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

2014 ◽  
Vol 36 ◽  
pp. 61-67
Author(s):  
D. Pesaresi ◽  
M. Romanelli ◽  
C. Barnaba ◽  
P. L. Bragato ◽  
G. Durì
Keyword(s):  
Real Time ◽  
Seismic Station ◽  
Broad Band ◽  
Seismic Monitoring ◽  
Seismic Network ◽  
Research Centre ◽  
Seismic Stations ◽  
The North ◽  
North Eastern ◽  
Borehole Seismic

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

The national seismic network for the Maltese islands: Update 2021

2021 ◽  
Author(s):  
Pauline Galea ◽  
Matthew Agius ◽  
George Bozionelos ◽  
Sebastiano D'Amico ◽  
Daniela Farrugia
Keyword(s):  
Real Time ◽  
Site Response ◽  
Seismic Monitoring ◽  
Seismic Network ◽  
Local Network ◽  
Time Data ◽  
African Plate ◽  
Seismic Stations ◽  
Maltese Islands ◽  
Sicily Channel

<p>The Maltese islands are a small country 15 km wide by 30 km long located about 100 km south of Sicily, Italy. Since 2015 Malta has set up a national seismic network. The primary aim of this network is to monitor in real-time and to locate more accurately the seismicity close to the islands and the seismicity in the Sicily Channel, offshore between Sicily, Tunisia and Libya. This Channel presents a range of interesting and complex tectonic processes that have developed in response to various regional stress fields mainly as a result of the collision between the African plate with Europe. The Maltese islands are known to have been affected by a number of earthquakes originating in the Channel, with some of these events estimated to be very close to the islands.</p><p>The seismotectonic characteristics of the Sicily channel, particularly south of the Maltese islands, is not well understood. This situation is being partially addressed through an increase in the number of seismic stations on the Maltese archipelago. The Malta Seismic Network (FDSN code ML), managed by the Seismic Monitoring and Research Group, within the Department of Geosciences, University of Malta, currently comprises 8 broadband, 3-component stations over an area slightly exceeding 300 km<sup>2</sup>. We present a technical description of the MSN including quality control tests such as spectral analysis (Power Spectral Density and HVSR), station orientations and timings as well as examples of local and regional earthquakes recorded on the network. We describe the upgrades to real-time data transmission and archiving, and automated epicentre location for continuous seismic monitoring using the local network amalgamated with a virtual seismic network to monitor the seismicity in the extended Mediterranean region. Such a dense national network, besides improving epicentral location in the Sicily Channel, is providing valuable information on microearthquake activity known to occur in close proximity to the islands, which has been very difficult to study in the past. It also provides an important tool for analysing site response and site amplification related to underlying geology, which constitutes a major component of seismic hazard analysis on the islands. Furthermore, the increase in seismic stations to the seismic monitoring system provides more robust earthquake estimates for the tsunami monitoring/simulation system.</p><p>Funding for stations was provided by Interreg Italia-Malta projects (SIMIT and SIMIT-THARSY, Codes B1-2.19/11 and C1-3.2-57) and by Transport Malta.</p>

scholarly journals Automatic moment tensor determination for the Hellenic Unified Seismic Network.

2016 ◽  
Vol 47 (3) ◽  
pp. 1308
Author(s):  
N. Triantafyllis ◽  
E. Sokos ◽  
A. Ilias
Keyword(s):  
Real Time ◽  
Seismic Station ◽  
Moment Tensor ◽  
Broad Band ◽  
Seismic Network ◽  
Global Networks ◽  
First Case ◽  
Inversion Procedure ◽  
Using Data ◽  
Seismic Networks

Modern seismic networks with broadband sensors and real time digital telemetry made Moment Tensor (MT) determination a routine procedure. Automatic MT’s are now provided by global networks and a few very dense regional networks, within minutes after a significant event. An automatic MT determination wasn’t possible for the broader Hellenic area since seismic station density wasn’t sufficient. The creation of the Hellenic Unified Seismic Network (HUSN) provided the opportunity to apply an automated MT procedure using the available broad band data from almost    one hundred stations. Thus the ISOLA code was extended towards the automatic operation based on Linux OS shell scripts, stand alone Fortran codes and SAC2000. Software supports both manual and automatic mode; at the first case, the user manually runs the program with the desired input parameters while at the latter, the system monitors a mailbox or RSS feed and if it receives an appropriate notification triggers the MT inversion procedure based on certain conditions. As it is setup now it calculates automatically the moment tensor of earthquakes larger than 3.5M  w using data from HUSN. Application of an automated MT inversion procedure for HUSN will provide important real time information for studies like ground motion evaluation, tsunami warning etc.

