ºÝºÝߣshows by User: mrozhkov / http://www.slideshare.net/images/logo.gif ºÝºÝߣshows by User: mrozhkov / Thu, 19 Dec 2013 14:00:36 GMT ºÝºÝߣShare feed for ºÝºÝߣshows by User: mrozhkov Performance of waveform cross correlation using a global and regular grid of master events /slideshow/rozhkov-global-grid-29366570/29366570 rozhkovglobalgrid-131219140036-phpapp01
Seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) requires a uniform distribution of detection threshold over the earth. By design, the Primary Seismic Network of the International Monitoring System (IMS) provides an appropriate coverage. In order to effectively use the cross correlation technique and the archive waveforms from the International Data Centre (IDC) in global monitoring we have introduced a dense (spacing of ~ 140 km) and regular grid of master events with high quality templates at IMS array stations. In seismically active zones, we populated the grid with real masters. For aseismic zones, we developed an extended set of synthetic templates for virtual master events. This set includes a few simple double-couple source mechanisms in 1D and 2D velocity structures as well as explosion sources of varying size and at different depths of burial. All synthetics were first tested in seismic areas and showed the detection threshold similar to that demonstrated by real templates. We have designed three versions of the grid: V1.0 with only synthetic templates, V2.0 with real masters added where possible, and V3.0 with grand masters added. Their performance has been assessed by full processing of a few data days and a direct comparison with the Reviewed Event Bulletin issued by the IDC. ]]>
Seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) requires a uniform distribution of detection threshold over the earth. By design, the Primary Seismic Network of the International Monitoring System (IMS) provides an appropriate coverage. In order to effectively use the cross correlation technique and the archive waveforms from the International Data Centre (IDC) in global monitoring we have introduced a dense (spacing of ~ 140 km) and regular grid of master events with high quality templates at IMS array stations. In seismically active zones, we populated the grid with real masters. For aseismic zones, we developed an extended set of synthetic templates for virtual master events. This set includes a few simple double-couple source mechanisms in 1D and 2D velocity structures as well as explosion sources of varying size and at different depths of burial. All synthetics were first tested in seismic areas and showed the detection threshold similar to that demonstrated by real templates. We have designed three versions of the grid: V1.0 with only synthetic templates, V2.0 with real masters added where possible, and V3.0 with grand masters added. Their performance has been assessed by full processing of a few data days and a direct comparison with the Reviewed Event Bulletin issued by the IDC. ]]> Thu, 19 Dec 2013 14:00:36 GMT /slideshow/rozhkov-global-grid-29366570/29366570 mrozhkov@slideshare.net(mrozhkov) Performance of waveform cross correlation using a global and regular grid of master events mrozhkov Seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) requires a uniform distribution of detection threshold over the earth. By design, the Primary Seismic Network of the International Monitoring System (IMS) provides an appropriate coverage. In order to effectively use the cross correlation technique and the archive waveforms from the International Data Centre (IDC) in global monitoring we have introduced a dense (spacing of ~ 140 km) and regular grid of master events with high quality templates at IMS array stations. In seismically active zones, we populated the grid with real masters. For aseismic zones, we developed an extended set of synthetic templates for virtual master events. This set includes a few simple double-couple source mechanisms in 1D and 2D velocity structures as well as explosion sources of varying size and at different depths of burial. All synthetics were first tested in seismic areas and showed the detection threshold similar to that demonstrated by real templates. We have designed three versions of the grid: V1.0 with only synthetic templates, V2.0 with real masters added where possible, and V3.0 with grand masters added. Their performance has been assessed by full processing of a few data days and a direct comparison with the Reviewed Event Bulletin issued by the IDC. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovglobalgrid-131219140036-phpapp01-thumbnail.jpg?width=120&amp;height=120&amp;fit=bounds" /><br> Seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) requires a uniform distribution of detection threshold over the earth. By design, the Primary Seismic Network of the International Monitoring System (IMS) provides an appropriate coverage. In order to effectively use the cross correlation technique and the archive waveforms from the International Data Centre (IDC) in global monitoring we have introduced a dense (spacing of ~ 140 km) and regular grid of master events with high quality templates at IMS array stations. In seismically active zones, we populated the grid with real masters. For aseismic zones, we developed an extended set of synthetic templates for virtual master events. This set includes a few simple double-couple source mechanisms in 1D and 2D velocity structures as well as explosion sources of varying size and at different depths of burial. All synthetics were first tested in seismic areas and showed the detection threshold similar to that demonstrated by real templates. We have designed three versions of the grid: V1.0 with only synthetic templates, V2.0 with real masters added where possible, and V3.0 with grand masters added. Their performance has been assessed by full processing of a few data days and a direct comparison with the Reviewed Event Bulletin issued by the IDC.
