We performed a seismo-acoustic "Ground Coupling Experiment" at the CTBTO infrasound test site near the Conrad Observatory, Austria. Seismic and acoustic signals were generated by hammer beats, fireworks (rockets and crackers), human steps and wind. Seismo-acoustic signals were recorded by 99 Fairfield ZLand geophone nodes and four Hyperion IFS 5111 seismically decoupled infrasound sensors, as...
The Cyprus Department of Meteorology (DoM) has developed a state-of-the-art network of Automatic Weather Stations (AWS). Each station can accommodate virtually any kind of sensor and is also equipped with an industrial computer, capable of data pre- and post-processing. Station measurements are available in real time to end users and end up in DoM's climatological database for further quality...
The Royal Netherlands Meteorological Institute (KNMI) operates a three-dimensional
microbarometer array at the Cabauw Experimental Site for Atmospheric Research observatory.
The array consists of five microbarometers on a meteorological tower up to an altitude of 200 m.
Ten ground-based microbarometers surround the tower with an array aperture of 800 m. This
unique setup allows for the...
The primary standard for sound pressure is defined through the reciprocity calibration method specified in the International Electrotechnical Commission (IEC) Standard 61094-2:2009. This method is based on the use of closed couplers and is routinely applied by the National Metrology Institutes for a large frequency range; however, infrasonic frequencies below 2 Hz have not been explored until...
Explosive events in the atmosphere create significant pressure waves in the air. Those pressure waves propagate as shock waves near the source and quickly transitioned into acoustic waves in the far-field. Since low-frequency acoustic waves, so called infrasound, propagate long distances without significant loss of energy, acoustic signals induced by explosions are used to determine explosion...
Accurate infrasound propagation modeling is important for both understanding atmospheric processes and detailed infrasound source studies. Recent research has shown that over local distances (<15 km), topography is often the dominant influence on recorded infrasound signals. In addition to reflection or diffraction from interference with the topographic surface, infrasonic waves may also...
In routine processing of IMS infrasound data at the IDC, microbaroms with dominant frequencies ranging from 0.1 to 0.5 Hz appear in overlapping frequency bands and are considered as noise. In this study, microbarom signals were used as calibration signals, and their amplitudes at the German infrasound station IS26 were modelled based on operational ocean wave interaction simulations and a...
Long-range infrasound propagation is greatly affected by winds and temperature gradients in the atmosphere. To understand these effects and accurately determine acoustic source information, detailed characterization of the spatial and temporal variability of the atmosphere is vital. Alaska Volcano Observatory Ground-to-Space (AVO-G2S) is an open source atmospheric reconstruction model that...
While stochastic parameterizations in Global Climate Models (GCMs) are promising for improving longstanding climate predictions, there is no consensus regarding the values of tunable parameters. In this work, we propose a Bayesian hierarchical approach to calibrate the input parameters of a stochastic multiwave gravity wave (GW) scheme, which is currently in use in the LMD GCM. The GW field is...
The International Monitoring System infrasound network dedicates to the verification of the Comprehensive Nuclear Test-Ban-Treaty. However, due to its high potential for scientific applications as well as the clamor for the access international scientific community, data from IMS stations were made available for use in other applications, like investigations about thunderstorms. Some studies...
The motion and friction between soil particles and the crack propagation in the soil mass will generate infrasound waves before earthiness landslide sliding. In order to analysis the characteristics of infrasound signals of earthiness landslide critical-sliding, six groups of landslide simulation experiments are carried out on the soil slope model, at the same time, acquiring the infrasound...
The ability of the International Monitoring System (IMS) network to detect atmospheric explosions and events of interest strongly depends on station-specific ambient noise signatures. Around 0.2 Hz, a persistent source of signals that radiate microbaroms over spatially extended regions is generated by the second order non-linear interaction of ocean waves, mostly during severe storms. A...
Kazakh national Data Center operates three infrasound and five seismic arrays. Detection of the microbarom and microseism has been done in the arrays records for the years 2014 - 2017. On the basis of the search and also the source and propagation modelling for microbaroms, two basic conclusions were made concerning the nature of microseism and microbarom recorded within Kazakhstan. It was...
