Based on accumulated PSD statistics a Probability Density Function (PDF) is also determined from which low and high noise curves for each sensor are
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3. ADVANCES IN SENSORS, NETWORKS AND OBSERVATIONAL TECHNOLOGIES Conveners: PATRICK GRENARD International Monitoring System Division CTBTO MATTHIAS AUER International Monitoring System Division CTBTO JOHN BERGER Scripps Institution of Oceanography United States of America Invited Speakers: MICHEL ANDRÉ Technical University of Catalonia Spain DAVID SIMPSON Institutions for Seismology (IRIS) United States of America
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ORAL PRESENTATIONS: T3 – O1. Integrated solutions for a sustainable development of the offshore industry: live monitoring of noise and acoustics events Michel André , Mike van der Schaar , Serge Zaugg , Ludwig Houegnigan , Antonio M. Sánchez , Alex Mas Laboratory of Applied Bioacoustics, Technical, Spain Contact: michel.andre@upc.edu The next decades will see increasing levels of offshore industrial development that will lead to increased amounts of noise pollution in the oceans. Amongst these developments, oil and gas prospection, navy exercises as well as offshore windmills are alrea dy playing a leading role in introducing considerable amount of noise in an increasing number of areas, but demand for offshore nuclear power plants is expected to be high in regions experiencing power shortages and requiring stable energy supplies. Underw ater sound sources produced by these activities present the highest intensity amongst those anthropogenically generated in the sea, reaching more than 230 dB re 1 Pa at 1m from the source. These sounds can have physical, physiological and behavioural effe cts on the marine fauna in the area of action: mammals, reptiles, fish and invertebrates can be affected at various levels depending on the distance to the sound source. Marine mammals could be one of the more sensitive groups of marine species because the y have a highly developed auditory system and use sound actively for feeding and for social communication. It is also known that marine mammals are vulnerable to the effects of habitat loss or reduced survival and reproduction rates. The problem faced by t he industry, and more generally by the society, is that many economically important activities at sea are at risk because of a lack of information about the effects of anthropogenic sound on marine mammals and especially a lack of available tools to mitiga te these effects. The challenge here is to implement technological developments that combine the interests of the industry and the good environmental status of the oceans. Based on the existing technology successfully implemented at underwater observatorie s worldwide (European Sea – floor Observatories Network of Excellence, ESONET, European Member States; ANTARES, France; NEPTUNE, Canada; Kushiro, Japan) by the Laboratory of Applied Bioacoustics of the Technical University of Catalonia (LIDO, Listen to the D eep – Ocean Environment, http://listentothedeep.com), a real – time passive acoustic monitoring solution is available to mitigate the potential effects of noise associated to the offshore industry. The LIDO acoustic detection, classification and localization ( DCL) system can be integrated in a series of expandable radio – linked autonomous buoys that are timely deployed in areas of action. In that case, the DCL is performed at buoy level. A mesh network allows buoy – to – buoy communication and an alert service provi des the ship/offshore platform with the DCL analysis: the real – time continuous monitoring of cetacean presence. The advantages are relevant: – The LIDO DCL is automated and performed regardless sea state or light conditions – No expertise is needed onboar d the survey vessels/offshore platforms since the alert service informs on the identification and position of cetacean species that is displayed on a user – friendly interface – The real – time continuous monitoring of cetaceans allows determining areas of exc lusion depending on the sound source and the species involved. – The decision – taking regarding the management of the offshore activity in presence of cetaceans falls under scientifically contrasted, objective and standardised procedures that ensure the sus tainable development of the activity. – The LIDO DCL is supported by virtually any hardware, e.g. towed arrays, gliders, AUV, ROV, radio – linked autonomous buoys, cabled observatories. We also show some T – phase observed by DONET. The array of instruments pl aced on the seafloor operates as a monitoring system for ocean acoustic wave generations. Many acoustic waves with duration of approximately 100 seconds arrive at DONET from southwest. According to the theoretical travel time calculated from JMA hypocenter bulletin, we found that they are T – phase associated with earthquakes generated along Ryukyu trench. T3 – O2. Open data resources and shared instrumentation facilities to support research in seismology David Simpson IRIS Consortium, United States of America Contact: simpson@iris.edu Over the past three decades, improvements in sensor design, digital signal processing, communications technologies, power systems and data management have led to remarkable advances in our ability to remo tely and continuously monitor many aspects of the geo – environment. These technologies and their use in seismology (many of which grew out of nuclear monitoring programs in the 1960 – spectrum of research programs on the nature of the earthquake source, deep Earth structure and the dynamics of the crust and lithosphere, and for practical applications in earthquake monitoring, hazard assessment, climate change and resource exploration. The IRIS Consortium, led by the US aca demic research community and in collaboration with US federal agencies and many international partners, has helped establish a national and