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

2013 ◽  
Vol 34 ◽  
pp. 5-8 ◽  
Author(s):  
P. L. Bragato ◽  
D. Pesaresi ◽  
A. Saraò ◽  
P. Di Bartolomeo ◽  
G. Durì
Keyword(s):  
Real Time ◽  
Data Exchange ◽  
Broad Band ◽  
Main Tool ◽  
Seismic Network ◽  
Time Data ◽  
Seismic Stations ◽  
Short Period ◽  
Real Time Data ◽  
Northeastern Italy

Abstract. The Centro di Ricerche Sismologiche (CRS, Seismological Research Center) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS (Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude Mw = 6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 12 very sensitive broad band and 21 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data centre in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of 93 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of Northeastern Italy, as shown in Fig. 1 (Bragato et al., 2011; Saraò et al., 2010). Since 2002 OGS-CRS is using the Antelope software suite as the main tool for collecting, analyzing, archiving and exchanging seismic data, initially in the framework of the EU Interreg IIIA project "Trans-national seismological networks in the South-Eastern Alps" (Bragato et al., 2010; Pesaresi et al., 2008). SeisComP is also used as a real time data exchange server tool. In order to improve the seismological monitoring of the Northeastern Italy area, at OGS-CRS we tuned existing programs and created ad hoc ones like: a customized web server named PickServer to manually relocate earthquakes, a script for automatic moment tensor determination, scripts for web publishing of earthquake parametric data, waveforms, state of health parameters and shaking maps, noise characterization by means of automatic spectra analysis, and last but not least scripts for email/SMS/fax alerting. A new OGS-CRS real time seismological website (http://rts.crs.inogs.it/) has also been operative since several years.

scholarly journals SISMIKO: emergency network deployment and data sharing for the 2016 central Italy seismic sequence

2016 ◽  
Vol 59 ◽  
Author(s):  
Milena Moretti ◽  
Silvia Pondrelli ◽  
Lucia Margheriti ◽  
Luigi Abruzzese ◽  
Mario Anselmi ◽  
...  
Keyword(s):  
Seismic Station ◽  
Central Italy ◽  
Strong Motion ◽  
Monitoring Network ◽  
Seismic Monitoring ◽  
Seismic Network ◽  
Seismic Sequence ◽  
British Geological Survey ◽  
Epicentral Area ◽  
Seismic Stations

<p>At 01:36 UTC (03:36 local time) on August 24th 2016, an earthquake Mw 6.0 struck an extensive sector of the central Apennines (coordinates: latitude 42.70° N, longitude 13.23° E, 8.0 km depth). The earthquake caused about 300 casualties and severe damage to the historical buildings and economic activity in an area located near the borders of the Umbria, Lazio, Abruzzo and Marche regions. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) located in few minutes the hypocenter near Accumoli, a small town in the province of Rieti. In the hours after the quake, dozens of events were recorded by the National Seismic Network (Rete Sismica Nazionale, RSN) of the INGV, many of which had a ML &gt; 3.0. The density and coverage of the RSN in the epicentral area meant the epicenter and magnitude of the main event and subsequent shocks that followed it in the early hours of the seismic sequence were well constrained. However, in order to better constrain the localizations of the aftershock hypocenters, especially the depths, a denser seismic monitoring network was needed. Just after the mainshock, SISMIKO, the coordinating body of the emergency seismic network at INGV, was activated in order to install a temporary seismic network integrated with the existing permanent network in the epicentral area. From August the 24th to the 30th, SISMIKO deployed eighteen seismic stations, generally six components (equipped with both velocimeter and accelerometer), with thirteen of the seismic station transmitting in real-time to the INGV seismic monitoring room in Rome. The design and geometry of the temporary network was decided in consolation with other groups who were deploying seismic stations in the region, namely EMERSITO (a group studying site-effects), and the emergency Italian strong motion network (RAN) managed by the National Civil Protection Department (DPC). Further 25 BB temporary seismic stations were deployed by colleagues of the British Geological Survey (BGS) and the School of Geosciences, University of Edinburgh in collaboration with INGV. All data acquired from SISMIKO stations, are quickly available at the European Integrated Data Archive (EIDA). The data acquired by the SISMIKO stations were included in the preliminary analysis that was performed by the Bollettino Sismico Italiano (BSI), the Centro Nazionale Terremoti (CNT) staff working in Ancona, and the INGV-MI, described below.</p>