Low frequency sound between 0.01-20 Hz, known as infrasound, is produced by a variety of natural and anthropogenic sources. Within this frequency band, wind is a persistent source of infrasonic noise. Infrasound sensors measure pressure fluctuations, which scale with the ambient density and velocity fluctuations of ground winds. Therefore, reducing wind velocity works to lower the signal...
Surface vertical vibration arising from earthquake is considered to excite sound and it has been observed by barometer or microphone. Pressure change after earthquake is mainly generated by following three reasons. 1) Air vibration (compressional wave) is excited by earthquake ground motion around barograph. 2) Internal mechanical response is accelerated by earthquake. 3) Barograph itself...
On September 1st, 2018 a devastating explosion occurred on the facility of an oil refinery near Ingolstadt, Germany. We analyzed data of 400 permanent and temporary seismic stations and find strong seismo-acoustic signals on more than 80 seismic stations. The infrasound signal is detectable on seismic stations within 10 - 350 km from the source, with 40 km spatial resolution. We confirm the...
Traditionally, infrasound research has been driven largely by defense needs, namely to monitor nuclear and chemical explosions. However, there are growing numbers of potential scientific and civil applications for infrasonic observing systems. This field of very low frequency acoustics is globally well developed, which the world nowadays has an extensive worldwide network of infrasound sensors...
The Poster : Intrduction The modern area of infrasound studies was ushered in by the nuclear age, and the attendant needs to monitor the Earth and its atmosphere for clandestine nuclear test. Monitoring requirements became more eargent with the initiation of the Comprehensive Nuclear Test Ban Treaty CTBTO, Which sought to ban all nuclear tests.The IMS dat could become an important archive for...
The PTS has made a concerted effort over the last 10 years to explore and test multiple infrasound sensors, which could be approved for deployment within the IMS infrasound network. Approving a sensor model for use in the IMS network (type approval) involves many steps including, but not limited to, sensor testing at accredited laboratories, testing within operational conditions, assessment of...
The International Monitoring System comprises four technologies: seismological, radionuclide, hydroacoustic, and infrasound. An important limitation of these technologies is due to the fact that the structure of the propagation medium is partially known. This is especially true for infrasound and indeed, a current trend is to take into account the impact of atmospheric small-scale structures...
In Jordanian National Data Center (NDC-JO) we are looking forward to a PTS portable infrasound array which will deploy for one year or more, within a collaboration project between JSO and PTS of the Preparatory Commission for CTBTO. This joint experiment aims to contribute in many important and interesting objects like: advanced understanding of infrasound sources in Middle East, training...
Recent developments of portable infrasound arrays I69CR and IVTCR. It has been possible to locate some infrasound events near the Latin American and Caribbean area. On April 23, 2019, at 21:07:22 (local time), infrasound stations in Costa Rica detected and located Aguas Zarcas meteorite, that fall in the territory of Costa Rica, this event was possible to detect by infrasound stations I69CR,...
An invaluable tool in characterizing any receiver is a source with known and repeatable signal characteristics. This talk discusses development and characterization of a non-explosive, coherent source within the IMS infrasound band for the purpose of on-site calibration and detection system testing. Development of an infrasound band source is challenging because of the requirement to move a...
The ShakeMap is a key component in the initial relief e_orts following an earthquake disaster. It depicts the distribution of shaking intensity in the epicentral region and is used to guide emergency responders to the region. In regions where seismic instrumentation is limited, such ShakeMaps are poorly constrained and can take days to generate. We show, that pseudo-ShakeMaps that indicate the...
Seismoacoustic effects of the Hovsgol earthquake of December 5, 2014 (51.37N, 100.63E, MW=4.9) and Khoitogol earthquake of March 29, 2019 (51.71N, 101.54E, MW=4.7) were studied. Earthquakes occurred in the south-western part of the Baikal rift system: the first event located in the Hovsgol basin at 3 km depth, the second – in the Khoitogol basin at the depth 10 km. An acoustic signals were...
A long-term field study is being performed at Sandia National Laboratories (SNL) Facility for Acceptance, Calibration, and Testing (FACT) to compare the performance of several infrasound sensors in active use. The goal of this study, which was initiated at the beginning of 2018 and is continuing into 2019, is to evaluate the relative performance of the sensors in a field environment in which...