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international culture of open data sharing and pooled instrumentation resources to support the collection, archiving and distribution of data for use in monitoring earthquakes and supporting seismological research. The data from these multi – user facilities, and research results that emerge from their use, find direct application in many aspects of research and monitorin g related to the Comprehensive Test Ban Treaty. T3 – O3. Challenges and growth for NEPTUNE Canada Lucie Pautet , Christopher R. Barnes , Fern Johnson , Mairi M. R. Best , Benoit Pirenne NEPTUNE Canada Contact: lpautet@uvic.ca – optic cable loop which powers a series of scientific nodes located at the coast (Folger Passage), continental slope (ODP 889; Barkley Canyon), abyssal plain (ODP 1027), and ocean – spreading ridge (Endeavour) in water depths of 20 – 2660m. Over the 25 years of the s ystem design life, scientists will be able to investigate a wide range of ocean processes and events as well as collect real time data and imagery to be stored in a unique database. Initial data flow started in December 2009, with over 10TB of data and vid eo imagery archived to date. Challenges have been and continue to be considerable. Beyond the difficulties encountered when designing, manufacturing and installing the main infrastructure, instruments and cables normally used for short term experiments hav e to be adapted to long term deployments in extreme environments such as a ridge. On the data side, the ever increasing size of the database, the diversity of data types and data products increases the complexity of a data delivery system which aims at bei ng transparent to the users. Still, the main challenge is to ensure a continuous growth in the user base as the real power of the network lies with the scientists. The more they become involved, and interact in multidisciplinary groups, the more relevant a nd the more efficient NC will become. T3 – O4. The effectiveness of radionuclide monitoring: assessed with a natural airborne tracer Murray Matthews New Zealand Contact: murray.matthews@xtra.co.nz In atmospheric radioactivity major importance. Above – ground nuclear explosions deposit most radioactive debris toward the tropopause and a key component in monitoring site selection is the degree of coupli ng between a station and the upper difficult to assess experimentally but monitoring experience over the last decade indicates the possible applicat ion in this of a naturally occurring tracer, sodium – 24. Sodium – 24 is produced in the atmosphere by cosmic – radiation spallation reactions with argon and detected in the IMS particulate radionuclide network. Its production rate peaks in the upper – troposphere /lower – stratosphere and the 15h radioactive half – life limits long – range transport. Intuitively, detection in ground – level air is the result mainly of vertical transport from high altitudes. Variations in rates of 24Na detection between IMS monitoring stati ons may therefore provide clues as to relative degrees of atmospheric coupling. This paper analyses 24Na detection rates at IMS radionuclide stations since 2005. Detection rates vary widely, from ~20% of samples at one station to almost zero at others. A f ew stations demonstrate the expected annual variations in detection frequency, but most do not. Latitudinal effects are evident but the significant gaps in detection could mean the IMS network effectiveness is seriously impaired by lack of coupling at many stations. Application of ¬24Na to the coupling issue is discussed and differences between stations analysed geographically. The need for further meteorological effort combined with 24Na data analysis is highlighted. T3 – O5. The Optical Seismometer a ne w technology for seismographic observations Jonathan Berger , Mark Zumberge Scripps Institution of Oceanography, United States of America Contact: jberger@ucsd.edu We have developed a new optical interferometric seis mometer that has significant advantages over conventional feedback seismometers. The new seismometer employs laser interferometry to measure the motion of an inertial mass relative to its frame rather than the traditional electronic displacement transducer . Advantages include: 1. The linear, high – resolution, optical displacement transducer provides about a 30 – bit resolution digital output without a high – resolution analog – digital converter; 2. It measures absolute displacement referenced to the wavelength of the laser light; 3. The bandwidth and resolution are sufficient to resolve the GSN low noise model from DC to > 15 Hz. 4. The dynamic range is sufficient to record the largest teleseisms and most regional and local earthquakes.