Performance of waveform cross correlation using a global and regular grid of master events from Mikhail Rozhkov
]]> 447 2 https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovglobalgrid-131219140036-phpapp01-thumbnail.jpg?width=120&height=120&fit=bounds presentation White http://activitystrea.ms/schema/1.0/post http://activitystrea.ms/schema/1.0/posted 0 The Chelyabinsk meteor: joint interpretation of infrasound, acoustic, and seismic waves /mrozhkov/rozhkov-meteorite-fin5 rozhkovmeteoritefin5-131219135102-phpapp01
The Chelyabinsk meteor was an event testing the capability of the International Monitoring System to measure and the International Data Centre to analyze sources similar to nuclear explosions. Monitoring of the Comprehensive Nuclear-Test-Ban Treaty suggests the possibility to detect infrasound (acoustic) and seismic signals from atmospheric and underground events and to locate their sources. The shock wave from the Chelyabinsk meteor generated an I-phase recorded by IMS infrasound stations and a series of seismic phases. The Pn-waves were observed by five near-regional seismic stations together with Sn- and Lg-waves. They are most likely associated with the impact of the meteor debris and the location associated with their source differs by tens of kilometers from that obtained by Rayleigh and Love waves. The latter were generated by acoustic (low-amplitude shock) waves hitting the ground beneath the trajectory of the meteor. Surprisingly, these surface waves associated with the meteor and observed at least at distances of 45º were not associated with the event in the Reviewed Event Bulletin. This implies a conceptual gap in the IDC processing and fusion of acoustic and seismic waves. We present an approximate distribution of energy release along the trajectory and thus the amplitude of the generated shock wave. This allows interpreting the period and amplitude dependence of the LR and LQ waves on the trajectory altitude. Corresponding relationships were obtained from the set of historical atmospheric nuclear tests. We also compare the Chelyabinsk meteor with seismic observations from the 1984 Chulym River (Siberia) bolide, which was approximately 1000 km east of the studied event. We estimate the energy of both bodies and its distribution between various waves in order to interpret their respective sources and to discuss possible mechanisms of acoustic/seismic wave generation and conversion. ]]>
The Chelyabinsk meteor was an event testing the capability of the International Monitoring System to measure and the International Data Centre to analyze sources similar to nuclear explosions. Monitoring of the Comprehensive Nuclear-Test-Ban Treaty suggests the possibility to detect infrasound (acoustic) and seismic signals from atmospheric and underground events and to locate their sources. The shock wave from the Chelyabinsk meteor generated an I-phase recorded by IMS infrasound stations and a series of seismic phases. The Pn-waves were observed by five near-regional seismic stations together with Sn- and Lg-waves. They are most likely associated with the impact of the meteor debris and the location associated with their source differs by tens of kilometers from that obtained by Rayleigh and Love waves. The latter were generated by acoustic (low-amplitude shock) waves hitting the ground beneath the trajectory of the meteor. Surprisingly, these surface waves associated with the meteor and observed at least at distances of 45º were not associated with the event in the Reviewed Event Bulletin. This implies a conceptual gap in the IDC processing and fusion of acoustic and seismic waves. We present an approximate distribution of energy release along the trajectory and thus the amplitude of the generated shock wave. This allows interpreting the period and amplitude dependence of the LR and LQ waves on the trajectory altitude. Corresponding relationships were obtained from the set of historical atmospheric nuclear tests. We also compare the Chelyabinsk meteor with seismic observations from the 1984 Chulym River (Siberia) bolide, which was approximately 1000 km east of the studied event. We estimate the energy of both bodies and its distribution between various waves in order to interpret their respective sources and to discuss possible mechanisms of acoustic/seismic wave generation and conversion. ]]> Thu, 19 Dec 2013 13:51:02 GMT /mrozhkov/rozhkov-meteorite-fin5 mrozhkov@slideshare.net(mrozhkov) The Chelyabinsk meteor: joint interpretation of infrasound, acoustic, and seismic waves mrozhkov The Chelyabinsk meteor was an event testing the capability of the International Monitoring System to measure and the International Data Centre to analyze sources similar to nuclear explosions. Monitoring of the Comprehensive Nuclear-Test-Ban Treaty suggests the possibility to detect infrasound (acoustic) and seismic signals from atmospheric and underground events and to locate their sources. The shock wave from the Chelyabinsk meteor generated an I-phase recorded by IMS infrasound stations and a series of seismic phases. The Pn-waves were observed by five near-regional seismic stations together with Sn- and Lg-waves. They are most likely