According to NASA agency there are 789 fireballs were recorded from 1988 to 2019, there are two fireballs recorded as greatest fireballs in the world (greater than 100 kilotons of TNT) and detected by the International Monitoring System (IMS). One of these largest fireballs recorded over the RUSSIA On February 15, 2013 with 440 kilotons of TNT with extreme range reached to 20 IMS infrasound...
In operational condition, infrasound sensors are subject to extraneous disturbances including environmental variations and in particular variation of the ambient air temperature. Susceptibility of sensors to these variations is considered to be a key point that contributes to the overall level of expected performance and confidence in measurement in complement to basic calibration. A new...
We evaluate experimental shrouds mounted on Hyperion IFS-5201W digital infrasound sensors. The experimental shrouds were designed by Doug Seastrand and Gary Walker of the Nevada National Security Site, National Nuclear Security Administration, as a means to further reduce wind noise. The shrouds inter-mix air pressure sampled, around the axially-symmetrical sensor body, through...
As a result of the long term sensor comparison testing at the Sandia National Labs FACT site,
the U.S. is in the process of replacing the Chaparral 50A at US IMS arrays and installing a
reference sensor at each element. We will present the installation and testing of the replacement
Hyperion sensors at I53US and how the reference sensors will be implemented and used.
This work was...
The Ground Coupling Experiment was performed in May 2019 at the CTBTO test site near the Conrad observatory in Austria - to study propagation and coupling of mechanical waves above and below ground. Signals were generated by hammer shots, explosives, rockets, steps, and wind. Infrasound was recorded by seismically-decoupled infrasound sensors (4 Hyperion IFS-5111 with wind shielding buckets),...
Recent developments in infrasonic event association and location methods rely on prior probability distributions for infrasound signal parameters. Whilst numerical acoustic propagation modelling through atmospheric specifications may be used to provide both range dependent and time specific priors for signal parameters (e.g., celerity), analyses of ground truth data sets are necessary to...
The International Data Center operates in real time, performing network processing to localize events. In this context, the relevance of full-wave modeling is unclear for two reasons. First, atmospheric specifications are necessarily statistical in nature, whereas sound propagates through a particular atmospheric state, which is indeed not known. While a current trend is to undertake the...
At approximately 10:08 UTC on February 18th, 2019, a large atmospheric explosion originating over Zambia was detected at 8 infrasound arrays belonging to the International Monitoring System (IMS) of the Comprehensive Nuclear Test-ban Treaty Organization (CTBTO). This explosion, later associated with a bolide, was detected as far away as Alaska, at a range of more than 15,000 km. Here we show...
The IDC advances its methods and continuously improves its automatic system for the infrasound technology. The IDC focuses on enhancing the automatic system for the identification of valid signals and the optimization of the network detection threshold by identifying ways to refine signal characterization methodology and association criteria. Alongside these efforts, the IDC and its partners...
Namibia, rich in resources has a number of open pit mines. We have an infrasound station 15 km North of Tsumeb that forms part of the International Monitoring System, (IMS). Explosions used in mining operations have similar signal forms to that of nuclear explosions. Change in the topography is monitored by remote sensing techniques (satellite images).The objective is to know if the...
In-situ reference sensors (without wind noise reduction systems) are being installed at IMS infrasound arrays, next to each operational sensor. Without additional information, coherence measures between the reference and operational sensor recordings are unable to separate time periods for which the ambient pressure fluctuations across both sensors are dominated by either long wavelength...
The Central and Eastern European Infrasound Network was established in 2017 and it joins 9 recently installed infrasound arrays located in Hungary, Romania, Czechia, Austria and Ukraine. The collaboration aims to contribute both to advanced understanding of infrasound sources in Central Europe and to the ARISE design study project, as an enhancement of the European infrasound network. The...
Meteorites that penetrate the atmospheric layers can cause horror and may have an impact on population and infrastructure. When meteorites explodes in upper atmosphere it produces infrasound waves that can travel long distances with considerable no lose. The data of IMS infrasound stations used with PMCC algorism for interpretation, detecting the location and statistical analysis of two...