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5. The technology allows the laser and other electronic elements to be located hundreds of meters from the sensors with the only connection made by fiber. 6. It is suitable for either vault or borehole installations. Electronics in the seismometer are unnecessary only an optical fiber connection to the seismometer is required, eliminating heat from electronics in the sensor package, noise pickup from connecting electrical cables, and susceptibility to lightning strikes. 7. Unlike standard feedback seismometers whose outputs depen d upon numerous electronic and mechanical components, the calibration and response of the optical seismometers are described by only three simple and time – invariant parameters whose values can be confirmed at any time through examination of the data. We pr esent data demonstrating the performance of our prototype vertical and horizontal component optical seismometers, which meet CTBTO requirements. T3 – O6. Data for OSI multi – spectral and infrared instrument development John Henderson , Milton Smith , Michael Zelinski Lawrence Livermore National Laboratory, United States of America Contact: henderson9@llnl.gov The Comprehensive Nuclear – Test – Ban Treaty (CTBT) permits Multi – Spectral and InfraRed Imaging (MSIR) as part of an On – Site Inspection (OSI) to reduce the search area for the location of a possible underground nuclear so commercial satell ite data has been used to determine if there are MSIR observables associated with recent observables which can be used to greatly reduce the search area for the location of the UNE. The techniques used (e.g., change detection) typically identify a region of interest less than 1 km^2 in size (compared to the nominal 1,000 km^2 search area), and the few false positives have been resolvable as such by using visi ble imagery. Commercial satellite data can be used to characterize those observables and help generate the technical specification for airborne MSIR sensors to support an on – site inspection as allowed by the CTBT. Prior published literature describes using commercial satellite spectral data to measure environmental factors, and surface shock from underground explosions. T3 – O7. The Optical Fiber Infrasound Sensor improved wind noise reduction Mark Zumberge , Kris Walker , Jonathan Berger Scripps Institution of Oceanography, United States of America Contact: mzumberge@ucsd.edu The Optical Fiber Infrasound Sensor (OFIS) has now been under development for twelve years. The instrument has undergone extensive testing and has proven to have a number of advantages over traditional pipe rosettes fitted with microbarometers or microphones. These include: 1. Reduction in wind noise of up to 10 dB (at 1 Hz) compared to pipe – arrays of similar size; 2. A design that nullifies resonance; 3. A wide dynamic range digitization system, integral to the sensor, removing the need for a highresolution data recorder; 4. A configuration in which the sensor is completely buried beneath the ground surface (save for a s olar panel and data link antenna) removing the need for any above ground obstructions; 5. A sensor comprising a sealed volume, reducing potential for water intrusion; 6. The capability to undergo continuous calibration without interruption of data collecti on; 7. Configurable such that the laser and other electronic elements can be sited hundreds of meters from the sensors with the only connections being made by optical fiber. We present data demonstrating the performance of an OFIS in varying wind condition s, deployed adjacent to an operational IMS infrasound array (I57US). T3 – O8. A new underground radionuclide laboratory – RL16 Joel Forrester , Craig Aalseth , Larry Greenwood , Harry Miley , Cory Overman Pacific Northwest National Laboratory, United States of America Contact: joel.forrester@pnl.gov The International Monitoring System (IMS), in addition to a series of radionuclide monitoring stations, mandate s sixteen laboratories capable of verification of radionuclide field measurements, as well as more in – depth studies of field – obtained samples. Several State Parties host and maintain such a radionuclide laboratory (RL) and all RLs participate in a series o f round – robin testing exercises to ensure consistent quality of laboratory verification capabilities. This presentation highlights new developments in a low – background detector system for radionuclide particulate measurements being built in a new shallow u nderground clean facility at Pacific Northwest National Laboratory. Specifics such as low – background materials, active shielding methods, and
