics is a term guaranteed to strike fear into the heart of the bravest high school science student. Using math to describe the earth can involve complex equations that can only be deciphered by enigmatic computer programs. But high school science students in the Las Vegas Valley have been given a unique opportunity to gather important research information while learning about geophysics, real-time data collection, and Internet communications in a less threatening environment. Three seismograph stations funded by the Department of Energy and the University of Nevada, Las Vegas have been installed in three different high schools in the Clark County School District. These three stations form a triangle in the Las Vegas Valley basin covering areas where the basin depths change significantly. The geophones are buried outside and a cable connects the sensors and GPS receiver to a digitizer on a local PC. The data is transmitted continuously in real-time via Internet communications protocols to the Seismic Explorer Monitoring Network. There it is available to all schools and to researchers who will analyze the data. These short-period geophones will record small local earthquakes and larger more distant events contributing to real-time seismic network operations in southern Nevada. Students at a school site are able to see live real-time data from other school stations as well as from seismograph stations in southern Nevada, the western US, and the world. Mentored by researchers at the University of Nevada, Reno and University of Nevada, Las Vegas, the teachers and students conduct simple waveform analysis to determine earthquake locations and magnitudes and operate the stations in this cooperative research effort. The goal of this partnership between secondary and university educational systems is to create a successful alliance that will benefit the research community as well as the classroom teacher and his/her students. Researchers will use the data collected

The Los Alamos Seismic Network (LASN): Recent Network Upgrades and Northern New Mexico Earthquake Catalog Updates

NASA Astrophysics Data System (ADS)

Roberts, P. M.; House, L. S.; Greene, M.; Ten Cate, J. A.; Schultz-Fellenz, E. S.; Kelley, R.

2012-12-01

From the first data recorded in the fall of 1973 to now, the Los Alamos Seismograph Network (LASN) has operated for nearly 40 years. LASN data have been used to locate more than 2,500 earthquakes in north-central New Mexico. The network was installed for seismic verification research, as well as to monitor and locate earthquakes near Los Alamos National Laboratory (LANL). LASN stations are the only earthquake monitoring stations in New Mexico north of Albuquerque. In the late 1970s, LASN included 22 stations spread over a geographic area of 150 km (N-S) by 350 km (E-W), of northern New Mexico. In the early 1980s, the available funding limited the stations that could be operated to a set of 7, located within an area of about 15 km (N-S) by 15 km (E-W), centered on Los Alamos. Over the last 3 years, 6 additional stations have been installed, which have considerably expanded the spatial coverage of the network. These new stations take advantage of broadband state-of-the-art sensors as well as digital recording and telemetry technology. Currently, 7 stations have broadband, three-component seismometers with digital telemetry, and the remaining 6 have traditional 1 Hz short-period seismometers with analog telemetry. In addition, a vertical array of accelerometers was installed in a wellbore on LANL property. This borehole station has 3-component digital strong-motion sensors. In addition, four forensic strong-motion accelerometers (SMA) are operated at LANL facilities. With 3 of the new broadband stations in and around the nearby Valles Caldera, LASN is now able to monitor any very small volcano-seismic events that may be associated with the caldera. We will present a complete description of the current LASN station, instrumentation and telemetry configurations, as well as the data acquisition and event-detection software structure used to record events in Earthworm. More than 2,000 earthquakes were detected and located in north-central New Mexico during the first 11

The AlpArray-CASE project: temporary broadband seismic network deployment and characterization

NASA Astrophysics Data System (ADS)

Dasović, Iva; Molinari, Irene; Stipčević, Josip; Šipka, Vesna; Salimbeni, Simone; Jarić, Dejan; Prevolnik, Snježan; Kissling, Eduard; Clinton, John; Giardini, Domenico

2017-04-01

While the northern part of the Adriatic microplate will be accurately imaged within the AlpArray project, its central and southern parts deserve detailed studies to obtain a complete picture of its structure and evolution. The Adriatic microplate forms the upper plate in the Western and Central Alps whereas it forms the lower plate in the Apennines and the Dinarides. However, the tectonics of Adriatic microplate is not well constrained and remains controversial, especially with regard to its contact with the Dinarides. The primary goal of the Central Adriatic Seismic Experiment (CASE) is to provide high quality seismological data and to shed light on seismicity and 3D lithospheric structure of the central Adriatic microplate and its boundaries. The CASE project is an international AlpArray Complementary Experiment carried out by four institutions: Department of Earth Sciences and Swiss Seismological Service of ETH Zürich (CH), Department of Geophysics and Croatian Seismological Service of Faculty of Science at University of Zagreb (HR), Republic Hydrometeorological Service of Republic of Srpska (BIH) and Istituto Nazionale di Geofisica e Vulcanologia (I). It establishes a temporary seismic network, expected to be operational at least for one year, composed by existing permanent and temporary seismic stations operated by the institutions involved and newly deployed temporary seismic stations, installed in November and December 2016, provided by ETH Zürich and INGV: five in Croatia, four in Bosnia and Herzegovina and two in Italy. In this work, we present stations sites and settings and discuss their characteristics in terms of site-effects and noise level of each station. In particular, we analyse the power spectral density estimates in order to investigate major sources of noise and background noise.

PG&E's Seismic Network Goes Digital With Strong Motion: Successes and Challenges

NASA Astrophysics Data System (ADS)

Stanton, M. A.; Cullen, J.; McLaren, M. K.

2008-12-01

Pacific Gas and Electric Company (PG&E) is in year 3 of a 5-year project to upgrade the Central Coast Seismic Network (CCSN) from analog to digital. Located along the south-central California coast, the CCSN began operation in 1987, with 20 analog stations; 15 vertical component and 5 dual gain 3-component S-13 sensors. The analog signals travel over FM radio telemetry links and voice channels via PG&E's microwave network to our facility in San Francisco (SF), where the A/D conversion is performed on a computer running Earthworm v7.1, which also transmits the data to the USGS in Menlo Park. At the conversion point the dynamic ranges of the vertical and dual-gain sensors are 40-50dB and 60-70dB, respectively. Dynamic range exceedance (data clipping) generally occurs for a M2.5 or greater event within about 40 km of a station. The motivations to upgrade the seismic network were the need for higher dynamic range and to retire obsolete analog transmission equipment. The upgraded digital stations consist of the existing velocity sensors, a 131A-02/3 accelerometer and a Reftek 130-01 Broadband Seismic Recorder for digital data recording and transmission to SF. Vertical only stations have one component of velocity and 3 components of acceleration. Dual gain sites have 3 components of velocity and 3 of acceleration. To date we have successfully upgraded 6 sites; 3 more will be installed by the end of 2008. Some of the advantages of going digital are 1) data is recorded at each site and in SF, 2) substantially increased dynamic range of the velocity sensors to 120dB, as observed by on scale, close-by recordings from a M3.9 San Simeon aftershock on 04/29/2008, 3) accelerometers for on scale recording of large earthquakes, and 4) ability to contribute our strong motion data to USGS ShakeMaps. A significant challenge has been consistent radio communications. To resolve this issue we are installing point-to-multipoint Motorola Canopy spread spectrum radios at the stations and

Seismic Readings from the Deepest Borehole in the New Madrid Seismic Zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woolery, Edward W; Wang, Zhenming; Sturchio, Neil C

2006-03-01

Since the 1980s, the research associated with the UK network has been primarily strong-motion seismology of engineering interest. Currently the University of Kentucky operates a strong-motion network of nine stations in the New Madrid Seismic Zone. A unique feature of the network is the inclusions of vertical strong-motion arrays, each with one or two downhole accelerometers. The deepest borehole array is 260 m below the surfaces at station VASA in Fulton County, Kentucky. A preliminary surface seismic refraction survey was conducted at the site before drilling the hole at VSAS (Woolery and Wang, 2002). The depth to the Paleozoic bedrockmore » at the site was estimated to be approximately 595 m, and the depth to the first very stiff layer (i.e. Porters Creek Clay) was found to be about 260 m. These depths and stratigraphic interpretation correlated well with a proprietary seismic reflection line and the Ken-Ten Oil Exploration No. 1 Sanger hole (Schwalb, 1969), as well as our experience in the area (Street et al., 1995; Woolery et al., 1999).« less

Seismic Structure of Perth Basin (Australia) and surroundings from Passive Seismic Deployments

NASA Astrophysics Data System (ADS)

Issa, N.; Saygin, E.; Lumley, D. E.; Hoskin, T. E.

2016-12-01

We image the subsurface structure of Perth Basin, Western Australia and surroundings by using ambient seismic noise data from 14 seismic stations recently deployed by University of Western Australia (UWA) and other available permanent stations from Geoscience Australia seismic network and the Australian Seismometers in Schools program. Each of these 14 UWA seismic stations comprises a broadband sensor and a high fidelity 3-component 10 Hz geophone, recording in tandem at 250 Hz and 1000 Hz. The other stations used in this study are equipped with short period and broadband sensors. In addition, one shallow borehole station is operated with eight 3 component geophones at depths of between 2 and 44 m. The network is deployed to characterize natural seismicity in the basin and to try and identify any microseismic activity across Darling Fault Zone (DFZ), bounding the basin to the east. The DFZ stretches to approximately 1000 km north-south in Western Australia, and is one of the longest fault zones on the earth with a limited number of detected earthquakes. We use seismic noise cross- and auto-correlation methods to map seismic velocity perturbations across the basin and the transition from DFZ to the basin. Retrieved Green's functions are stable and show clear dispersed waveforms. Travel times of the surface wave Green's functions from noise cross-correlations are inverted with a two-step probabilistic framework to map the absolute shear wave velocities as a function of depth. The single station auto-correlations from the seismic noise yields P wave reflectivity under each station, marking the major discontinuities. Resulting images show the shear velocity perturbations across the region. We also quantify the variation of ambient seismic noise at different depths in the near surface using the geophones in the shallow borehole array.

Wind/seismic comparisons for upgrading existing structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giller, R.A.

1989-10-01

This paper depicts the analysis procedures and methods used to evaluate three existing building structures for extreme wind loads. The three structures involved in this evaluation are located at the US Department of Energy's Hanford Site near Richland, Washington. This site is characterized by open flat grassland with few surrounding obstructions and has extreme winds in lieu of tornados as a design basis accident condition. This group of buildings represents a variety of construction types, including a concrete stack, a concrete load-bearing wall structure, and a rigid steel-frame building. The three structures included in this group have recently been evaluatedmore » for response to the design basis earthquake that included non-linear time history effects. The resulting loads and stresses from the wind analyses were compared to the loads and stresses resulting from seismic analyses. This approach eliminated the need to prepare additional capacity calculations that were already contained in the seismic evaluations. 4 refs., 5 figs., 5 tabs.« less

Characterizing and comparing seismicity at Cascade Range (USA) volcanoes

NASA Astrophysics Data System (ADS)

Moran, S. C.; Thelen, W. A.

2010-12-01

The Cascade Range includes 13 volcanic systems across Washington, Oregon, and northern California that are considered to have the potential to erupt at any time, including two that have erupted in the last 100 years (Mount St. Helens (MSH) and Lassen Peak). We investigated how seismicity compares among these volcanoes, and whether the character of seismicity (rate, type, style of occurrence over time, etc.) is related to eruptive activity at the surface. Seismicity at Cascade volcanoes has been monitored by seismic networks of variable apertures, station densities, and lengths of operation, which makes a direct comparison of seismicity among volcanoes somewhat problematic. Here we present results of two non-network-dependent approaches to making such seismicity comparisons. In the first, we used network geometry and a grid-search method to compute the minimum magnitude required for a network to locate an earthquake (“theoretical location threshold”, defined as an event recorded on at least 4 stations with gap of <135o) for each volcano out to 7 km. We then selected earthquakes with magnitudes greater than the highest theoretical location threshold determined for any Cascade volcano. To account for improving network densities with time, we used M 2.1 (location threshold for the Three Sisters 1980s-90s network) for 1987-1999 and M 1.6 (threshold for the Crater Lake 2000s network) for 2000-2010. In order to include only background seismicity, we excluded earthquakes occurring at any volcano during the 2004-2008 MSH eruption. We found that Mount Hood, Lassen Peak, and MSH had the three highest seismicity rates over that period, with Mount Hood, Medicine Lake volcano, and MSH having the three highest cumulative seismic energy releases. The Medicine Lake energy release is dominated by a single swarm in September 1988; if that swarm is removed, then Lassen would have the third-highest cumulative seismic energy release. For the second comparison, we determined the

Women and the Hanford Site

NASA Astrophysics Data System (ADS)

Gerber, Michele

2014-03-01

When we study the technical and scientific history of the Manhattan Project, women's history is sometimes left out. At Hanford, a Site whose past is rich with hard science and heavy construction, it is doubly easy to leave out women's history. After all, at the World War II Hanford Engineer Works - the earliest name for the Hanford Site - only nine percent of the employees were women. None of them were involved in construction, and only one woman was actually involved in the physics and operations of a major facility - Dr. Leona Woods Marshall. She was a physicist present at the startup of B-Reactor, the world's first full-scale nuclear reactor - now a National Historic Landmark. Because her presence was so unique, a special bathroom had to be built for her in B-Reactor. At World War II Hanford, only two women were listed among the nearly 200 members of the top supervisory staff of the prime contractor, and only one regularly attended the staff meetings of the Site commander, Colonel Franklin Matthias. Overall, women comprised less than one percent of the managerial and supervisory staff of the Hanford Engineer Works, most of them were in nursing or on the Recreation Office staff. Almost all of the professional women at Hanford were nurses, and most of the other women of the Hanford Engineer Works were secretaries, clerks, food-service workers, laboratory technicians, messengers, barracks workers, and other support service employees. The one World War II recruiting film made to attract women workers to the Site, that has survived in Site archives, is entitled ``A Day in the Life of a Typical Hanford Girl.'' These historical facts are not mentioned to criticize the past - for it is never wise to apply the standards of one era to another. The Hanford Engineer Works was a 1940s organization, and it functioned by the standards of the 1940s. Just as we cannot criticize the use of asbestos in constructing Hanford (although we may wish they hadn't used so much of it), we

A PC-based computer package for automatic detection and location of earthquakes: Application to a seismic network in eastern sicity (Italy)

NASA Astrophysics Data System (ADS)

Patanè, Domenico; Ferrari, Ferruccio; Giampiccolo, Elisabetta; Gresta, Stefano

Few automated data acquisition and processing systems operate on mainframes, some run on UNIX-based workstations and others on personal computers, equipped with either DOS/WINDOWS or UNIX-derived operating systems. Several large and complex software packages for automatic and interactive analysis of seismic data have been developed in recent years (mainly for UNIX-based systems). Some of these programs use a variety of artificial intelligence techniques. The first operational version of a new software package, named PC-Seism, for analyzing seismic data from a local network is presented in Patanè et al. (1999). This package, composed of three separate modules, provides an example of a new generation of visual object-oriented programs for interactive and automatic seismic data-processing running on a personal computer. In this work, we mainly discuss the automatic procedures implemented in the ASDP (Automatic Seismic Data-Processing) module and real time application to data acquired by a seismic network running in eastern Sicily. This software uses a multi-algorithm approach and a new procedure MSA (multi-station-analysis) for signal detection, phase grouping and event identification and location. It is designed for an efficient and accurate processing of local earthquake records provided by single-site and array stations. Results from ASDP processing of two different data sets recorded at Mt. Etna volcano by a regional network are analyzed to evaluate its performance. By comparing the ASDP pickings with those revised manually, the detection and subsequently the location capabilities of this software are assessed. The first data set is composed of 330 local earthquakes recorded in the Mt. Etna erea during 1997 by the telemetry analog seismic network. The second data set comprises about 970 automatic locations of more than 2600 local events recorded at Mt. Etna during the last eruption (July 2001) at the present network. For the former data set, a comparison of the

Absolute earthquake locations using 3-D versus 1-D velocity models below a local seismic network: example from the Pyrenees

NASA Astrophysics Data System (ADS)

Theunissen, T.; Chevrot, S.; Sylvander, M.; Monteiller, V.; Calvet, M.; Villaseñor, A.; Benahmed, S.; Pauchet, H.; Grimaud, F.

2018-03-01

Local seismic networks are usually designed so that earthquakes are located inside them (primary azimuthal gap <<180°) and close to the seismic stations (0-100 km). With these local or near-regional networks (0°-5°), many seismological observatories still routinely locate earthquakes using 1-D velocity models. Moving towards 3-D location algorithms requires robust 3-D velocity models. This work takes advantage of seismic monitoring spanning more than 30 yr in the Pyrenean region. We investigate the influence of a well-designed 3-D model with station corrections including basins structure and the geometry of the Mohorovicic discontinuity on earthquake locations. In the most favourable cases (GAP < 180° and distance to the first station lower than 15 km), results using 1-D velocity models are very similar to 3-D results. The horizontal accuracy in the 1-D case can be higher than in the 3-D case if lateral variations in the structure are not properly resolved. Depth is systematically better resolved in the 3-D model even on the boundaries of the seismic network (GAP > 180° and distance to the first station higher than 15 km). Errors on velocity models and accuracy of absolute earthquake locations are assessed based on a reference data set made of active seismic, quarry blasts and passive temporary experiments. Solutions and uncertainties are estimated using the probabilistic approach of the NonLinLoc (NLLoc) software based on Equal Differential Time. Some updates have been added to NLLoc to better focus on the final solution (outlier exclusion, multiscale grid search, S-phases weighting). Errors in the probabilistic approach are defined to take into account errors on velocity models and on arrival times. The seismicity in the final 3-D catalogue is located with a horizontal uncertainty of about 2.0 ± 1.9 km and a vertical uncertainty of about 3.0 ± 2.0 km.

Teacher Directed Design: Content Knowledge, Pedagogy and Assessment under the Nevada K-12 Real-Time Seismic Network

NASA Astrophysics Data System (ADS)

Cantrell, P.; Ewing-Taylor, J.; Crippen, K. J.; Smith, K. D.; Snelson, C. M.

2004-12-01

Education professionals and seismologists under the emerging SUN (Shaking Up Nevada) program are leveraging the existing infrastructure of the real-time Nevada K-12 Seismic Network to provide a unique inquiry based science experience for teachers. The concept and effort are driven by teacher needs and emphasize rigorous content knowledge acquisition coupled with the translation of that knowledge into an integrated seismology based earth sciences curriculum development process. We are developing a pedagogical framework, graduate level coursework, and materials to initiate the SUN model for teacher professional development in an effort to integrate the research benefits of real-time seismic data with science education needs in Nevada. A component of SUN is to evaluate teacher acquisition of qualified seismological and earth science information and pedagogy both in workshops and in the classroom and to assess the impact on student achievement. SUN's mission is to positively impact earth science education practices. With the upcoming EarthScope initiative, the program is timely and will incorporate EarthScope real-time seismic data (USArray) and educational materials in graduate course materials and teacher development programs. A number of schools in Nevada are contributing real-time data from both inexpensive and high-quality seismographs that are integrated with Nevada regional seismic network operations as well as the IRIS DMC. A powerful and unique component of the Nevada technology model is that schools can receive "stable" continuous live data feeds from 100's seismograph stations in Nevada, California and world (including live data from Earthworm systems and the IRIS DMC BUD - Buffer of Uniform Data). Students and teachers see their own networked seismograph station within a global context, as participants in regional and global monitoring. The robust real-time Internet communications protocols invoked in the Nevada network provide for local data acquisition

Detecting Seismic Activity with a Covariance Matrix Analysis of Data Recorded on Seismic Arrays

NASA Astrophysics Data System (ADS)

Seydoux, L.; Shapiro, N.; de Rosny, J.; Brenguier, F.

2014-12-01

Modern seismic networks are recording the ground motion continuously all around the word, with very broadband and high-sensitivity sensors. The aim of our study is to apply statistical array-based approaches to processing of these records. We use the methods mainly brought from the random matrix theory in order to give a statistical description of seismic wavefields recorded at the Earth's surface. We estimate the array covariance matrix and explore the distribution of its eigenvalues that contains information about the coherency of the sources that generated the studied wavefields. With this approach, we can make distinctions between the signals generated by isolated deterministic sources and the "random" ambient noise. We design an algorithm that uses the distribution of the array covariance matrix eigenvalues to detect signals corresponding to coherent seismic events. We investigate the detection capacity of our methods at different scales and in different frequency ranges by applying it to the records of two networks: (1) the seismic monitoring network operating on the Piton de la Fournaise volcano at La Réunion island composed of 21 receivers and with an aperture of ~15 km, and (2) the transportable component of the USArray composed of ~400 receivers with ~70 km inter-station spacing.

How prepared were the Puerto Rico Seismic Network sites for the arrival of Hurricane Maria? Lessons learned on communications, power and infrastructure.

NASA Astrophysics Data System (ADS)

Vanacore, E. A.; Lopez, A. M.; Huerfano, V.; Lugo, J.; Baez-Sanchez, G.

2017-12-01

For exactly 85 years the island of Puerto Rico in the northeastern Caribbean was spared from catastrophic category 4 hurricane winds. Then Hurricane Maria arrived on September 20, 2017 with maximum sustained winds of up to 155 mph. The eye of the hurricane crossed the island from southeast to northwest in eight hours leaving almost a meter of rainfall on its path. Sustained winds, gusts and precipitation were most certainly going to affect the seismic and geodetic equipment the Puerto Rico Seismic Network (PRSN) use for locating earthquakes in the region. PRSN relies on 35 seismic stations (velocity and strong-motion) to characterize the seismic behavior of the island and 15 geodetic (GNSS) stations to determine crustal deformation of the Puerto Rico - Virgin Islands microplate. PRSN stations have been designed to withstand earthquakes. However, the equipment suffered considerable damage due to the strong winds especially station communication towers. This coupled with catastrophic damage to the telecommunication and power grids of the island had severe effects on the network. Additionally, the level of devastation was such that it hampered the ability of PRSN staff to visit the sites for assessment and repair. Here we present the effects of category 4 hurricane had on our seismic and geodetic sites, examine the susceptibility of the PRSN stations' power and communications, and discuss future plans to recuperate and improve station resiliency for future catastrophic events. These lessons learned hopefully will help harden sites of networks, agencies and/or institutions that rely on similar infrastructure.

The INGV seismic monitoring system: activities during the first month of the 2016 Amatrice seismic sequence.

NASA Astrophysics Data System (ADS)

Scognamiglio, L.; Margheriti, L.; Moretti, M.; Pintore, S.

2016-12-01

At 01:36:32 UTC on August 24, 2016 an earthquake of ML=6.0 occurred in Central Italy, near Amatrice village; 21 s after the origin time, the first automatic location became available while the first magnitude estimate followed 47s after. The INGV seismologists on duty provided the alert to the Italian Civil Protection Department and thereby triggered the seismic emergency protocol In the hours after the earthquake, hundreds of events were recorded by the Italian Seismic Network of the INGV. SISMIKO, the coordinating body of the emergency seismic network, was activated few minutes after the mainshock. The main goal of this emergency group is to install temporary dense seismic network integrated with the existing permanent networks in the epicentral area to better constrain the aftershock hypocenters. From August the 24th to the 30th, SISMIKO deployed 18 seismic stations, generally six components (equipped with both seismometer and accelerometer), 13 of which were transmitting in real-time to the INGV seismic surveillance room in Rome. All data acquired are available at the European Integrated Data Archive (EIDA). The seismic sequence in the first month generated thousands of earthquakes which were processed and detected by the INGV automated localization system. We analyzed the performance of this system. Hundreds of those events were located by seismologists on shifts, the others were left to be analyzed by the Bollettino Sismico Italiano (BSI). The procedures of the BSI revise and integrate all available data. This allows for a better constrained location and for a more realistic hypocentral depth estimation. The first eight hours of August 24th were the most critical for the INGV surveillance room. Data recorded in these hours were carefully re-analyzed by BSI operators and the number of located events increased from 133 to 408, while the magnitude of completeness dropped significantly from about 3.5 to 2.7.

Cross-correlation analysis of 2012-2014 seismic events in Central-Northern Italy: insights from the geochemical monitoring network of Tuscany

NASA Astrophysics Data System (ADS)

Pierotti, Lisa; Facca, Gianluca; Gherardi, Fabrizio

2015-04-01

Since late 2002, a geochemical monitoring network is operating in Tuscany, Central Italy, to collect data and possibly identify geochemical anomalies that characteristically occur before regionally significant (i.e. with magnitude > 3) seismic events. The network currently consists of 6 stations located in areas already investigated in detail for their geological setting, hydrogeological and geochemical background and boundary conditions. All these stations are equipped for remote, continuous monitoring of selected physicochemical parameters (temperature, pH, redox potential, electrical conductivity), and dissolved concentrations of CO2 and CH4. Additional information are obtained through in situ discrete monitoring. Field surveys are periodically performed to guarantee maintenance and performance control of the sensors of the automatic stations, and to collect water samples for the determination of the chemical and stable isotope composition of all the springs investigated for seismic precursors. Geochemical continuous signals are numerically processed to remove outliers, monitoring errors and aseismic effects from seasonal and climatic fluctuations. The elaboration of smoothed, long-term time series (more than 200000 data available today for each station) allows for a relatively accurate definition of geochemical background values. Geochemical values out of the two-sigma relative standard deviation domain are inspected as possible indicators of physicochemical changes related to regional seismic activity. Starting on November 2011, four stations of the Tuscany network located in two separate mountainous areas of Northern Apennines separating Tuscany from Emilia-Romagna region (Equi Terme and Gallicano), and Tuscany from Emilia-Romagna and Umbria regions (Vicchio and Caprese Michelangelo), started to register anomalous values in pH and CO2 partial pressure (PCO2). Cross-correlation analysis indicates an apparent relationship between the most important seismic

Hanford Site Solid Waste Acceptance Criteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-11-17

This manual defines the Hanford Site radioactive, hazardous, and sanitary solid waste acceptance criteria. Criteria in the manual represent a guide for meeting state and federal regulations; DOE Orders; Hanford Site requirements; and other rules, regulations, guidelines, and standards as they apply to acceptance of radioactive and hazardous solid waste at the Hanford Site. It is not the intent of this manual to be all inclusive of the regulations; rather, it is intended that the manual provide the waste generator with only the requirements that waste must meet in order to be accepted at Hanford Site TSD facilities.

One perspective on stakeholder involvement at Hanford.

PubMed

Martin, Todd

2011-11-01

The Hanford nuclear site in Washington State had a major role in the production of nuclear weapons materials during the Manhattan Project in World War II and during the Cold War that followed. The production of weapons-grade radionuclides produced a large amount of radioactive byproducts that have been stored since the mid-1900s at the Hanford Site. These by-product radionuclides have leaked from containment facilities into the groundwater, contaminated buildings used for radionuclide processing, and also contaminated the nuclear reactors used to produce weapons-grade uranium and plutonium. This issue has been a major concern to Hanford stakeholders for several decades, and the U.S. Department of Energy, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology established a Tri-Party Agreement in 1989, at which time Hanford ceased production of nuclear weapons materials and began a major effort to clean up and remediate the Hanford Site's contaminated groundwater, soil, and facilities. This paper describes the concerns of stakeholders in the production of nuclear weapons, the secrecy of Hanford operations, and the potential impacts to public health and the environment from the unintended releases of weapons-grade materials and by-products associated with their production at the Hanford Site. It also describes the involvement of public stakeholders in the development and oversight by the Hanford Advisory Board of the steps that have been taken in cleanup activities at the Hanford Site that began as a major effort about two decades ago. The importance of involvement of the general public and public interest organizations in developing and implementing the Hanford cleanup strategy are described in detail.

Mining induced seismic event on an inactive fault in view of local surface and in mine underground networksS

NASA Astrophysics Data System (ADS)

Rudzinski, Lukasz; Lizurek, Grzegorz; Plesiewicz, Beata

2014-05-01

On 19th March 2013 tremor shook the surface of Polkowice town were "Rudna" mine is located. This event of ML=4.2 was third most powerful seismic event recorded in Legnica Głogów Copper District (LGCD). Citizens of the area reported that felt tremors were bigger and last longer than any other ones felt in last couple years. The event was studied with use of two different networks: underground network of "Rudna" mine and surface local network run by IGF PAS (LUMINEOS network). The first one is composed of 32 vertical seismometers at mining level, except 5 sensors placed in elevator shafts, seismometers location depth varies from 300 down to 1000 meters below surface. The seismometers used in this network are vertical short period Willmore MkII and MkIII sensors, with the frequency band from 1Hz to 100Hz. At the beginning of 2013th the local surface network of the Institute of Geophysics Polish Academy of Sciences (IGF PAS) with acronym LUMINEOS was installed under agreement with KGHM SA and "Rudna" mine officials. This network at the moment of the March 19th 2013 event was composed of 4 short-period one-second triaxial seismometers LE-3D/1s manufactured by Lenartz Electronics. Analysis of spectral parameters of the records from in mine seismic system and surface LUMINEOS network along with broadband station KSP record were carried out. Location of the event was close to the Rudna Główna fault zone, the nodal planes orientations determined with two different approaches were almost parallel to the strike of the fault. The mechanism solutions were also obtained in form of Full Moment Tensor inversion from P wave amplitude pulses of underground records and waveform inversion of surface network seismograms. Final results of the seismic analysis along with macroseismic survey and observed effects from the destroyed part of the mining panel indicate that the mechanism of the event was thrust faulting on inactive tectonic fault. The results confirm that the fault zones

Korea Integrated Seismic System tool(KISStool) for seismic monitoring and data sharing at the local data center

NASA Astrophysics Data System (ADS)

Park, J.; Chi, H. C.; Lim, I.; Jeong, B.

2011-12-01

The Korea Integrated Seismic System(KISS) is a back-bone seismic network which distributes seismic data to different organizations in near-real time at Korea. The association of earthquake monitoring institutes has shared their seismic data through the KISS from 2003. Local data centers operating remote several stations need to send their free field seismic data to NEMA(National Emergency Management Agency) by the law of countermeasure against earthquake hazard in Korea. It is very important the efficient tool for local data centers which want to rapidly detect local seismic intensity and to transfer seismic event information toward national wide data center including PGA, PGV, dominant frequency of P-wave, raw data, and etc. We developed the KISStool(Korea Integrated Seismic System tool) for easy and convenient operation seismic network in local data center. The KISStool has the function of monitoring real time waveforms by clicking station icon on the Google map and real time variation of PGA, PGV, and other data by opening the bar type monitoring section. If they use the KISStool, any local data center can transfer event information to NEMA(National Emergency Management Agency), KMA(Korea Meteorological Agency) or other institutes through the KISS using UDP or TCP/IP protocols. The KISStool is one of the most efficient methods to monitor and transfer earthquake event at local data center in Korea. KIGAM will support this KISStool not only to the member of the monitoring association but also local governments.

