Download or read book Discrimination of Seismic Events from Several Specific Areas in Israel and Its Vicinity Recorded by the National Seismic Network written by J. Kurpan and published by . This book was released on 2004 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discrimination of Seismic Events from Israel Recorded by the Israel Seismic Network written by Julia Kurpan and published by . This book was released on 2004 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discrimination of Seismic Sources Using Israel Seismic Network written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We addressed the problem of automated event discrimination in both the local and teleseismic ranges using the Israel Seismic Network, as an example of a dense regional seismic network. A new high resolution technique was developed, based on multistation representation of the seismic signal: spectral semblance, measuring coherency of spectral shapes, and velogram, characterizing kinematic features. Semblance and energy spectral ratio statistics, applied to a wide variety of local and teleseismic events, showed, for specific spectral bands, almost total separation of explosions and earthquakes. Efficient automated classifiers based on combinations of different physical features of the events have been designed. The discrimination results for the teleseismic data were compared for the ISN and NORESS, showing almost equivalent performance. Noise recordings and teleseismic signals were used to evaluate the ISN detectability by array technique, including adaptive beamforming, optimal detectors, maximum likelihood estimators and phase correlation analysis, applied to the ISN subnetworks with promising results. Experimental relationships between charge weight and magnitude for local single quarry shots and underwater Dead Sea explosions with outstanding high coupling were developed, providing a basis for the execution of effective calibration explosions currently lacking in the region.
Download or read book Abstracts written by Ḥevrah ha-ge'ologit ha-Yiśre'elit. Kenes and published by . This book was released on 2004 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detection Location and Discrimination of Seismic Events by the Seismic Network of Israel written by A. Shapira and published by . This book was released on 1995 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Israeli Seismic Network (ISN) consists of 36 short period stations distributed throughout the country. In addition, a Broad Band station is operating at the geophysical observatory near Bar Giyyora, Israel (BGIO) and a small aperture seismic array is under construction in the central Negev desert. The ISN is a regional network which aims to monitor the seismicity in the area bounded by latitudes 27. ON - 36.0N and longitudes 32.0E - 38. OE. It is tuned to detect all seismic events of magnitudes ML>2.0 occurring in Israel. Triggered events are routinely analyzed, yielding a seismological bulletin which provides the seismic event source parameters and classifies the events as earthquakes, explosions, possible explosions and distant events. The detection capabilities of the ISN within Israel is proven to be ML>2.0. In many locations around the country, the threshold magnitude is as low as 0.5. Comparisons of the detection performance of the ISN with those of other international organizations has shown the superiority of the ISN in monitoring the eastern Mediterranean and Middle East regions. Less than 10% of the events detected by the ISN are local and regional earthquakes. Most of the detected events are quarry blasts in Israel, Lebanon and Jordan and detonations associated with infrastructure developments. Sonic wave detectors are used to identify quarry blasts. In parallel, ground truth information is used do develop analytical procedures for discrimination. Presently, the azimuth-invariant, low-frequency spectral modulation method is used to identify the quarry blasts and underwater explosions (UWE) caused by ripple firing and bubbling effects, respectively.
Download or read book Africa Geoscience Review written by and published by . This book was released on 2005 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring the Comprehensive Nuclear Test Ban Treaty Data Processing and Infrasound written by Zoltan A. Der and published by Springer Science & Business Media. This book was released on 2002-05-01 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: On September 10, 1996, The United Nations General Assembly adopted the Copmprehensive Nuclear-Test-Ban Treaty (CTBT), prohibiting nuclear explosions worldwide, in all environments. The treaty calls for a global verification system, including a network of 321 monitoring stations distributed around the globe, a data communications network, an international data center (IDC), and on-site inspections, to verify compliance. This volume presents certain recent research results pertaining on methods used to process data recorded by instruments of the International Monitoring System (IMS) and addressing recording infrasound signals generated by atmospheric explosions. Six papers treating data processing provide an important selection of topics expected to contribute to improving our ability to successfully monitor a CTBT. Five papers concerning infrasound include descriptions of ways in which that important research area can contribute to CTBT monitoring, the automatic processing of infrasound data, and site conditions that serve to improve the quality of infrasound data.
Download or read book Fractal Approach to the Regional Seismic Event Discrimination Problem written by D. N. Belyashov and published by . This book was released on 2000 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the framework of the Comprehensive Test Ban Treaty, development of reliable methods to discriminate between underground nuclear explosions and earthquakes at regional distances (less than 2500km) continues to be very important especially in connection with the last (in May, 1998) nuclear explosions conducted at Indian and Pakistan test sites. Since the lithosphere is a fractal, we suppose the signals, which propagate through the media, inherit its self similar' (scaling) features. We assumed that these features of explosions and earthquakes or their topological reconstructions (embeddings) have to be different. Scaling reflects correlations of more high order then it is possible to estimate by linear discriminating methods and can be used as base of non-linear discrimination. We propose to build a universal geometrical model of a seismic signal using the canon algorithm of F. Takens and to estimate scaling of the model. The scaling features were used as patterns of seismic signals for entering them into an artificial neural network. Records of nuclear explosions and earthquakes from different regions were included into the training set. The net was trained to classify types of seismic events. Results have shown 80% correct classification of the unknown signals. As additional tools for distinguishing between nuclear explosions and earthquakes we propose to use Hurst's method and the cross correlation method. Results of using these methods are demonstrated on examples of some explosions and earthquakes.