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expected improvements in sensitivity, as well as the benefits of operating in a shallow underground location and i n a cleanroom environment, will be covered. T3 – O9. Figure of merit for choosing Xe background study locations Paul Eslinger , Derek Haas , Harry Miley Pacific Northwest National Laboratory, United States of America Contact: paul.eslinger@pnl.gov The International Noble Gas Experiment (INGE) is ringing the Earth with a network of 40 xenon monitoring systems, of which is about 2/3 are in operation. The occasional detection of radioactive xenon in the atmosphere by this network, in the absence of a nuclear explosion, poses a discrimination challenge: how reliably can one screen out normal civilian nuclear activities like power generation and medical isotope production? Discrimination may rely o n the ratios of any of several xenon isotopes detected, such as Xe – 133m/Xe – 133. To create and test screening methods using xenon isotopic ratios, a small international collaboration led by the Provisional Technical Secretariat of the CTBTO has been measuri ng the background of xenon isotopes in various parts of the Earth where few xenon measurements have been made or where large xenon sources are known. It has been proposed that to optimize the study of xenon backgrounds, a Figure of Merit could be construct ed, using atmospheric transport calculations and the known locations of reactors and medical isotope facilities. It should be possible to identify and prioritize locations for scientific study by computation of expected signal intensity and careful conside ration of current INGE network coverage. We present the results of ongoing studies to define an acceptable Figure of Merit based on forward calculations of xenon concentrations from nuclear facilities that currently exist, are planned, or are likely to exi st in the next 5 years. By removing locations that are well covered by INGE, the best locations for background study can be selected. T3 – O10. Production of Xe standards for the calibration of noble gas sampler stations and laboratory equipment Kari Peräjärvi 1 , Tommi Eronen 2 , Dimitry Gorelov 2 , Jani Hakala 2 , Ari Jokinen 2 , Anu Kankainen 2 , Heikki Kettunen 2 , Veli Kolhinen 2 , Mikko Laitinen 2 , Iain Moore 2 , Heikki Penttilä 2 , Juho Rissanen 2 , Antti Saastamoinen 2 , Harri Toivonen 1 , Jani Turunen 1 , Juha Äystö 2 1 STUK – Radiation and Nuclear Safety Authority Finland 2 Department of Physics University of Jyväskylä Contact: kari.perajarvi@stuk.fi Recent achievements on producing pure samples of 1 31mXe, 133mXe, 133Xe and 135Xe at the Accelerator Laboratory of the University of Jyväskylä, Finland, are presented. A high resolution mass purification process employing the IGISOL/JYFLTRAP facility ends in the implantation of an ultra – pure beam of ions i nto solid catcher foils. Solid catchers are employed due to the low kinetic energy of the mass – purified ions (30 keV) and the requirement of excellent vacuum inside the Penning trap setup. Since often gaseous xenon samples are needed for the calibration of noble gas collection and detection setups, work related to the foil – to – gas conversion has been started in Finland. In particular, we have studied the diffusion properties of xenon atoms in aluminium and graphite. Based on improved understanding we have ma de a preliminary design of a device capable to efficiently transfer the xenon from the foil to a measurement cell or to a transportation container.Currently the Laboratory at Jyväskylä is being upgraded and the construction work should be finished by the e nd of 2011. Among other devices this upgrade introduces a third particle accelerator to the University of Jyväskylä. The K=30 MeV cyclotron will mainly serve the upgraded IGISOL/JYFLTRAP facility making the scheduling of xenon production runs much easier. Current status of the construction work will also be presented.