Seismicity and active tectonics in the Alboran Sea, Western Mediterranean: Constraints from an offshore-onshore seismological network and swath bathymetry data

NASA Astrophysics Data System (ADS)

Grevemeyer, Ingo; Gràcia, Eulàlia; Villaseñor, Antonio; Leuchters, Wiebke; Watts, Anthony B.

2015-12-01

Seismicity and tectonic structure of the Alboran Sea were derived from a large amphibious seismological network deployed in the offshore basins and onshore in Spain and Morocco, an area where the convergence between the African and Eurasian plates causes distributed deformation. Crustal structure derived from local earthquake data suggests that the Alboran Sea is underlain by thinned continental crust with a mean thickness of about 20 km. During the 5 months of offshore network operation, a total of 229 local earthquakes were located within the Alboran Sea and neighboring areas. Earthquakes were generally crustal events, and in the offshore domain, most of them occurred at crustal levels of 2 to 15 km depth. Earthquakes in the Alboran Sea are poorly related to large-scale tectonic features and form a 20 to 40 km wide NNE-SSW trending belt of seismicity between Adra (Spain) and Al Hoceima (Morocco), supporting the case for a major left-lateral shear zone across the Alboran Sea. Such a shear zone is in accord with high-resolution bathymetric data and seismic reflection imaging, indicating a number of small active fault zones, some of which offset the seafloor, rather than supporting a well-defined discrete plate boundary fault. Moreover, a number of large faults known to be active as evidenced from bathymetry, seismic reflection, and paleoseismic data such as the Yusuf and Carboneras faults were seismically inactive. Earthquakes below the Western Alboran Basin occurred at 70 to 110 km depth and hence reflected intermediate depth seismicity related to subducted lithosphere.

Mammoth Mountain, California broadband seismic experiment

NASA Astrophysics Data System (ADS)

Dawson, P. B.; Pitt, A. M.; Wilkinson, S. K.; Chouet, B. A.; Hill, D. P.; Mangan, M.; Prejean, S. G.; Read, C.; Shelly, D. R.

2013-12-01

Mammoth Mountain is a young cumulo-volcano located on the southwest rim of Long Valley caldera, California. Current volcanic processes beneath Mammoth Mountain are manifested in a wide range of seismic signals, including swarms of shallow volcano-tectonic earthquakes, upper and mid-crustal long-period earthquakes, swarms of brittle-failure earthquakes in the lower crust, and shallow (3-km depth) very-long-period earthquakes. Diffuse emissions of C02 began after a magmatic dike injection beneath the volcano in 1989, and continue to present time. These indications of volcanic unrest drive an extensive monitoring effort of the volcano by the USGS Volcano Hazards Program. As part of this effort, eleven broadband seismometers were deployed on Mammoth Mountain in November 2011. This temporary deployment is expected to run through the fall of 2013. These stations supplement the local short-period and broadband seismic stations of the Northern California Seismic Network (NCSN) and provide a combined network of eighteen broadband stations operating within 4 km of the summit of Mammoth Mountain. Data from the temporary stations are not available in real-time, requiring the merging of the data from the temporary and permanent networks, timing of phases, and relocation of seismic events to be accomplished outside of the standard NCSN processing scheme. The timing of phases is accomplished through an interactive Java-based phase-picking routine, and the relocation of seismicity is achieved using the probabilistic non-linear software package NonLinLoc, distributed under the GNU General Public License by Alomax Scientific. Several swarms of shallow volcano-tectonic earthquakes, spasmodic bursts of high-frequency earthquakes, a few long-period events located within or below the edifice of Mammoth Mountain and numerous mid-crustal long-period events have been recorded by the network. To date, about 900 of the ~2400 events occurring beneath Mammoth Mountain since November 2011 have

Surface Wave Dispersion Measurements and Tomography From Ambient Seismic Noise in China

DTIC Science & Technology

2007-12-20

Recovering the Green’s function from field - field correlations in an open scattering medium (L), J. Acoust. Soc. Amer. 113 (6), 2973- 2976, 2003. Eagle, D...The basic approach can be traced back much earlier studies of random fields in seismology (Aki, 1957; Toksoz, 1964; Claerbout, 1968), in...Seismic Network (CNDSN), Center of China Digital Seismic Network (CCDSN) stations, and China Seismic Network ( CSN ). We refer here as China National

Hanford Site 1998 Environmental Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

RL Dirkes; RW Hanf; TM Poston

This Hanford Site environmental report is prepared annually to summarize environmental data and information, to describe environmental management performance, to demonstrate the status of compliance with environmental regulations, and to highlight major environmental programs and efforts. The report is written to meet requirements and guidelines of the U.S. Department of Energy (DOE) and to meet the needs of the public. This summary has been written with a minimum of technical terminology. Individual sections of the report are designed to: describe the Hanford Site and its mission; summarize the status of compliance with environmental regulations; describe the environmental programs at themore » Hanford Site; discuss the estimated radionuclide exposure to the public from 1998 Hanford Site activities; present the effluent monitoring, environmental surveillance, and groundwater protection and monitoring information; and discuss the activities to ensure quality.« less

Seismic interaction between a building network and a sedimentary basin

NASA Astrophysics Data System (ADS)

Kham, M.; Semblat, J. F.; Bard, P. Y.; Gueguen, P.

2003-04-01

The classical procedure to assess the seismic risk for a superficial structure consists in distinguishing firstly the characterization of the seismic hazard and secondly the analysis of the structure vulnerability. But, as far as the entire urban area is concerned by the seismic risk, a network of superficial structures may influence the free-field motion. In this way, convergent observations were made during the 1985 Mexico earthquake where the large increase in duration may not be completely explained only by site effects. This phenomenon involving the interaction between a city and the sedimentary basin is called Site-City Interaction (SCI) and was firstly underlined by Gueguen [1] in Volvi european test site. Under seismic excitation, the energy radiated by the city back into the soil seems to be mainly controlled by the eigenfrequency ratio fB/fs between the buildings and the soil as well as the urban density. Nevertheless, the key parameters supporting or controlling the SCI effect mainly remain unknown. This point is all the more obvious since present studies on the issue suffer a lack of experimental data characterizing the "urban free field". In the present work, we aim to quantify the specific role of some parameters characterizing the city on seismic hazard modification, such as the urban density, the resonance frequency of the buildings in the city, its homogeneity level (one or several types of different buildings) or the periodicity (or not) of the buildings distribution. To this purpose, a boundary element model is considered which comprises alluvial layers over a rigid elastic basement and superficial buildings. Impedance contrast is taken to 5 in order to support the trapping of the incident energy inside the superficial layers. The whole system is then submitted to a Ricker signal which frequency is successively adjusted to the city and the soil fundamental frequencies. The case of Nice city (France) over a two dimensional basin is then considered

HANFORD SCIENCE & TECHNOLOGY NEEDS STATEMENTS 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

WIBLE, R.A.

This document: (a) provides a comprehensive listing of the Hanford sites science and technology needs for fiscal year (FY) 2002; and (b) identifies partnering and commercialization opportunities within industry, other federal and state agencies, and the academic community. These needs were prepared by the Hanford projects (within the Project Hanford Management Contract, the Environmental Restoration Contract and the River Protection Project) and subsequently reviewed and endorsed by the Hanford Site Technology Coordination Group (STCG). The STCG reviews included participation of DOE-RL and DOE-ORP Management, site stakeholders, state and federal regulators, and Tribal Nations. These needs are reviewed and updated onmore » an annual basis and given a broad distribution.« less

Hanford Site Environmental Report 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

TM Poston; RW Hanf; RL Dirkes

This Hanford Site environmental report is prepared annually to summarize environmental data and information, to describe environmental management performance, to demonstrate the status of compliance with environmental regulations, and to highlight major environmental programs and efforts. The report is written to meet requirements and guidelines of the U.S. Department of Energy (DOE) and to meet the needs of the public. This summary has been written with a minimum of technical terminology. Individual sections of the report are designed to: (1) describe the Hanford Site and its mission; (2) summarize the status of compliance with environmental regulations; (3) describe the environmentalmore » programs at the Hanford Site; (4) discuss the estimated radionuclide exposure to the public from 1999 Hanford Site activities; (5) present the effluent monitoring, environmental surveillance, groundwater protection and monitoring information; and (6) discuss the activities to ensure quality.« less

North Korea nuclear test analysis results using KMA seismic and infrasound networks

NASA Astrophysics Data System (ADS)

Jeon, Y. S.; Park, E.; Lee, D.; Min, K.; CHO, S.

2017-12-01

Democratic People's Republic of Korea(DPRK) carried out 6th nuclear test on 3 Sep. 2017 at 03:30 UTC. Seismic and infrasound network operated by Korea Meteorological Administration(KMA) successfully detected signals took place in the DPRK's test site, Punggye-ri. First, we checked that Pg/Lg spectral amplitude ratio greater than 1 in the frequency range from 1.0 to 10.0 Hz is useful to discriminate between DPRK test signals and natural earthquakes. KMA's infrasound stations of Cheorwon(CW) and Yanggu(YG) successfully monitored the azimuth direction of the arrival of the infrasound signals generated from DPRK underground nuclear explosions, including the recent test on September 03, 2017. The azimuthal direction of 210(CW) and 130 (YG) point out Punggye-ri test site. Complete waveforms at stations MDJ, CHC2, YNCB in long period(0.05 to 0.1 HZ) are jointly inverted with local P-wave polarities to generate moment tensor inversion result of the explosive moment 1.20e+24 dyne cm(Mw 5.31) and 65% of ISO. The moment magnitude of 5th, 4th and 3rd are 4.61, 4.69 and 4.46 respectively. Source type moment tensor inversion result of DPRK nuclear tests show that the event is significantly away from the deviatoric line of the Hudson et at. (1989) source-type diagram and identifies as having a significant explosive component. Analysis results using seismic and infrasound network verify that the DPRK's explosion tests classified as nuclear test.

An automated multi-scale network-based scheme for detection and location of seismic sources

NASA Astrophysics Data System (ADS)

Poiata, N.; Aden-Antoniow, F.; Satriano, C.; Bernard, P.; Vilotte, J. P.; Obara, K.

2017-12-01

We present a recently developed method - BackTrackBB (Poiata et al. 2016) - allowing to image energy radiation from different seismic sources (e.g., earthquakes, LFEs, tremors) in different tectonic environments using continuous seismic records. The method exploits multi-scale frequency-selective coherence in the wave field, recorded by regional seismic networks or local arrays. The detection and location scheme is based on space-time reconstruction of the seismic sources through an imaging function built from the sum of station-pair time-delay likelihood functions, projected onto theoretical 3D time-delay grids. This imaging function is interpreted as the location likelihood of the seismic source. A signal pre-processing step constructs a multi-band statistical representation of the non stationary signal, i.e. time series, by means of higher-order statistics or energy envelope characteristic functions. Such signal-processing is designed to detect in time signal transients - of different scales and a priori unknown predominant frequency - potentially associated with a variety of sources (e.g., earthquakes, LFE, tremors), and to improve the performance and the robustness of the detection-and-location location step. The initial detection-location, based on a single phase analysis with the P- or S-phase only, can then be improved recursively in a station selection scheme. This scheme - exploiting the 3-component records - makes use of P- and S-phase characteristic functions, extracted after a polarization analysis of the event waveforms, and combines the single phase imaging functions with the S-P differential imaging functions. The performance of the method is demonstrated here in different tectonic environments: (1) analysis of the one year long precursory phase of 2014 Iquique earthquake in Chile; (2) detection and location of tectonic tremor sources and low-frequency earthquakes during the multiple episodes of tectonic tremor activity in southwestern Japan.

Local magnitude calibration of the Hellenic Unified Seismic Network

NASA Astrophysics Data System (ADS)

Scordilis, E. M.; Kementzetzidou, D.; Papazachos, B. C.

2016-01-01

A new relation is proposed for accurate determination of local magnitudes in Greece. This relation is based on a large number of synthetic Wood-Anderson (SWA) seismograms corresponding to 782 regional shallow earthquakes which occurred during the period 2007-2013 and recorded by 98 digital broad-band stations. These stations are installed and operated by the following: (a) the National Observatory of Athens (HL), (b) the Department of Geophysics of the Aristotle University of Thessaloniki (HT), (c) the Seismological Laboratory of the University of Athens (HA), and (d) the Seismological Laboratory of the Patras University (HP). The seismological networks of the above institutions constitute the recently (2004) established Hellenic Unified Seismic Network (HUSN). These records are used to calculate a refined geometrical spreading factor and an anelastic attenuation coefficient, representative for Greece and surrounding areas, proper for accurate calculation of local magnitudes in this region. Individual station corrections depending on the crustal structure variations in their vicinity and possible inconsistencies in instruments responses are also considered in order to further ameliorate magnitude estimation accuracy. Comparison of such calculated local magnitudes with corresponding original moment magnitudes, based on an independent dataset, revealed that these magnitude scales are equivalent for a wide range of values.

Hanford Site Environmental Report 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dirkes, R.L.; Hanf, R.W.; Woodruff, R.K.

The Hanford Site Environmental Report is prepared annually to summarize environmental data and information, describe environmental management performance, and demonstrate the status of compliance with environmental regulations. The report also highlights major environmental programs and efforts. The report is written to meet reporting requirements and Guidelines of the U.S. Department of Energy (DOE) an to meet the needs of the public. This summary has been written with a minimum of technical terminology. Individual sections of the report are designed to (a) describe the Hanford Site and its mission, (b) summarize the status in 1993 of compliance with environmental regulations, (c)more » describe the environmental programs at the Hanford Site, (d) discuss estimated radionuclide exposure to the public from 1993 Hanford activities, (e) present information on effluent monitoring and environmental surveillance, including ground-water protection and monitoring, (f) discuss activities to ensure quality. More detailed information can be found in the body of the report, the appendixes, and the cited references.« less

Improvements of Real Time First Motion Focal Mechanism and Noise Characteristics of New Sites at the Puerto Rico Seismic Network

NASA Astrophysics Data System (ADS)

Williams, D. M.; Lopez, A. M.; Huerfano, V.; Lugo, J.; Cancel, J.

2011-12-01

Seismic networks need quick and efficient ways to obtain information related to seismic events for the purposes of seismic activity monitoring, risk assessment, and scientific knowledge among others. As part of an IRIS summer internship program, two projects were performed to provide a tool for quick faulting mechanism and improve seismic data at the Puerto Rico Seismic Network (PRSN). First, a simple routine to obtain a focal mechanisms, the geometry of the fault, based on first motions was developed and implemented for data analysts routine operations at PRSN. The new tool provides the analyst a quick way to assess the probable faulting mechanism that occurred while performing the interactive earthquake location procedure. The focal mechanism is generated on-the-fly when data analysts pick P wave arrivals onsets and motions. Once first motions have been identified, an in-house PRSN utility is employed to obtain the double couple representation and later plotted using GMT's psmeca utility. Second, we addressed the issue of seismic noise related to thermal fluctuations inside seismic vaults. Seismic sites can be extremely noisy due to proximity to cultural activities and unattended thermal fluctuations inside sensor housings, thus resulting in skewed readings. In the past, seismologists have used different insulation techniques to reduce the amount of unwanted noise that a seismometers experience due to these thermal changes with items such as Styrofoam, and fiber glass among others. PRSN traditionally uses Styrofoam boxes to cover their seismic sensors, however, a proper procedure to test how these method compare to other new techniques has never been approached. The deficiency of properly testing these techniques in the Caribbean and especially Puerto Rico is that these thermal fluctuations still happen because of the intense sun and humidity. We conducted a test based on the methods employed by the IRIS Transportable Array, based on insulation by sand burial of

Improvements of the Regional Seismic network of Northwestern Italy in the framework of ALCoTra program activities

NASA Astrophysics Data System (ADS)

Bosco, Fabrizio

2014-05-01

Arpa Piemonte (Regional Agency for Environmental Protection), in partnership with University of Genoa, manages the regional seismic network, which is part of the Regional Seismic network of Northwestern Italy (RSNI). The network operates since the 80s and, over the years, it has developed in technological features, analysis procedures and geographical coverage. In particular in recent years the network has been further enhanced through the integration of Swiss and French stations installed in the cross-border area. The environmental context enables the installation of sensors in sites with good conditions as regards ambient noise and limited local amplification effects (as proved by PSD analysis, signal quality monitoring via PQLX, H/V analysis). The instrumental equipment consists of Broadband and Very Broadband sensors (Nanometrics Trillium 40" and 240") and different technological solutions for signals real-time transmission (cable, satellite, GPRS), according to the different local environment, with redundant connections and with experimental innovative systems. Digital transmission and acquisition systems operate through standard protocols (Nanometrics, SeedLink), with redundancy in data centers (Genoa, Turin, Rome). Both real-time automatic and manual operational procedures are in use for signals analysis (events detection, picking, focal parameters and ground shaking determination). In the framework of cross-border cooperation program ALCoTra (http://www.interreg-alcotra.org), approved by the European Commission, several projects have been developed to improve the performances of seismic monitoring systems used by partners (Arpa Piemonte, Aosta Valley Region, CNRS, Joseph Fourier University). The cross-border context points out first of all the importance of signals sharing (from 14 to 23 stations in narrow French-Italian border area, with an increase of over 50%) and of coordination during new stations planning and installation in the area. In the ongoing

Investigating subduction reversal in Papua New Guinea from automatic analysis of seismicity recorded on a temporary local network

NASA Astrophysics Data System (ADS)

Hicks, S. P.; Harmon, N.; Rychert, C.; Tharimena, S.; Bogiatzis, P.; Savage, B.; Shen, Y.; Baillard, C.

2017-12-01

The area of Papua New Guinea is one of the most seismically active regions on the planet. Seismicity in the region results from oblique convergence between the Pacific and India-Australia plates, with deformation occurring across a broad region involving several microplates. The region gives an excellent natural laboratory to test geodynamic models of subduction polarity reversal, microplate interaction, and to delineate the structure of subducting plates and relic structures at depth. However, a lack of permanent seismic stations means that routine earthquake locations for small to intermediate sized earthquakes have significant location errors. In 2014, we deployed a temporary network of eight broadband stations on islands in eastern Papua New Guinea to record ongoing seismic deformation. The network straddles a complex region where subduction of the Solomon plate occurs to the south and possible subduction of the Ontong-Java plateau occurs to the north. The stations were installed for 27 months. During the deployment period, there were 13 M>6.5 earthquakes in the area, including M7.5 doublet events in 2015, giving a rich seismic dataset. A high-quality catalogue of local events was formed by a multi-step process. Using the scanloc module of SeisComp3, we first detect P-onsets using a STA/LTA detection. Once clusters of P onsets are found, S-wave picks are incorporated based on a pre-defined window length of maximum S-P time. Groups of onsets are then associated to events, giving us a starting catalogue of 269 events (1765 P-onsets) with minimum magnitude of M 3.5. In a second step, we refine onset times using a Kurtosis picker to improve location accuracy. To form robust hypocentral locations using an appropriate structural model for the area and to constrain crust and mantle structure in the region, we derive a minimum 1-D velocity model using the VELEST program. We use a starting model from Abers et al. (1991) and we restrict our catalogue to events with an

Investigating subduction reversal in Papua New Guinea from automatic analysis of seismicity recorded on a temporary local network

NASA Astrophysics Data System (ADS)

Hicks, S. P.; Harmon, N.; Rychert, C.; Tharimena, S.; Bogiatzis, P.; Savage, B.; Shen, Y.; Baillard, C.

2016-12-01

The area of Papua New Guinea is one of the most seismically active regions on the planet. Seismicity in the region results from oblique convergence between the Pacific and India-Australia plates, with deformation occurring across a broad region involving several microplates. The region gives an excellent natural laboratory to test geodynamic models of subduction polarity reversal, microplate interaction, and to delineate the structure of subducting plates and relic structures at depth. However, a lack of permanent seismic stations means that routine earthquake locations for small to intermediate sized earthquakes have significant location errors. In 2014, we deployed a temporary network of eight broadband stations on islands in eastern Papua New Guinea to record ongoing seismic deformation. The network straddles a complex region where subduction of the Solomon plate occurs to the south and possible subduction of the Ontong-Java plateau occurs to the north. The stations were installed for 27 months. During the deployment period, there were 13 M>6.5 earthquakes in the area, including M7.5 doublet events in 2015, giving a rich seismic dataset. A high-quality catalogue of local events was formed by a multi-step process. Using the scanloc module of SeisComp3, we first detect P-onsets using a STA/LTA detection. Once clusters of P onsets are found, S-wave picks are incorporated based on a pre-defined window length of maximum S-P time. Groups of onsets are then associated to events, giving us a starting catalogue of 269 events (1765 P-onsets) with minimum magnitude of M 3.5. In a second step, we refine onset times using a Kurtosis picker to improve location accuracy. To form robust hypocentral locations using an appropriate structural model for the area and to constrain crust and mantle structure in the region, we derive a minimum 1-D velocity model using the VELEST program. We use a starting model from Abers et al. (1991) and we restrict our catalogue to events with an

Aspects regarding the use of the INFREP network for identifying possible seismic precursors

NASA Astrophysics Data System (ADS)

Dolea, Paul; Cristea, Octavian; Dascal, Paul Vladut; Moldovan, Iren-Adelina; Biagi, Pier Francesco

In the last decades, one of the main research directions in identifying seismic precursors involved monitoring VLF (Very Low Frequency) and LF (Low Frequency) radio waves and analysing their propagation characteristics. Essentially this method consists of monitoring different available VLF and LF transmitters from long distance reception points. The received signal has two major components: the ground wave and the sky wave, where the sky wave propagates by reflection on the lower layers of the ionosphere. It is assumed that before and during major earthquakes, unusual changes may occur in the lower layers of the ionosphere, such as the modification of the charged particles number density and the altitude of the reflection zone. Therefore, these unusual changes in the ionosphere may generate unusual variations in the received signal level. The International Network for Frontier Research on Earthquake Precursors (INFREP) was developed starting with 2009 and consists of several dedicated VLF and LF radio receivers used for monitoring various radio transmitters located throughout Europe. The receivers' locations were chosen so that the propagation path from these VLF/LF stations would pass over high seismicity regions while others were chosen to obtain different control paths. The monitoring receivers are capable of continuously measuring the received signal amplitude from the VLF/LF stations of interest. The recorded data is then stored and sent to an INFREP database, which is available on the Internet for scientific researchers. By processing and analysing VLF and LF data samples, collected at different reception points and at different periods of the year, one may be able to identify some distinct patterns in the envelope of the received signal level over time. Significant deviations from these patterns may have local causes such as the electromagnetic pollution at the monitoring point, regional causes like existing electrical storms over the propagation path or

Preferential attachment in evolutionary earthquake networks

NASA Astrophysics Data System (ADS)

Rezaei, Soghra; Moghaddasi, Hanieh; Darooneh, Amir Hossein

2018-04-01

Earthquakes as spatio-temporal complex systems have been recently studied using complex network theory. Seismic networks are dynamical networks due to addition of new seismic events over time leading to establishing new nodes and links to the network. Here we have constructed Iran and Italy seismic networks based on Hybrid Model and testified the preferential attachment hypothesis for the connection of new nodes which states that it is more probable for newly added nodes to join the highly connected nodes comparing to the less connected ones. We showed that the preferential attachment is present in the case of earthquakes network and the attachment rate has a linear relationship with node degree. We have also found the seismic passive points, the most probable points to be influenced by other seismic places, using their preferential attachment values.

Seismic link at plate boundary

NASA Astrophysics Data System (ADS)

Ramdani, Faical; Kettani, Omar; Tadili, Benaissa

2015-06-01

Seismic triggering at plate boundaries has a very complex nature that includes seismic events at varying distances. The spatial orientation of triggering cannot be reduced to sequences from the main shocks. Seismic waves propagate at all times in all directions, particularly in highly active zones. No direct evidence can be obtained regarding which earthquakes trigger the shocks. The first approach is to determine the potential linked zones where triggering may occur. The second step is to determine the causality between the events and their triggered shocks. The spatial orientation of the links between events is established from pre-ordered networks and the adapted dependence of the spatio-temporal occurrence of earthquakes. Based on a coefficient of synchronous seismic activity to grid couples, we derive a network link by each threshold. The links of high thresholds are tested using the coherence of time series to determine the causality and related orientation. The resulting link orientations at the plate boundary conditions indicate that causal triggering seems to be localized along a major fault, as a stress transfer between two major faults, and parallel to the geothermal area extension.

Seismic Tomography and the Development of a State Velocity Profile

NASA Astrophysics Data System (ADS)

Marsh, S. J.; Nakata, N.

2017-12-01

Earthquakes have been a growing concern in the State of Oklahoma in the last few years and as a result, accurate earthquake location is of utmost importance. This means using a high resolution velocity model with both lateral and vertical variations. Velocity data is determined using ambient noise seismic interferometry and tomography. Passive seismic data was acquired from multiple IRIS networks over the span of eight years (2009-2016) and filtered for earthquake removal to obtain the background ambient noise profile for the state. Seismic Interferometry is applied to simulate ray paths between stations, this is done with each possible station pair for highest resolution. Finally the method of seismic tomography is used to extract the velocity data and develop the state velocity map. The final velocity profile will be a compilation of different network analyses due to changing station availability from year to year. North-Central Oklahoma has a dense seismic network and has been operating for the past few years. The seismic stations are located here because this is the most seismically active region. Other parts of the state have not had consistent coverage from year to year, and as such a reliable and high resolution velocity profile cannot be determined from this network. However, the Transportable Array (TA) passed through Oklahoma in 2014 and provided a much wider and evenly spaced coverage. The goal of this study is to ultimately combine these two arrays over time, and provide a high quality velocity profile for the State of Oklahoma.

Transient Inverse Calibration of Hanford Site-Wide Groundwater Model to Hanford Operational Impacts - 1943 to 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Charles R.; Bergeron, Marcel P.; Wurstner, Signe K.

2001-05-31

This report describes a new initiative to strengthen the technical defensibility of predictions made with the Hanford site-wide groundwater flow and transport model. The focus is on characterizing major uncertainties in the current model. PNNL will develop and implement a calibration approach and methodology that can be used to evaluate alternative conceptual models of the Hanford aquifer system. The calibration process will involve a three-dimensional transient inverse calibration of each numerical model to historical observations of hydraulic and water quality impacts to the unconfined aquifer system from Hanford operations since the mid-1940s.

Seismic excitation by space shuttles

USGS Publications Warehouse

Kanamori, H.; Mori, J.; Sturtevant, B.; Anderson, D.L.; Heaton, T.

1992-01-01

Shock waves generated by the space shuttles Columbia (August 13, 1989), Atlantis (April 11, 1991) and Discovery (September 18, 1991) on their return to Edwards Air Force Base, California, were recorded by TERRAscope (Caltech's broadband seismic network), the Caltech-U.S.G.S Southern California Seismic Network (SCSN), and the University of Southern California (USC) Los Angeles Basin Seismic Network. The spatial pattern of the arrival times exhibits hyperbolic shock fronts from which the path, velocity and altitude of the space shuttle could be determined. The shock wave was acoustically coupled to the ground, converted to a seismic wave, and recorded clearly at the broadband TERRAscope stations. The acoustic coupling occurred very differently depending on the conditions of the Earth's surface surrounding the station. For a seismic station located on hard bedrock, the shock wave (N wave) was clearly recorded with little distortion. Aside from the N wave, very little acoustic coupling of the shock wave energy to the ground occurred at these sites. The observed N wave record was used to estimate the overpressure of the shock wave accurately; a pressure change of 0.5 to 2.2 mbars was obtained. For a seismic station located close to the ocean or soft sedimentary basins, a significant amount of shock wave energy was transferred to the ground through acoustic coupling of the shock wave and the oceanic Rayleigh wave. A distinct topography such as a mountain range was found effective to couple the shock wave energy to the ground. Shock wave energy was also coupled to the ground very effectively through large man made structures such as high rise buildings and offshore oil drilling platforms. For the space shuttle Columbia, in particular, a distinct pulse having a period of about 2 to 3 seconds was observed, 12.5 s before the shock wave, with a broadband seismograph in Pasadena. This pulse was probably excited by the high rise buildings in downtown Los Angeles which were

Historical Seismicity of Central Panama

NASA Astrophysics Data System (ADS)

Camacho, E.

2013-05-01

Central Panama lies in the Panama microplate, neighboring seismically active regions of Costa Rica and Colombia. This region, crossed by the Panama Canal, concentrates most of the population and economic activity of the Republic of Panama. Instrumental observation of earthquakes in Panama began on 1882 by the Compagnie Universelle du Canal Interocéanique de Panama and continued from 1904 to 1977 by the Panama Canal Company. From October 1997 to March 1998 the USGS deployed a temporary digital seismic network. Since 2003 this region is monitored by a digital seismic network operated by the Panama Canal Authority and I complemented by the broad band stations of the University of Panama seismic network. The seismicity in this region is very diffuse and the few events which are recorded have magnitudes less than 3.0. Historical archives and antique newspapers from Spain, Colombia, Panama and the United Sates have been searched looking for historical earthquake information which could provide a better estimate of the seismicity in this region. We find that Panama City has been shaken by two destructive earthquakes in historical times. One by a local fault (i.e. Pedro Miguel fault) on May 2, 1621 (I=Vlll MM), and a subduction event from the North Panama Deformed Belt (NPDB) on September 7, 1882 (I=Vll MM). To test these findings two earthquakes scenarios were generated, using SELENA, for Panama City Old Quarter. Panama City was rebuilt on January 21, 1673, on a rocky point facing the Pacific Ocean after the sack by pirate Morgan on January 28, 1671. The pattern of damage to calicanto (unreinforced colonial masonry) and wood structures for a crustal local event are higher than those for an event from the NPDB and seem to confirm that the city has not been shaken by a major local event since May 2, 1621 and a subduction event since September 7, 1882

The Advanced National Seismic System; management and implementation

USGS Publications Warehouse

Benz, H.M.; Shedlock, K.M.; Buland, R.P.

2001-01-01

What is the Advanced National Seismic System? The Advanced National Seismic System (ANSS) is designed to organize, modernize, and standardize operations of seismic networks in the United States to improve the Nation’s ability to respond effectively to damaging earthquakes, volcanoes, and tsunamis. To achieve this, the ANSS will link more than 7,000 national, regional and urban monitoring stations in real time

Hanford Site Environmental Report for calendar year 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodruff, R.K.; Hanf, R.W.; Lundgren, R.E.