Saturday, Desember 22th 2018, 09.27 PM western indonesian time, Lampung Province region (South Lampung District) and Banten Province (Pandeglang and Serang District), struck by devastating tsunami landslide caused by Anak Krakatau eruption. We conduct seismic waveform analysis and several tsunami modelling scenario caused by landslide to find the source of tsunami and the effect to the region...
Monitoring our global environment with the infrasound array network to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), has also proved useful in several other man-made and natural phenomena, particularly in geo-hazards applications. Infrasound waves emissions from natural phenomenon such as volcanic eruption travel through the atmospheric layers resulting in pressure...
A magnitude 7.5 earthquake occurred on 28 September 2018 at 10:02:43 UTC near the city of Palu on the Indonesian island of Sulawesi. It was a shallow, strike-slip earthquake with fractures up to the surface and a rupture length of about 150 km. Moreover, this earthquake was identified as one of very few events having a super shear rupture speed. Clear and long-lasting infrasound signatures...
Infrasound is one of three waveform technologies used in the CTBT verification regime and the Commission has an interest in advancing the capability of the IMS to detect explosions in the atmosphere. On 26 August 2009, 24 and 26 January 2011, the CTBTO make three large-scale explosives had equivalent TNT yields of 96.0, 7.4, and 76.8 t for infrasound experiments. In Jordanian NDC the local...
Argentina is a Member State of the Comprehensive Nuclear-Test Ban Treaty Organization (CTBTO) and as such has stations that form part of the International Monitoring System (IMS) network, part of which consists of Infrasound Stations. As part of corrective maintenance measures, two agents/operators from the Nuclear Regulatory Authority (ARN) performed tests on the noise reduction system on one...
Infrasound is one of four technologies used in the CTBT verification regime and the Commission has an interest in advancing the capability of the IMS to detect explosions in the atmosphere. On 26 August 2009, 24 and 26 January 2011, the CTBTO make three large-scale explosives had equivalent TNT yields of 96.0, 7.4, and 76.8 t for infrasound experiments. In Jordanian NDC the local station is...
Inaudible sound, i.e., infrasound, is generated by glacial run-off and during calving events. Such sounds can be continuously monitored with microbarometer arrays. Changes in the rate of events can be retrieved with a resolution of a few seconds. Applying array processing techniques enables the identification of individual glaciers over ranges of tens of kilometers. We concentrated on the...
Three infrasound stations has been deployed on the Romanian territory by National Institute for Earth Physics (NIEP): IPLOR 6-element array of 2.5 km aperture, in operation since 2009 in the central part of the country, BURARI 4-element research array of 1.2 km aperture, installed in July 2016, in the northern Romania, under a joint effort with Air Force Technical Application Center AFTAC...
The International Monitoring System (IMS) is in place for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Part of the IMS are 60 infrasound arrays, of which 51 currently provide real-time infrasound recordings from around the world. Those arrays play a central role in the characterization of the global infrasonic wavefield and localization of infrasound sources (e.g.,...
In the frame of its activities in exploiting and processing IS48 data using DTK-tools , NDC-TN initiated a project which aims to produce a regional infrasound sources catalogue. As first part of our study and in order to gain in time and effort, an Infrasound Data Daily Automatic Processing was developed based on the exploitation of DTK-PMCC in order to produce a daily bulletin of the IS48...
Jordan is a relatively small country situated at the junction of the Levantine and Arabian areas of the Middle East. The Dead Sea fault zone is a major left-lateral strike-slip fault. South of the Dead Sea basin, the Wadi Araba fault extends over 160 km to the Gulf of Aqaba. The Dead Sea fault zone (DSTF) is known to have produced several relatively large historical earthquakes. However, the...
Low-frequency infrasound observations (0.01-0.1 Hz) of so-called mountain-associated waves (MAWs) were initially reported in the 1970s. Those observations were limited to sets of regional microbarometer arrays. Different theories on the source generation mechanism evolved; however, the atmospheric variability seemed to complicate assessing the exact mechanism. Nowadays, the infrasound network...