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T3 – O11. Xenon diffusion reduction using surface coatings on plastic scintillators in beta – gamma coincidence detection systems Lisa Bläckberg¹ , Alexander Fay² , Anders Ringbom³ , Lars Mårtensson³ , Klas Elmgren³ , Fredrik Nielsen³ , Tomas Fritioff³ , Steven Biegalski² , Henrik Sjöstrand¹ , Mattias Klintenberg¹ ¹Uppsala Universitet, Sweden ²University of Texas at Austin, United States of America ³Swedish Defence Research Agency (FOI), Sweden Contact: lisa.blackberg@physics.uu.se A major drawback with the current setup of the beta – gamma coincidence detector systems used within the IMS to detect radioxenon is that during measurements the radioactive gas diffuses into the plastic scintillator cell holding the sample. It has been estimated th at 3 – 4% of the xenon sample remains in the cell after it has been evacuated. This residual activity results in an elevated detection limit for the following measurements. to radioxenon with a material able to stop xenon diffusion without significantly impairing detector properties such as efficiency and resolution. In this work two coating materials have been investigated. Al2O3 and SiO2 of varying thicknesses (20 – 400 nm) have been deposited onto flat plastic scintillator surfaces using Atomic Layer Deposition and Plasma Enhanced Chemical Vapour Deposition, respectively. The coatings have been tested, with respect to their ability of stopping xenon diffusion, by exposure to radioactive xenon and subsequent measurement of the residual activity. The study shows that all coated samples present less memory effect than uncoated ones. For Al2O3 a dependence on coating thickness was observed, and a 400 nm coating was found to almos t completely remove the memory effect. The successful coating will now be tested with respect to detector efficiency and resolution using a complete betagamma coincidence detector system. The work presented is a collaboration between Uppsala University, the Swedish Defence Research Agency (FOI) and University of Texas at Austin. T3 – O12. The EarthScope USArray Transportable Array: Results from large – scale network operations Robert Woodward , Robert Busby , Katrin Hafner , David Simpson Incorporated Research Institutions for Seismology, United States of America Contact: woodward@iris.edu The EarthScope USArray Transportable Array is providing unpreced ented seismological observations for continental – and global – scale studies of Earth structure and seismicity. The rolling deployment of the Transportable Array (TA) component of USArray has now occupied over 1,000 sites in the western half of the United St ates, from the Pacific coast to the Mississippi River. The three – component broadband TA stations are deployed in a grid – like arrangement, with 70 km separation between stations. At any given time, there are approximately 400 installed stations and each sta tion is operated for two years. All data are distributed openly and without restriction. The stations utilize a highly uniform design, which facilitates both efficient operations and utilization of the data. The full 400 station array routinely delivers gr eater than 98% data availability in real time, and provides consistently low – noise performance with simple vaults installed in a wide range of terrains. Automated analysis of station state – of – health channels, combined with innovations in quality review of the data, contributes to the overall performance of the network. Over time the station design has also been carefully evolved to enhance performance and acquire new observations. Most recently the TA stations are being augmented with absolute barometric pr essure and infrasound sensors. T3 – O13. Measuring mesopause temperature perturbations caused by infrasonic waves – An innovative sensor approach Michael Bittner , Kathrin Höppner , Christoph Pilger , Carsten Schmidt DLR, Germany Contact: michael.bittner@dlr.de Many geo – hazards such as earthquakes, tsunamis, volcanic eruptions, severe weather, but also nuclear explosions, produce acoustic waves with sub – audible frequency, so called infrasound. This sound propagates from the surface to the middle and upper atmosphere causing pressure and temperature perturbations. Temperature fluctuations connected with the above mentioned events usually are very weak at the surface, but the amplitud e increases with height because of the exponential decrease of atmospheric pressure with increasing altitude. At the mesopause region (80 100 km height) signal amplitudes are about two to three orders of magnitude larger than on the ground. The GRIPS (GRou nd – based Infrared P – branch Spectrometer) measurement system operated by the German Remote Sensing Data Center of the German Aerospace Center (DLR) derives temperatures of the mesopause region by observing hydroxyl (OH) airglow emissions in the near infrare d atmospheric emission spectrum originating from a thin layer at approximately 87 km height.