1993-06-01

This report is prepared annually to summarize environmental data and information, describe environmental management performance, and demonstrate the status of compliance with environmental regulations at the Hanford Site. The following sections: describe the Hanford Site and its mission; summarize the status in 1992 of compliance with environmental regulations; describe the environmental programs at the Hanford Site; discuss public dose estimates from 1992 Hanford activities; present information on effluent monitoring and environmental surveillance, including ground-water protection and monitoring, and discuss activities to ensure quality.

Seismicity in 2010 and major earthquakes recorded and located in Costa Rica from 1983 until 2012, by the local OVSICORI-UNA seismic network

NASA Astrophysics Data System (ADS)

Ronnie, Q.; Segura, J.; Burgoa, B.; Jimenez, W.; McNally, K. C.

2013-05-01

This work is the result of the analysis of existing information in the earthquake database of the Observatorio Sismológico y Vulcanológico de Costa Rica, Universidad Nacional (OVSICORI-UNA), and seeks disclosure of basic seismological information recorded and processed in 2010. In this year there was a transition between the software used to record, store and locate earthquakes. During the first three months of 2010, we used Earthworm (http://folkworm.ceri.memphis.edu/ew-doc), SEISAN (Haskov y Ottemoller, 1999) and Hypocenter (Lienert y Haskov, 1995) to capture, store and locate the earthquakes, respectively; in April 2010, ANTELOPE (http://www.brtt.com/software.html) start to be used for recording and storing and GENLOC (Fan at al, 2006) and LOCSAT (Bratt and Bache 1988), to locate earthquakes. GENLOC was used for local events and LOCSAT for regional and distant earthquakes. The local earthquakes were located using the 1D velocity model of Quintero and Kissling (2001) and for regional and distant earthquakes IASPEI91 (Kennett and Engdahl, 1991) was used. All the events for 2010 and shown in this work were rechecked by the authors. We located 3903 earthquakes in and around Costa Rica and 746 regional and distant seismic events were recorded (see Figure 1). In this work we also give a summary of major earthquakes recorded and located by OVSICORI-UNA network between 1983 and 2012. Seismicity recorded by OVSICORI-UNA network in 2010

Pre-, Co-, and Post-Seismic Fault Slip in the Northern Chile Seismic Gap Associated with the April 1, 2014 (Mw 8.2) Pisagua Earthquake.

NASA Astrophysics Data System (ADS)

Simons, M.; Duputel, Z.; Fielding, E. J.; Galetzka, J.; Genrich, J. F.; Jiang, J.; Jolivet, R.; Kanamori, H.; Moore, A. W.; Ortega Culaciati, F. H.; Owen, S. E.; Riel, B. V.; Rivera, L. A.; Carrizo, D.; Cotte, N.; Jara, J.; Klotz, J.; Norabuena, E. O.; Ortega, I.; Socquet, A.; Samsonov, S. V.; Valderas Bermejo, M.

2014-12-01

The April 1, 2014 (Mw 8.2) Pisagua Earthquake occurred in Northern Chile, within a long recognized seismic gap in the Central Andean region that last experienced major megathrust events in 1868 and 1877. We built a continuous GPS network starting in 2005, with the ultimate goal of understanding the kinematics and dynamics of this portion of the subduction zone. Using observations from this network, as well as others in the region, combined with InSAR, seismic and tsunami observations, we obtain estimates of inter-seismic, co-seismic and initial post-seismic fault slip using an internally consistent Bayesian unregularized approach. We evaluate the extent of spatial overlap between regions of fault slip during this different time periods. Of particular interest to this event is the extent and nature of any geodetic evidence for transient slow fault slip preceding the Pisagua Earthquake mainshock. To this end, we compare daily and high rate GPS solutions, the former of which shows long period transient motion started about 15 days before the mainshock and with maximum registered amplitude of 14.2 +/- 2 [mm] at site PSGA. Contrary to published findings, we find that pre-seismic deformation seen by the GPS network can be explained as coseismic motion associated with the multiple foreshocks.

Development of an event search and download system for analyzing waveform data observed at seafloor seismic network, DONET

NASA Astrophysics Data System (ADS)

Takaesu, M.; Horikawa, H.; Sueki, K.; Kamiya, S.; Nakamura, T.; Nakano, M.; Takahashi, N.; Sonoda, A.; Tsuboi, S.

2014-12-01

Mega-thrust earthquakes are anticipated to occur in the Nankai Trough in southwest Japan. In the source areas, we installed seafloor seismic network, DONET (Dense Ocean-floor Network System for Earthquake and Tsunamis), in 2010 in order to monitor seismicity, crustal deformations, and tsunamis. DONET system consists of totally 20 stations, which is composed of six kinds of sensors; strong-motion and broadband seismometers, quartz and differential pressure gauges, hydrophone, and thermometer. The stations are densely distributed with an average spatial interval of 15-20 km and cover near coastal areas to the trench axis. Observed data are transferred to a land station through a fiber-optical cable and then to JAMSTEC (Japan Agency for Marine-Earth Science and Technology) data management center through a private network in real time. The data are based on WIN32 format in the private network and finally archived in SEED format in the management center to combine waveform data with related metadata. We are developing a web-based application system to easily download seismic waveform data of DONET. In this system, users can select 20 Hz broadband (BH type) and 200 Hz strong-motion (EH type) data and download them in SEED. Users can also search events from the options of time periods, magnitude, source area and depth in a GUI platform. Event data are produced referring to event catalogues from USGS and JMA (Japan Meteorological Agency). The thresholds of magnitudes for the production are M6 for far-field and M4 for local events using the USGS and JMA lists, respectively. Available data lengths depend on magnitudes and epicentral distances. In this presentation, we briefly introduce DONET stations and then show our developed application system. We open DONET data through the system and want them to be widely recognized so that many users analyze. We also discuss next plans for further developments of the system.

The seismic project of the National Tsunami Hazard Mitigation Program

USGS Publications Warehouse

Oppenheimer, D.H.; Bittenbinder, A.N.; Bogaert, B.M.; Buland, R.P.; Dietz, L.D.; Hansen, R.A.; Malone, S.D.; McCreery, C.S.; Sokolowski, T.J.; Whitmore, P.M.; Weaver, C.S.

2005-01-01

In 1997, the Federal Emergency Management Agency (FEMA), National Oceanic and Atmospheric Administration (NOAA), U.S. Geological Survey (USGS), and the five western States of Alaska, California, Hawaii, Oregon, and Washington joined in a partnership called the National Tsunami Hazard Mitigation Program (NTHMP) to enhance the quality and quantity of seismic data provided to the NOAA tsunami warning centers in Alaska and Hawaii. The NTHMP funded a seismic project that now provides the warning centers with real-time seismic data over dedicated communication links and the Internet from regional seismic networks monitoring earthquakes in the five western states, the U.S. National Seismic Network in Colorado, and from domestic and global seismic stations operated by other agencies. The goal of the project is to reduce the time needed to issue a tsunami warning by providing the warning centers with high-dynamic range, broadband waveforms in near real time. An additional goal is to reduce the likelihood of issuing false tsunami warnings by rapidly providing to the warning centers parametric information on earthquakes that could indicate their tsunamigenic potential, such as hypocenters, magnitudes, moment tensors, and shake distribution maps. New or upgraded field instrumentation was installed over a 5-year period at 53 seismic stations in the five western states. Data from these instruments has been integrated into the seismic network utilizing Earthworm software. This network has significantly reduced the time needed to respond to teleseismic and regional earthquakes. Notably, the West Coast/Alaska Tsunami Warning Center responded to the 28 February 2001 Mw 6.8 Nisqually earthquake beneath Olympia, Washington within 2 minutes compared to an average response time of over 10 minutes for the previous 18 years. ?? Springer 2005.

Patterned basal seismicity shows sub-ice stream bedforms

NASA Astrophysics Data System (ADS)

Barcheck, C. G.; Tulaczyk, S. M.; Schwartz, S. Y.

2017-12-01

Patterns in seismicity emanating from the bottom of fast-moving ice streams and glaciers may indicate localized patches of higher basal resistance— sometimes called 'sticky spots', or otherwise varying basal properties. These seismogenic basal areas resist an unknown portion of the total driving stress of the Whillans Ice Plain (WIP), in West Antarctica, but may play an important role in the WIP stick-slip cycle and ice stream slowdown. To better understand the mechanism and importance of basal seismicity beneath the WIP, we analyze seismic data collected by a small aperture (< 3km) network of 8 surface and 5 borehole seismometers installed in the main central sticky spot of the WIP. We use a network beamforming technique to detect and roughly locate thousands of small (magnitude < 0), local basal micro-earthquakes in Dec 2014, and we compare the resulting map of seismicity to ice bottom depth measured by airborne radar. The number of basal earthquakes per area within the network is spatially heterogeneous, but a pattern of two 400m wide streaks of high seismicity rates is evident, with >50-500 earthquakes detected per 50x50m grid cell in 2 weeks. These seismically active streaks are elongated approximately in the ice flow direction with a spacing of 750m. Independent airborne radar measurements of ice bottom depth from Jan 2013 show a low-amplitude ( 5m) undulation in the basal topography superposed on a regional gradient in ice bottom depth. The flow-perpendicular wavelength of these low-amplitude undulations is comparable to the spacing of the high seismicity bands, and the streaks of high seismicity intersect local lows in the undulating basal topography. We interpret these seismic and radar observations as showing seismically active sub-ice stream bedforms that are low amplitude and elongated in the direction of ice flow, comparable to the morphology of mega scale glacial lineations (MSGLs), with high basal seismicity rates observed in the MSGL troughs

Seismic Observation of Infrasonic Signals

DTIC Science & Technology

1984-11-01

The implication of these results is that an infra - sonic monitoring capability already exists in the current seismic network and... infra - sonic signal recorded by the microbarographs. This arrival is linearly polarized, with a near-vertical orientation of the state vector. The...TECHNICAL REPORT NO. 84-7 cn "^ SEISMIC OBSERVATION p INFRASONIC SIGNALS D < FINAL REPORT by JACK C. SWANSON and J. CRAIG WOERPEL The views and

MSNoise: a Python Package for Monitoring Seismic Velocity Changes using Ambient Seismic Noise

NASA Astrophysics Data System (ADS)

Lecocq, T.; Caudron, C.; Brenguier, F.

2013-12-01

Earthquakes occur every day all around the world and are recorded by thousands of seismic stations. In between earthquakes, stations are recording "noise". In the last 10 years, the understanding of this noise and its potential usage have been increasing rapidly. The method, called "seismic interferometry", uses the principle that seismic waves travel between two recorders and are multiple-scattered in the medium. By cross-correlating the two records, one gets an information on the medium below/between the stations. The cross-correlation function (CCF) is a proxy to the Green Function of the medium. Recent developments of the technique have shown those CCF can be used to image the earth at depth (3D seismic tomography) or study the medium changes with time. We present MSNoise, a complete software suite to compute relative seismic velocity changes under a seismic network, using ambient seismic noise. The whole is written in Python, from the monitoring of data archives, to the production of high quality figures. All steps have been optimized to only compute the necessary steps and to use 'job'-based processing. We present a validation of the software on a dataset acquired during the UnderVolc[1] project on the Piton de la Fournaise Volcano, La Réunion Island, France, for which precursory relative changes of seismic velocity are visible for three eruptions betwee 2009 and 2011.

Hanford science and technology needs statements document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piper, L.L.

This document is a compilation of the Hanford science and technology needs statements for FY 1998. The needs were developed by the Hanford Site Technology Coordination Group (STCG) with full participation and endorsement of site user organizations, stakeholders, and regulators. The purpose of this document is to: (a) provide a comprehensive listing of Hanford science and technology needs, and (b) identify partnering and commercialization opportunities with industry, other federal and state agencies, and the academic community. The Hanford STCG reviews and updates the needs annually. Once completed, the needs are communicated to DOE for use in the development and prioritizationmore » of their science and technology programs, including the Focus Areas, Cross-Cutting Programs, and the Environmental Management Science Program. The needs are also transmitted to DOE through the Accelerating Cleanup: 2006 Plan. The public may access the need statements on the Internet on: the Hanford Home Page (www.hanford.gov), the Pacific Rim Enterprise Center`s web site (www2.pacific-rim.org/pacific rim), or the STCG web site at DOE headquarters (em-52.em.doegov/ifd/stcg/stcg.htm). This page includes links to science and technology needs for many DOE sites. Private industry is encouraged to review the need statements and contact the Hanford STCG if they can provide technologies that meet these needs. On-site points of contact are included at the ends of each need statement. The Pacific Rim Enterprise Center (206-224-9934) can also provide assistance to businesses interested in marketing technologies to the DOE.« less

Discriminating Induced-Microearthquakes Using New Seismic Features

NASA Astrophysics Data System (ADS)

Mousavi, S. M.; Horton, S.

2016-12-01

We studied characteristics of induced-microearthquakes on the basis of the waveforms recorded on a limited number of surface receivers using machine-learning techniques. Forty features in the time, frequency, and time-frequency domains were measured on each waveform, and several techniques such as correlation-based feature selection, Artificial Neural Networks (ANNs), Logistic Regression (LR) and X-mean were used as research tools to explore the relationship between these seismic features and source parameters. The results show that spectral features have the highest correlation to source depth. Two new measurements developed as seismic features for this study, spectral centroids and 2D cross-correlations in the time-frequency domain, performed better than the common seismic measurements. These features can be used by machine learning techniques for efficient automatic classification of low energy signals recorded at one or more seismic stations. We applied the technique to 440 microearthquakes-1.7Reference: Mousavi, S.M., S.P. Horton, C. A. Langston, B. Samei, (2016) Seismic features and automatic discrimination of deep and shallow induced-microearthquakes using neural network and logistic regression, Geophys. J. Int. doi: 10.1093/gji/ggw258.

Active normal fault network of the Apulian Ridge (Eastern Mediterranean Sea) imaged by multibeam bathymetry and seismic data

NASA Astrophysics Data System (ADS)

Pellegrini, Claudio; Marchese, Fabio; Savini, Alessandra; Bistacchi, Andrea

2016-04-01

The Apulian ridge (North-eastern Ionian margin - Mediterranean Sea) is formed by thick cretaceous carbonatic sequences and discontinuous tertiary deposits crosscut by a NNW-SSE penetrative normal fault system and is part of the present foreland system of both the Apennine to the west and the Hellenic arc to the east. The geometry, age, architecture and kinematics of the fault network were investigated integrating data of heterogeneous sources, provided by previous studies: regional scale 2D seismics and three wells collected by oil companies from the '60s to the '80s, more recent seismics collected during research projects in the '90s, very high resolution seismic (VHRS - Sparker and Chirp-sonar data), multi-beam echosounder bathymetry and results from sedimentological and geo-chronological analysis of sediment samples collected on the seabed. Multibeam bathymetric data allowed in particular assessing the 3D continuity of structures imaged in 2D seismics, thanks to the occurrence of continuous fault scarps on the seabed (only partly reworked by currents and covered by landslides), revealing the vertical extent and finite displacement associated to fault scarps. A penetrative network of relatively small faults, always showing a high dip angle, composes the NNW-SSE normal fault system, resulting in frequent relay zones, which are particularly well imaged by seafloor geomorphology. In addition, numerous fault scarps appear to be roughly coeval with quaternary submarine mass-wasting deposits colonised by Cold-Water Corals (CWC). Coral colonies, yielding ages between 11 and 14 kA, develop immediately on top of late Pleistocene mass-wasting deposits. Mutual cross-cutting relationships have been recognized between fault scarps and landslides, indicating that, at least in places, these features may be coeval. We suppose that fault activity lasted at least as far as the Holocene-Pleistocene boundary and that the NNW-SSW normal fault network in the Apulian Plateau can be

Microearthquake spectra from the Anza, California, seismic network: site response and source scaling

USGS Publications Warehouse

Frankel, Arthur D.; Wennerberg, Leif

1989-01-01

We analyzed spectra of local microearthquakes recorded by the Anza, California, seismic network to isolate the effects of site response and to investigate the scaling of source parameters for small earthquakes. Spectra of microearthquakes (M < 2; Mo< 1019 dyne-cm) at Anza have shapes characteristic of the receiver sites and are generally independent of the source region. Thus, the site response is a major conditioner of the observed spectral shape. To remove the effects of site response from the spectra of a M ∼ 3 event and isolate its source spectrum, we divided by the spectra of an adjacent aftershock used as an empirical Green's function event. The spectral ratios indicate that the apparent corner frequencies of small earthquakes (Mo < 1019dyne-cm) observed at even the high-fmax stations on hard rock are much lower than the source corner frequencies. The spectral ratios are consistent with stress drop remaining constant with decreasing seismic moment, for events with moments as small as 1018 dyne-cm. The spectral ratios display remarkable agreement between sites which showed vast differences in their original spectra, indicating that the spectral division effectively removed the site response. The source spectrum of the M ∼ 3 event has a high-frequency spectral fall-off of about ω−2. An apparent dependence of high-frequency fall-off with seismic moment in the original spectra can also be explained by the effects of site response. The difference between the P- and S-wave corner frequencies and high-frequency roll-offs in the observed spectra for these events is the result of the site response and is not a source property. The shapes of the spectra of microearthquakes at Anza can largely be explained by attenuation at shallow depth with a frequency-independent Q. For some sites, near-surface resonances are also apparent in the spectra of microearthquakes. It is indicated by t* values determined for each site that Qp ∼ Qsfor the shallow

Updated Colombian Seismic Hazard Map

NASA Astrophysics Data System (ADS)

Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

2013-05-01

The Colombian seismic hazard map used by the National Building Code (NSR-98) in effect until 2009 was developed in 1996. Since then, the National Seismological Network of Colombia has improved in both coverage and technology providing fifteen years of additional seismic records. These improvements have allowed a better understanding of the regional geology and tectonics which in addition to the seismic activity in Colombia with destructive effects has motivated the interest and the need to develop a new seismic hazard assessment in this country. Taking advantage of new instrumental information sources such as new broad band stations of the National Seismological Network, new historical seismicity data, standardized global databases availability, and in general, of advances in models and techniques, a new Colombian seismic hazard map was developed. A PSHA model was applied. The use of the PSHA model is because it incorporates the effects of all seismic sources that may affect a particular site solving the uncertainties caused by the parameters and assumptions defined in this kind of studies. First, the seismic sources geometry and a complete and homogeneous seismic catalog were defined; the parameters of seismic rate of each one of the seismic sources occurrence were calculated establishing a national seismotectonic model. Several of attenuation-distance relationships were selected depending on the type of seismicity considered. The seismic hazard was estimated using the CRISIS2007 software created by the Engineering Institute of the Universidad Nacional Autónoma de México -UNAM (National Autonomous University of Mexico). A uniformly spaced grid each 0.1° was used to calculate the peak ground acceleration (PGA) and response spectral values at 0.1, 0.2, 0.3, 0.5, 0.75, 1, 1.5, 2, 2.5 and 3.0 seconds with return periods of 75, 225, 475, 975 and 2475 years. For each site, a uniform hazard spectrum and exceedance rate curves were calculated. With the results, it is

HANFORD DOUBLE SHELL TANK (DST) THERMAL & SEISMIC PROJECT BUCKLING EVALUATION METHODS & RESULTS FOR THE PRIMARY TANKS

DOE Office of Scientific and Technical Information (OSTI.GOV)

MACKEY, T.C.

2006-03-17

This report documents a detailed buckling evaluation of the primary tanks in the Hanford double shell waste tanks. The analysis is part of a comprehensive structural review for the Double-Shell Tank Integrity Project. This work also provides information on tank integrity that specifically responds to concerns raise by the Office of Environment, Safety, and Health (ES&H) Oversight (EH-22) during a review (in April and May 2001) of work being performed on the double-shell tank farms, and the operation of the aging waste facility (AWF) primary tank ventilation system.

Continuous, Large-Scale Processing of Seismic Archives for High-Resolution Monitoring of Seismic Activity and Seismogenic Properties

NASA Astrophysics Data System (ADS)

Waldhauser, F.; Schaff, D. P.

2012-12-01

Archives of digital seismic data recorded by seismometer networks around the world have grown tremendously over the last several decades helped by the deployment of seismic stations and their continued operation within the framework of monitoring earthquake activity and verification of the Nuclear Test-Ban Treaty. We show results from our continuing effort in developing efficient waveform cross-correlation and double-difference analysis methods for the large-scale processing of regional and global seismic archives to improve existing earthquake parameter estimates, detect seismic events with magnitudes below current detection thresholds, and improve real-time monitoring procedures. We demonstrate the performance of these algorithms as applied to the 28-year long seismic archive of the Northern California Seismic Network. The tools enable the computation of periodic updates of a high-resolution earthquake catalog of currently over 500,000 earthquakes using simultaneous double-difference inversions, achieving up to three orders of magnitude resolution improvement over existing hypocenter locations. This catalog, together with associated metadata, form the underlying relational database for a real-time double-difference scheme, DDRT, which rapidly computes high-precision correlation times and hypocenter locations of new events with respect to the background archive (http://ddrt.ldeo.columbia.edu). The DDRT system facilitates near-real-time seismicity analysis, including the ability to search at an unprecedented resolution for spatio-temporal changes in seismogenic properties. In areas with continuously recording stations, we show that a detector built around a scaled cross-correlation function can lower the detection threshold by one magnitude unit compared to the STA/LTA based detector employed at the network. This leads to increased event density, which in turn pushes the resolution capability of our location algorithms. On a global scale, we are currently building

Development of a time synchronization methodology for a wireless seismic array

NASA Astrophysics Data System (ADS)

Moure-García, David; Torres-González, Pedro; del Río, Joaquín; Mihai, Daniel; Domínguez Cerdeña, Itahiza

2017-04-01

Seismic arrays have multiple applications. In the past, the main use was nuclear tests monitoring that began in mid-twentieth century. The major difference with a seismic network is the hypocenter location procedure. With a seismic network the hypocenter's 3D coordinates are calculated while using an array, the source direction of the seismic signal is determined. Seismic arrays are used in volcanology to obtain the source azimuth of volcanic signals related to fluids movement, magma and/or gases, that do not show a clear seismic phases' onset. A key condition in the seismic array operativity is the temporal synchronization of all the sensors, better than 1 microsecond. Because of that, usually all sensors are connected to the acquisition system by cable to ensure an identical sampling time. In this work we present the design of a wireless low-cost and low-power consumption volcanic monitoring seismic array where all nodes (sensors) acquire data synchronously and transmit them to the center node where a coherent signal is pursued in near real time.

Neural network analysis of crosshole tomographic images: The seismic signature of gas hydrate bearing sediments in the Mackenzie Delta (NW Canada)

NASA Astrophysics Data System (ADS)

Bauer, K.; Pratt, R. G.; Haberland, C.; Weber, M.

2008-10-01

Crosshole seismic experiments were conducted to study the in-situ properties of gas hydrate bearing sediments (GHBS) in the Mackenzie Delta (NW Canada). Seismic tomography provided images of P velocity, anisotropy, and attenuation. Self-organizing maps (SOM) are powerful neural network techniques to classify and interpret multi-attribute data sets. The coincident tomographic images are translated to a set of data vectors in order to train a Kohonen layer. The total gradient of the model vectors is determined for the trained SOM and a watershed segmentation algorithm is used to visualize and map the lithological clusters with well-defined seismic signatures. Application to the Mallik data reveals four major litho-types: (1) GHBS, (2) sands, (3) shale/coal interlayering, and (4) silt. The signature of seismic P wave characteristics distinguished for the GHBS (high velocities, strong anisotropy and attenuation) is new and can be used for new exploration strategies to map and quantify gas hydrates.

HANFORD SITE RIVER CORRIDOR CLEANUP

DOE Office of Scientific and Technical Information (OSTI.GOV)

BAZZELL, K.D.

2006-02-01

In 2005, the US Department of Energy (DOE) launched the third generation of closure contracts, including the River Corridor Closure (RCC) Contract at Hanford. Over the past decade, significant progress has been made on cleaning up the river shore that bordes Hanford. However, the most important cleanup challenges lie ahead. In March 2005, DOE awarded the Hanford River Corridor Closure Contract to Washington Closure Hanford (WCH), a limited liability company owned by Washington Group International, Bechtel National and CH2M HILL. It is a single-purpose company whose goal is to safely and efficiently accelerate cleanup in the 544 km{sup 2} Hanfordmore » river corridor and reduce or eliminate future obligations to DOE for maintaining long-term stewardship over the site. The RCC Contract is a cost-plus-incentive-fee closure contract, which incentivizes the contractor to reduce cost and accelerate the schedule. At $1.9 billion and seven years, WCH has accelerated cleaning up Hanford's river corridor significantly compared to the $3.2 billion and 10 years originally estimated by the US Army Corps of Engineers. Predictable funding is one of the key features of the new contract, with funding set by contract at $183 million in fiscal year (FY) 2006 and peaking at $387 million in FY2012. Another feature of the contract allows for Washington Closure to perform up to 40% of the value of the contract and subcontract the balance. One of the major challenges in the next few years will be to identify and qualify sufficient subcontractors to meet the goal.« less

Data Delivery Latency Improvements And First Steps Towards The Distributed Computing Of The Caltech/USGS Southern California Seismic Network Earthquake Early Warning System

NASA Astrophysics Data System (ADS)

Stubailo, I.; Watkins, M.; Devora, A.; Bhadha, R. J.; Hauksson, E.; Thomas, V. I.

2016-12-01

The USGS/Caltech Southern California Seismic Network (SCSN) is a modern digital ground motion seismic network. It develops and maintains Earthquake Early Warning (EEW) data collection and delivery systems in southern California as well as real-time EEW algorithms. Recently, Behr et al., SRL, 2016 analyzed data from several regional seismic networks deployed around the globe. They showed that the SCSN was the network with the smallest data communication delays or latency. Since then, we have reduced further the telemetry delays for many of the 330 current sites. The latency has been reduced on average from 2-6 sec to 0.4 seconds by tuning the datalogger parameters and/or deploying software upgrades. Recognizing the latency data as one of the crucial parameters in EEW, we have started archiving the per-packet latencies in mseed format for all the participating sites in a similar way it is traditionally done for the seismic waveform data. The archived latency values enable us to understand and document long-term changes in performance of the telemetry links. We can also retroactively investigate how latent the waveform data were during a specific event or during a specific time period. In addition the near-real time latency values are useful for monitoring and displaying the real-time station latency, in particular to compare different telemetry technologies. A future step to reduce the latency is to deploy the algorithms on the dataloggers at the seismic stations and transmit either the final solutions or intermediate parameters to a central processing center. To implement this approach, we are developing a stand-alone version of the OnSite algorithm to run on the dataloggers in the field. This will increase the resiliency of the SCSN to potential telemetry restrictions in the immediate aftermath of a large earthquake, either by allowing local alarming by the single station, or permitting transmission of lightweight parametric information rather than continuous

Hanford internal dosimetry program manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, E.H.; Sula, M.J.; Bihl, D.E.

1989-10-01

This document describes the Hanford Internal Dosimetry program. Program Services include administrating the bioassay monitoring program, evaluating and documenting assessments of internal exposure and dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating internal radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. 13 refs., 16 figs., 42 tabs.

HANFORD FACILITY ANNUAL DANGEROUS WASTE REPORT CY2005

DOE Office of Scientific and Technical Information (OSTI.GOV)

SKOLRUD, J.O.

2006-02-15

The Hanford Facility Annual Dangerous Waste Report (ADWR) is prepared to meet the requirements of Washington Administrative Code Sections 173-303-220, Generator Reporting, and 173-303-390, Facility Reporting. In addition, the ADWR is required to meet Hanford Facility RCR4 Permit Condition I.E.22, Annual Reporting. The ADWR provides summary information on dangerous waste generation and management activities for the Calendar Year for the Hanford Facility EPA ID number assigned to the Department of Energy for RCRA regulated waste, as well as Washington State only designated waste and radioactive mixed waste. An electronic database is utilized to collect and compile the large array ofmore » data needed for preparation of this report. Information includes details of waste generated on the Hanford Facility, waste generated offsite and sent to Hanford for management, and other waste management activities conducted at Hanford, including treatment, storage, and disposal. Report details consist of waste descriptions and weights, waste codes and designations, and waste handling codes, In addition, for waste shipped to Hanford for treatment and/or disposal, information on manifest numbers, the waste transporter, the waste receiving facility, and the original waste generators are included. In addition to paper copies, the report is also transmitted electronically to a web site maintained by the Washington State Department of Ecology.« less

Data quality control and tools in passive seismic experiments exemplified on the Czech broadband seismic pool MOBNET in the AlpArray collaborative project

NASA Astrophysics Data System (ADS)

Vecsey, Luděk; Plomerová, Jaroslava; Jedlička, Petr; Munzarová, Helena; Babuška, Vladislav; AlpArray Working Group

2017-12-01

This paper focuses on major issues related to the data reliability and network performance of 20 broadband (BB) stations of the Czech (CZ) MOBNET (MOBile NETwork) seismic pool within the AlpArray seismic experiments. Currently used high-resolution seismological applications require high-quality data recorded for a sufficiently long time interval at seismological observatories and during the entire time of operation of the temporary stations. In this paper we present new hardware and software tools we have been developing during the last two decades while analysing data from several international passive experiments. The new tools help to assure the high-quality standard of broadband seismic data and eliminate potential errors before supplying data to seismological centres. Special attention is paid to crucial issues like the detection of sensor misorientation, timing problems, interchange of record components and/or their polarity reversal, sensor mass centring, or anomalous channel amplitudes due to, for example, imperfect gain. Thorough data quality control should represent an integral constituent of seismic data recording, preprocessing, and archiving, especially for data from temporary stations in passive seismic experiments. Large international seismic experiments require enormous efforts from scientists from different countries and institutions to gather hundreds of stations to be deployed in the field during a limited time period. In this paper, we demonstrate the beneficial effects of the procedures we have developed for acquiring a reliable large set of high-quality data from each group participating in field experiments. The presented tools can be applied manually or automatically on data from any seismic network.

Testing the global capabilities of the Antelope software suite: fast location and Mb determination of teleseismic events using the ASAIN and GSN seismic networks

NASA Astrophysics Data System (ADS)

Pesaresi, D.; Russi, M.; Plasencia, M.; Cravos, C.