With the strong mandate to sustain high annual data availability throughout the network in face of harsh environmental, logistical, and meteorological challenges, it becomes imperative to design power systems with increased resiliency, added redundancy and trusted components, which passed the test of time. The design and deployment of the next-generation IMS power systems thus creates a window...
Variations in acoustic pressure in the event of an atmospheric phenomenon such as auroral arcs occurrence generate infrasonic signals that are sensitive to microbarometer sensors of the infrasound network deployed globally. The International Monitoring System (IMS) infrasound network monitors and detects these non-verification-related low frequency acoustic signals periodically. These auroral...
As part of the International Monitoring System a dedicated 60-element infrasound network is currently under construction to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty. As of now, 51 out of these 60 stations are certified and operational. The infrasound signals of interest are typically in the range from 0.02 to 4 Hz. The measurement of these acoustic signals takes place...
The 18 December 2018, a large bolide exploded over Bering Sea. More than three months after the event, NASA reported its geographic location, its altitude and velocity at peak brightness, so that this event can be considered as a ground truth event. Bolide-generated acoustic signals were detected by 18 IMS infrasound stations up to more than 15000 km at I55US (Antarctica), tens of...
Infrasound waves are emitted by various geophysical sources such as volcanoes, northern lights and ocean swell. In many situations, the middle-atmosphere can behave as a waveguide and infrasound can propagate up to thousands of kilometers. In such cases, infrasound signals can be recorded by stations of the International Monitoring System (IMS). Reliable simulation-based predictions of...
One approach for meeting the on-site calibration requirements for infrasound stations of the International Monitoring System (IMS) involves installation of one or more reference sensors at each element. Sandia National Laboratories (SNL) has equipped two of its Facility for Acceptance, Calibration and Testing (FACT) Site Array (FSA) elements with reference sensors – two at each of the two...
Infrasound monitoring is a key technology in the CTBT verification regime and the Commission has an interest in advancing the capability of the IMS to detect explosions in the atmosphere. In the past the PTS is sponsoring an infrasound calibration experiment in the eastern Mediterranean region. The experiment is to calibrate and validate the processing methods used by the CTBTO to detect and...
The infrasound portable array deployment in Jordan is proposed in this research. The deployment and installation of CTBTO infrasound in active tectonics in Jordan would be beneficial for advancing the understanding of infrasound sources in the Dead Sea Transform (DST) region and around. In the region including Jordan, the DST system is responsible for the earthquakes as well as the previous...
A quality assurance infrastructure for IMS infrasound measurements has been developed to comply with the certification, revalidation and calibration requirements defined in the Operational Manual for Infrasound Monitoring and the International Exchange of Infrasound Data (CTBT/WGB/TL-11,17/17/Rev.6). This quality assurance infrastructure follows guidance from the Report of Working Group B to...
The NCPA has developed an infrasound calibration facility capable of calibrating sensors over frequencies from 0.002-20 Hz and amplitudes from a few milli-pascal to 40 Pa. The static pressure in the tank can be varied from 40 kPa to 120 kPa, and the effects of temperature can be tested for variations from -20°C to ±45°C. Here we discuss quality assurance (QA) evaluation of different types of...
The characterization of infrasound sources detected by I17CI station was carried out using CEA infrasound bulletins from October 2009 to June 2016. The signals were processed in the frequency range [1 - 2] Hz. Two types of regional infrasound wave emitting sources were found. The emitting sources are seasonal and permanent sources. Seasonal sources are mainly convective systems over West...
As moderate devastated earthquake that impacted the economic loss was about $ 1.68 million U.S, the 2018 Kalibening earthquake quite shocked where the faulting mechanism still unconfirmed. So do with any reference that did not indicated the existence of faulting zone exactly on the earthquake sequence. We take benefit from temporary network with density 2 km which deployed while macroseismic...
California a State in the United States of America is covered locally and regionally by the CTBTO IMS network of infrasound and seismic (primary and auxiliary) stations. An earthquake occurred in Coso Junction outside of Ridgecrest on July 6, 2019 (3:19 GMT). The location of event was estimated with seismic and infrasound (I57US) data obtained from local and regional IMS stations that recorded...