The Northwest Mexico Seismic Network: Real‐Time Seismic Monitoring in Northern Baja California and Northwestern Sonora, Mexico

2018 ◽  
Vol 89 (2A) ◽  
pp. 324-337 ◽  
Author(s):  
J. Antonio Vidal‐Villegas ◽  
Luis Munguía ◽  
J. Alejandro González‐Ortega ◽  
M. Alejandra Nuñez‐Leal ◽  
Erik Ramírez ◽  
...  
Keyword(s):  
Real Time ◽  
Baja California ◽  
Seismic Monitoring ◽  
Seismic Network ◽  
Northwest Mexico

Recent seismic swarms in the Tjornes fracture zone, N-Iceland

2020 ◽  
Author(s):  
Kristín Jónsdóttir ◽  
Gunnar B. Guðmundsson ◽  
Luigi Passarelli ◽  
Sigurjón Jónsson ◽  
Yesim Cubuncu ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Seismic Station ◽  
B Value ◽  
Correlation Study ◽  
Seismic Network ◽  
The North ◽  
Aftershock Sequences ◽  
Volcanic Seismicity ◽  
Seismic Swarms ◽  
Seismic Moment Release

&lt;p&gt;The Tj&amp;#246;rnes fracture zone (TFZ) in N-Iceland is a seismically active zone with on average 4000 earthquakes detected annually since 1993 by the regional seismic network operated by the Icelandic Meteorological Office (IMO). Most of the earthquakes occur offshore and with only one seismic station on the Gr&amp;#237;msey island north of Iceland, the seismic network detects earthquakes down to magnitude M-0.5. The fracture zone, essentially a transform between the northern volcanic zone of Iceland and the Mid-Atlantic Ridge north of Iceland, has three major segments; the Gr&amp;#237;msey Oblique Rift (GOR) farthest to the North which accounts for 60% of the seismicity of the TFZ, the H&amp;#250;sav&amp;#237;k-Flatey Fault (HFF) in the middle, where 38% of the TFZ earthquakes occur and the least active Dalv&amp;#237;k Lineament (DL) farthest to the south (only 2% of TFZ seismicity). The IMO&amp;#8217;s seismic catalogue clearly draws up the most active segments of the TFZ, where each extends laterally roughly 100 km. The largest earthquakes occur on the HFF where the accumulated seismic moment release is an order of magnitude higher than the GOR and three orders of magnitude higher than the DL.&lt;/p&gt;&lt;p&gt;There are other interesting differences between the segments. There are several known central volcanoes aligned along the GOR and the oblique rifting is likely to cause both tectonic and volcanic seismicity which shows up as a catalogue of many but similarly sized earthquakes, in other words a catalogue with a higher b-value than the neighbouring HFF. Despite these differences, seismic swarms, without a clear mainshock or aftershock sequences, counting thousands of earthquakes with a duration of a few days upto weeks, are recorded every 2-3 years both in GOR and HFF. In late March 2019, one of this seismic swarms took place on GOR, mostly on a single NNE-SSW striking fault near K&amp;#243;pasker. Relative earthquake locations draw the fault up nicely and in addition a few shorter faults with similar strike of 15&amp;#176;deg. The temporal evolution of the swarm shows an upwards migration and how the seismicity starts at the middle of the fault, jumps a little to the north and migrates in two days to the southern end of the fault over 7 km. When that point is reached, the largest earthquake in the swarm takes place, M4.2, however in the very northern end of the fault. The focal mechanism of this largest event shows a left-lateral strike-slip as do the smaller earthquakes. A b-value plot of the 2300 earthquakes that were recorded during the swarm reveal a value of 1.2, which is typical for volcanic seismicity. The size of active fault is considerable larger than expected from a M4.2 earthquake and the question rises if part of the motion is taken up as aseismic slip.&lt;/p&gt;&lt;p&gt;We will present examples of recent swarms in the TFZ along with new results of a cross-correlation study of the waveforms recorded during the swarm activity.&lt;/p&gt;