2009-04-01

The Italian National Institute for Oceanography and Experimental Geophysics (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, OGS) is running the Antarctic Seismographic Argentinean Italian Network (ASAIN), made of 5 seismic stations located in the Scotia Sea region in Antarctica and in Argentina: data from these stations are transferred in real time to the OGS headquarters in Trieste (Italy) via satellite links. OGS is also running, in close cooperation with the Friuli-Venezia Giulia Civil Defense, the North East (NI) Italy seismic network, making use of the Antelope commercial software suite from BRTT as the main acquisition system. As a test to check the global capabilities of Antelope, we set up an instance of Antelope acquiring data in real time from both the regional ASAIN seismic network in Antarctica and a subset of the Global Seismic Network (GSN) funded by the Incorporated Research Institution for Seismology (IRIS). The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for real time access to waveform required in this study. Preliminary results over 1 month period indicated that about 82% of the earthquakes with magnitude M>5.0 listed in the PDE catalogue of the National Earthquake Information Center (NEIC) of the United States Geological Survey (USGS) were also correctly detected by Antelope, with an average location error of 0.05 degrees and average body wave magnitude Mb estimation error below 0.1. The average time difference between event origin time and the actual time of event determination by Antelope was of about 45': the comparison with 20', the IASPEI91 P-wave travel time for 180 degrees distance, and 25', the estimate of our test system data latency, indicate that Antelope is a serious candidate for regional and global early warning systems. Updated figures calculated over a longer period of time will be presented and discussed.

Improving Seismic Event Characterisation

DTIC Science & Technology

1996-07-22

classificat i,; and further phase identification . 6.4.3 Seismic event interpretation The’ system of event processing is based on an assumption tree ...and is enhanced with usez by a network. 14, SUBJECT TERMSý 15. NUMBER OF PAGES seismic models, travel. timtes phase identification 16 PRICE CODE 17...hesimwinlia’ rati of t lieDl scisillograonis is 2/3 secondIs andI the receiver spaci mi is 1 /3 degreeus. ’lIi iiaiiiii iltdiwic’ ewe ii rayv-the~oret~icaIl

Seismic data classification and artificial neural networks: can software replace eyeballs?

NASA Astrophysics Data System (ADS)

Reusch, D. B.; Larson, A. M.

2006-05-01

Modern seismic datasets are providing many new opportunities for furthering our understanding of our planet, ranging from the deep earth to the sub-ice sheet interface. With many geophysical applications, the large volume of these datasets raises issues of manageability in areas such as quality control (QC) and event identification (EI). While not universally true, QC can be a labor intensive, subjective (and thus not entirely reproducible) and uninspiring task when such datasets are involved. The EI process shares many of these drawbacks but has the benefit of (usually) being closer to interesting science-based questions. Here we explore two techniques from the field of artificial neural networks (ANNs) that seek to reduce the time requirements and increase the objectivity of QC and EI on seismic datasets. In particular, we focus on QC of receiver functions from broadband seismic data collected by the 2000-2003 Transantarctic Mountains Seismic Experiment (TAMSEIS). Self-organizing maps (SOMs) enable unsupervised classification of large, complex geophysical data sets (e.g., time series of the atmospheric circulation) into a fixed number of distinct generalized patterns or modes representing the probability distribution function of the input data. These patterns are organized spatially as a two-dimensional grid such that distances represent similarity (adjacent patterns will be most similar). After training, input data are matched to their most similar generalized pattern to produce frequency maps, i.e., what fraction of the data is represented best by each individual SOM pattern. Given a priori information on data quality (from previous manual grading) or event type, a probabilistic classification can be developed that gives a likelihood for each category of interest for each SOM pattern. New data are classified by identifying the closest matching pattern (without retraining) and examining the associated probabilities. Feed-forward ANNs (FFNNs) are a supervised

Back to the Future: Long-Term Seismic Archives Revisited

NASA Astrophysics Data System (ADS)

Waldhauser, F.; Schaff, D. P.

2007-12-01

Archives of digital seismic data recorded by seismometer networks around the world have grown tremendously over the last several decades helped by the deployment of seismic stations and their continued operation within the framework of monitoring seismic activity. These archives typically consist of waveforms of seismic events and associated parametric data such as phase arrival time picks and the location of hypocenters. Catalogs of earthquake locations are fundamental data in seismology, and even in the Earth sciences in general. Yet, these locations have notoriously low spatial resolution because of errors in both the picks and the models commonly used to locate events one at a time. This limits their potential to address fundamental questions concerning the physics of earthquakes, the structure and composition of the Earth's interior, and the seismic hazards associated with active faults. We report on the comprehensive use of modern waveform cross-correlation based methodologies for high- resolution earthquake location - as applied to regional and global long-term seismic databases. By simultaneous re-analysis of two decades of the digital seismic archive of Northern California, reducing pick errors via cross-correlation and model errors via double-differencing, we achieve up to three orders of magnitude resolution improvement over existing hypocenter locations. The relocated events image networks of discrete faults at seismogenic depths across various tectonic settings that until now have been hidden in location uncertainties. Similar location improvements are obtained for earthquakes recorded at global networks by re- processing 40 years of parametric data from the ISC and corresponding waveforms archived at IRIS. Since our methods are scaleable and run on inexpensive Beowulf clusters, periodic re-analysis of entire archives may thus become a routine procedure to continuously improve resolution in existing catalogs. We demonstrate the role of seismic archives

Vascular Plants of the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackschewsky, Michael R.; Downs, Janelle L.

This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Bringham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years.more » Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations on the biological environment, including impacts to rare habitats and to species listed as endangered or\\ threatened. This document includes a listing of plants currently listed as endangered, threatened, or otherwise of concern to the Washington Natural Heritage Program or the U.S. Fish and Wildlife Service, as well as those that are currently listed as noxious weeds by the State of Washington. Also provided is an overview of how plants on the Hanford Site can be used by people. This information may be useful in developing risk assessment models, and as supporting information for clean-up level and remediation decisions.« less

Learnings from the Monitoring of Induced Seismicity in Western Canada over the Past Three Years

NASA Astrophysics Data System (ADS)

Yenier, E.; Moores, A. O.; Baturan, D.; Spriggs, N.

2017-12-01

In response to induced seismicity observed in western Canada, existing public networks have been densified and a number of private networks have been deployed to closely monitor the earthquakes induced by hydraulic fracturing operations in the region. These networks have produced an unprecedented volume of seismic data, which can be used to map pre-existing geological structures and understand their activation mechanisms. Here, we present insights gained over the past three years from induced seismicity monitoring (ISM) for some of the most active operators in Canada. First, we discuss the benefits of high-quality ISM data sets for making operational decisions and how their value largely depends on choice of instrumentation, seismic network design and data processing techniques. Using examples from recent research studies, we illustrate the key role of robust modeling of regional source, attenuation and site attributes on the accuracy of event magnitudes, ground motion estimates and induced seismicity hazard assessment. Finally, acknowledging that the ultimate goal of ISM networks is assisting operators to manage induced seismic risk, we share some examples of how ISM data products can be integrated into existing protocols for developing effective risk management strategies.

Hanford Site Raptor Nest Monitoring Report for Calendar Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nugent, John J.; Lindsey, Cole T.; Wilde, Justin W.

2014-02-13

The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and track data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE activities. Ecological monitoring data provide baseline information about the plants, animals, and habitat under DOE-RL stewardship at Hanford required for decision-making under the National Environmental Policy Act (NEPA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Hanford Site Comprehensive Land Use Plan (CLUP, DOE/EIS-0222-F) which is the Environmental Impact Statement for Hanford Site activities, helps ensure that DOE-RL, its contractors, and othermore » entities conducting activities on the Hanford Site are in compliance with NEPA. The Hanford Site supports a large and diverse community of raptorial birds (Fitzner et al. 1981), with 26 species of raptors observed on the Hanford Site.« less

Seismic activity prediction using computational intelligence techniques in northern Pakistan

NASA Astrophysics Data System (ADS)

Asim, Khawaja M.; Awais, Muhammad; Martínez-Álvarez, F.; Iqbal, Talat

2017-10-01

Earthquake prediction study is carried out for the region of northern Pakistan. The prediction methodology includes interdisciplinary interaction of seismology and computational intelligence. Eight seismic parameters are computed based upon the past earthquakes. Predictive ability of these eight seismic parameters is evaluated in terms of information gain, which leads to the selection of six parameters to be used in prediction. Multiple computationally intelligent models have been developed for earthquake prediction using selected seismic parameters. These models include feed-forward neural network, recurrent neural network, random forest, multi layer perceptron, radial basis neural network, and support vector machine. The performance of every prediction model is evaluated and McNemar's statistical test is applied to observe the statistical significance of computational methodologies. Feed-forward neural network shows statistically significant predictions along with accuracy of 75% and positive predictive value of 78% in context of northern Pakistan.

Landslide seismic magnitude

NASA Astrophysics Data System (ADS)

Lin, C. H.; Jan, J. C.; Pu, H. C.; Tu, Y.; Chen, C. C.; Wu, Y. M.

2015-11-01

Landslides have become one of the most deadly natural disasters on earth, not only due to a significant increase in extreme climate change caused by global warming, but also rapid economic development in topographic relief areas. How to detect landslides using a real-time system has become an important question for reducing possible landslide impacts on human society. However, traditional detection of landslides, either through direct surveys in the field or remote sensing images obtained via aircraft or satellites, is highly time consuming. Here we analyze very long period seismic signals (20-50 s) generated by large landslides such as Typhoon Morakot, which passed though Taiwan in August 2009. In addition to successfully locating 109 large landslides, we define landslide seismic magnitude based on an empirical formula: Lm = log ⁡ (A) + 0.55 log ⁡ (Δ) + 2.44, where A is the maximum displacement (μm) recorded at one seismic station and Δ is its distance (km) from the landslide. We conclude that both the location and seismic magnitude of large landslides can be rapidly estimated from broadband seismic networks for both academic and applied purposes, similar to earthquake monitoring. We suggest a real-time algorithm be set up for routine monitoring of landslides in places where they pose a frequent threat.

Hanford Facility Annual Dangerous Waste Report Calendar Year 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

FREEMAN, D.A.

2003-02-01

Hanford CY 2002 dangerous waste generation and management forms. The Hanford Facility Annual Dangerous Waste Report (ADWR) is prepared to meet the requirements of Washington Administrative Code Sections 173-303-220, Generator Reporting, and 173-303-390, Facility Reporting. In addition, the ADWR is required to meet Hanford Facility RCRA Permit Condition I.E.22, Annual Reporting. The ADWR provides summary information on dangerous waste generation and management activities for the Calendar Year for the Hanford Facility EPA ID number assigned to the Department of Energy for RCRA regulated waste, as well as Washington State only designated waste and radioactive mixed waste. The Solid Waste Informationmore » and Tracking System (SWITS) database is utilized to collect and compile the large array of data needed for preparation of this report. Information includes details of waste generated on the Hanford Facility, waste generated offsite and sent to Hanford for management, and other waste management activities conducted at Hanford, including treatment, storage, and disposal. Report details consist of waste descriptions and weights, waste codes and designations, and waste handling codes. In addition, for waste shipped to Hanford for treatment and/or disposal, information on manifest numbers, the waste transporter, the waste receiving facility, and the original waste generators are included. In addition to paper copies, electronic copies of the report are also transmitted to the regulatory agency.« less

PNNL Supports Hanford Waste Treatment

ScienceCinema

None

2018-04-16

For more than 40 years, technical assistance from PNNL has supported the operations and processing of Hanford tank waste. Our expertise in tank waste chemistry, fluid dynamics and scaling, waste forms, and safety bases has helped to shape the site’s waste treatment baseline and solve operational challenges. The historical knowledge and unique scientific and technical expertise at PNNL are essential to the success of the Hanford mission.

Kinematics and Seismotectonics of the Montello Thrust Fault (Southeastern Alps, Italy) Revealed by Local GPS and Seismic Networks

NASA Astrophysics Data System (ADS)

Serpelloni, E.; Anderlini, L.; Cavaliere, A.; Danesi, S.; Pondrelli, S.; Salimbeni, S.; Danecek, P.; Massa, M.; Lovati, S.

2014-12-01

The southern Alps fold-and-thrust belt (FTB) in northern Italy is a tectonically active area accommodating large part of the ~N-S Adria-Eurasia plate convergence, that in the southeastern Alps ranges from 1.5 to 2.5 mm/yr, as constrained by a geodetically defined rotation pole. Because of the high seismic hazard of northeastern Italy, the area is well monitored at a regional scale by seismic and GPS networks. However, more localized seismotectonic and kinematic features, at the scale of the fault segments, are not yet resolved, limiting our knowledge about the seismic potential of the different fault segments belonging to the southeastern Alps FTB. Here we present the results obtained from the analysis of data collected during local seismic and geodetic experiments conducted installing denser geophysical networks across the Montello-Bassano-Belluno system, a segment of the FTB that is presently characterized by a lower sismicity rate with respect to the surrounding domains. The Montello anticline, which is the southernmost tectonic features of the southeastern Alps FTB (located ~15 km south of the mountain front), is a nice example of growing anticline associated with a blind thrust fault. However, how the Adria-Alps convergence is partitioned across the FTB and the seismic potential of the Montello thrust (the area has been struck by a Mw~6.5 in 1695 but the causative fault is still largely debated) remained still unresolved. The new, denser, GPS data show that this area is undergoing among the highest geodetic deformation rates of the entire south Alpine chain, with a steep velocity gradient across the Montello anticline. The earthquakes recorded during the experiment, precisely relocated with double difference methods, and the new earthquake focal mechanisms well correlate with available information about sub-surface geological structures and highlight the seismotectonic activity of the Montello thrust fault. We model the GPS velocities using elastic

Relocation of Groningen seismicity using refracted waves

NASA Astrophysics Data System (ADS)

Ruigrok, E.; Trampert, J.; Paulssen, H.; Dost, B.

2015-12-01

The Groningen gas field is a giant natural gas accumulation in the Northeast of the Netherlands. The gas is in a reservoir at a depth of about 3 km. The naturally-fractured gas-filled sandstone extends roughly 45 by 25 km laterally and 140 m vertically. Decades of production have led to significant compaction of the sandstone. The (differential) compaction is thought to have reactivated existing faults and being the main driver of induced seismicity. Precise earthquake location is difficult due to a complicated subsurface, and that is the likely reason, the current hypocentre estimates do not clearly correlate with the well-known fault network. The seismic velocity model down to reservoir depth is quite well known from extensive seismic surveys and borehole data. Most to date earthquake detections, however, were made with a sparse pre-2015 seismic network. For shallow seismicity (<5 km depth) horizontal source-receiver distances tend to be much larger than vertical distances. Consequently, preferred source-receiver travel paths are refractions over high-velocity layers below the reservoir. However, the seismic velocities of layers below the reservoir are poorly known. We estimated an effective velocity model of the main refracting layer below the reservoir and use this for relocating past seismicity. We took advantage of vertical-borehole recordings for estimating precise P-wave (refraction) onset times and used a tomographic approach to find the laterally varying velocity field of the refracting layer. This refracting layer is then added to the known velocity model, and the combined model is used to relocate the past seismicity. From the resulting relocations we assess which of the faults are being reactivated.

Precisely relocated seismicity using 3-D seismic velocity model by double-difference tomography method and orogenic processes in central and southern Taiwan

NASA Astrophysics Data System (ADS)

Nagai, S.; Wu, Y.; Suppe, J.; Hirata, N.

2009-12-01

The island of Taiwan is located in the site of ongoing arc-continent collision zone between the Philippine Sea Plate and the Eurasian Plate. Numerous geophysical and geological studies are done in and around Taiwan to develop various models to explain the tectonic processes in the Taiwan region. The active and young tectonics and the associated high seismicity in Taiwan provide us with unique opportunity to explore and understand the processes in the region related to the arc-continent collision. Nagai et al. [2009] imaged eastward dipping alternate high- and low-velocity bodies at depths of 5 to 25 km from the western side of the Central Mountain Range to the eastern part of Taiwan, by double-difference tomography [Zhang and Thurber, 2003] using three temporary seismic networks with the Central Weather Bureau Seismic Network(CWBSN). These three temporary networks are the aftershock observation after the 1999 Chi-Chi Taiwan earthquake and two dense linear array observations; one is across central Taiwan in 2001, another is across southern Taiwan in 2005, respectively. We proposed a new orogenic model, ’Upper Crustal Stacking Model’ inferred from our tomographic images. To understand the detailed seismic structure more, we carry on relocating earthquakes more precisely in central and southern Taiwan, using three-dimensional velocity model [Nagai et al., 2009] and P- and S-wave arrival times both from the CWBSN and three temporary networks. We use the double-difference tomography method to improve relative and absolute location accuracy simultaneously. The relocated seismicity is concentrated and limited along the parts of boundaries between low- and high-velocity bodies. Especially, earthquakes occurred beneath the Eastern Central Range, triggered by 1999 Chi-Chi earthquake, delineate subsurface structural boundaries, compared with profiles of estimated seismic velocity. The relocated catalog and 3-D seismic velocity model give us some constraints to reconstruct

Hanford Site Anuran Monitoring Report for Calendar Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilde, Justin W.; Johnson, Scott J.; Lindsey, Cole T.

2014-02-13

The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and track data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE activities. Ecological monitoring data provide baseline information about the plants, animals, and habitat under DOE-RL stewardship at Hanford required for decision-making under the National Environmental Policy Act (NEPA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Hanford Site Comprehensive Land Use Plan (CLUP, DOE/EIS-0222-F) which is the Environmental Impact Statement for Hanford Site activities, helps ensure that DOE-RL, its contractors, and othermore » entities conducting activities on the Hanford Site are in compliance with NEPA.« less

Post-processing of seismic parameter data based on valid seismic event determination

DOEpatents

McEvilly, Thomas V.

1985-01-01

An automated seismic processing system and method are disclosed, including an array of CMOS microprocessors for unattended battery-powered processing of a multi-station network. According to a characterizing feature of the invention, each channel of the network is independently operable to automatically detect, measure times and amplitudes, and compute and fit Fast Fourier transforms (FFT's) for both P- and S- waves on analog seismic data after it has been sampled at a given rate. The measured parameter data from each channel are then reviewed for event validity by a central controlling microprocessor and if determined by preset criteria to constitute a valid event, the parameter data are passed to an analysis computer for calculation of hypocenter location, running b-values, source parameters, event count, P- wave polarities, moment-tensor inversion, and Vp/Vs ratios. The in-field real-time analysis of data maximizes the efficiency of microearthquake surveys allowing flexibility in experimental procedures, with a minimum of traditional labor-intensive postprocessing. A unique consequence of the system is that none of the original data (i.e., the sensor analog output signals) are necessarily saved after computation, but rather, the numerical parameters generated by the automatic analysis are the sole output of the automated seismic processor.

Romanian Data Center: A modern way for seismic monitoring

NASA Astrophysics Data System (ADS)

Neagoe, Cristian; Marius Manea, Liviu; Ionescu, Constantin

2014-05-01

The main seismic survey of Romania is performed by the National Institute for Earth Physics (NIEP) which operates a real-time digital seismic network. The NIEP real-time network currently consists of 102 stations and two seismic arrays equipped with different high quality digitizers (Kinemetrics K2, Quanterra Q330, Quanterra Q330HR, PS6-26, Basalt), broadband and short period seismometers (CMG3ESP, CMG40T, KS2000, KS54000, KS2000, CMG3T,STS2, SH-1, S13, Mark l4c, Ranger, gs21, Mark l22) and acceleration sensors (Episensor Kinemetrics). The data are transmitted at the National Data Center (NDC) and Eforie Nord (EFOR) Seismic Observatory. EFOR is the back-up for the NDC and also a monitoring center for the Black Sea tsunami events. NIEP is a data acquisition node for the seismic network of Moldova (FDSN code MD) composed of five seismic stations. NIEP has installed in the northern part of Bulgaria eight seismic stations equipped with broadband sensors and Episensors and nine accelerometers (Episensors) installed in nine districts along the Danube River. All the data are acquired at NIEP for Early Warning System and for primary estimation of the earthquake parameters. The real-time acquisition (RT) and data exchange is done by Antelope software and Seedlink (from Seiscomp3). The real-time data communication is ensured by different types of transmission: GPRS, satellite, radio, Internet and a dedicated line provided by a governmental network. For data processing and analysis at the two data centers Antelope 5.2 TM is being used running on 3 workstations: one from a CentOS platform and two on MacOS. Also a Seiscomp3 server stands as back-up for Antelope 5.2 Both acquisition and analysis of seismic data systems produce information about local and global parameters of earthquakes. In addition, Antelope is used for manual processing (event association, calculation of magnitude, creating a database, sending seismic bulletins, calculation of PGA and PGV, etc.), generating

Global Seismic Monitoring: Past, Present, and Future

NASA Astrophysics Data System (ADS)

Zoback, M.; Benz, H.; Oppenheimer, D.

2007-12-01

Global seismological observations began in April 1889 when an earthquake in Tokyo, Japan was accurately recorded in Germany on two different horizontal pendulum instruments. However, modern global observational seismology really began 46 years ago when the 120-station World Wide Standard Seismograph Network was installed by the US to monitor underground nuclear tests and earthquakes using well-calibrated short- and long- period stations. At the same time rapid advances in computing technology enabled researchers to begin sophisticated analysis of the increasing amount of seismic data, which led to better understanding of earthquake source properties and their use in establishing plate tectonics. Today, global seismic networks are operated by German (Geophon), France (Geoscope), the United States (Global Seismograph Network) and the International Monitoring System. Presently, the Federation of Digital Seismograph Networks registers more than 1,000 broadband stations world-wide, a small percentage of the total number of digital seismic stations around the world. Following the devastating Kobe, Japan and Northridge, California earthquakes, Japan and the US have led the world in the integration of existing seismic sensor systems (weak and strong motion) into development of near-real-time, post-earthquake response products like ShakeMap, detailing the spatial distribution of strong shaking. Future challenges include expanding real-time integration of both seismic and geodetic sensor systems to produce early warning of strong shaking, rapid source determination, as well as near-realtime post- earthquake damage assessment. Seismic network data, hydro-acoustic arrays, deep water tide gauges, and satellite imagery of wave propagation should be integrated in real-time to provide input for hydrodynamic modeling yielding the distribution, timing and size of tsunamis runup--which would then be available instantly on the web, e.g. in a Google Earth format. Dense arrays of strong

The Seismic Broad Band Western Mediterranean (wm) Network and the Obs Fomar Pool: Current state and Obs activities.

NASA Astrophysics Data System (ADS)

Pazos, Antonio; Davila, Jose Martin; Buforn, Elisa; Bezzeghoud, Mourad; Harnafi, Mimoun; Mattesini, Mauricio; Caldeira, Bento; Hanka, Winfried; El Moudnib, Lahcen; Strollo, Angelo; Roca, Antoni; Lopez de Mesa, Mireya; Dahm, Torsten; Cabieces, Roberto

2016-04-01

The Western Mediterranean (WM) seismic network started in 1996 as an initiative of the Royal Spanish Navy Observatory (ROA) and the Universidad Complutense de Madrid (UCM), with the collaboration of the GeoForschungsZentrum (GFZ) of Potsdam. A first broad band seismic station (SFUC) was installed close to Cádiz (South Spain). Since then, additional stations have been installed in the Ibero-Moghrebian region. In 2005, the "WM" code was assigned by the FDSN and new partners were jointed: Evora University (UEVO, Portugal), the Scientifique Institute of Rabat (ISRABAT, Morocco), and GFZ. Now days, the WM network is composed by 15 BB stations, all of them with Streckaisen STS-2 or STS-2.5 sensors, Quanterra or Earthdata digitizers and SeiscomP. Most them have co-installed a permanent geodetic GPS stations, and some them also have an accelerometer. There are 10 stations deployed in Spanish territory (5 in the Iberian peninsula, 1 in Balearic islands and 4 in North Africa Spanish places) with VSAT or Internet communications, 2 in Portugal (one of them without real time), and 3 in Morocco (2 VSAT and 1 ADSL). Additionally, 2 more stations (one in South Spain and one in Morocco) will be installed along this year. Additionally ROA has deployed a permanent real time VBB (CMG-3T: 360s) station at the Alboran Island. Due to the fact that part of the seismic activity is located at marine areas, and also because of the poor geographic azimuthal coverage at some zones provided by the land stations (specially in the SW of the San Vicente Cape area), ROA and UCM have acquired six broad band "LOBSTERN" OBS, manufactured by KUM (Kiel, Germany), conforming the OBS FOMAR pool. Three of them with CMG-40T sensor and the other with Trillium 120. These OBS were deployed along the Gibraltar strait since January to November 2014 to study the microseismicity in the Gibraltar strait area. In September 2015 FOMAR network has been deployed in SW of the San Vicente Cape for 8 months as a part of

Hanford Site National Environmental Policy Act (NEPA) Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neitzel, Duane A.; Antonio, Ernest J.; Eschbach, Tara O.

2001-09-01

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, andmore » Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.« less

Hanford Site National Environmental Policy Act (NEPA) Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neitzel, Duane A.; Bunn, Amoret L.; Duncan, Joanne P.

2002-09-01

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, andmore » Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.« less

Online monitoring of seismic damage in water distribution systems

NASA Astrophysics Data System (ADS)

Liang, Jianwen; Xiao, Di; Zhao, Xinhua; Zhang, Hongwei

2004-07-01

It is shown that water distribution systems can be damaged by earthquakes, and the seismic damages cannot easily be located, especially immediately after the events. Earthquake experiences show that accurate and quick location of seismic damage is critical to emergency response of water distribution systems. This paper develops a methodology to locate seismic damage -- multiple breaks in a water distribution system by monitoring water pressure online at limited positions in the water distribution system. For the purpose of online monitoring, supervisory control and data acquisition (SCADA) technology can well be used. A neural network-based inverse analysis method is constructed for locating the seismic damage based on the variation of water pressure. The neural network is trained by using analytically simulated data from the water distribution system, and validated by using a set of data that have never been used in the training. It is found that the methodology provides an effective and practical way in which seismic damage in a water distribution system can be accurately and quickly located.

Hanford Site Environmental Report for Calender Year 2006

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poston, Ted M.; Hanf, Robert W.; Duncan, Joanne P.

This report is prepared annually for DOE and provides an overview of activities at the Hanford Site. The report summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Although this report is primarily written to meet DOE reporting requirements and guidelines, it also provides useful summary information for the public, Indian tribes, public officials, regulatory agencies, Hanford contractors, and public officials.

An assessment of seismic monitoring in the United States; requirement for an Advanced National Seismic System

USGS Publications Warehouse

,

1999-01-01

This report assesses the status, needs, and associated costs of seismic monitoring in the United States. It sets down the requirement for an effective, national seismic monitoring strategy and an advanced system linking national, regional, and urban monitoring networks. Modernized seismic monitoring can provide alerts of imminent strong earthquake shaking; rapid assessment of distribution and severity of earthquake shaking (for use in emergency response); warnings of a possible tsunami from an offshore earthquake; warnings of volcanic eruptions; information for correctly characterizing earthquake hazards and for improving building codes; and data on response of buildings and structures during earthquakes, for safe, cost-effective design, engineering, and construction practices in earthquake-prone regions.

Updated Tomographic Seismic Imaging at Kilauea Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Okubo, P.; Johnson, J.; Felts, E. S.; Flores, N.

2013-12-01

Improved and more detailed geophysical, geological, and geochemical observations and measurements at Kilauea, along with prolonged eruptions at its summit caldera and east rift zone, are encouraging more ambitious interpretation and modeling of volcanic processes over a range of temporal and spatial scales. We are updating three-dimensional models of seismic wave-speed distributions within Kilauea using local earthquake arrival time tomography to support waveform-based modeling of seismic source mechanisms. We start from a tomographic model derived from a combination of permanent seismic stations comprising the Hawaiian Volcano Observatory (HVO) seismographic network and a dense deployment of temporary stations in the Kilauea caldera region in 1996. Using P- and S-wave arrival times measured from the HVO network for local earthquakes from 1997 through 2012, we compute velocity models with the finite difference tomographic seismic imaging technique implemented by Benz and others (1996), and applied to numerous volcanoes including Kilauea. Particular impetus to our current modeling was derived from a focused effort to review seismicity occurring in Kilauea's summit caldera and adjoining regions in 2012. Our results reveal clear P-wave low-velocity features at and slightly below sea level beneath Kilauea's summit caldera, lying between Halemaumau Crater and the north-facing scarps that mark the southern caldera boundary. The results are also suggestive of changes in seismic velocity distributions between 1996 and 2012. One example of such a change is an apparent decrease in the size and southeastward extent, compared to the earlier model, of the low VP feature imaged with the more recent data. However, we recognize the distinct possibility that these changes are reflective of differences in earthquake and seismic station distributions in the respective datasets, and we need to further populate the more recent HVO seismicity catalogs to possibly address this concern

Seismic Noise Characterization in the Northern Mississippi Embayment

NASA Astrophysics Data System (ADS)

Wiley, S.; Deshon, H. R.; Boyd, O. S.

2009-12-01

We present a study of seismic noise sources present within the northern Mississippi embayment near the New Madrid Seismic Zone (NMSZ). The northern embayment contains up to 1 km of unconsolidated coastal plain sediments overlying bedrock, making it an inherently noisy environment for seismic stations. The area is known to display high levels of cultural noise caused by agricultural activity, passing cars, trains, etc. We characterize continuous broadband seismic noise data recorded for the months of March through June 2009 at six stations operated by the Cooperative New Madrid Seismic Network. We looked at a single horizontal component of data during nighttime hours, defined as 6:15PM to 5:45AM Central Standard Time, which we determined to be the lowest amplitude period of noise for the region. Hourly median amplitudes were compared to daily average wind speeds downloaded from the National Oceanic and Atmospheric Administration. We find a correlation between time periods of increased noise and days with high wind speeds, suggesting that wind is likely a prevalent source of seismic noise in the area. The effects of wind on seismic recordings may result from wind induced tree root movement which causes ground motion to be recorded at the vaults located ~3m below ground. Automated studies utilizing the local network or the EarthScope Transportable Array, scheduled to arrive in the area in 2010-11, should expect to encounter wind induced noise fluctuations and must account for this in their analysis.

An Assessment of the Seismicity of the Bursa Region from a Temporary Seismic Network

NASA Astrophysics Data System (ADS)

Gok, Elcin; Polat, Orhan

2012-04-01

A temporary earthquake station network of 11 seismological recorders was operated in the Bursa region, south of the Marmara Sea in the northwest of Turkey, which is located at the southern strand of the North Anatolian Fault Zone (NAFZ). We located 384 earthquakes out of a total of 582 recorded events that span the study area between 28.50-30.00°E longitudes and 39.75-40.75°N latitudes. The depth of most events was found to be less than 29 km, and the magnitude interval ranges were between 0.3 ≤ ML ≤ 5.4, with RMS less than or equal to 0.2. Seismic activities were concentrated southeast of Uludag Mountain (UM), in the Kestel-Igdir area and along the Gemlik Fault (GF). In the study, we computed 10 focal mechanisms from temporary and permanents networks. The predominant feature of the computed focal mechanisms is the relatively widespread near horizontal northwest-southeast (NW-SE) T-axis orientation. These fault planes have been used to obtain the orientation and shape factor (R, magnitude stress ratio) of the principal stress tensors (σ1, σ2, σ3). The resulting stress tensors reveal σ1 closer to the vertical (oriented NE-SW) and σ2, σ3 horizontal with R = 0.5. These results confirm that Bursa and its vicinity could be defined by an extensional regime showing a primarily normal to oblique-slip motion character. It differs from what might be expected from the stress tensor inversion for the NAFZ. Different fault patterns related to structural heterogeneity from the north to the south in the study area caused a change in the stress regime from strike-slip to normal faulting.