Sound waves with frequencies less than 10 Hz are referred to as infrasound. These waves have long wavelengths ranging from tens of meters at 10 Hz t several tens of kilometers near 0.01 Hz. Natural Sources of infrasound in Jordan include: earthquakes, aircraft and machinery such as wind turbines. Infrasound Technology is to detect and locate explosions in the atmosphere. It can be used in...
For infrasound station capability related.
The level of confidence expected by the measurement produced by geophysical measurement chains is a guarantee of quality for the data that are processed in the subsequent analysis and the elements necessary for the resulting decision-making. The CEA's metrology activity in the infrasound field has historically contributed to the development of this confidence. The fields of low-frequency...
In accordance with our ongoing quality approach, a running-in step for infrasound sensors has been investigated and implemented. Once the metrology process is completed, objective is to keep monitoring on sensitivity of MB3a sensors during several days, using the in-situ electrical calibration capability. For this purpose, a bench has been designed and characterized. Different sensitivity...
Stromboli volcano (918 m a.s.l.) is located in a small Italian island of the same name that belongs to the Aeolian archipelago, in the Mediterranean sea. Its continuous explosive activity and persistent degassing since at least 3-7 AD (Rossi et al., 2000) makes it probably the world's best-known volcano due its spectacular basaltic explosions interspersed by lava fountains up to 250 m...
Infrasound monitoring is one of the three waveform technologies utilized by the CTBT (Comprehensive Nuclear-Test-Ban Treaty) verification regime. The International Monitoring System (IMS) of the CTBT verification regime contains a global network of 60 infrasound stations, situated in 35 countries around the world.The infrasound station consists of 10 measurement points, each with one...
The infrasound component of the International Monitoring System (IMS), often referred to as the IMS infrasound network, is composed of sixty stations. Fifty-one of these stations are already certified and transmit data in near real-time to the International Data Centre, Vienna, Austria. The Provisional Technical Secretariat (PTS) of the Preparatory Commission for the Comprehensive...
The characteristics of infrasound waves (such as frequency spectra, amplitudes, attenuation over ground surface) generated by a water dam are presented in this paper. A possible infrasound generation mechanism is proposed based on earlier models of infrasound generation by large objects falling into water. The mechanism suggests that the water falling through dam’s ducts into absorption pool...
At the moment, the researches in the field of seismic and infrasound monitoring are very interested in historical air nuclear tests. This interest is first of all connected with the task on detecting and discriminating nuclear tests within the CTBT, calibration and creation of reference events database for the existing IMS network et al. Lop Nor Test Site is located at Xinjiang province, about...
The Infrasound Station IS32, herein referred to as "the station", is located about 10 km to the NNE of the city of Nairobi within Karura forest in Kenya. The thick forest canopy offers an excellent environment for the station by significantly minimizing cultural noise. In July-August 2019, the station underwent a major upgrade at all the seven element array sites and the Central facility (CF)...
Comparison of infrasound sensor responses from field-based testing at the Sandia National Labs FACT site has revealed notable deviations from lab-based calibrations under standard conditions of temperature and pressure. All sensors tested have exhibited amplitude variations occurring on both long-term (months) and short-term (diurnal) timescales. Here we present results from continued field...
The station IS41 is located in Paraguay, in the middle of South America. It is composed by 4 elements and was certified in December 2003. The environment features stand out for the frequent occurrences of electric storms, high temperatures, copious rains and sometimes the access to the log elements becomes very complicated. It is presented the most common and recurrent problems of the station...
Infrasound technology uses to detect very low-frequency sound waves in the atmosphere produced by events such as nuclear explosions, movements of glaciers, marine storms, hurricanes and tornadoes, mines and chemical explosions and landslides and avalanches. The IMS consist of no. of infrasound stations at Indian Ocean Region and record valuable information which helps in identifying different...
Cote d’Ivoire NDC in collaboration with CTBTO deployed from January to December 2018, a mobile infrasound array (I68CI) in North-East (Comoe Reserve) of Cote d’Ivoire. This portable array had 5 sensors and had been sampling at 50Hz. I68CI detected local, regional and distant infrasound sources. In this tropical region, during monsoon season, the main sources detected by the portable array are...