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POSTER PRESENTATIONS: T3 – P1. Characterization of 2010 Mentawai earthquake based on source mechanism analysis by using regional and CTBT monitoring station Sugeng Pribadi 1 , Nanang T. Puspito 1 , Hendar Gunawan 2 1 Bandung Institute of Technology, Indonesia 2 Indonesian Meteorological Climatological and Geophysical Agency, Indonesia Contact: sugengmsc@gmail.com Since 1990 2010 the authors collect 30 tsunamigenic earthquake around Indonesia region (95º E – 141º E / 11º S 6º N). Furthermore we make the characterization of those events to support tsunami warning consideration. Some events categorized as tsunami earthquake which has various magnitude, shallow depth, long rupture duration, high rupture energy and unfelt shaking, e.g. 1994 and 2006 Java. Recently 2010 Mentawai earthquake was confusing to be characterized as the anomalous tsunami because of the anoma lous tsunami has not included in the system of Indonesian Tsunami Early Warning System (Ina – TEWS) which is only based on magnitude and hypocenter determination. The aim of research is to make the accurate and fast determination type of tsunami event to con firm the level of tsunami warning. The improvements is derived by using source mechanism parameters with W – phase method which has succeded to identify tsunami earthquake the 1992 Nicaragua and established in JMA and PTWC. It can explain energy and long wav e period of P, PP, SP separeted from surface waves. The velocity of 4.5 9.0 km/s is faster than Rayleigh wave because of non – effected by various material of plate tectonic. The input parameter of long period seismogram derived from IRIS and CTBT stations which the distance less than 40º. T3 – P2. Analysis of the first arrival of P – wave of Ina – TEWS and CTBT stations to support earthquake early warning Hendar Gunawan 1 , Gunawan Ibrahim 2 , Sugeng Pribadi 2 1 Indonesian Meteorological Climatological and Geophysical Agency (BMKG), Indonesia 2 Bandung Institute of Technology, Indonesia Contact: hendargunawan@hotmail.com The authors make the analysis of first arrivals of the P wave from Indonesian Tsunami Ea rly Warning System (Ina – TEWS) and CTBT stations. These are used for earthquake early warning, Magnitude determination, and potential earthquake hazard mitigation based on Seismogram acceleration. This research is focused on the study of energy duration of high frequency, and the maximum displacement of P – waves by observing broadband seismograms. The further analysis consists of deconvolution, recursive filtering for data restitution, and applying a Butterworth filter of second order. The Butterworth filter uses high frequency 0.075 Hz to cut the effect of drift, and band – pass frequency 2 – 4 Hz for use in magnitude calculation. We choose potentially damaging earthquakes to be greater than Mw 6.0. Based on the trigger on the 3 seconds the first arrival P – wave, the dominant period (Td) was calculated by using data Cisompet Seismological station, Garut (CISI station) and tested for data CTBT, Bandung (LEM station). This research resulted determination of the P – wave arrival time accurately using integrated skewnes s and kurtosis. Performent data from CTBT stations is very high. Signal to noise ratio >1000 after passing through the filter. Such riset conducted to find out a rapid magnitude estimations from predominant frequency of displacement are Log Td = 0.2406 M 1.3665, (R= 0.73) or M= 4.156 log (Td) + 5.6797. Furthermore, this formula can be used to support earthquake early warning in West of Java. T3 – P3. Detection of tsunami and T – phase by the Dense Oceanfloor Network System for Earthquakes and Tsunamis (DONET) Seiji Tsuboi , Takeshi Nakamura , Masaru Nakano , Tomoki Watanabe , Akiko To , Yoshiyuki Kaneda Japan Agency for Marine – Earth Science and T echnology Contact: tsuboi@jamstec.go.jp DONET is a cabled network observatory with real – time recording systems in the seismogenic zone of M8 class mega – thrust earthquake off – shore of Kii – peninsula in the Southern part of Japanese Islands. The network consists of an array of 20 stations with an interval of 15 – 20km, and each station includes broadband seismometer, strong motion seismometer, quartz – type pressure gauge, differential pressure gauge, hydrophone and thermometer. The network has partly inaugur ated its operation in 2010. An early detection of tsunami is one of the main observation targets of DONET. Tsunamis, generated by August 13, 2010 Mariana Islands earthquake (Mw 6.8), were successfully detected by the pressure gauge of DONET. The arrival ti me and amplitude of observed tsunami are well explained by synthetics computed with the fault mechanism solution of this earthquake. The observed tsunami shows clear dispersion of group velocity, presumably due to the emplacement of stations in the deep oc ean. They were detected at DONET stations