HANFORD WASTE MINERALOGY REFERENCE REPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

DISSELKAMP RS

2010-06-29

This report lists the observed mineral phases present in the Hanford tanks. This task was accomplished by performing a review of numerous reports that used experimental techniques including, but not limited to: x-ray diffraction, polarized light microscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron energy loss spectroscopy, and particle size distribution analyses. This report contains tables that can be used as a quick reference to identify the crystal phases observed in Hanford waste.

HANFORD WASTE MINEROLOGY REFERENCE REPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

DISSELKAMP RS

2010-06-18

This report lists the observed mineral phase phases present in the Hanford tanks. This task was accomplished by performing a review of numerous reports using experimental techniques including, but not limited to: x-ray diffraction, polarized light microscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron energy loss spectroscopy, and particle size distribution analyses. This report contains tables that can be used as a quick reference to identify the crystal phases present observed in Hanford waste.

75 FR 64718 - Environmental Management Site-Specific Advisory Board, Hanford

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Hanford AGENCY... Environmental Management Site-Specific Advisory Board (EM SSAB), Hanford. The Federal Advisory Committee Act.... ADDRESSES: Red Lion Hanford House, 802 George Washington Way, Richland, Washington. FOR FURTHER INFORMATION...

75 FR 8051 - Environmental Management Site-Specific Advisory Board, Hanford

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Hanford AGENCY... the Environmental Management Site-Specific Advisory Board (EM SSAB), Hanford (known locally as the Hanford Advisory Board [HAB]), River and Plateau, Tank Waste, Public Involvement, Health Safety and...

76 FR 4645 - Environmental Management Site-Specific Advisory Board, Hanford

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-26

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Hanford AGENCY... Environmental Management Site-Specific Advisory Board (EM SSAB), Hanford. The Federal Advisory Committee Act.... ADDRESSES: Red Lion Hanford House, 802 George Washington Way, Richland, Washington 99352. FOR FURTHER...

The Pollino Seismic Sequence: Activated Graben Structures in a Seismic Gap

NASA Astrophysics Data System (ADS)

Rößler, Dirk; Passarelli, Luigi; Govoni, Aladino; Bindi, Dino; Cesca, Simone; Hainzl, Sebatian; Maccaferri, Francesco; Rivalta, Eleonora; Woith, Heiko; Dahm, Torsten

2015-04-01

The Mercure Basin (MB) and the Castrovillari Fault (CF) in the Pollino range (Southern Apennines, Italy) represent one of the most prominent seismic gaps in the Italian seismic catalogue, with no M>5.5 earthquakes during the last centuries. In historical times several swarm-like seismic sequences occurred in the area including two intense swarms within the past two decades. The most energetic one started in 2010 and has been still active in 2014. The seismicity culminated in autumn 2012 with a M=5 event on 25 October. The range hosts a number of opposing normal faults forming a graben-like structure. Their rheology and their interactions are unclear. Current debates include the potential of the MB and the CF to host large earthquakes and the style of deformation. Understanding the seismicity and the behaviour of the faults is necessary to assess the tectonics and the seismic hazard. The GFZ German Research Centre for Geosciences and INGV, Italy, have jointly monitored the ongoing seismicity using a small-aperture seismic array, integrated in a temporary seismic network. Based on this installation, we located more than 16,000 local earthquakes that occurred between November 2012 and September 2014. Here we investigate quantitatively all the phases of the seismic sequence starting from January 2010. Event locations along with moment tensor inversion constrain spatially the structures activated by the swarm and the migration pattern of the seismicity. The seismicity forms clusters concentrated within the southern part of the MB and along the Pollino Fault linking MB and CF. Most earthquakes are confined to the upper 10 km of the crust in an area of ~15x15 km2. However, sparse seismicity at depths between 15 and 20 km and moderate seismicity further north with deepening hypocenters also exist. In contrast, the CF appears aseismic; only the northern part has experienced micro-seismicity. The spatial distribution is however more complex than the major tectonic structures

Seismic monitoring at Deception Island volcano (Antarctica): the 2010-2011 survey

NASA Astrophysics Data System (ADS)

Martín, R.; Carmona, E.; Almendros, J.; Serrano, I.; Villaseñor, A.; Galeano, J.

2012-04-01

As an example of the recent advances introduced in seismic monitoring of Deception Island volcano (Antarctica) during recent years, we describe the instrumental network deployed during the 2010-2011 survey by the Instituto Andaluz de Geofísica of University of Granada, Spain (IAG-UGR). The period of operation extended from December 19, 2010 to March 5, 2011. We deployed a wireless seismic network composed by four three-component seismic stations. These stations are based on 24-bit SL04 SARA dataloggers sampling at 100 sps. They use a PC with embedded linux and SEISLOG data acquisition software. We use two types of three-component seismometers: short-period Mark L4C with natural frequency of 1 Hz and medium-period Lennartz3D/5s with natural frequency of 0.2 Hz. The network was designed for an optimum spatial coverage of the northern half of Deception, where a magma chamber has been reported. Station locations include the vicinity of the Spanish base "Gabriel de Castilla" (GdC), Obsidianas Beach, a zone near the craters from the 1970 eruptions, and the Chilean Shelter located south of Pendulum Cove. Continuous data from the local seismic network are received in real-time in the base by wifi transmission. We used Ubiquiti Networks Nanostation2 antennas with 2.4 GHz, dual-polarity, 10 dBi gain, and 54 Mbps transmission rate. They have shown a great robustness and speed for real-time applications. To prioritize data acquisition when the battery level is low, we have designed a circuit that allows independent power management for the seismic station and wireless transmission system. The reception antenna located at GdC is connected to a computer running SEISCOMP. This software supports several transmission protocols and manages the visualization and recording of seismic data, including the generation of summary plots to show the seismic activity. These twelve data channels are stored in miniseed format and displayed in real time, which allows for a rapid evaluation of

Foreshocks and Swarms of Induced Seismicity in Southern Kansas

NASA Astrophysics Data System (ADS)

Rubinstein, J. L.; Skoumal, R.; Dougherty, S. L.; Cochran, E. S.

2017-12-01

Protracted foreshock sequences and swarm-like behavior have been observed for a number of induced earthquakes, including Guy-Greenbrier, Raton Basin, Youngstown, and the Fairview sequences. Many other induced earthquake sequences have seen intermittent seismicity before the largest earthquake in the sequence. The prevalence of foreshocks and swarms as part of induced earthquake sequences likely reflects the ongoing increase in and expansion of fluid pressure in a region, such that higher magnitude events will occur once a large region has been sufficiently influenced by fluid injection. Diffusion of fluid pressure has been observed in some induced seismicity sequences whereby seismicity moves away from an injector, making the earlier events foreshocks. Natural seismicity in other parts of the central and eastern United States experience far fewer foreshock sequences. This is additional evidence that injection-caused increase in fluid pressure is the reason that these foreshocks and swarms are occurring. To better understand foreshocks and swarm-like behavior of induced seismicity, we examine the seismicity in southern Kansas from 2014-2017. The seismic network in southern Kansas represents the densest, longest-running (>3.5 years) network with publicly available data in near-real-time in an area of induced seismicity. This has yielded a magnitude of completeness of 2.0, which is lower than in most other areas of induced seismicity. We further enhance this catalog by using template matching. With this expanded catalog, we identify and examine foreshock and swarm behavior for all M3.5 and larger mainshocks in Kansas.

An Experimental Seismic Data and Parameter Exchange System for Interim NEAMTWS

NASA Astrophysics Data System (ADS)

Hanka, W.; Hoffmann, T.; Weber, B.; Heinloo, A.; Hoffmann, M.; Müller-Wrana, T.; Saul, J.

2009-04-01

In 2008 GFZ Potsdam has started to operate its global earthquake monitoring system as an experimental seismic background data centre for the interim NEAMTWS (NE Atlantic and Mediterranean Tsunami Warning System). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project was extended to test the export and import of individual processing results within a cluster of SC3 systems. The initiated NEAMTWS SC3 cluster consists presently of the 24/7 seismic services at IMP, IGN, LDG/EMSC and KOERI, whereas INGV and NOA are still pending. The GFZ virtual real-time seismic network (GEOFON Extended Virtual Network - GEVN) was substantially extended by many stations from Western European countries optimizing the station distribution for NEAMTWS purposes. To amend the public seismic network (VEBSN - Virtual European Broadband Seismic Network) some attached centres provided additional private stations for NEAMTWS usage. In parallel to the data collection by Internet the GFZ VSAT hub for the secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and the first data links were established. In 2008 the experimental system could already prove its performance since a number of relevant earthquakes have happened in NEAMTWS area. The results are very promising in terms of speed as the automatic alerts (reliable solutions based on a minimum of 25 stations and disseminated by emails and SMS) were issued between 2 1/2 and 4 minutes for Greece and 5 minutes for Iceland. They are also promising in terms of accuracy since epicenter coordinates, depth and magnitude estimates were sufficiently accurate from the very beginning, usually don't differ substantially from the final solutions and provide a good starting point for the operations of the interim NEAMTWS. However, although an automatic seismic system is a good first step, 24/7 manned RTWCs are mandatory for regular manual verification

Shallow Moho with aseismic upper crust and deep Moho with seismic lower crust beneath the Japanese Islands obtained by seismic tomography using data from dense seismic network

NASA Astrophysics Data System (ADS)

Matsubara, Makoto; Obara, Kazushige

2015-04-01

P-wave seismic velocity is well known to be up to 7.0 km/s and over 7.5 km/s in the lower crust and in the mantle, respectively. A large velocity gradient is the definition of the Moho discontinuity between the crust and mantle. In this paper, we investigates the configuration of Moho discontinuity defined as an isovelocity plane with large velocity gradient derived from our fine-scale three-dimensional seismic velocity structure beneath Japanese Islands using data obtained by dense seismic network with the tomographic method (Matsubara and Obara, 2011). Japanese Islands are mainly on the Eurasian and North American plates. The Philippine Sea and Pacific plates are subducting beneath these continental plates. We focus on the Moho discontinuity at the continental side. We calculate the P-wave velocity gradients between the vertical grid nodes since the grid inversion as our tomographic method does not produce velocity discontinuity. The largest velocity gradient is 0.078 (km/s)/km at velocities of 7.2 and 7.3 km/s. We define the iso-velocity plane of 7.2 km/s as the Moho discontinuity. We discuss the Moho discontinuity above the upper boundary of the subducting oceanic plates with consideration of configuration of plate boundaries of prior studies (Shiomi et al., 2008; Kita et al., 2010; Hirata et al, 2012) since the Moho depth derived from the iso-velocity plane denotes the oceanic Moho at the contact zones of the overriding continental plates and the subducting oceanic plates. The Moho discontinuity shallower than 30 km depth is distributed within the tension region like northern Kyushu and coastal line of the Pacific Ocean in the northeastern Japan and the tension region at the Cretaceous as the northeastern Kanto district. These regions have low seismicity within the upper crust. Positive Bouguer anomaly beneath the northeastern Kanto district indicates the ductile material with large density in lower crust at the shallower portion and the aseismic upper crust

Bridging the Gap - Networking Educators using Real-Time Seismic Data

NASA Astrophysics Data System (ADS)

Ortiz, A. M.; Renwald, M. D.; Baldwin, T. K.; Hall, M. K.

2004-12-01

After nearly a decade, the seismology community has made critical advances in identifying what is effective and what is needed for success in incorporating real-time seismic data in the classroom. Today's K-16 classroom teachers have many options and opportunities for incorporating short- and long-term inquiry activities for monitoring earthquakes and analyzing seismic data in their daily instruction. Through the SpiNet program, we are providing web-based tools that support educators working with real-time seismic data (http://www.scieds.com/spinet/). Our site includes a Recent Seismicity section, which allows users to share seismic data in real-time, and provides near real-time information about global seismicity. Our Activities section provides data and lessons to assist educators who wish to integrate seismology into their classroom. The Research section, currently under development, will allow educators to share general information about how they teach seismology in their classroom through a discussion board and by posting lesson plans. In addition, we are developing a user-friendly tool for students to post results of their research projects. Designing a website which targets a range of users requires a working knowledge of both user needs and website programming and design. User needs include providing a logical navigational structure and accounting for differences in browser functionality, internet access, and users' abilities. Using website development tools, such as PHP, MySQL, RDF feeds, and specialized geoscience applications, we are automating site maintenance; incorporating databases for information storage and retrieval; and providing accessibility for users with a range of skills and physical limitations. By incorporating these features, we have built a dynamic interface for a broad range of users interested in educational seismology.

Hanford Environmental Dose Reconstruction Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cannon, S.D.; Finch, S.M.

1992-10-01

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

A Dense Small-Scale Seismic Network in the Ngorongoro Conservation Area (Northern Tanzania)

NASA Astrophysics Data System (ADS)

Parisi, L.; Lombardo, L.; Rodriguez-Mustafa, M.; Mai, P. M.

2017-12-01

A temporary deployment consisting of sixteen broadband seismic stations is conducted for the first time in the Ngorongoro Conservation Area (NCA, Northern Tanzania), located at the boundary between the Tanzanian Craton and East African Rift. A deep knowledge of the faulting systems and tectonics of the area is needed to better understand the contribution of the synsedimentary faults to the deposition of the Olduvai and surrounding basins affecting the landscapes of the Homo Habilis first settlements. Complex fault systems have been mapped in the field but their connection, especially at depth, is not well known. A first batch of ten instruments was installed in June 2016. In June 2017 two stations were dismissed and a second batch of six stations was installed in new locations. The current network of fourteen stations will record until May 2018. Stations are equipped with Nanometrics Trillium Compact Posthole 120 s sensor and Centaur digitiser recording continuously at 200 Hz. The whole network covers 1400 km2 and station interspace ranges from 8 to 15 km. We analyse probabilistic power spectra densities of the seismic noise to obtain insights of its origin and test the performances of the stations. Although factories do not exist in the area and most of the stations are far from roads, ambient noise in the range 0.01 - 1 s is relatively high (between -120 dB and -100dB at 0.1 s) probably because of the abundance of livestock living in the NCA. Ambient noise in the period range 1 - 10 s (secondary microseisms) decreases from east to west. Although the main source of the microseisms is located in the Indian Ocean (east of the study area), a contribution from the low period tremors coming from the nearby active volcano Ol Doinyo Lengai (north-east of the study area) is expected. Whereas the longer period noise (10 - 100 s) is very low in the vertical component seismograms, it is higher than the high noise model in the horizontal components for most of the stations

Operating a global seismic network - perspectives from the USGS GSN

NASA Astrophysics Data System (ADS)

Gee, L. S.; Derr, J. S.; Hutt, C. R.; Bolton, H.; Ford, D.; Gyure, G. S.; Storm, T.; Leith, W.

2007-05-01

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

Effects on Chilean Vertical Reference Frame due to the Maule Earthquake co-seismic and post-seismic effects

NASA Astrophysics Data System (ADS)

Montecino, Henry D.; de Freitas, Silvio R. C.; Báez, Juan C.; Ferreira, Vagner G.

2017-12-01

The Maule Earthquake (Mw = 8.8) of February 27, 2010 is among the strongest earthquakes that occurred in recent years throughout the world. The crustal deformation caused by this earthquake has been widely studied using GNSS, InSAR and gravity observations. However, there is currently no estimation of the possible vertical deformations produced by co-seismic and post-seismic effects in segments of the Chilean Vertical Reference Frame (CHVRF). In this paper, we present an estimation of co-seismic and post-seismic deformations on the CHVRF using an indirect approach based on GNSS and Gravity Recovery and Climate Experiment (GRACE) data as well as by applying a trajectory model. GNSS time series were used from 10 continuous GNSS stations in the period from 2007 to 2015, as well as 28 GNSS temporary stations realized before and after the earthquake, and 34 vertical deformation vectors in the region most affected by the earthquake. We considered a set of 147 monthly solutions of spherical harmonic gravity field that were expanded up to degree, as well as order 96 of the GRACE mission provided by Center for Space Research, University of Texas at Austin (UT-CSR) process center. The magnitude of vertical deformation was estimated in part of the Chilean vertical network due to the co-seismic and post-seismic effects. Once we evaluated the hydrological effect, natural and artificial jumps, and the effect of glacial isostatic adjustment in GNSS and GRACE time series, the maximum values associated to co- and post-seismic deformations on orthometric height were found to be ∼-34 cm and 5 cm, respectively. Overall, the deformation caused by the Maule earthquake in orthometric heights is almost entirely explained by the variation in the ellipsoidal heights (over 85% in co-seismic jump); however, coseismic jump in the geoid reached -3.3 mm, and could influence the maintenance of a modern vertical reference network in a medium to long term. We evaluated the consistency for a

Puerto Rico Seismic Network Operations During and After the Hurricane Maria: Response, Continuity of Operations, and Experiences

NASA Astrophysics Data System (ADS)

Vanacore, E. A.; Baez-Sanchez, G.; Huerfano, V.; Lopez, A. M.; Lugo, J.

2017-12-01

The Puerto Rico Seismic Network (PRSN) is an integral part of earthquake and tsunami monitoring in Puerto Rico and the Virgin Islands. The PRSN conducts scientific research as part of the University of Puerto Rico Mayaguez, conducts the earthquake monitoring for the region, runs extensive earthquake and tsunami education and outreach programs, and acts as a Tsunami Warning Focal Point Alternate for Puerto Rico. During and in the immediate aftermath of Hurricane Maria, the PRSN duties and responsibilities evolved from a seismic network to a major information and communications center for the western side of Puerto Rico. Hurricane Maria effectively destroyed most communications on island, critically between the eastern side of the island where Puerto Rico's Emergency Management's (PREMA) main office and the National Weather Service (NWS) is based and the western side of the island. Additionally, many local emergency management agencies on the western side of the island lost a satellite based emergency management information system called EMWIN which provides critical tsunami and weather information. PRSN's EMWIN system remained functional and consequently via this system and radio communications PRSN became the only information source for NWS warnings and bulletins, tsunami alerts, and earthquake information for western Puerto Rico. Additionally, given the functional radio and geographic location of the PRSN, the network became a critical communications relay for local emergency management. Here we will present the PRSN response in relation to Hurricane Maria including the activation of the PRSN devolution plan, adoption of duties, experiences and lessons learned for continuity of operations and adoption of responsibilities during future catastrophic events.

Seismicity in Pennsylvania: Evidence for Anthropogenic Events?

NASA Astrophysics Data System (ADS)

Homman, K.; Nyblade, A.

2015-12-01

The deployment and operation of the USArray Transportable Array (TA) and the PASEIS (XY) seismic networks in Pennsylvania during 2013 and 2014 provide a unique opportunity for investigating the seismicity of Pennsylvania. These networks, along with several permanent stations in Pennsylvania, resulted in a total of 104 seismometers in and around Pennsylvania that have been used in this study. Event locations were first obtained with Antelope Environmental Monitoring Software using P-wave arrival times. Arrival times were hand picked using a 1-5 Hz bandpass filter to within 0.1 seconds. Events were then relocated using a velocity model developed for Pennsylvania and the HYPOELLIPSE location code. In this study, 1593 seismic events occurred between February 2013 and December 2014 in Pennsylvania. These events ranged between magnitude (ML) 1.04 and 2.89 with an average MLof 1.90. Locations of the events occur across the state in many areas where no seismicity has been previously reported. Preliminary results indicate that most of these events are related to mining activity. Additional work using cross-correlation techniques is underway to examine a number of event clusters for evidence of hydraulic fracturing or wastewater injection sources.

75 FR 8050 - Environmental Management Site-Specific Advisory Board, Hanford

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Hanford AGENCY... Environmental Management Site-Specific Advisory Board (EM SSAB), Hanford. The Federal Advisory Committee Act...: The meeting is open to the public. The EM SSAB, Hanford, welcomes the attendance of the public at its...

Seismicity of Cascade Volcanoes: Characterization and Comparison

NASA Astrophysics Data System (ADS)

Thelen, W. A.

2016-12-01

Here we summarize and compare the seismicity around each of the Very High Threat Volcanoes of the Cascade Range of Washington, Oregon and California as defined by the National Volcanic Early Warning System (NVEWS) threat assessment (Ewert et al., 2005). Understanding the background seismic activity and processes controlling it is critical for assessing changes in seismicity and their implications for volcanic hazards. Comparing seismicity at different volcanic centers can help determine what critical factors or processes affect the observed seismic behavior. Of the ten Very High Threat Volcanoes in the Cascade Range, five volcanoes are consistently seismogenic when considering earthquakes within 10 km of the volcanic center or caldera edge (Mount Rainier, Mount St. Helens, Mount Hood, Newberry Caldera, Lassen Volcanic Center). Other Very High Threat volcanoes (South Sister, Mount Baker, Glacier Peak, Crater Lake and Mount Shasta) have comparatively low rates of seismicity and not enough recorded earthquakes to calculate catalog statistics. Using a swarm definition of 3 or more earthquakes occurring in a day with magnitudes above the largest of the network's magnitude of completenesses (M 0.9), we find that Lassen Volcanic Center is the "swarmiest" in terms of percent of seismicity occurring in swarms, followed by Mount Hood, Mount St. Helens and Rainier. The predominance of swarms at Mount Hood may be overstated, as much of the seismicity is occurring on surrounding crustal faults (Jones and Malone, 2005). Newberry Caldera has a relatively short record of seismicity since the permanent network was installed in 2011, however there have been no swarms detected as defined here. Future work will include developing discriminates for volcanic versus tectonic seismicity to better filter the seismic catalog and more precise binning of depths at some volcanoes so that we may better consider different processes. Ewert J. W., Guffanti, M. and Murray, T. L. (2005). An

Epistemic uncertainty in California-wide synthetic seismicity simulations

USGS Publications Warehouse

Pollitz, Fred F.

2011-01-01

The generation of seismicity catalogs on synthetic fault networks holds the promise of providing key inputs into probabilistic seismic-hazard analysis, for example, the coefficient of variation, mean recurrence time as a function of magnitude, the probability of fault-to-fault ruptures, and conditional probabilities for foreshock–mainshock triggering. I employ a seismicity simulator that includes the following ingredients: static stress transfer, viscoelastic relaxation of the lower crust and mantle, and vertical stratification of elastic and viscoelastic material properties. A cascade mechanism combined with a simple Coulomb failure criterion is used to determine the initiation, propagation, and termination of synthetic ruptures. It is employed on a 3D fault network provided by Steve Ward (unpublished data, 2009) for the Southern California Earthquake Center (SCEC) Earthquake Simulators Group. This all-California fault network, initially consisting of 8000 patches, each of ∼12 square kilometers in size, has been rediscretized into Graphic patches, each of ∼1 square kilometer in size, in order to simulate the evolution of California seismicity and crustal stress at magnitude M∼5–8. Resulting synthetic seismicity catalogs spanning 30,000 yr and about one-half million events are evaluated with magnitude-frequency and magnitude-area statistics. For a priori choices of fault-slip rates and mean stress drops, I explore the sensitivity of various constructs on input parameters, particularly mantle viscosity. Slip maps obtained for the southern San Andreas fault show that the ability of segment boundaries to inhibit slip across the boundaries (e.g., to prevent multisegment ruptures) is systematically affected by mantle viscosity.

Epistemic uncertainty in California-wide synthetic seismicity simulations

USGS Publications Warehouse

Pollitz, F.F.

2011-01-01

The generation of seismicity catalogs on synthetic fault networks holds the promise of providing key inputs into probabilistic seismic-hazard analysis, for example, the coefficient of variation, mean recurrence time as a function of magnitude, the probability of fault-to-fault ruptures, and conditional probabilities for foreshock-mainshock triggering. I employ a seismicity simulator that includes the following ingredients: static stress transfer, viscoelastic relaxation of the lower crust and mantle, and vertical stratification of elastic and viscoelastic material properties. A cascade mechanism combined with a simple Coulomb failure criterion is used to determine the initiation, propagation, and termination of synthetic ruptures. It is employed on a 3D fault network provided by Steve Ward (unpublished data, 2009) for the Southern California Earthquake Center (SCEC) Earthquake Simulators Group. This all-California fault network, initially consisting of 8000 patches, each of ~12 square kilometers in size, has been rediscretized into ~100;000 patches, each of ~1 square kilometer in size, in order to simulate the evolution of California seismicity and crustal stress at magnitude M ~ 5-8. Resulting synthetic seismicity catalogs spanning 30,000 yr and about one-half million events are evaluated with magnitude-frequency and magnitude-area statistics. For a priori choices of fault-slip rates and mean stress drops, I explore the sensitivity of various constructs on input parameters, particularly mantle viscosity. Slip maps obtained for the southern San Andreas fault show that the ability of segment boundaries to inhibit slip across the boundaries (e.g., to prevent multisegment ruptures) is systematically affected by mantle viscosity.

Incorporating seismic phase correlations into a probabilistic model of global-scale seismology

NASA Astrophysics Data System (ADS)

Arora, Nimar

2013-04-01

We present a probabilistic model of seismic phases whereby the attributes of the body-wave phases are correlated to those of the first arriving P phase. This model has been incorporated into NET-VISA (Network processing Vertically Integrated Seismic Analysis) a probabilistic generative model of seismic events, their transmission, and detection on a global seismic network. In the earlier version of NET-VISA, seismic phase were assumed to be independent of each other. Although this didn't affect the quality of the inferred seismic bulletin, for the most part, it did result in a few instances of anomalous phase association. For example, an S phase with a smaller slowness than the corresponding P phase. We demonstrate that the phase attributes are indeed highly correlated, for example the uncertainty in the S phase travel time is significantly reduced given the P phase travel time. Our new model exploits these correlations to produce better calibrated probabilities for the events, as well as fewer anomalous associations.

Hanford Site Environmental Report for Calendar Year 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poston, Ted M.; Hanf, Robert W.; Dirkes, Roger L.

This report is prepared annually to satisfy the requirements of DOE Orders. The report provides an overview of activities at the Hanford Site during 2002 and demonstrates the site's compliance with applicable federal, state, and local environmental laws, regulations, executive orders, and DOE policies; and to summarize environmental data that characterize Hanford Site environmental management performance. The purpose of the report is to provide useful summary information to members of the public, public officials, regulators, Hanford contractors, and elected representatives.

New seismic study begins in Puerto Rico

USGS Publications Warehouse

Tarr, A.C.

1974-01-01

A new seismological project is now underway in Puerto Rico to provide information needed for accurate assessment of the island's seismic hazard. The project should also help to increase understanding of the tectonics and geologic evolution of the Caribbean region. The Puerto Rico Seismic Program is being conducted by the Geological Survey with support provided by the Puerto Rico Water Resources Authority, an agency responsible for generation and distribution of electric power throughout the Commonwealth. The Program will include the installation of a network of high quality seismograph stations to monitor seismic activity on and around Puerto Rico. These stations will be distributed across the island to record the seismicity as uniformly as possible. The detection and accurate location of small earthquakes, as well as moderate magnitude shocks, will aid in mapping active seismic zones and in compiling frequency of occurrence statistics which ultimately wil be useful in seismic risk-zoning of hte island. 

Centrality in earthquake multiplex networks

NASA Astrophysics Data System (ADS)

Lotfi, Nastaran; Darooneh, Amir Hossein; Rodrigues, Francisco A.

2018-06-01

Seismic time series has been mapped as a complex network, where a geographical region is divided into square cells that represent the nodes and connections are defined according to the sequence of earthquakes. In this paper, we map a seismic time series to a temporal network, described by a multiplex network, and characterize the evolution of the network structure in terms of the eigenvector centrality measure. We generalize previous works that considered the single layer representation of earthquake networks. Our results suggest that the multiplex representation captures better earthquake activity than methods based on single layer networks. We also verify that the regions with highest seismological activities in Iran and California can be identified from the network centrality analysis. The temporal modeling of seismic data provided here may open new possibilities for a better comprehension of the physics of earthquakes.

On the reliability of Quake-Catcher Network earthquake detections

USGS Publications Warehouse

Yildirim, Battalgazi; Cochran, Elizabeth S.; Chung, Angela I.; Christensen, Carl M.; Lawrence, Jesse F.

2015-01-01

Over the past two decades, there have been several initiatives to create volunteer‐based seismic networks. The Personal Seismic Network, proposed around 1990, used a short‐period seismograph to record earthquake waveforms using existing phone lines (Cranswick and Banfill, 1990; Cranswicket al., 1993). NetQuakes (Luetgert et al., 2010) deploys triaxial Micro‐Electromechanical Systems (MEMS) sensors in private homes, businesses, and public buildings where there is an Internet connection. Other seismic networks using a dense array of low‐cost MEMS sensors are the Community Seismic Network (Clayton et al., 2012; Kohler et al., 2013) and the Home Seismometer Network (Horiuchi et al., 2009). One main advantage of combining low‐cost MEMS sensors and existing Internet connection in public and private buildings over the traditional networks is the reduction in installation and maintenance costs (Koide et al., 2006). In doing so, it is possible to create a dense seismic network for a fraction of the cost of traditional seismic networks (D’Alessandro and D’Anna, 2013; D’Alessandro, 2014; D’Alessandro et al., 2014).

Modelling induced seismicity due to fluid injection

NASA Astrophysics Data System (ADS)

Murphy, S.; O'Brien, G. S.; Bean, C. J.; McCloskey, J.; Nalbant, S. S.

2011-12-01

Injection of fluid into the subsurface alters the stress in the crust and can induce earthquakes. The science of assessing the risk of induced seismicity from such ventures is still in its infancy despite public concern. We plan to use a fault network model in which stress perturbations due to fluid injection induce earthquakes. We will use this model to investigate the role different operational and geological factors play in increasing seismicity in a fault system due to fluid injection. The model is based on a quasi-dynamic relationship between stress and slip coupled with a rate and state fiction law. This allows us to model slip on fault interfaces over long periods of time (i.e. years to 100's years). With the use of the rate and state friction law the nature of stress release during slipping can be altered through variation of the frictional parameters. Both seismic and aseismic slip can therefore be simulated. In order to add heterogeneity along the fault plane a fractal variation in the frictional parameters is used. Fluid injection is simulated using the lattice Boltzmann method whereby pore pressure diffuses throughout a permeable layer from the point of injection. The stress perturbation this causes on the surrounding fault system is calculated using a quasi-static solution for slip dislocation in an elastic half space. From this model we can generate slip histories and seismicity catalogues covering 100's of years for predefined fault networks near fluid injection sites. Given that rupture is a highly non-linear process, comparison between models with different input parameters (e.g. fault network statistics and injection rates) will be based on system wide features (such as the Gutenberg-Richter b-values), rather than specific seismic events. Our ultimate aim is that our model produces seismic catalogues similar to those observed over real injection sites. Such validation would pave the way to probabilistic estimation of reactivation risk for

Designing a low-cost effective network for monitoring large scale regional seismicity in a soft-soil region (Alsace, France)

NASA Astrophysics Data System (ADS)

Bès de Berc, M.; Doubre, C.; Wodling, H.; Jund, H.; Hernandez, A.; Blumentritt, H.