Micro-seismicity of the Northern Sea of Galilee - Before and During the July-August 2018 Seismic Swarm

2020 ◽  
Author(s):  
Ittai Kurzon
Keyword(s):  
Seismic Activity ◽  
Time Windows ◽  
Sampling Rate ◽  
Seismic Network ◽  
Seismic Stations ◽  
Seismic Swarm ◽  
The North ◽  
Seismic Catalogue ◽  
High Sampling ◽  
High Sampling Rate

&lt;p&gt;This study presents observations and analysis from a high-sampling-rate micro-seismic network, located at the north of the Sea of Galilee, Israel. Stations&amp;#8217; locations were chosen following the seismic swarm at the North of the Sea of Galilee, in October 2013, aiming to perceive a better understanding of the seismicity and structure of this area, in light of that anomaly seismic swarm, and of the seismic activity along the Dead Sea Fault. The micro-seismic network was active between May 2016 to August 2018, with six stations altogether, in distances of 3-5km around the northern Sea of Galilee.&amp;#160; Each of the micro-seismic stations had two collocated sensors: 1) GS-1 Geospace, 1 Hz vertical seismometers, sampled at 500 samples per second, and 2) 3-channel Episensor embedded in a Rock+ Kinemetrics datalogger, sampled at 200 samples per second. Towards the dismantling of the network, another swarm, stronger in magnitude, and longer in duration, has occurred in July-August 2018, roughly at the same location. Meanwhile, a significant upgrade of the Israel Seismic Network (ISN) was taking place, also densifying the number of stations around the Sea of Galilee.&lt;/p&gt;&lt;p&gt;The seismic processing presented here has many steps of verification, at all levels: detection, association, and location.&amp;#160; Processing begins with the local high-sampling-rate micro-seismic stations, tuning the most appropriate micro-seismic detectors, and association, location and magnitude parameters. Then this new generated micro-seismic catalogue is used to reveal lower magnitude events within the ISN stations, followed by relocation and re-magnitude estimations, done to those events that have additional information from the ISN stations. Running this process for increasing time-windows, it is demonstrated how the use of micro-seismic instrumentation can increase the seismic catalogue by an order of magnitude, providing higher resolution of the seismicity, both in space and time.&lt;/p&gt;&lt;p&gt;These efforts, of increasing the seismic catalogue, and improving their locations, are utilised for two main goals: a) obtaining a clearer picture of the seismicity and structure in the area before and during the seismic swarm of July-August 2018, b) Zooming into the interesting micro-seismic activity just before the initiation of the swarm.&lt;/p&gt;

scholarly journals NORTHERN CAUCASUS

2019 ◽  
pp. 82-95 ◽  
Author(s):  
Irina Gabsatarov ◽  
L. Koroletski ◽  
E. Selivanova ◽  
E. Artyomova ◽  
O. Kamenskaya
Keyword(s):  
Seismic Energy ◽  
Seismic Network ◽  
Northern Caucasus ◽  
North Caucasus ◽  
Tectonic Structures ◽  
The Caucasus ◽  
Seismic Stations ◽  
The North ◽  
Weak Earthquakes ◽  
Digital Equipment

. It is reported that 59 seismic stations operated in the region in 2013. In the western and eastern parts of the region, new stations equipped with Russian digital equipment UGRA were opened: Aibga, Fisht, Karaman. The seismic network recorded 1941 earthquakes and 34 explosions in industrial quarries. 37 earthquakes were felt in the settlements of the Caucasus. The maximum shaking intensity, equal to Imax=6 on the MSK-64 scale, was felt during earthquakes on April 16 at 12h26m with КР=11.8 in the settlements of Kichi-Gamri, Mamaul, Myurego of Dagestan. Swarms of weak earthquakes with КР=4–8 were recorded in the Greater So-chi, Krasnaya Polyana areas, in Kabardino-Balkaria, and in the adjacent territory of Georgia in the area of Kazbek volcano. The area of manifestation of earthquakes with intermediate hypocenter depths, which previously belonged only to the Terek-Caspian trough (the territory of the Chechen Republic) along the diagonal Benoy-Eldarov suture zone, expanded in 2013 to the southeast and advanced under the structures of the Dagestan wedge. According to the level of seismic energy released, seismicity of the territory of the North Caucasus in 2013 characterized in accordance with the scale of the seismicity level as “background low” for the period of observations from 1962 to 2013. The strongest earthquakes occur in the connection zones of the main tectonic structures.