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significantly earlier than at terrestrial stations, which demonstrate a capability of the accurate early tsunami warnings along the coast of Japanese Islands. T3 – P4. A technique to determine the self – noise of sei smic sensors for performance screening Horst Rademacher 1 , Darren Hart 2 , Cansun Guralp 1 1 Guralp Systems Ltd., United States of America 2 Sandia National Laboratory , United States of America Contact: hrademacher@guralp.com Seismic noise affects the performance of a seismic sensor and is thereby a limiting factor for the detection threshold of monitoring networks. Among the various sources of noise, the intrinsic selfnoise of a seismic sensor is most d iffcult to determine, because it is mostly masked by natural and anthropogenic ground noise and is also affected by the noise characteristic of the digitizer. Here we present a new technique to determine the self – noise of a seismic system (digitizer + sens ors). It is based on a method introduced by Sleeman et al. (2005) to test the noise performance of digitizers. We infer the self – noise of a triplet of identical sensors by comparing coherent waveforms over a wide spectral band across the set – up. We will sh ow first results from a proof – of – concept study done in a vault near Albuquerque, New Mexico. We will show, how various methods of shielding the sensors affect the results of this technique. This method can also be used as a means of quality control during sensor production, because poorly performing sensors can easily be identified. T3 – P5. Seismic noise analysis at some broadband stations of Egyptian National Seismological Network Abd El – Aziz Khairy Abd El – Aal National Research Institute of Astronomy and Geophysics, Egyptain National Seismological Netwok, and National Data Center IDC, Egypt Contact: dewaky@yahoo.com The background noise at some investigated sties named Siwa, Hurghada, Abou – Dabbab, and Farafra sites was analyzed to assess the effects of permanent seismic vault construction. Also to determine the time needed for noise at these sites to stabilize and to choose the non – noise sites for installing and constructing the permanent broad band stations. W e calculated the power spectral densities of background noise for each component of each broadband seismometer deployed in the different investigated sites. We compared them with the high – noise model and low – noise model of Peterson (1993). Noise levels wer e considerably higher at Abou – Dabab site, but it still below of high – noise model of Peterson (1993). Based on the obtained analysis, the seismology department decided to install the broad band stations at these sites taking into consideration all required precautions for installing these stations. After construction we measured the noise stability and the efficiency of station to record regional and teleseismic events. The results of this study could be used to evaluate station quality, improve those proces ses that require background noise values, such as automatic association and to improve the estimation of station and network detection and location thresholds. T3 – P6. Improvement of the equipment for measurements of atmospheric xenon radionuclides Sergei Pakhomov , Yuri Dubasov Khlopin Radium Institute, Russian Federation Contact: s_a_pakhomov@mail.ru Khlopin Radium Institute has developed the improved version of equipment for the measurement of atmospheric xenon r adionuclides. This equipment includes new kind of high – efficiency sampling installation combined with the sample – processing unit and special low – background gas – volume spectrometer of – – coincidences. This equipment is suitable solution to a wide range of tasks, including atmospheric xenon monitoring in areas of NPP emission influence, on – site inspections and measurements of background xenon radioactivity and can be used both in mobile and in stationary deployment variants. The main feature of developed equ ipment is the reaching of the cryogenic temperatures, required for xenon adsorption, using the analyzed air itself instead of the external helium gas – cooling machine. The performance of sampling is 25 m3 per hour with efficiency 65%, the sampling cycle dur ation ranges from 3 to 7 hours. On the base of the developed complex in the Khlopin Radium Institute the prototype of mobile laboratory has been organized. The main task of this laboratory is the monitoring of xenon radionuclides in the atmospheric air and the further improvement of designed equipment. T3 – P7. Using the Garni IMS auxiliary station records in operation of the next – generation real – time seismic intensity display system in Armenia Valery Arzumanyan National Survey for Se ismic Protection, Ministry of Emergency Situations, Armenia Contact: valeryson@yahoo.com
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