2015-12-01

The Seismological Observatory of the North-East of France (ObSNEF) is developing its monitoring network within the framework of several projects. Among these project, RESIF (Réseau sismologique et géodésique français) allows the instrumentation of broad-band seismic stations, separated by 50-100 km. With the recent and future development of geothermal industrial projects in the Alsace region, the ObSNEF is responsible for designing, building and operating a dense regional seismic network in order to detect and localize earthquakes with both a completeness magnitude of 1.5 and no clipping for M6.0. The realization of the project has to be done prior to the summer 2016Several complex technical and financial constraints constitute such a projet. First, most of the Alsace Région (150x150 km2), particularly the whole Upper Rhine Graben, is a soft-soil plain where seismic signals are dominated by a high frequency noise level. Second, all the signals have to be transmitted in near real-time. And finally, the total cost of the project must not exceed $450,000.Regarding the noise level in Alsace, in order to make a reduction of 40 dB for frequencies above 1Hz, we program to instrument into 50m deep well with post-hole sensor for 5 stations out of 8 plane new stations. The 3 remaining would be located on bedrock along the Vosges piedmont. In order to be sensitive to low-magnitude regional events, we plan to install a low-noise short-period post-hole velocimeter. In order to avoid saturation for high potentiel local events (M6.0 at 10km), this velocimeter will be coupled with a surface strong-motion sensor. Regarding the connectivity, these stations will have no wired network, which reduces linking costs and delays. We will therefore use solar panels and a 3G/GPRS network. The infrastructure will be minimal and reduced to an outdoor box on a secured parcel of land. In addition to the data-logger, we will use a 12V ruggedized computer, hosting a seed-link server for near

Citizen Science Seismic Stations for Monitoring Regional and Local Events

NASA Astrophysics Data System (ADS)

Zucca, J. J.; Myers, S.; Srikrishna, D.

2016-12-01

The earth has tens of thousands of seismometers installed on its surface or in boreholes that are operated by many organizations for many purposes including the study of earthquakes, volcanos, and nuclear explosions. Although global networks such as the Global Seismic Network and the International Monitoring System do an excellent job of monitoring nuclear test explosions and other seismic events, their thresholds could be lowered with the addition of more stations. In recent years there has been interest in citizen-science approaches to augment government-sponsored monitoring networks (see, for example, Stubbs and Drell, 2013). A modestly-priced seismic station that could be purchased by citizen scientists could enhance regional and local coverage of the GSN, IMS, and other networks if those stations are of high enough quality and distributed optimally. In this paper we present a minimum set of hardware and software specifications that a citizen seismograph station would need in order to add value to global networks. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Micro-seismic earthquakes characteristics at natural and exploited hydrothermal systems in West Java, Indonesia

NASA Astrophysics Data System (ADS)

Jousset, P. G.; Jaya, M. S.; Sule, R.; Diningrat, W.; Gassner, A.; Akbar, F.; Ryannugroho, R.; Hendryana, A.; Kusnadi, Y.; Syahbana, D.; Nugraha, A. D.; Umar, M.; Indrinanto, Y.; Erbas, K.

2013-12-01

The assessment of geothermal resources requires the understanding of the structure and the dynamics of geothermal reservoirs. We deployed a multidisciplinary geophysical network around geothermal areas in the south of Bandung, West Java, Indonesia. The first deployment included a network of 30 broadband and 4 short-period seismic stations with Güralp and Trillium sensors (0.008 - 100 Hz) since October 2012. In a second step, we extended the network in June 2013 with 16 short-period (1 Hz) seismometers. We describe the set-up of the seismic networks and discuss first observations and results. The co-existence of a large variety of intense surface manifestations like geysers, hot-steaming grounds, hot water pools, and active volcanoes suggest an intimate coupling between volcanic, tectonic and hydrothermal processes in this area. Preliminary location of earthquakes is performed using a non-linear algorithm, which allows us to define at least 3 seismic clusters. We discuss this seismic pattern within the geothermal fields.

Hanford Internal Dosimetry Program Manual, PNL-MA-552

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

2009-09-24

This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP), which is operated by the Pacific Northwest National Laboratory.( ) for the U.S. Department of Energy Richland Operations Office, Office of River Protection and their Hanford Site contractors. The manual describes the roles of and relationships between the IDP and the radiation protection programs of the Hanford Site contractors. Recommendations and guidance are also provided for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs.

Seismic event classification system

DOEpatents

Dowla, Farid U.; Jarpe, Stephen P.; Maurer, William

1994-01-01

In the computer interpretation of seismic data, the critical first step is to identify the general class of an unknown event. For example, the classification might be: teleseismic, regional, local, vehicular, or noise. Self-organizing neural networks (SONNs) can be used for classifying such events. Both Kohonen and Adaptive Resonance Theory (ART) SONNs are useful for this purpose. Given the detection of a seismic event and the corresponding signal, computation is made of: the time-frequency distribution, its binary representation, and finally a shift-invariant representation, which is the magnitude of the two-dimensional Fourier transform (2-D FFT) of the binary time-frequency distribution. This pre-processed input is fed into the SONNs. These neural networks are able to group events that look similar. The ART SONN has an advantage in classifying the event because the types of cluster groups do not need to be pre-defined. The results from the SONNs together with an expert seismologist's classification are then used to derive event classification probabilities.

Three-dimensional ground-motion simulations of earthquakes for the Hanford area, Washington

USGS Publications Warehouse

Frankel, Arthur; Thorne, Paul; Rohay, Alan

2014-01-01

This report describes the results of ground-motion simulations of earthquakes using three-dimensional (3D) and one-dimensional (1D) crustal models conducted for the probabilistic seismic hazard assessment (PSHA) of the Hanford facility, Washington, under the Senior Seismic Hazard Analysis Committee (SSHAC) guidelines. The first portion of this report demonstrates that the 3D seismic velocity model for the area produces synthetic seismograms with characteristics (spectral response values, duration) that better match those of the observed recordings of local earthquakes, compared to a 1D model with horizontal layers. The second part of the report compares the response spectra of synthetics from 3D and 1D models for moment magnitude (M) 6.6–6.8 earthquakes on three nearby faults and for a dipping plane wave source meant to approximate regional S-waves from a Cascadia great earthquake. The 1D models are specific to each site used for the PSHA. The use of the 3D model produces spectral response accelerations at periods of 0.5–2.0 seconds as much as a factor of 4.5 greater than those from the 1D models for the crustal fault sources. The spectral accelerations of the 3D synthetics for the Cascadia plane-wave source are as much as a factor of 9 greater than those from the 1D models. The differences between the spectral accelerations for the 3D and 1D models are most pronounced for sites with thicker supra-basalt sediments and for stations with earthquakes on the Rattlesnake Hills fault and for the Cascadia plane-wave source.

Real-time Seismic Alert System of NIED

NASA Astrophysics Data System (ADS)

Horiuchi, S.; Fujinawa, Y.; Negishi, H.; Matsumoto, T.; Fujiwara, H.; Kunugi, T.; Hayashi, Y.

2001-12-01

An extensive seismic network has been constructed nationwide composed of hi-sensitivity seismographic network, broadband seismographic network and strong motion seismographic network. All these data from some 3,000 sites belonging to NIED, JMA and universities are to be accumulated and distributed through NIED to any scientists and engineering through INTERNET under the coordination of the National Seismic Research Committee of MEXT. As a practical application of those data we are now developing a real-time seismic alert information system for the purpose of providing short-term warning of imminent strong grounds motions from major earthquakes from several seconds to a few days. The contents of information are seismic focal parameters (several seconds), seismic fault plane solutions (some 10 seconds), after-shock activities (several minutes-a few days ). The fundamental fault parameters are used to build specific information at sites for particular users for use of triggering automated and /or half-automated responses. The most important application is an immediate estimate of expected shaking distribution and damages in a district using synthetic database and site effects for local governments to initial proper measures of hazard mitigation. Another application is estimation of arrival time and shaking strength at any individual site for human lives to be safeguarded. The system could also start an automatic electrical isolation and protection of computer systems, protection of hazardous chronic systems, transportation systems and so on. The information are corrected successively as seismic ground motion are received at a larger number of sites in time with the result that more accurate and more sophisticated earthquake information is transmitted to any user. Besides the rapid determination of seismic parameters, one of essential items in this alert system is the data transmission means. The data transmission is chosen to assure negligibly small delay of data

Quantifying the seismicity on Taiwan

NASA Astrophysics Data System (ADS)

Wu, Yi-Hsuan; Chen, Chien-Chih; Turcotte, Donald L.; Rundle, John B.

2013-07-01

We quantify the seismicity on the island of Taiwan using the frequency-magnitude statistics of earthquakes since 1900. A break in Gutenberg-Richter scaling for large earthquakes in global seismicity has been observed, this break is also observed in our Taiwan study. The seismic data from the Central Weather Bureau Seismic Network are in good agreement with the Gutenberg-Richter relation taking b ≈ 1 when M < 7. For large earthquakes, M ≥ 7, the seismic data fit Gutenberg-Richter scaling with b ≈ 1.5. If the Gutenberg-Richter scaling for M < 7 earthquakes is extrapolated to larger earthquakes, we would expect a M > 8 earthquake in the study region about every 25 yr. However, our analysis shows a lower frequency of occurrence of large earthquakes so that the expected frequency of M > 8 earthquakes is about 200 yr. The level of seismicity for smaller earthquakes on Taiwan is about 12 times greater than in Southern California and the possibility of a M ≈ 9 earthquake north or south of Taiwan cannot be ruled out. In light of the Fukushima, Japan nuclear disaster, we also discuss the implications of our study for the three operating nuclear power plants on the coast of Taiwan.

Time-lapse seismic tomography using the data of microseismic monitoring network and analysis of mine-induced events, seismic tomography results and technological data in Pyhäsalmi mine, Finland

NASA Astrophysics Data System (ADS)

Nevalainen, Jouni; Kozlovskaya, Elena

2016-04-01

We present results of a seismic travel-time tomography applied to microseismic data from the Pyhäsalmi mine, Finland. The data about microseismic events in the mine is recorded since 2002 when the passive microseismic monitoring network was installed in the mine. Since that over 130000 microseismic events have been observed. The first target of our study was to test can the passive microseismic monitoring data be used with travel-time tomography. In this data set the source-receiver geometry is based on non-even distribution of natural and mine-induced events inside and in the vicinity of the mine and hence, is a non-ideal one for the travel-time tomography. The tomographic inversion procedure was tested with the synthetic data and real source-receiver geometry from Pyhäsalmi mine and with the real travel-time data of the first arrivals of P-waves from the microseismic events. The results showed that seismic tomography is capable to reveal differences in seismic velocities in the mine area corresponding to different rock types. For example, the velocity contrast between the ore body and surrounding rock is detectable. The velocity model recovered agrees well with the known geological structures in the mine area. The second target of the study was to apply the travel-time tomography to microseismic monitoring data recorded during different time periods in order to track temporal changes in seismic velocities within the mining area as the excavation proceeds. The result shows that such a time-lapse travel-time tomography can recover such changes. In order to obtain good ray coverage and good resolution, the time interval for a single tomography round need to be selected taking into account the number of events and their spatial distribution. The third target was to compare and analyze mine-induced event locations, seismic tomography results and mining technological data (for example, mine excavation plans) in order to understand the influence of mining technology

Hanford Site National Environmental Policy Act (NEPA) Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cushing, C.E.

1992-12-01

This fifth revision of the Hanford Site National Environmental Policy (NEPA) Characterization presents current environmental data regarding the Hanford Site and its immediate environs. This information is intended for use in preparing Site-related NEPA documentation. Information is presented on climate and meteorology, geology and hydrology, ecology, history and archaeology, socioeconomics, land use, and noise levels, prepared by Pacific Northwest Laboratory (PNL) staff. Models are described that are to be used in simulating realized or potential impacts from nuclear materials at the Hanford Site. Included are models of radionuclide transport in groundwater and atmospheric pathways, and of radiation dose to populationsmore » via all known pathways from known initial conditions. Federal and state regulations, DOE orders and permits, and environmental standards directly applicable for the NEPA documents at the Hanford Site, are provided.« less

Newberry EGS Seismic Velocity Model

DOE Data Explorer

Templeton, Dennise

2013-10-01

We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

Estimation of seismic quality factor: Artificial neural networks and current approaches

NASA Astrophysics Data System (ADS)

Yıldırım, Eray; Saatçılar, Ruhi; Ergintav, Semih

2017-01-01

The aims of this study are to estimate soil attenuation using alternatives to traditional methods, to compare results of using these methods, and to examine soil properties using the estimated results. The performances of all methods, amplitude decay, spectral ratio, Wiener filter, and artificial neural network (ANN) methods, are examined on field and synthetic data with noise and without noise. High-resolution seismic reflection field data from Yeniköy (Arnavutköy, İstanbul) was used as field data, and 424 estimations of Q values were made for each method (1,696 total). While statistical tests on synthetic and field data are quite close to the Q value estimation results of ANN, Wiener filter, and spectral ratio methods, the amplitude decay methods showed a higher estimation error. According to previous geological and geophysical studies in this area, the soil is water-saturated, quite weak, consisting of clay and sandy units, and, because of current and past landslides in the study area and its vicinity, researchers reported heterogeneity in the soil. Under the same physical conditions, Q value calculated on field data can be expected to be 7.9 and 13.6. ANN models with various structures, training algorithm, input, and number of neurons are investigated. A total of 480 ANN models were generated consisting of 60 models for noise-free synthetic data, 360 models for different noise content synthetic data and 60 models to apply to the data collected in the field. The models were tested to determine the most appropriate structure and training algorithm. In the final ANN, the input vectors consisted of the difference of the width, energy, and distance of seismic traces, and the output was Q value. Success rate of both ANN methods with noise-free and noisy synthetic data were higher than the other three methods. Also according to the statistical tests on estimated Q value from field data, the method showed results that are more suitable. The Q value can be estimated

Hanford Site Environmental Report for Calendar Year 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poston, Ted M.; Duncan, Joanne P.; Dirkes, Roger L.

The Hanford Site environmental report is prepared annually for the U.S. Department of Energy (DOE) in accordance with regulatory requirements. The report provides an overview of activities at the Hanford Site; demonstrates the status of the site’s compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and DOE policies and directives; and summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Some historical and early 2009 information is included where appropriate.

Hanford Site Environmental Report for Calendar Year 2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poston, Ted M.; Duncan, Joanne P.; Dirkes, Roger L.

The Hanford Site environmental report is prepared annually for the U.S. Department of Energy (DOE) in accordance with regulatory requirements. The report provides an overview of activities at the Hanford Site; demonstrates the status of the site’s compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and DOE policies and directives; and summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Some historical and early 2010 information is included where appropriate.

Hanford Site Environmental Report for Calendar Year 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poston, Ted M.; Duncan, Joanne P.; Dirkes, Roger L.

The Hanford Site environmental report is prepared annually for the U.S. Department of Energy (DOE) in accordance with regulatory requirements. The report provides an overview of activities at the Hanford Site; demonstrates the status of the site's compliance with applicable federal, state, and local environmental laws and regulations, executive orders, and DOE policies and directives; and summarizes environmental data that characterize Hanford Site environmental management performance. The report also highlights significant environmental and public protection programs and efforts. Some historical and early 2011 information is included where appropriate.

Seismic-monitoring changes and the remote deployment of seismic stations (seismic spider) at Mount St. Helens, 2004-2005: Chapter 7 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

McChesney, Patrick J.; Couchman, Marvin R.; Moran, Seth C.; Lockhart, Andrew B.; Swinford, Kelly J.; LaHusen, Richard G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

The instruments in place at the start of volcanic unrest at Mount St. Helens in 2004 were inadequate to record the large earthquakes and monitor the explosions that occurred as the eruption developed. To remedy this, new instruments were deployed and the short-period seismic network was modified. A new method of establishing near-field seismic monitoring was developed, using remote deployment by helicopter. The remotely deployed seismic sensor was a piezoelectric accelerometer mounted on a surface-coupled platform. Remote deployment enabled placement of stations within 250 m of the active vent.

Seismic source parameters of the induced seismicity at The Geysers geothermal area, California, by a generalized inversion approach

NASA Astrophysics Data System (ADS)

Picozzi, Matteo; Oth, Adrien; Parolai, Stefano; Bindi, Dino; De Landro, Grazia; Amoroso, Ortensia

2017-04-01

The accurate determination of stress drop, seismic efficiency and how source parameters scale with earthquake size is an important for seismic hazard assessment of induced seismicity. We propose an improved non-parametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for the attenuation and site contributions. Then, the retrieved source spectra are inverted by a non-linear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (ML 2-4.5) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations of the Lawrence Berkeley National Laboratory Geysers/Calpine surface seismic network, more than 17.000 velocity records). We find for most of the events a non-selfsimilar behavior, empirical source spectra that requires ωγ source model with γ > 2 to be well fitted and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes, and that the proportion of high frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with the earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that, in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping fault in the fluid pressure diffusion.

Hanford Site National Environmental Policy Act (NEPA) Characterization Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neitzel, Duane A.; Bunn, Amoret L.; Cannon, Sandra D.

2004-09-22

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the sixteenth revision of the original document published in 1988 and is (until replaced by the seventeenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, andmore » Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety and health, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.« less

Gas Reservoir Identification Basing on Deep Learning of Seismic-print Characteristics

NASA Astrophysics Data System (ADS)

Cao, J.; Wu, S.; He, X.

2016-12-01

Reservoir identification based on seismic data analysis is the core task in oil and gas geophysical exploration. The essence of reservoir identification is to identify the properties of rock pore fluid. We developed a novel gas reservoir identification method named seismic-print analysis by imitation of the vocal-print analysis techniques in speaker identification. The term "seismic-print" is referred to the characteristics of the seismic waveform which can identify determinedly the property of the geological objectives, for instance, a nature gas reservoir. Seismic-print can be characterized by one or a few parameters named as seismic-print parameters. It has been proven that gas reservoirs are of characteristics of negative 1-order cepstrum coefficient anomaly and Positive 2-order cepstrum coefficient anomaly, concurrently. The method is valid for sandstone gas reservoir, carbonate reservoir and shale gas reservoirs, and the accuracy rate may reach up to 90%. There are two main problems to deal with in the application of seismic-print analysis method. One is to identify the "ripple" of a reservoir on the seismogram, and another is to construct the mapping relationship between the seismic-print and the gas reservoirs. Deep learning developed in recent years is of the ability to reveal the complex non-linear relationship between the attribute and the data, and of ability to extract automatically the features of the objective from the data. Thus, deep learning could been used to deal with these two problems. There are lots of algorithms to carry out deep learning. The algorithms can be roughly divided into two categories: Belief Networks Network (DBNs) and Convolutional Neural Network (CNN). DBNs is a probabilistic generative model, which can establish a joint distribution of the observed data and tags. CNN is a feedforward neural network, which can be used to extract the 2D structure feature of the input data. Both DBNs and CNN can be used to deal with seismic data

Automated seismic detection of landslides at regional scales: a Random Forest based detection algorithm

NASA Astrophysics Data System (ADS)

Hibert, C.; Michéa, D.; Provost, F.; Malet, J. P.; Geertsema, M.

2017-12-01

Detection of landslide occurrences and measurement of their dynamics properties during run-out is a high research priority but a logistical and technical challenge. Seismology has started to help in several important ways. Taking advantage of the densification of global, regional and local networks of broadband seismic stations, recent advances now permit the seismic detection and location of landslides in near-real-time. This seismic detection could potentially greatly increase the spatio-temporal resolution at which we study landslides triggering, which is critical to better understand the influence of external forcings such as rainfalls and earthquakes. However, detecting automatically seismic signals generated by landslides still represents a challenge, especially for events with small mass. The low signal-to-noise ratio classically observed for landslide-generated seismic signals and the difficulty to discriminate these signals from those generated by regional earthquakes or anthropogenic and natural noises are some of the obstacles that have to be circumvented. We present a new method for automatically constructing instrumental landslide catalogues from continuous seismic data. We developed a robust and versatile solution, which can be implemented in any context where a seismic detection of landslides or other mass movements is relevant. The method is based on a spectral detection of the seismic signals and the identification of the sources with a Random Forest machine learning algorithm. The spectral detection allows detecting signals with low signal-to-noise ratio, while the Random Forest algorithm achieve a high rate of positive identification of the seismic signals generated by landslides and other seismic sources. The processing chain is implemented to work in a High Performance Computers centre which permits to explore years of continuous seismic data rapidly. We present here the preliminary results of the application of this processing chain for years

National Earthquake Information Center Seismic Event Detections on Multiple Scales

NASA Astrophysics Data System (ADS)

Patton, J.; Yeck, W. L.; Benz, H.; Earle, P. S.; Soto-Cordero, L.; Johnson, C. E.

2017-12-01

The U.S. Geological Survey National Earthquake Information Center (NEIC) monitors seismicity on local, regional, and global scales using automatic picks from more than 2,000 near-real time seismic stations. This presents unique challenges in automated event detection due to the high variability in data quality, network geometries and density, and distance-dependent variability in observed seismic signals. To lower the overall detection threshold while minimizing false detection rates, NEIC has begun to test the incorporation of new detection and picking algorithms, including multiband (Lomax et al., 2012) and kurtosis (Baillard et al., 2014) pickers, and a new bayesian associator (Glass 3.0). The Glass 3.0 associator allows for simultaneous processing of variably scaled detection grids, each with a unique set of nucleation criteria (e.g., nucleation threshold, minimum associated picks, nucleation phases) to meet specific monitoring goals. We test the efficacy of these new tools on event detection in networks of various scales and geometries, compare our results with previous catalogs, and discuss lessons learned. For example, we find that on local and regional scales, rapid nucleation of small events may require event nucleation with both P and higher-amplitude secondary phases (e.g., S or Lg). We provide examples of the implementation of a scale-independent associator for an induced seismicity sequence (local-scale), a large aftershock sequence (regional-scale), and for monitoring global seismicity. Baillard, C., Crawford, W. C., Ballu, V., Hibert, C., & Mangeney, A. (2014). An automatic kurtosis-based P-and S-phase picker designed for local seismic networks. Bulletin of the Seismological Society of America, 104(1), 394-409. Lomax, A., Satriano, C., & Vassallo, M. (2012). Automatic picker developments and optimization: FilterPicker - a robust, broadband picker for real-time seismic monitoring and earthquake early-warning, Seism. Res. Lett. , 83, 531-540, doi: 10

LONG-TERM STEWARDSHIP AT DOE HANFORD SITE - 12575

DOE Office of Scientific and Technical Information (OSTI.GOV)

MOREN RJ; GRINDSTAFF KD

2012-01-11

The U.S. Department of Energy's (DOE) Hanford Site is located in southeast Washington and consists of 1,518 square kilometers (586 square miles) of land. Established in 1943 as part of the Manhattan Project, Hanford workers produced plutonium for our nation's nuclear defense program until the mid 1980's. Since then, the site has been in cleanup mode that is being accomplished in phases. As we achieve remedial objectives and complete active cleanup, DOE will manage Hanford land under the Long-Term Stewardship (LTS) Program until completion of cleanup and the site becomes ready for transfer to the post cleanup landlord - currentlymore » planned for DOE's Office of Legacy Management (LM). We define Hanford's LTS Program in the ''Hanford Long-Term Stewardship Program Plan,'' (DOE/RL-201 0-35)[1], which describes the scope including the relationship between the cleanup projects and the LTS Program. DOE designed the LTS Program to manage and provide surveillance and maintenance (S&M) of institutional controls and associated monitoring of closed waste sites to ensure the protection of human health and the environment. DOE's Richland Operations Office (DOE-RL) and Hanford cleanup and operations contractors collaboratively developed this program over several years. The program's scope also includes 15 key activities that are identified in the DOE Program Plan (DOE/RL-2010-35). The LTS Program will transition 14 land segments through 2016. The combined land mass is approximately 570 square kilometers (220 square miles), with over 1,300 active and inactive waste sites and 3,363 wells. Land segments vary from buffer zone property with no known contamination to cocooned reactor buildings, demolished support facilities, and remediated cribs and trenches. DOE-RL will transition land management responsibilities from cleanup contractors to the Mission Support Contract (MSC), who will then administer the LTS Program for DOE-RL. This process requires an environment of cooperation

Based on records of Three Gorge Telemetric Seismic Network to analyze Vibration process of micro fracture of rock landslide

NASA Astrophysics Data System (ADS)

WANG, Q.

2017-12-01

Used the finite element analysis software GeoStudio to establish vibration analysis model of Qianjiangping landslide, which locates at the Three Gorges Reservoir area. In QUAKE/W module, we chosen proper Dynamic elasticity modulus and Poisson's ratio of soil layer and rock stratum. When loading, we selected the waveform data record of Three Gorge Telemetric Seismic Network as input ground motion, which includes five rupture events recorded of Lujiashan seismic station. In dynamic simulating, we mainly focused on sliding process when the earthquake date record was applied. The simulation result shows that Qianjiangping landslide wasn't not only affected by its own static force, but also experienced the dynamic process of micro fracture-creep-slip rupture-creep-slip.it provides a new approach for the early warning feasibility of rock landslide in future research.

Post-seismic velocity changes following the 2010 Mw 7.1 Darfield earthquake, New Zealand, revealed by ambient seismic field analysis

NASA Astrophysics Data System (ADS)

Heckels, R. EG; Savage, M. K.; Townend, J.

2018-05-01

Quantifying seismic velocity changes following large earthquakes can provide insights into fault healing and reloading processes. This study presents temporal velocity changes detected following the 2010 September Mw 7.1 Darfield event in Canterbury, New Zealand. We use continuous waveform data from several temporary seismic networks lying on and surrounding the Greendale Fault, with a maximum interstation distance of 156 km. Nine-component, day-long Green's functions were computed for frequencies between 0.1 and 1.0 Hz for continuous seismic records from immediately after the 2010 September 04 earthquake until 2011 January 10. Using the moving-window cross-spectral method, seismic velocity changes were calculated. Over the study period, an increase in seismic velocity of 0.14 ± 0.04 per cent was determined near the Greendale Fault, providing a new constraint on post-seismic relaxation rates in the region. A depth analysis further showed that velocity changes were confined to the uppermost 5 km of the subsurface. We attribute the observed changes to post-seismic relaxation via crack healing of the Greendale Fault and throughout the surrounding region.

Central Plateau Cleanup at DOE's Hanford Site - 12504

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dowell, Jonathan

The discussion of Hanford's Central Plateau includes significant work in and around the center of the Hanford Site - located about 7 miles from the Columbia River. The Central Plateau is the area to which operations will be shrunk in 2015 when River Corridor cleanup is complete. This work includes retrieval and disposal of buried waste from miles of trenches; the cleanup and closure of massive processing canyons; the clean-out and demolition to 'slab on grade' of the high-hazard Plutonium Finishing Plant; installation of key groundwater treatment facilities to contain and shrink plumes of contaminated groundwater; demolition of all othermore » unneeded facilities; and the completion of decisions about remaining Central Plateau waste sites. A stated goal of EM has been to shrink the footprint of active cleanup to less than 10 square miles by 2020. By the end of FY2011, Hanford will have reduced the active footprint of cleanup by 64 percent exceeding the goal of 49 percent. By 2015, Hanford will reduce the active footprint of cleanup by more than 90 percent. The remaining footprint reduction will occur between 2015 and 2020. The Central Plateau is a 75-square-mile region near the center of the Hanford Site including the area designated in the Hanford Comprehensive Land Use Plan Environmental Impact Statement (DOE 1999) and Record of Decision (64 FR 61615) as the Industrial-Exclusive Area, a rectangular area of about 20 square miles in the center of the Central Plateau. The Industrial-Exclusive Area contains the 200 East and 200 West Areas that have been used primarily for Hanford's nuclear fuel processing and waste management and disposal activities. The Central Plateau also encompasses the 200 Area CERCLA National Priorities List site. The Central Plateau has a large physical inventory of chemical processing and support facilities, tank systems, liquid and solid waste disposal and storage facilities, utility systems, administrative facilities, and groundwater

Hanford analytical sample projections FY 1998--FY 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joyce, S.M.

1998-02-12

Analytical Services projections are compiled for the Hanford site based on inputs from the major programs for the years 1998 through 2002. Projections are categorized by radiation level, protocol, sample matrix and program. Analyses requirements are also presented. This document summarizes the Hanford sample projections for fiscal years 1998 to 2002. Sample projections are based on inputs submitted to Analytical Services covering Environmental Restoration, Tank Waste Remediation Systems (TWRS), Solid Waste, Liquid Effluents, Spent Nuclear Fuels, Transition Projects, Site Monitoring, Industrial Hygiene, Analytical Services and miscellaneous Hanford support activities. In addition, details on laboratory scale technology (development) work, Sample Management,more » and Data Management activities are included. This information will be used by Hanford Analytical Services (HAS) and the Sample Management Working Group (SMWG) to assure that laboratories and resources are available and effectively utilized to meet these documented needs.« less

Reprocessing Seismic Data - Using Wits Seismic Exploration Data to Image the Karoo Basin

NASA Astrophysics Data System (ADS)

Webb, S. J.; Scheiber-Enslin, S. E.; Manzi, M. S.