scholarly journals The Italian National Seismic Network and the earthquake and tsunami monitoring and surveillance systems

2016 ◽  
Vol 43 ◽  
pp. 31-38 ◽  
Author(s):  
Alberto Michelini ◽  
Lucia Margheriti ◽  
Marco Cattaneo ◽  
Gianpaolo Cecere ◽  
Giuseppe D'Anna ◽  
...  
Keyword(s):  
Real Time ◽  
Service Providers ◽  
Warning System ◽  
Strong Motion ◽  
Seismic Network ◽  
Surveillance Systems ◽  
Civil Protection ◽  
Tsunami Warning System ◽  
Moment Tensors ◽  
The North

Abstract. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) is an Italian research institution, with focus on Earth Sciences. INGV runs the Italian National Seismic Network (Rete Sismica Nazionale, RSN) and other networks at national scale for monitoring earthquakes and tsunami as a part of the National Civil Protection System coordinated by the Italian Department of Civil Protection (Dipartimento di Protezione Civile, DPC). RSN is composed of about 400 stations, mainly broadband, installed in the Country and in the surrounding regions; about 110 stations feature also co-located strong motion instruments, and about 180 have GPS receivers and belong to the National GPS network (Rete Integrata Nazionale GPS, RING). The data acquisition system was designed to accomplish, in near-real-time, automatic earthquake detection, hypocenter and magnitude determination, moment tensors, shake maps and other products of interest for DPC. Database archiving of all parametric results are closely linked to the existing procedures of the INGV seismic monitoring environment and surveillance procedures. INGV is one of the primary nodes of ORFEUS (Observatories &amp; Research Facilities for European Seismology) EIDA (European Integrated Data Archive) for the archiving and distribution of continuous, quality checked seismic data. The strong motion network data are archived and distributed both in EIDA and in event based archives; GPS data, from the RING network are also archived, analyzed and distributed at INGV. Overall, the Italian earthquake surveillance service provides, in quasi real-time, hypocenter parameters to the DPC. These are then revised routinely by the analysts of the Italian Seismic Bulletin (Bollettino Sismico Italiano, BSI). The results are published on the web, these are available to both the scientific community and the general public. The INGV surveillance includes a pre-operational tsunami alert service since INGV is one of the Tsunami Service providers of the North-eastern Atlantic and Mediterranean Tsunami warning System (NEAMTWS).

scholarly journals MUYAKAN EARTHQUAKE SEQUENCE in 2015 (Northern Baikal Region)

2021 ◽  
pp. 245-257
Author(s):  
N. Gileva ◽  
V. Melnikova ◽  
A. Filippova ◽  
Ya. Radziminovich ◽  
E. Kobeleva
Keyword(s):  
Baikal Region ◽  
Seismic Station ◽  
Local Stress ◽  
Baikal Rift Zone ◽  
Focal Mechanisms ◽  
Macroseismic Data ◽  
The North ◽  
Macroseismic Effects ◽  
North Eastern ◽  
Spatio Temporal

We present the results of studies of the seismic regime, focal mechanisms, and macroseismic data in the area of the largest Muyakan activation in 2015 (northern Baikal region). Due to the deployment of a network of temporary seismic stations, the number of registered earthquakes (KR≥3) increased significantly in 2015 and reached  30 thousand. Spatio-temporal development of the considered activation is characterized by stable low values of earthquake hypocenters and dividing the epicentral field into two clusters – eastern and north-western ones. Both clusters are connected with local stress-strain field (rift type and strike-slip, respectively), while the general regime of seismotectonic deformations of the crust in the activation area, calculated from the statistical analysis of 77 focal mechanisms of Muyakan earthquakes (KR≥9.2), demonstrates the predominance of submeri-dional horizontal extension. Macroseismic effects from the largest earthquakes of the Muyakan sequence were felt, predominantly, in Severomuysk settlement (=10–15 km, I=5). New data on strong motions, obtained from the records of the seismic station with the same name, have significantly complemented the database for the territory of the north-eastern flank of the Baikal rift zone. In general, the obtained results could be used to clarify the seismic hazard of the considered area and to improve the instrumental part of seismic scales.

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