associated with the impact of the meteor debris and the location associated with their source differs by tens of kilometers from that obtained by Rayleigh and Love waves. The latter were generated by acoustic (low-amplitude shock) waves hitting the ground beneath the trajectory of the meteor. Surprisingly, these surface waves associated with the meteor and observed at least at distances of 45º were not associated with the event in the Reviewed Event Bulletin. This implies a conceptual gap in the IDC processing and fusion of acoustic and seismic waves. We present an approximate distribution of energy release along the trajectory and thus the amplitude of the generated shock wave. This allows interpreting the period and amplitude dependence of the LR and LQ waves on the trajectory altitude. Corresponding relationships were obtained from the set of historical atmospheric nuclear tests. We also compare the Chelyabinsk meteor with seismic observations from the 1984 Chulym River (Siberia) bolide, which was approximately 1000 km east of the studied event. We estimate the energy of both bodies and its distribution between various waves in order to interpret their respective sources and to discuss possible mechanisms of acoustic/seismic wave generation and conversion. <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovmeteoritefin5-131219135102-phpapp01-thumbnail.jpg?width=120&amp;height=120&amp;fit=bounds" /><br> The Chelyabinsk meteor was an event testing the capability of the International Monitoring System to measure and the International Data Centre to analyze sources similar to nuclear explosions. Monitoring of the Comprehensive Nuclear-Test-Ban Treaty suggests the possibility to detect infrasound (acoustic) and seismic signals from atmospheric and underground events and to locate their sources. The shock wave from the Chelyabinsk meteor generated an I-phase recorded by IMS infrasound stations and a series of seismic phases. The Pn-waves were observed by five near-regional seismic stations together with Sn- and Lg-waves. They are most likely associated with the impact of the meteor debris and the location associated with their source differs by tens of kilometers from that obtained by Rayleigh and Love waves. The latter were generated by acoustic (low-amplitude shock) waves hitting the ground beneath the trajectory of the meteor. Surprisingly, these surface waves associated with the meteor and observed at least at distances of 45º were not associated with the event in the Reviewed Event Bulletin. This implies a conceptual gap in the IDC processing and fusion of acoustic and seismic waves. We present an approximate distribution of energy release along the trajectory and thus the amplitude of the generated shock wave. This allows interpreting the period and amplitude dependence of the LR and LQ waves on the trajectory altitude. Corresponding relationships were obtained from the set of historical atmospheric nuclear tests. We also compare the Chelyabinsk meteor with seismic observations from the 1984 Chulym River (Siberia) bolide, which was approximately 1000 km east of the studied event. We estimate the energy of both bodies and its distribution between various waves in order to interpret their respective sources and to discuss possible mechanisms of acoustic/seismic wave generation and conversion.
The Chelyabinsk meteor: joint interpretation of infrasound, acoustic, and seismic waves from Mikhail Rozhkov
]]> 420 3 https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovmeteoritefin5-131219135102-phpapp01-thumbnail.jpg?width=120&height=120&fit=bounds presentation White http://activitystrea.ms/schema/1.0/post http://activitystrea.ms/schema/1.0/posted 0 Synapse Hydrofrac Monitoring /slideshow/synapse-slides-hare/14914313 synapseslideshare-121027161248-phpapp02
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]]> Sat, 27 Oct 2012 16:12:46 GMT /slideshow/synapse-slides-hare/14914313 mrozhkov@slideshare.net(mrozhkov) Synapse Hydrofrac Monitoring mrozhkov <img style="border:1px solid #C3E6D8;float:right;" alt="" src="https://cdn.slidesharecdn.com/ss_thumbnails/synapseslideshare-121027161248-phpapp02-thumbnail.jpg?width=120&amp;height=120&amp;fit=bounds" /><br>
Synapse Hydrofrac Monitoring from Mikhail Rozhkov
]]> 612 4 https://cdn.slidesharecdn.com/ss_thumbnails/synapseslideshare-121027161248-phpapp02-thumbnail.jpg?width=120&height=120&fit=bounds presentation White http://activitystrea.ms/schema/1.0/post http://activitystrea.ms/schema/1.0/posted 0 https://cdn.slidesharecdn.com/profile-photo-mrozhkov-48x48.jpg?cb=1523483567 http://www.synapse.ru https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovglobalgrid-131219140036-phpapp01-thumbnail.jpg?width=320&height=320&fit=bounds slideshow/rozhkov-global-grid-29366570/29366570 Performance of wavefor... https://cdn.slidesharecdn.com/ss_thumbnails/rozhkovmeteoritefin5-131219135102-phpapp01-thumbnail.jpg?width=320&height=320&fit=bounds mrozhkov/rozhkov-meteorite-fin5 The Chelyabinsk meteor... https://cdn.slidesharecdn.com/ss_thumbnails/synapseslideshare-121027161248-phpapp02-thumbnail.jpg?width=320&height=320&fit=bounds slideshow/synapse-slides-hare/14914313 Synapse Hydrofrac Moni...