2016-12-01

During the heyday of seismic exploration of the Witwatersrand Basin, Anglo American's Gold Division acquired several thousand kilometres of Vibroseis reflection seismic data. These data, acquired from 1983-1994, were collected with the goal of finding extensions to the Witwatersrand Basin. In a prescient move, over 500 line kilometres were collected at 16 s two way travel time (TWT), extending to depths of 50 -70 km and have provided critical insight into the formation of the Kaapvaal Craton. In addition to these deep seismic lines, Anglo American acquired an extensive network of heretofore unpublished seismic lines that were collected at 6 sec TWT extending well beyond the known limits of the Witwatersrand Basin. The South African government as part of the national geophysical program in the late 1980s acquired six research reflection seismic lines in varied geological settings accruing another 700 km of data. Many of these data are now hosted at the University of the Witwatersrand's newly established Seismic Research Centre and represent unprecedented coverage and research opportunities. With recent global interest in shale gas, attention focused on the Karoo Basin in South Africa. Early exploration seismic data acquired by Soekor in the 1970s has been lost; however, digitized paper records indicate clear reflection targets. Here we examine one of the AngloGold seismic lines that was acquired in the middle of the Karoo Basin just south of Trompsburg extending to the southeast towards Molteno. This 150 km long line crosses the edge of the Kaapvaal Craton and shows clear reflectors throughout the Karoo Basin. These include the well-defined base of the Karoo and a number of dolerite sills within it. Nearby gas escape structures have been identified on surface and it is likely that several disruptions along this line are related to these or to dykes associated with the sills.

Observations and modeling of seismic background noise

USGS Publications Warehouse

Peterson, Jon R.

1993-01-01

The preparation of this report had two purposes. One was to present a catalog of seismic background noise spectra obtained from a worldwide network of seismograph stations. The other purpose was to refine and document models of seismic background noise that have been in use for several years. The second objective was, in fact, the principal reason that this study was initiated and influenced the procedures used in collecting and processing the data.With a single exception, all of the data used in this study were extracted from the digital data archive at the U.S. Geological Survey's Albuquerque Seismological Laboratory (ASL). This archive dates from 1972 when ASL first began deploying digital seismograph systems and collecting and distributing digital data under the sponsorship of the Defense Advanced Research Projects Agency (DARPA). There have been many changes and additions to the global seismograph networks during the past twenty years, but perhaps none as significant as the current deployment of very broadband seismographs by the U.S. Geological Survey (USGS) and the University of California San Diego (UCSD) under the scientific direction of the IRIS consortium. The new data acquisition systems have extended the bandwidth and resolution of seismic recording, and they utilize high-density recording media that permit the continuous recording of broadband data. The data improvements and continuous recording greatly benefit and simplify surveys of seismic background noise.Although there are many other sources of digital data, the ASL archive data were used almost exclusively because of accessibility and because the data systems and their calibration are well documented for the most part. Fortunately, the ASL archive contains high-quality data from other stations in addition to those deployed by the USGS. Included are data from UCSD IRIS/IDA stations, the Regional Seismic Test Network (RSTN) deployed by Sandia National Laboratories (SNL), and the TERRAscope network

Multi-Use seismic stations offer strong deterrent to clandestine nuclear weapons testing

NASA Astrophysics Data System (ADS)

Hennet, C. B.; Van der Vink, G. E.; Richards, P. G.; Adushkin, V. V.; Kopnichev, Y. F.; Geary, R.

As the United States and other nations push for the signing of a Comprehensive Test Ban Treaty, representatives are meeting in Geneva this year to develop an International Seismic Monitoring System to verify compliance with the treaty's restrictions. In addition to the official monitoring system, regional networks developed for earthquake studies and basic research can provide a strong deterrent against clandestine testing. The recent release of information by the U.S. Department of Energy (DoE) on previously unannounced nuclear tests provides an opportunity to assess the ability of multi-use seismic networks to help monitor nuclear testing across the globe.Here we look at the extent to which the formerly unannounced tests were recorded and identified on the basis of publicly available seismographic data recorded by five seismic networks. The data were recorded by networks in southern Nevada and northern California at stations less than 1500 km from the Nevada Test Site (NTS), and two networks in the former Soviet Union at stations farther than 1500 km from the NTS.

Small aperture seismic arrays for studying planetary interiors and seismicity

NASA Astrophysics Data System (ADS)

Schmerr, N. C.; Lekic, V.; Fouch, M. J.; Panning, M. P.; Siegler, M.; Weber, R. C.

2017-12-01

Seismic arrays are a powerful tool for understanding the interior structure and seismicity across objects in the Solar System. Given the operational constraints of ground-based lander investigations, a small aperture seismic array can provide many of the benefits of a larger-scale network, but does not necessitate a global deployment of instrumentation. Here we define a small aperture array as a deployment of multiple seismometers, with a separation between instruments of 1-1000 meters. For example, small aperture seismic arrays have been deployed on the Moon during the Apollo program, the Active Seismic Experiments of Apollo 14 and 16, and the Lunar Seismic Profiling Experiment deployed by the Apollo 17 astronauts. Both were high frequency geophone arrays with spacing of 50 meters that provided information on the layering and velocity structure of the uppermost kilometer of the lunar crust. Ideally such arrays would consist of instruments that are 3-axis short period or broadband seismometers. The instruments must have a sampling rate and frequency range sensitivity capable of distinguishing between waves arriving at each station in the array. Both terrestrial analogs and the data retrieved from the Apollo arrays demonstrate the efficacy of this approach. Future opportunities exist for deployment of seismic arrays on Europa, asteroids, and other objects throughout the Solar System. Here we will present both observational data and 3-D synthetic modeling results that reveal the sensing requirements and the primary advantages of a small aperture seismic array over single station approach. For example, at the smallest apertures of < 1 m, we constrain that sampling rates must exceed 500 Hz and instrument sensitivity must extend to 100 Hz or greater. Such advantages include the improved ability to resolve the location of the sources near the array through detection of backazimuth and differential timing between stations, determination of the small-scale structure

Seismic properties of fluid bearing formations in magmatic geothermal systems: can we directly detect geothermal activity with seismic methods?

NASA Astrophysics Data System (ADS)

Grab, Melchior; Scott, Samuel; Quintal, Beatriz; Caspari, Eva; Maurer, Hansruedi; Greenhalgh, Stewart

2016-04-01

Seismic methods are amongst the most common techniques to explore the earth's subsurface. Seismic properties such as velocities, impedance contrasts and attenuation enable the characterization of the rocks in a geothermal system. The most important goal of geothermal exploration, however, is to describe the enthalpy state of the pore fluids, which act as the main transport medium for the geothermal heat, and to detect permeable structures such as fracture networks, which control the movement of these pore fluids in the subsurface. Since the quantities measured with seismic methods are only indirectly related with the fluid state and the rock permeability, the interpretation of seismic datasets is difficult and usually delivers ambiguous results. To help overcome this problem, we use a numerical modeling tool that quantifies the seismic properties of fractured rock formations that are typically found in magmatic geothermal systems. We incorporate the physics of the pore fluids, ranging from the liquid to the boiling and ultimately vapor state. Furthermore, we consider the hydromechanics of permeable structures at different scales from small cooling joints to large caldera faults as are known to be present in volcanic systems. Our modeling techniques simulate oscillatory compressibility and shear tests and yield the P- and S-wave velocities and attenuation factors of fluid saturated fractured rock volumes. To apply this modeling technique to realistic scenarios, numerous input parameters need to be indentified. The properties of the rock matrix and individual fractures were derived from extensive literature research including a large number of laboratory-based studies. The geometries of fracture networks were provided by structural geologists from their published studies of outcrops. Finally, the physical properties of the pore fluid, ranging from those at ambient pressures and temperatures up to the supercritical conditions, were taken from the fluid physics

Spots of Seismic Danger Extracted by Properties of Low-Frequency Seismic Noise

NASA Astrophysics Data System (ADS)

Lyubushin, Alexey

2013-04-01

A new method of seismic danger estimate is presented which is based on using properties of low-frequency seismic noise from broadband networks. Two statistics of noise waveforms are considered: multi-fractal singularity spectrum support width D and minimum normalized entropy En of squared orthogonal wavelet coefficients. The maps of D and En are plotted in the moving time window. Let us call the regions extracted by low values of D and high values of En as "spots of seismic danger" - SSD. Mean values of D and En are strongly anti-correlated - that is why statistics D and En extract the same SSD. Nevertheless their mutual considering is expedient because these parameters are based on different approaches. The physical mechanism which underlies the method is consolidation of small blocks of the Earth's crust into the large one before the strong earthquake. This effect has a consequence that seismic noise does not include spikes which are connected with mutual movements of small blocks. The absence of irregular spikes in the noise follows the decreasing of D and increasing of entropy En. The stability in space and size of the SSD provides estimates of the place and energy of the probable future earthquake. The increasing or decreasing of SSD size and minimum or maximum values of D and En within SSD allows estimate the trend of seismic danger. The method is illustrating by the analysis of seismic noise from broadband seismic network F-net in Japan [1-5]. Statistically significant decreasing of D allowed a hypothesis about approaching Japan to a future seismic catastrophe to be formulated at the middle of 2008. The peculiarities of correlation coefficient estimate within 1 year time window between median values of D and generalized Hurst exponent allowed to make a decision that starting from July of 2010 Japan come to the state of waiting strong earthquake [3]. The method extracted a huge SSD near Japan which includes the region of future Tohoku mega-earthquake and the

3D seismic detection of shallow faults and fluid migration pathways offshore Southern Costa Rica: Application of neural-network meta-attributes

NASA Astrophysics Data System (ADS)

Kluesner, J. W.; Silver, E. A.; Nale, S. M.; Bangs, N. L.; McIntosh, K. D.

2013-12-01

We employ a seismic meta-attribute workflow to detect and analyze probable faults and fluid-pathways in 3D within the sedimentary section offshore Southern Costa Rica. During the CRISP seismic survey in 2011 we collected an 11 x 55 km grid of 3D seismic reflection data and high-resolvability EM122 multibeam data, with coverage extending from the incoming plate to the outer-shelf. We mapped numerous seafloor seep indicators, with distributions ranging from the lower-slope to ~15 km landward of the shelf break [Kluesner et al., 2013, G3, doi:10.1002/ggge.20058; Silver et al., this meeting]. We used the OpendTect software package to calculate meta-attribute volumes from the 3D seismic data in order to detect and visualize seismic discontinuities in 3D. This methodology consists of dip-steered filtering to pre-condition the data, followed by combining a set of advanced dip-steered seismic attributes into a single object probability attribute using a user-trained neural-network pattern-recognition algorithm. The parameters of the advanced seismic attributes are set for optimal detection of the desired geologic discontinuity (e.g. faults or fluid-pathways). The product is a measure of probability for the desired target that ranges between 0 and 1, with 1 representing the highest probability. Within the sedimentary section of the CRISP survey the results indicate focused fluid-migration pathways along dense networks of intersecting normal faults with approximately N-S and E-W trends. This pattern extends from the middle slope to the outer-shelf region. Dense clusters of fluid-migration pathways are located above basement highs and deeply rooted reverse faults [see Bangs et al., this meeting], including a dense zone of fluid-pathways imaged below IODP Site U1413. In addition, fault intersections frequently show an increased signal of fluid-migration and these zones may act as major conduits for fluid-flow through the sedimentary cover. Imaged fluid pathways root into high

Modernization of the USGS Hawaiian Volcano Observatory Seismic Processing Infrastructure

NASA Astrophysics Data System (ADS)

Antolik, L.; Shiro, B.; Friberg, P. A.

2016-12-01

The USGS Hawaiian Volcano Observatory (HVO) operates a Tier 1 Advanced National Seismic System (ANSS) seismic network to monitor, characterize, and report on volcanic and earthquake activity in the State of Hawaii. Upgrades at the observatory since 2009 have improved the digital telemetry network, computing resources, and seismic data processing with the adoption of the ANSS Quake Management System (AQMS) system. HVO aims to build on these efforts by further modernizing its seismic processing infrastructure and strengthen its ability to meet ANSS performance standards. Most notably, this will also allow HVO to support redundant systems, both onsite and offsite, in order to provide better continuity of operation during intermittent power and network outages. We are in the process of implementing a number of upgrades and improvements on HVO's seismic processing infrastructure, including: 1) Virtualization of AQMS physical servers; 2) Migration of server operating systems from Solaris to Linux; 3) Consolidation of AQMS real-time and post-processing services to a single server; 4) Upgrading database from Oracle 10 to Oracle 12; and 5) Upgrading to the latest Earthworm and AQMS software. These improvements will make server administration more efficient, minimize hardware resources required by AQMS, simplify the Oracle replication setup, and provide better integration with HVO's existing state of health monitoring tools and backup system. Ultimately, it will provide HVO with the latest and most secure software available while making the software easier to deploy and support.

Disposal of Radioactive Waste at Hanford Creates Problems

ERIC Educational Resources Information Center

Chemical and Engineering News, 1978

1978-01-01

Radioactive storage tanks at the Hanford facility have developed leaks. The situation is presently considered safe, but serious. A report from the National Academy of Science has recommended that the wastes be converted to stable solids and stored at another site on the Hanford Reservation. (Author/MA)

Hawaiian Volcano Observatory seismic data, January to December 2005

USGS Publications Warehouse

Nakata, Jennifer S.

2006-01-01

The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M-1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries will simply be identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered. A report by Klein and Koyanagi (1980) tabulates instrumentation, calibration, and recording history of each seismic station in the network. It is designed as a reference for users of seismograms and phase data and includes and augments the information in the station table in this summary.

Hawaiian Volcano Observatory Seismic Data, January to December 2006

USGS Publications Warehouse

Nakata, Jennifer

2007-01-01

Introduction The Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during the year. The seismic summary is offered without interpretation as a source of preliminary data. It is complete in the sense that most data for events of M>1.5 routinely gathered by the Observatory are included. The HVO summaries have been published in various forms since 1956. Summaries prior to 1974 were issued quarterly, but cost, convenience of preparation and distribution, and the large quantities of data dictated an annual publication beginning with Summary 74 for the year 1974. Summary 86 (the introduction of CUSP at HVO) includes a description of the seismic instrumentation, calibration, and processing used in recent years. Beginning with 2004, summaries are simply identified by the year, rather than Summary number. The present summary includes background information on the seismic network and processing to allow use of the data and to provide an understanding of how they were gathered. A report by Klein and Koyanagi (1980) tabulates instrumentation, calibration, and recording history of each seismic station in the network. It is designed as a reference for users of seismograms and phase data and includes and augments the information in the station table in this summary.

Leaching Characteristics of Hanford Ferrocyanide Wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, Matthew K.; Fiskum, Sandra K.; Peterson, Reid A.

2009-12-21

A series of leach tests were performed on actual Hanford Site tank wastes in support of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The samples were targeted composite slurries of high-level tank waste materials representing major complex, radioactive, tank waste mixtures at the Hanford Site. Using a filtration/leaching apparatus, sample solids were concentrated, caustic leached, and washed under conditions representative of those planned for the Pretreatment Facility in the WTP. Caustic leaching was performed to assess the mobilization of aluminum (as gibbsite, Al[OH]3, and boehmite AlO[OH]), phosphates [PO43-], chromium [Cr3+] and, to a lesser extent, oxalates [C2O42-]). Ferrocyanidemore » waste released the solid phase 137Cs during caustic leaching; this was antithetical to the other Hanford waste types studied. Previous testing on ferrocyanide tank waste focused on the aging of the ferrocyanide salt complex and its thermal compatibilities with nitrites and nitrates. Few studies, however, examined cesium mobilization in the waste. Careful consideration should be given to the pretreatment of ferrocyanide wastes in light of this new observed behavior, given the fact that previous testing on simulants indicates a vastly different cesium mobility in this waste form. The discourse of this work will address the overall ferrocyanide leaching characteristics as well as the behavior of the 137Cs during leaching.« less

Broadband seismic effects from train vibrations

NASA Astrophysics Data System (ADS)

Fuchs, Florian; Bokelmann, Götz

2017-04-01

Seismologists rarely study train induced vibrations which are mainly regarded an unwanted source of noise for classical seismological applications such as earthquake monitoring. A few seismological studies try to utilize train vibrations however as active sources, e.g. for subsurface imaging, but they do not focus on the characteristics of the train signal itself. Most available studies on train induced vibrations take an engineering approach and aim at better understanding the generation and short-distance propagation of train induced vibrations, mainly for mitigation and construction purposes. They mostly rely on numerical simulations and/or short-period or accelerometer recordings obtained directly on the train track or up to few hundred meters away and almost no studies exist with seismic recordings further away from the track. In some of these previous studies sharp and equidistant peaks are present in the vibration spectrum of heavy freight trains, but they do not attempt to explain them. Here we show and analyze various train vibration signals obtained from a set of seismic broadband stations installed in the context of the temporary, large-scale regional seismic network AlpArray. The geometrical restrictions of this seismic network combined with budget and safety considerations resulted in a number of broad-band instruments deployed in the vicinity of busy railway lines. On these stations we observe very characteristic seismic signals associated with different types of trains, typically showing pronounced equidistant spectral lines over a wide frequency range. In this study we analyze the nature of such signals and discuss if they are generated by a source effect or by wave propagation effects in near-surface soil layers.

Crustal Seismic Velocity Models of Texas

NASA Astrophysics Data System (ADS)

Borgfeldt, T.; Walter, J. I.; Frohlich, C.

2016-12-01

Crustal seismic velocity models are used to locate earthquake hypocenters. Typically, one dimensional velocity models are 3 - 8 fixed-thickness layers of varying P and S velocities with depth. On occasion, the layers of the upper crust (0-2 kilometers) are constrained with well log data from nearby wells, when available. Past velocity models used in Texas to locate earthquakes were made with little regard to deeper geologic units because shallow earthquakes with a localized seismic network only require velocity models of the upper crust. A recently funded statewide seismic network, TexNet, will require deeper crustal velocity models. Using data of geologic provinces, tectonics, sonic logs, tomography and receiver function studies, new regional velocity models of the state of Texas will allow researchers to more accurately locate hypocenters of earthquakes. We tested the accuracy of the initial models and then refine the layers of the 1-D regional models by using previously located earthquakes the USArray Transportable Array with earthquake location software. Geologic information will be integrated into a 3D velocity model at 0.5 degreee resolution for the entire state of Texas.

The seismicity related to the southern part of the Kenya Rift

NASA Astrophysics Data System (ADS)

Hollnack, D.; Stangl, R.

1998-04-01

In 1990 the Geology Department of the University of Nairobi started to build up a seismological network for Kenya, which has been operating since 1993. In this paper the actual state of this seismological network is described. Additionally, the first results on the seismic activity in the southern part of Kenya and adjacent areas between October 1993 and August 1996 are presented and are compared with historical data. Out of more than 2000 recorded local earthquakes 435 could be localised within the study area with local magnitudes of up to 5. The distribution of the events shows three areas of prominent seismicity: the Rift Valley between Nakuru and northern Tanzania; the area northeast of Kilimanjaro; and the Nyanza Rift in western Kenya. In a first attempt to assess the seismic hazard for the study area, a seismic energy map for the period of observation is given.

Overview of Hanford Single Shell Tank (SST) Structural Integrity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rast, Richard S.; Washenfelder, Dennis J.; Johnson, Jeremy M.

2013-11-14

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration, Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for themore » Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The structural integrity of the tanks is a key element in completing the cleanup mission at the Hanford Site. There are eight primary recommendations related to the structural integrity of Hanford Single-Shell Tanks. Six recommendations are being implemented through current and planned activities. The structural integrity of the Hanford is being evaluated through analysis, monitoring, inspection, materials testing, and construction document review. Structural evaluation in the form of analysis is performed using modern finite element models generated in ANSYS. The analyses consider in-situ, thermal, operating loads and natural phenomena such as earthquakes. Structural analysis of 108 of 149 Hanford Single-Shell Tanks has concluded that the tanks are structurally sound and meet current industry standards. Analysis of the remaining Hanford Single-Shell Tanks is scheduled for FY2014. Hanford Single-Shell Tanks are monitored through a dome deflection program. The program looks for deflections of the tank dome greater than 1/4 inch. No such deflections have been recorded. The tanks are also subjected to visual inspection. Digital cameras record the interior

Brief communication: Co-seismic displacement on 26 and 30 October 2016 (Mw = 5.9 and 6.5) - earthquakes in central Italy from the analysis of a local GNSS network

NASA Astrophysics Data System (ADS)

De Guidi, Giorgio; Vecchio, Alessia; Brighenti, Fabio; Caputo, Riccardo; Carnemolla, Francesco; Di Pietro, Adriano; Lupo, Marco; Maggini, Massimiliano; Marchese, Salvatore; Messina, Danilo; Monaco, Carmelo; Naso, Salvatore

2017-11-01

On 24 August 2016 a strong earthquake (Mw = 6.0) affected central Italy and an intense seismic sequence started. Field observations, DInSAR (Differential INterferometry Synthetic-Aperture Radar) analyses and preliminary focal mechanisms, as well as the distribution of aftershocks, suggested the reactivation of the northern sector of the Laga fault, the southern part of which was already rebooted during the 2009 L'Aquila sequence, and of the southern segment of the Mt Vettore fault system (MVFS). Based on this preliminary information and following the stress-triggering concept (Stein, 1999; Steacy et al., 2005), we tentatively identified a potential fault zone that is very vulnerable to future seismic events just north of the earlier epicentral area. Accordingly, we planned a local geodetic network consisting of five new GNSS (Global Navigation Satellite System) stations located a few kilometres away from both sides of the MVFS. This network was devoted to working out, at least partially but in some detail, the possible northward propagation of the crustal network ruptures. The building of the stations and a first set of measurements were carried out during a first campaign (30 September and 2 October 2016). On 26 October 2016, immediately north of the epicentral area of the 24 August event, another earthquake (Mw = 5.9) occurred, followed 4 days later (30 October) by the main shock (Mw = 6.5) of the whole 2016 summer-autumn seismic sequence. Our local geodetic network was fully affected by the new events and therefore we performed a second campaign soon after (11-13 November 2016). In this brief note, we provide the results of our geodetic measurements that registered the co-seismic and immediately post-seismic deformation of the two major October shocks, documenting in some detail the surface deformation close to the fault trace. We also compare our results with the available surface deformation field of the broader area, obtained on the basis of the DIn

Seismic sequences in the Sombrero Seismic Zone

NASA Astrophysics Data System (ADS)

Pulliam, J.; Huerfano, V. A.; ten Brink, U.; von Hillebrandt, C.

2007-05-01

The northeastern Caribbean, in the vicinity of Puerto Rico and the Virgin Islands, has a long and well-documented history of devastating earthquakes and tsunamis, including major events in 1670, 1787, 1867, 1916, 1918, and 1943. Recently, seismicity has been concentrated to the north and west of the British Virgin Islands, in the region referred to as the Sombrero Seismic Zone by the Puerto Rico Seismic Network (PRSN). In the combined seismicity catalog maintained by the PRSN, several hundred small to moderate magnitude events can be found in this region prior to 2006. However, beginning in 2006 and continuing to the present, the rate of seismicity in the Sombrero suddenly increased, and a new locus of activity developed to the east of the previous location. Accurate estimates of seismic hazard, and the tsunamigenic potential of seismic events, depend on an accurate and comprehensive understanding of how strain is being accommodated in this corner region. Are faults locked and accumulating strain for release in a major event? Or is strain being released via slip over a diffuse system of faults? A careful analysis of seismicity patterns in the Sombrero region has the potential to both identify faults and modes of failure, provided the aggregation scheme is tuned to properly identify related events. To this end, we experimented with a scheme to identify seismic sequences based on physical and temporal proximity, under the assumptions that (a) events occur on related fault systems as stress is refocused by immediately previous events and (b) such 'stress waves' die out with time, so that two events that occur on the same system within a relatively short time window can be said to have a similar 'trigger' in ways that two nearby events that occurred years apart cannot. Patterns that emerge from the identification, temporal sequence, and refined locations of such sequences of events carry information about stress accommodation that is obscured by large clouds of

Hanford Reach Fall Chinook Redd Monitoring Report for Calendar Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindsey, Cole T.; Nugent, John J.

2014-02-10

The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and track data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE activities. Ecological monitoring data provide baseline information about the plants, animals, and habitat under DOE-RL stewardship at Hanford required for decision-making under the National Environmental Policy Act (NEPA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Hanford Site Comprehensive Land Use Plan (CLUP, DOE/EIS-0222-F) which is the Environmental Impact Statement for Hanford Site activities, helps ensure that DOE-RL, its contractors, and othermore » entities conducting activities on the Hanford Site are in compliance with NEPA.« less

Hanford Site Black-Tailed Jackrabbit Monitoring Report for Fiscal Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lindsey, Cole T.; Nugent, John J.; Wilde, Justin W.

2014-02-13

The U.S. Department of Energy, Richland Operations Office (DOE-RL) conducts ecological monitoring on the Hanford Site to collect and track data needed to ensure compliance with an array of environmental laws, regulations, and policies governing DOE activities. Ecological monitoring data provide baseline information about the plants, animals, and habitat under DOE-RL stewardship at Hanford required for decision-making under the National Environmental Policy Act (NEPA) and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The Hanford Site Comprehensive Land Use Plan (CLUP, DOE/EIS-0222-F) which is the Environmental Impact Statement for Hanford Site activities, helps ensure that DOE-RL, its contractors, and othermore » entities conducting activities on the Hanford Site are in compliance with NEPA.« less

Raptors of the Hanford Site and nearby areas of southcentral Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitzner, R.E.; Rickard, W.H.; Cadwell, L.L.

1981-05-01

This report is concerned with the birds of prey which use the Hanford Site not only during the nesting season but throughout the year. An ecological treatment of five nesting owls (great horned, long-eared, short-eared, barn and burrowing) and five nesting hawks (marsh hawk, red-tailed hawk, Swainson's hawk, prairie falcon and American kestrel) is provided and supportive information on non-nesting species is presented. Factors which control raptor densities and population dynamics throughout all seasons of the year are discussed. Information is also provided for raptors from other areas of southcentral Washington in order to yield a comprehensive picture of howmore » the Hanford Site fits in with regional bird of prey populations. The following were the objectives of this study: (1) to determine the numbers of birds of prey nesting on the Hanford Site, (2) to document the reproductive chronology of each nesting raptor species, (3) to provide analyses of food habits of birds of prey on the Hanford Site coupled with prey abundance data, (4) to determine the productivity of the dominant large birds of prey on the Hanford Site, (5) to determine the distribution and land use patterns of all raptors on the Hanford Site, (6) to determine the kinds and relative abundance of non-nesting raptors on the Hanford Site and adjacent areas of southcentral Washington (7) to document present land use practices on the Hanford Site and their effects on raptors, (8) to document radionuclide levels in birds of prey on the Hanford Site, and (9) to determine the role of birds of prey in radioecological monitoring.« less

A New Design of Seismic Stations Deployed in South Tyrol

NASA Astrophysics Data System (ADS)

Melichar, P.; Horn, N.

2007-05-01

When designing the seismic network in South Tyrol, the seismic service of Austria and the Civil defense in South Tyrol combined more that 10 years experience in running seismic networks and private communication systems. In recent years the high data return rate of > 99% and network uptime of > 99.% is achieved by the combination of high quality station design and equipment, and the use of the Antelope data acquisition and processing software which comes with suite of network monitoring & alerting tools including Nagios, etc. The new Data Center is located in city of Bolzano and is connected to the other Data Centers in Austria, Switzerland, and Italy for data back up purposes. Each Data Center uses also redundant communication system if the primary system fails. When designing the South Tyrol network, new improvements were made in seismometer installations, grounding, lighting protection and data communications in order to improve quality of data recorded as well as network up-time, and data return. The new 12 stations are equipped with 6 Channels Q330+PB14f connected to STS2 + EpiSensor sensor. One of the key achievements was made in the grounding concept for the whole seismic station - and aluminum boxes were introduced which delivered Faraday cage isolation. Lightning protection devices are used for the equipment inside the aluminum housing where seismometer and data logger are housed. For the seismometer cables a special shielding was introduced. The broadband seismometer and strong-motion sensor are placed on a thick glass plate and therefore isolated from the ground. The precise seismometer orientation was done by a special groove on the glass plate and in case of a strong earthquake; the seismometer is tide up to the base plate. Temperature stability was achieved by styrofoam sheets inside the seismometer aluminum protection box.

Neural Models: An Option to Estimate Seismic Parameters of Accelerograms

NASA Astrophysics Data System (ADS)

Alcántara, L.; García, S.; Ovando-Shelley, E.; Macías, M. A.

2014-12-01

Seismic instrumentation for recording strong earthquakes, in Mexico, goes back to the 60´s due the activities carried out by the Institute of Engineering at Universidad Nacional Autónoma de México. However, it was after the big earthquake of September 19, 1985 (M=8.1) when the project of seismic instrumentation assumes a great importance. Currently, strong ground motion networks have been installed for monitoring seismic activity mainly along the Mexican subduction zone and in Mexico City. Nevertheless, there are other major regions and cities that can be affected by strong earthquakes and have not yet begun their seismic instrumentation program or this is still in development.Because of described situation some relevant earthquakes (e.g. Huajuapan de León Oct 24, 1980 M=7.1, Tehuacán Jun 15, 1999 M=7 and Puerto Escondido Sep 30, 1999 M= 7.5) have not been registered properly in some cities, like Puebla and Oaxaca, and that were damaged during those earthquakes. Fortunately, the good maintenance work carried out in the seismic network has permitted the recording of an important number of small events in those cities. So in this research we present a methodology based on the use of neural networks to estimate significant duration and in some cases the response spectra for those seismic events. The neural model developed predicts significant duration in terms of magnitude, epicenter distance, focal depth and soil characterization. Additionally, for response spectra we used a vector of spectral accelerations. For training the model we selected a set of accelerogram records obtained from the small events recorded in the strong motion instruments installed in the cities of Puebla and Oaxaca. The final results show that neural networks as a soft computing tool that use a multi-layer feed-forward architecture provide good estimations of the target parameters and they also have a good predictive capacity to estimate strong ground motion duration and response spectra.

Building Nuclear Communities: The Hanford Education Action League.

ERIC Educational Resources Information Center

Ratliff, Jeanne; Salvador, Michael

Many scholars have examined the jeremiad in American rhetoric and political discourse. The Hanford Education Action League (HEAL), which influenced policy changes in the operations of the Hanford Nuclear Reservation in Washington, is a social movement organization whose founding members used the jeremiad to create a symbolic community which…

South-Central Tibetan Seismicity from HiCLIMB Seismic Array Data

NASA Astrophysics Data System (ADS)

Carpenter, S.; Nabelek, J.; Braunmiller, J.