Download or read book A Discrimination Analysis of Regional Seismic Data Recorded at Tonto Forest Observatory from Nevada Test Site Explosions and Nearby Earthquakes written by J. R. Murphy and published by . This book was released on 1981 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The principal objectives of the research reported here are to identify any diagnostic differences between regional seismic phases produced by earthquakes and underground nuclear explosions and to assess their applicability to events occurring in various regions of the U.S.S.R. Two approaches are used: one employs traditional time-domain amplitude and period measurements to compare the relative excitation of various regional phases for earthquakes and explosions, while the second focuses on more sophisticated measurement or processing techniques such as spectral ratios or narrow-band filtering to extract information about frequency differences in the signals generated by the two types of events. The research reported here was directed at identification of discriminants based on measurements of seismic phases at regional distances from a well-controlled set of Western U.S. explosions and nearby earthquakes. The set includes more than 50 Nevada Test Site events (explosions and nearby earthquakes) recorded at the Tonto Forest Observatory in Arizona. The investigation included spectral analyses of the short-period regional phases, Pn, Pg, and Lg which follows-up a previously reported study of time-domain characteristics of these phases. In addition, the current study includes an analysis of the time-domain characteristics of the long-period data from the Nevada Test Site event set, with particular emphasis on the potential applicability of the Ms/mb discriminant to the identification of small events (mb
Download or read book Seismic Discrimination Between Earthquakes and Explosions in the Middle East and North Africa written by and published by . This book was released on 1997 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recently signed Comprehensive Test Ban Treaty provides for an international network of primary and auxiliary seismic monitoring stations (IMS) to verify its compliance. Calibration is required to confidently use these stations to identify and discriminate between earthquakes, mine-related events and clandestine nuclear explosions, particularly for small to moderate seismic events recorded regionally at only a few stations. Given the lack of regional recordings of underground nuclear tests in most of the world, we are making use of mining and industrial explosions to test discriminants. For example we use the Multimax compiled dataset of small earthquakes and quarry explosions in Israel to test regional discriminants at local distances with mixed results. Further complicating calibration is the fact that many INK sites have not yet been installed and others have very short operating histories. When IMS data is available, there is often a lack of independent information (ground truth) on the seismic sources. Here we describe a procedure for calibrating stations with limited data and apply it to the IMS auxiliary station MDT in Morocco. Data was initially available for three months in 1990 when MDT was operated as part of MEDNET. An event detector was run over the continuous data and regional events identified and roughly located using S-P time and back azimuth. The procedure uses spatial and temporal clustering to identify ''known'' mine blasts. The spatial clustering is done using the waveform correlation technique of Harris (1991) to find events with similar sources and locations. Temporal clustering looks at the time of day and repetition in time of events with the mine blasts occurring during working hours and days repeatedly over a period of time. A set of ''known'' earthquakes is also determined using location, time of day, distribution in time and size criteria. With these independent libraries of identified seismic events, we evaluate promising regional discriminants such as high frequency P/Lg. We also examine distance and path effects on the discriminants. Preliminary results indicate high frequency P/Lg provides some separation between mine blasts and earthquakes at MDT.
Download or read book Annual Meeting written by Ḥevrah ha-geʾologit ha-Yiśreʾelit and published by . This book was released on 2004 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Discrimination of Earthquakes and Explosions with Application to the Southwestern United States written by D. H. VON Seggern and published by . This book was released on 1979 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines seismic discrimination between underground nuclear explosions and earthquakes in the Southwestern United States. A thorough review of theoretical and applied research on this problem, especially as it relates to that region, is presented first, followed by a presentation of the seismic discrimination parameters computed for a suite of events in the Southwest and a series of experiments with multi-dimensional discrimination. Review of past work finds some theoretical support for successful discrimination based upon several distinct measurements on seismic recordings. Although negative first motion and presence of pP both indicate a natural earthquake source, they cannot be found confidently in many cases. The relative level of shear-wave and Love-wave phases should be a good classification parameter. The long-period P spectrum of explosions should be diminished due to the surface interaction and consequent cancellation by pP. The region under study extends from California to the southern Rocky Mountains and from roughly 40 degrees N to the Gulf of California. A region of high seismicity, it is also a complex region encompassing several tectonic provinces, including the Basin-Range Province where the Nevada Test Site is located. In general, seismic discriminant parameters obtained from the recordings reflected the theoretical expectations of earthquake-explosion differences. Path-station effects were large for every parameter, especially for short-period data.
Download or read book Israel Journal of Earth Sciences written by and published by . This book was released on 1993 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discrimination of Earthquakes and Chemical Explosions with a Regional Network written by Peder Johansson and published by . This book was released on 1987 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geophysics Tectonics Abstracts written by and published by . This book was released on 1987 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gilat Area Seismic Reflection Survey written by Israel Institute for Petroleum Research and Geophysics and published by . This book was released on 1970 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations Into Seismic Discrimination Between Earthquakes Chemical Explosions and Nuclear Explosions written by and published by . This book was released on 1995 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this report we describe some results of investigations on a problem of discrimination between nuclear explosions, chemical explosions and earthquakes, carried out in the Complex Seismological Expedition of the Joint Institute of Physics of the Earth of the Russian Academy of Sciences. Records of underground nuclear explosions from the Semipalatinsk test site, and from region the Pre-Caspian depression, and also records of nearby chemical explosions and earthquakes were processed. We analysed records of permanent and temporary stations, located mainly in the North Tien Shan, northern Kazakhstan and Urals regions. We studied the influence of regional conditions on the effectiveness of seismic monitoring of nuclear explosions. Various amplitude criteria of the discrimination between explosions and earthquakes are considered. We analyzed possibilities to discriminate different source types using spectral-temporal characteristics of seismograms. The nature of some wave types, recorded at region distances, is investigated. We consider possibilities of discrimination between nuclear and chemical explosions and earthquakes using analysis of characteristics of irregular waves. We outline future investigations, connected with the study of the unique set of seismograms kept in the CSE.