2010-12-01

The HiCLIMB broadband passive seismic experiment (2002-2005) operated 233 sites along a 800-km long north-south array extending from the Himalayan foreland into the Central Tibetan Plateau and a flanking 350x350 km lateral array in southern Tibet and eastern Nepal. We use data from the experiment’s second phase (June 2004 to August 2005), when stations operated in Tibet, to locate earthquakes in south-central Tibet, a region with no permanent seismic network where little is known about its seismicity. We used the Antelope software for automatic detection and arrival time picking, event-arrival association and event location. Requiring a low detection and event association threshold initially resulted in ~110,000 declared events. The large database size rendered manual inspection unfeasible and we developed automated post-processing modules to weed out spurious detections and erroneous phase and event associations, which stemmed, e.g., from multiple coincident earthquakes within the array or misplaced seismicity from the great 2004 Sumatra earthquake. The resulting database contains ~32,000 events within 5° distance from the closest station. We consider ~7,600 events defined by more than 30 P and S arrivals well located and discuss them here. Seismicity in the subset correlates well with mapped faults and structures seen on satellite imagery attesting to high location quality. This is confirmed by non-systematic, kilometer-scale differences between automatic and manual locations for selected events. Seismicity in south-central Tibet is intense north of the Yarlung-Tsangpo Suture. Almost 90% of events occurred in the Lhasa Terrane mainly along north-south trending rifts. Vigorous activity (>4,800 events) accompanied two M>6 earthquakes in the Payang Basin (84°E), ~100 km west of the linear array. The Tangra-Yum Co (86.5°E) and Pumqu-Xianza (88°E) rifts were very active (~1,000 events) without dominant main shocks indicating swarm like-behavior possibly related

Could the IMS Infrasound Stations Support a Global Network of Small Aperture Seismic Arrays?

NASA Astrophysics Data System (ADS)

J, Gibbons, Steven; Kværna, Tormod; Mykkeltveit, Svein

2015-04-01

The infrasound stations of the International Monitoring System are arrays consisting of up to 15 sites and with apertures of up to 3 km. The arrays are distributed remarkably uniformly over the globe and provide excellent coverage of South America, Africa, and Antarctica. This is to say that there are many infrasound arrays in regions many thousands of kilometers from the closest seismic array. Several infrasound arrays are in the immediate vicinity of existing 3-component seismic stations and these provide us with examples of how typical seismic signals look at these locations. We can make idealized estimates of the predicted performance of seismic arrays, consisting of seismometers at each site of the infrasound arrays, by duplicating the signals from the 3-C stations at all sites of the array. However, the true performance of seismic arrays at these sites will depend both upon Signal-to-Noise Ratios of seismic signals and the coherence of both signal and noise between sensors. These properties can only be determined experimentally. Recording seismic data of sufficient quality at many of these arrays may require borehole deployments since the microbarometers in the infrasound arrays are often situated in vaults placed in soft sediments. The geometries of all the current IMS infrasound arrays are examined and compared and we demonstrate that, from a purely geometrical perspective, essentially all the array configurations would provide seismic arrays with acceptable slowness resolution for both regional and teleseismic phase arrivals. Seismic arrays co-located with the infrasound arrays in many regions would likely enhance significantly the seismic monitoring capability in parts of the world where only 3-component stations are currently available. Co-locating seismic and infrasound sensors would facilitate the development of seismic arrays that share the infrastructure of the infrasound arrays, reducing the development and operational costs. Hosting countries might

Analysis of induced seismicity in geothermal reservoirs – An overview

USGS Publications Warehouse

Zang, Arno; Oye, Volker; Jousset, Philippe; Deichmann, Nicholas; Gritto, Roland; McGarr, Arthur F.; Majer, Ernest; Bruhn, David

2014-01-01

In this overview we report results of analysing induced seismicity in geothermal reservoirs in various tectonic settings within the framework of the European Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs (GEISER) project. In the reconnaissance phase of a field, the subsurface fault mapping, in situ stress and the seismic network are of primary interest in order to help assess the geothermal resource. The hypocentres of the observed seismic events (seismic cloud) are dependent on the design of the installed network, the used velocity model and the applied location technique. During the stimulation phase, the attention is turned to reservoir hydraulics (e.g., fluid pressure, injection volume) and its relation to larger magnitude seismic events, their source characteristics and occurrence in space and time. A change in isotropic components of the full waveform moment tensor is observed for events close to the injection well (tensile character) as compared to events further away from the injection well (shear character). Tensile events coincide with high Gutenberg-Richter b-values and low Brune stress drop values. The stress regime in the reservoir controls the direction of the fracture growth at depth, as indicated by the extent of the seismic cloud detected. Stress magnitudes are important in multiple stimulation of wells, where little or no seismicity is observed until the previous maximum stress level is exceeded (Kaiser Effect). Prior to drilling, obtaining a 3D P-wave (Vp) and S-wave velocity (Vs) model down to reservoir depth is recommended. In the stimulation phase, we recommend to monitor and to locate seismicity with high precision (decametre) in real-time and to perform local 4D tomography for velocity ratio (Vp/Vs). During exploitation, one should use observed and model induced seismicity to forward estimate seismic hazard so that field operators are in a position to adjust well hydraulics (rate and volume of the

High-resolution seismic data regularization and wavefield separation

NASA Astrophysics Data System (ADS)

Cao, Aimin; Stump, Brian; DeShon, Heather

2018-04-01

We present a new algorithm, non-equispaced fast antileakage Fourier transform (NFALFT), for irregularly sampled seismic data regularization. Synthetic tests from 1-D to 5-D show that the algorithm may efficiently remove leaked energy in the frequency wavenumber domain, and its corresponding regularization process is accurate and fast. Taking advantage of the NFALFT algorithm, we suggest a new method (wavefield separation) for the detection of the Earth's inner core shear wave with irregularly distributed seismic arrays or networks. All interfering seismic phases that propagate along the minor arc are removed from the time window around the PKJKP arrival. The NFALFT algorithm is developed for seismic data, but may also be used for other irregularly sampled temporal or spatial data processing.

Characterizing Geological Facies using Seismic Waveform Classification in Sarawak Basin

NASA Astrophysics Data System (ADS)

Zahraa, Afiqah; Zailani, Ahmad; Prasad Ghosh, Deva

2017-10-01

Numerous effort have been made to build relationship between geology and geophysics using different techniques throughout the years. The integration of these two most important data in oil and gas industry can be used to reduce uncertainty in exploration and production especially for reservoir productivity enhancement and stratigraphic identification. This paper is focusing on seismic waveform classification to different classes using neural network and to link them according to the geological facies which are established using the knowledge on lithology and log motif of well data. Seismic inversion is used as the input for the neural network to act as the direct lithology indicator reducing dependency on well calibration. The interpretation of seismic facies classification map provides a better understanding towards the lithology distribution, depositional environment and help to identify significant reservoir rock

Upgrading the seismic and geodetic network of the Popocatépetl volcano (Mexico).

NASA Astrophysics Data System (ADS)

Calò, Marco; Iglesias Mendoza, Arturo; Legrand, Denis; Valdés González, Carlos Miguel; Perez Campos, Xyoli

2017-04-01

The Popocatépetl is one of the most active volcanoes in Mexico and is located only 70 km from Mexico City, populated by more than 20 millions of people, and only 35 km from the Puebla municipality with almost 1.5 millions of people living. The recent activity of the volcano is generally marked by explosions emitting ash plumes often reaching the densely populated regions. In the framework of the Mexican Fund for Prevention of Natural Disasters (FOPREDEN) we are renovating and upgrading the existing geodetic and seismic networks monitoring the volcano. In this project we are installing 10 broadband seismic stations (120s-050Hz) in shallow boreholes (3-5m depth) and 4 GPS with real time sampling rate of 1 Hz. All instruments are equipped with continuous recording systems for real time monitoring purposes and research. The Popocatépetl exceeds 5400m, and the altitude of the stations ranges from 2200 m to 4300 m making it difficult their installation and maintenance. Because of ash emissions and the hard working condition, the real-time transmission is split into two systems in order to ensure the monitoring of the volcano also during the highest expected activity. Therefore we set up a network of "first order", consisting of four stations located about 20 km from the crater and equipped with satellite transmission. These stations, being far enough from the crater, ensure the real time monitoring of the major events also during intense periods of activity of the volcano. The remaining six stations are installed near to the crater (less than 10 km) and take part of the "second order" network equipped with a telemetered radio system transmitting the data either directly to the National Center of Disaster Prevention (CENAPRED) and National Seismological Service (SSN) or to the first order stations (for the sites that have not direct visible line with the monitoring centers). The four GPS sensors are all installed in the second order sites in order to monitor the largest

HANFORD SITE CENTRAL PLATEAU CLEANUP COMPLETION STRATEGY

DOE Office of Scientific and Technical Information (OSTI.GOV)

BERGMAN TB

2011-01-14

Cleanup of the Hanford Site is a complex and challenging undertaking. The U.S. Department of Energy (DOE) has developed a comprehensive vision for completing Hanford's cleanup mission including transition to post-cleanup activities. This vision includes 3 principle components of cleanup: the {approx}200 square miles ofland adjacent to the Columbia River, known as the River Corridor; the 75 square miles of land in the center of the Hanford Site, where the majority of the reprocessing and waste management activities have occurred, known as the Central Plateau; and the stored reprocessing wastes in the Central Plateau, the Tank Wastes. Cleanup of themore » River Corridor is well underway and is progressing towards completion of most cleanup actions by 2015. Tank waste cleanup is progressing on a longer schedule due to the complexity of the mission, with construction of the largest nuclear construction project in the United States, the Waste Treatment Plant, over 50% complete. With the progress on the River Corridor and Tank Waste, it is time to place increased emphasis on moving forward with cleanup of the Central Plateau. Cleanup of the Hanford Site has been proceeding under a framework defmed in the Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement). In early 2009, the DOE, the State of Washington Department of Ecology, and the U.S. Environmental Protection Agency signed an Agreement in Principle in which the parties recognized the need to develop a more comprehensive strategy for cleanup of the Central Plateau. DOE agreed to develop a Central Plateau Cleanup Completion Strategy as a starting point for discussions. This DOE Strategy was the basis for negotiations between the Parties, discussions with the State of Oregon, the Hanford Advisory Board, and other Stakeholder groups (including open public meetings), and consultation with the Tribal Nations. The change packages to incorporate the Central Plateau Cleanup Completion Strategy were

Seismic event classification system

DOEpatents

Dowla, F.U.; Jarpe, S.P.; Maurer, W.

1994-12-13

In the computer interpretation of seismic data, the critical first step is to identify the general class of an unknown event. For example, the classification might be: teleseismic, regional, local, vehicular, or noise. Self-organizing neural networks (SONNs) can be used for classifying such events. Both Kohonen and Adaptive Resonance Theory (ART) SONNs are useful for this purpose. Given the detection of a seismic event and the corresponding signal, computation is made of: the time-frequency distribution, its binary representation, and finally a shift-invariant representation, which is the magnitude of the two-dimensional Fourier transform (2-D FFT) of the binary time-frequency distribution. This pre-processed input is fed into the SONNs. These neural networks are able to group events that look similar. The ART SONN has an advantage in classifying the event because the types of cluster groups do not need to be pre-defined. The results from the SONNs together with an expert seismologist's classification are then used to derive event classification probabilities. 21 figures.

GEODIS: A Portable Ocean Bottom Very Broadband Seismic Station

NASA Astrophysics Data System (ADS)

KARCZEWSKI, J.; MONTAGNER, J.; BEGUERY, L.; STUTZMANN, E.; ROULT, G.; LOGNONNE, P.; CACHO, S.; KOENIG, J.; SAVARY, J.

2001-12-01

The last ten years have seen the simultaneous development of a global seismic network coordinated through the FDSN (Federation of Digital Seismograph Networks) and of portable broadband seismic arrays. The same approach can be followed for improving our scientific understanding of the Earth processes below oceanic areas. Both components of ocean bottom geophysical networks, will be coordinated by ION (international Ocean Network). They are complementary since they enable to investigate the Earth structure and processes at different spatial and temporal scales. Geophysical Ocean bottom observatories (hereafter referred as GOBO) and portable seismic stations are sharing common technological problems. However, the issues of power supply and real-time data transmission are more crucial for a GOBO than for a portable temporary station. Since 1999, our group is developing a new "portable" geophysical ocean bottom autonomous station, named GEODIS. This station might be a basic element for a GOBO. It relies on the use of adapted VBB sensors issued from space experiments and technology and on improved electronics compared with previous ocean bottom experiments (SISMOBS/OFM 1992; MOISE 1997). The main characteristics of GEODIS are the following: - 3 axes VBB seismic sensors with a classical flat velocity response 360-0.2s. at 2500V/m/s (intrinsic noise level smaller than LNM). - Automatic (under software control) installation, levelling, centring of the 3 component seismic sensors. - 24 bit digitiser recording at 20sps, 3 seismic component and 1 infrasonic sensor. - Recording by a 16 bit converter at 1sps of the sea temperature in the vicinity of the instrument and housekeeping parameters (temperature, inclinations, power,...). - 1 year autonomy by using Lithium batteries. - Storage of data on Flash card and recording on hard disk every day. - Weight of GEODIS: 186kg in air and 110kg in water. - Overall dimensions: 930 x 930 x 440 mm. GEODIS can be easily installed by a

Conversion and correction factors for historical measurements of iodine-131 in Hanford-area vegetation, 1945--1947. Hanford Environmental Dose Reconstruction Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mart, E.I.; Denham, D.H.; Thiede, M.E.

1993-12-01

This report is a result of the Hanford Environmental Dose Reconstruction (HEDR) Project whose goal is to estimate the radiation dose that individuals could have received from emissions since 1944 at the U.S. Department of Energy`s (DOE) Hanford Site near Richland, Washington. The HEDR Project is conducted by Battelle, Pacific Northwest Laboratories (BNW). One of the radionuclides emitted that would affect the radiation dose was iodine-131. This report describes in detail the reconstructed conversion and correction factors for historical measurements of iodine-131 in Hanford-area vegetation which was collected from the beginning of October 1945 through the end of December 1947.

Artificial Neural Networks applied to estimate permeability, porosity and intrinsic attenuation using seismic attributes and well-log data

NASA Astrophysics Data System (ADS)

Iturrarán-Viveros, Ursula; Parra, Jorge O.

2014-08-01

Permeability and porosity are two fundamental reservoir properties which relate to the amount of fluid contained in a reservoir and its ability to flow. The intrinsic attenuation is another important parameter since it is related to porosity, permeability, oil and gas saturation and these parameters significantly affect the seismic signature of a reservoir. We apply Artificial Neural Network (ANN) models to predict permeability (k) and porosity (ϕ) for a carbonate aquifer in southeastern Florida and to predict intrinsic attenuation (1/Q) for a sand-shale oil reservoir in northeast Texas. In this study, the Gamma test (a revolutionary estimator of the noise in a data set) has been used as a mathematically non-parametric nonlinear smooth modeling tool to choose the best input combination of seismic attributes to estimate k and ϕ, and the best combination of well-logs to estimate 1/Q. This saves time during the construction and training of ANN models and also sets a lower bound for the mean squared error to prevent over-training. The Neural Network method successfully delineates a highly permeable zone that corresponds to a high water production in the aquifer. The Gamma test found nonlinear relations that were not visible to linear regression allowing us to generalize the ANN estimations of k, ϕ and 1/Q for their respective sets of patterns that were not used during the learning phase.

Seismic Imaging of a Prospective Geothermal Play, Using a Dense Geophone Array

NASA Astrophysics Data System (ADS)

Trow, A.; Pankow, K. L.; Wannamaker, P. E.; Lin, F. C.; Ward, K. M.

2017-12-01

In the summer of 2016 a dense array of 48 Nodal Seismic geophones was deployed near Beaver, Utah on the eastern flank of the Mineral Mountains. The array aperture was approximately 20 kilometers and recorded continuous seismic data for 30 days. Geophones were centered on a previously known shallow (5km depth) magnetolluric (MT) low-resistivity body. This region of low resistivity was interpreted to possibly contain hydrothermal/geothermal fluids and was targeted for further seismic investigation. The seismic array geometry was designed to optimize seismic event detection for small (magnitude of completeness zero) earthquakes and to facilitate seismic imaging at depths of 5 km and deeper. For the duration of the experiment, one ML 1 earthquake was detected underneath the array with 15 other earthquakes detected to the east and south in the more seismically active Pavant Range. Different passive imaging techniques, including ambient noise and earthquake tomography are being explored in order to produce a seismic velocity image. Understanding the subsurface, specifically the fracture network and fluid content of the bedrock is important for characterization of a geothermal prospect. If it is rich in fluids, it can be assumed that some fracture network is in place to accommodate such fluids. Both fractures and fluid content of the prospect will have an effect on the seismic velocities in the basement structure. These properties can help determine the viability of a geothermal system for power production.

Network capability estimation. Vela network evaluation and automatic processing research. Technical report. [NETWORTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snell, N.S.

1976-09-24

NETWORTH is a computer program which calculates the detection and location capability of seismic networks. A modified version of NETWORTH has been developed. This program has been used to evaluate the effect of station 'downtime', the signal amplitude variance, and the station detection threshold upon network detection capability. In this version all parameters may be changed separately for individual stations. The capability of using signal amplitude corrections has been added. The function of amplitude corrections is to remove possible bias in the magnitude estimate due to inhomogeneous signal attenuation. These corrections may be applied to individual stations, individual epicenters, ormore » individual station/epicenter combinations. An option has been added to calculate the effect of station 'downtime' upon network capability. This study indicates that, if capability loss due to detection errors can be minimized, then station detection threshold and station reliability will be the fundamental limits to network performance. A baseline network of thirteen stations has been performed. These stations are as follows: Alaskan Long Period Array, (ALPA); Ankara, (ANK); Chiang Mai, (CHG); Korean Seismic Research Station, (KSRS); Large Aperture Seismic Array, (LASA); Mashhad, (MSH); Mundaring, (MUN); Norwegian Seismic Array, (NORSAR); New Delhi, (NWDEL); Red Knife, Ontario, (RK-ON); Shillong, (SHL); Taipei, (TAP); and White Horse, Yukon, (WH-YK).« less

A high-resolution ambient seismic noise model for Europe

NASA Astrophysics Data System (ADS)

Kraft, Toni

2014-05-01

In the past several years, geological energy technologies receive growing attention and have been initiated in or close to urban areas. Some of these technologies involve injecting fluids into the subsurface (e.g., oil and gas development, waste disposal, and geothermal energy development) and have been found or suspected to cause small to moderate sized earthquakes. These earthquakes, which may have gone unnoticed in the past when they occurred in remote sparsely populated areas, are now posing a considerable risk for the public acceptance of these technologies in urban areas. The permanent termination of the EGS project in Basel, Switzerland after a number of induced ML~3 (minor) earthquakes in 2006 is one prominent example. It is therefore essential to the future development and success of these geological energy technologies to develop strategies for managing induced seismicity and keeping the size of induced earthquake at a level that is acceptable to all stakeholders. Most guidelines and recommendations on induced seismicity published since the 1970ies conclude that an indispensable component of such a strategy is the establishment of seismic monitoring in an early stage of a project. This is because an appropriate seismic monitoring is the only way to detect and locate induced microearthquakes with sufficient certainty to develop an understanding of the seismic and geomechanical response of the reservoir to the geotechnical operation. In addition, seismic monitoring lays the foundation for the establishment of advanced traffic light systems and is therefore an important confidence building measure towards the local population and authorities. Due to this development an increasing number of seismic monitoring networks are being installed in densely populated areas with strongly heterogeneous, and unfavorable ambient noise conditions. This poses a major challenge on the network design process, which aims to find the sensor geometry that optimizes the

Hanford Site National Environmental Policy Act (NEPA) Characterization, Revision 15

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neitzel, Duane A.; Bunn, Amoret L.; Burk, Kenneth W.

2003-09-01

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, andmore » Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.« less

Definition of a unique model for the improvement of the monitoring network and seismic risk reduction of the school buildings in Italy

NASA Astrophysics Data System (ADS)

Greco, M.; Console, R.; Colangelo, A.; Cioè, A.; Trivigno, L.

2015-12-01

In the latest decade the safety of the Italian schools against seismic risk is a crucial subject for the Italian legislation as well as to the UN Convention on the DRR and the more specific priorities adopted even within the OECD. Recently, the Italian Parliament approved a law (L98/2013) which launched the Commissioning Safety of School Buildings Plan and the Definition of a Unique Model, to be developed by the CGIAM, in order to improve monitoring network and seismic risk reduction (SRR). The objectives of such a law deals with increasing in the knowledge of public actions aimed to improve the effectiveness of the SRR policy on school buildings. The actions of the CGIAM will consist in the identification of a significant number of school buildings in Italy, mainly in terms of type of construction and material, on which calibrate specific synthetic parameters and test models. Furthermore, the activities are addressed to quantitatively evaluation of intervention efficacy, to set up simple systems of instrumental monitoring, even able to test the possibility of periodical checks of the state of general preservation. The main issues carried on by the CGIAM mainly concern the completion and enrichment of the existing data base of school buildings, even through the collaboration of the Ministries and other relevant Italian research institutions, the evaluation of seismic hazard and site condition analysis as well as the definition of other seismic risk factors. Nevertheless a cost-benefit analysis as well as application and dissemination of such tools are proposed too. At the same time, the CGIAM contributes to the definition of experimental installation and use of a Simplified Accelerometric Monitoring Network for school buildings comprehensive of testing phase on a limited number of structures. The work proposes a synthetic overview of the employed methodologies as well as the first results arising from the research and implementation activities.

Fluor Hanford ALARA Center is a D and D Resource

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waggoner, L.O.

2008-01-15

Figures I and II. The ALARA Center staff routinely researches and tests new technology, sponsor vendor demonstrations, and redistribute tools, equipment and temporary shielding that may not be needed at one facility to another facility that needs it. The ALARA Center staff learns about new technology in several ways. This includes past radiological work experience, interaction with vendors, lessons learned, networking with other DOE sites, visits to the Hanford Technical Library, attendance at off-site conferences and ALARA Workshops. Personnel that contact the ALARA Center for assistance report positive results when they implement the tools, equipment and work practices recommended by the ALARA Center staff. This has translated to reduced exposure for workers and reduced the risk of contamination spread. For example: using a hydraulic shear on one job saved 16 Rem of exposure that would have been received if workers had used saws-all tools to cut piping in twenty-nine locations. Currently, the ALARA Center staff is emphasizing D and D techniques on size-reducing materials, decontamination techniques, use of remote tools/video equipment, capture ventilation, fixatives, using containments and how to find lessons learned. The ALARA Center staff issues a weekly report that discusses their interaction with the workforce and any new work practices, tools and equipment being used by the Hanford contractors. Distribution of this weekly report is to about 130 personnel on site and 90 personnel off site. This effectively spreads the word about ALARA throughout the DOE Complex. DOE EM-23, in conjunction with the D and D and Environmental Restoration work group of the Energy Facility Contractors Organization (EFCOG) established the Hanford ALARA Center as the D and D Hotline for companies who have questions about how D and D work is accomplished. The ALARA Center has become a resource to the nuclear industry and routinely helps contractors at other DOE Sites, power reactors, DOD

Hanford Soil Inventory Model (SIM-v2) Calculated Radionuclide Inventory of Direct Liquid Discharges to Soil in the Hanford Site's 200 Areas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, William E.; Zaher, U.; Agnew, S.

The Hanford soil inventory model (SIM) provides the basic radionuclide and chemical soil inventories from historical liquid discharges to about 400 sites at the Hanford Site. Although liquid discharge inventory for chemicals is part of the SIM implementation, only radionuclide inventory is discussed here since the focus of this ECF is on providing radionuclides inputs for the composite analysis (CA) per DOE Order 435.1, Radioactive Waste Management, requirements. Furthermore, discharged inventories are only estimated for the soluble portions of the liquid discharges to waste sites/waste management areas located on the 200 Area of the Hanford Site (Central Plateau).

Seismic activity in northeastern Brazill-new perspectives

NASA Astrophysics Data System (ADS)

Ferreira, J. M.; Do Nascimento, A. F.; Vilar, C. S.; Bezerra, F. H.; Assumpcao, M.; Berrocal, J.; Fuck, R. A.

2007-05-01

Northeastern Brazil is the most seismic active region in the country. Some earthquakes with magnitude above 5.0 and intensity VII MM associated with swam-like seismic activity lasting for many years are a serious social concern. Since the 1980's macroseismic and instrumental surveys have been carried out in this region and they are an important data archive which allows the composition of a reliable catalogue of seismic activity for this region. Among the many scientific results it was possible to identify the main seismogenic areas, obtain reliable hypocentres and focal mechanisms. As a consequence, it was possible also to analyse the relationship between seismicity and geological features. It was also possible to determined maximum horizontal stress direction for the region. An important induced seismic activity case has also been reported in the area as being a classical example of pore pressure diffusion triggering mechanism. The majority of the results were obtained using analogic data. Recently, a new research project is being conducted and will allow us to provide a regional scale monitoring with 6 broad-band stations and a new portable six station digital seismic network equipped with short- period sensors. Thus, with the continuous seismic activity in the area we trust that the results of this project will increase the present knowledge of seismic activity in northeastern Brazil.

A deployment of broadband seismic stations in two deep gold mines, South Africa

USGS Publications Warehouse

McGarr, Arthur F.; Boettcher, Margaret S.; Fletcher, Jon Peter B.; Johnston, Malcolm J.; Durrheim, R.; Spottiswoode, S.; Milev, A.

2009-01-01

In-mine seismic networks throughout the TauTona and Mponeng gold mines provide precise locations and seismic source parameters of earthquakes. They also support small-scale experimental projects, including NELSAM (Natural Earthquake Laboratory in South African Mines), which is intended to record, at close hand, seismic rupture of a geologic fault that traverses the project region near the deepest part of TauTona. To resolve some questions regarding the in-mine and NELSAM networks, we deployed four portable broadband seismic stations at deep sites within TauTona and Mponeng for one week during September 2007 and recorded ground acceleration. Moderately large earthquakes within our temporary network were recorded with sufficiently high signal-to-noise that we were able to integrate the acceleration to ground velocity and displacement, from which moment tensors could be determined. We resolved the questions concerning the NELSAM and in-mine networks by using these moment tensors to calculate synthetic seismograms at various network recording sites for comparison with the ground motion recorded at the same locations. We also used the peak velocity of the S wave pulse, corrected for attenuation with distance, to estimate the maximum slip within the rupture zone of an earthquake. We then combined the maximum slip and seismic moment with results from laboratory friction experiments to estimate maximum slip rates within the same high-slip patches of the rupture zone. For the four largest earthquakes recorded within our network, all with magnitudes near 2, these inferred maximum slips range from 4 to 27 mm and the corresponding maximum slip rates range from 1 to 6 m/s. These results, in conjunction with information from previous ground motion studies, indicate that underground support should be capable of withstanding peak ground velocities of at least 5 m/s.

Detecting Seismic Infrasound Signals on Balloon Platforms

NASA Astrophysics Data System (ADS)

Krishnamoorthy, S.; Komjathy, A.; Cutts, J. A.; Pauken, M.; Garcia, R.; Mimoun, D.; Jackson, J. M.; Kedar, S.; Smrekar, S. E.; Hall, J. L.

2017-12-01

The determination of the interior structure of a planet requires detailed seismic investigations - a process that entails the detection and characterization of seismic waves due to geological activities (e.g., earthquakes, volcanoes, etc.). For decades, this task has primarily been performed on Earth by an ever-expanding network of terrestrial seismic stations. However, on planets such as Venus, where the surface pressure and temperature can reach as high as 90 atmospheres and 450 degrees Celsius respectively, placing seismometers on the planet's surface poses a vexing technological challenge. However, the upper layers of the Venusian atmosphere are more benign and capable of hosting geophysical payloads for longer mission lifetimes. In order to achieve the aim of performing geophysical experiments from an atmospheric platform, JPL and its partners (ISAE-SUPAERO and California Institute of Technology) are in the process of developing technologies for detection of infrasonic waves generated by earthquakes from a balloon. The coupling of seismic energy into the atmosphere critically depends on the density differential between the surface of the planet and the atmosphere. Therefore, the successful demonstration of this technique on Earth would provide ample reason to expect success on Venus, where the atmospheric impedance is approximately 60 times that of Earth. In this presentation, we will share results from the first set of Earth-based balloon experiments performed in Pahrump, Nevada in June 2017. These tests involved the generation of artificial sources of known intensity using a seismic hammer and their detection using a complex network of sensors, including highly sensitive micro-barometers suspended from balloons, GPS receivers, geophones, microphones, and seismometers. This experiment was the first of its kind and was successful in detecting infrasonic waves from the earthquakes generated by the seismic hammer. We will present the first comprehensive analysis

Extending Resolution of Fault Slip With Geodetic Networks Through Optimal Network Design

NASA Astrophysics Data System (ADS)

Sathiakumar, Sharadha; Barbot, Sylvain Denis; Agram, Piyush

2017-12-01

Geodetic networks consisting of high precision and high rate Global Navigation Satellite Systems (GNSS) stations continuously monitor seismically active regions of the world. These networks measure surface displacements and the amount of geodetic strain accumulated in the region and give insight into the seismic potential. SuGar (Sumatra GPS Array) in Sumatra, GEONET (GNSS Earth Observation Network System) in Japan, and PBO (Plate Boundary Observatory) in California are some examples of established networks around the world that are constantly expanding with the addition of new stations to improve the quality of measurements. However, installing new stations to existing networks is tedious and expensive. Therefore, it is important to choose suitable locations for new stations to increase the precision obtained in measuring the geophysical parameters of interest. Here we describe a methodology to design optimal geodetic networks that augment the existing system and use it to investigate seismo-tectonics at convergent and transform boundaries considering land-based and seafloor geodesy. The proposed network design optimization would be pivotal to better understand seismic and tsunami hazards around the world. Land-based and seafloor networks can monitor fault slip around subduction zones with significant resolution, but transform faults are more challenging to monitor due to their near-vertical geometry.

Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frary, R.; Louie, J.; Pullammanappallil, S.

Roxanna Frary, John N. Louie, Sathish Pullammanappallil, Amy Eisses, 2011, Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract T13G-07.

The Apollo passive seismic experiment

NASA Technical Reports Server (NTRS)

Latham, G. V.; Dorman, H. J.; Horvath, P.; Ibrahim, A. K.; Koyama, J.; Nakamura, Y.

1979-01-01

The completed data set obtained from the 4-station Apollo seismic network includes signals from approximately 11,800 events of various types. Four data sets for use by other investigators, through the NSSDC, are in preparation. Some refinement of the lunar model based on seismic data can be expected, but its gross features remain as presented two years ago. The existence of a small, molten core remains dependent upon the analysis of signals from a single, far-side impact. Analysis of secondary arrivals from other sources may eventually resolve this issue, as well as continued refinement of the magnetic field measurements. Evidence of considerable lateral heterogeneity within the moon continues to build. The mystery of the much meteoroid flux estimate derived from lunar seismic measurements, as compared with earth-based estimates, remains; although, significant correlations between terrestrial and lunar observations are beginning to emerge.

HANFORD FACILITY ANNUAL DANGEROUS WASTE REPORT CY2003 [SEC 1 & 2

DOE Office of Scientific and Technical Information (OSTI.GOV)