scholarly journals Registration opportunities of the temporary seismological network of IDG RAS on EEC

2020 ◽  
Vol 2 (2) ◽  
pp. 84-90
Author(s):  
Andrey Goev ◽  
Sergey Volosov ◽  
Irina Sanina ◽  
Nataliya Konstantinovskaya ◽  
Margarita Nesterkina
Keyword(s):  
Triple Junction ◽  
Deep Structure ◽  
Observation System ◽  
Seismic Section ◽  
Small Aperture ◽  
Seismic Stations ◽  
East European ◽  
Temporary Network ◽  
Collision Zone ◽  
Seismological Network

In 2017, as a part of the study of the deep structure of the central part of the East European craton (EEC), three temporary seismic observation points were installed. They were equipped with broadband three-component sensors. The position of the stations is due to the need to build a seismic section in the sub-latitudinal direction in order to study the collision zone of the triple junction of mega blocks in the central part of the EEC. Together with the small-aperture seismic array "Mikhnevo" (MHVAR), temporary seismic stations form an area observation system with distances between stations of the order of 100 km. In 2018, the stations of the temporary network of the IDG RAS had registered 765 events of various nature: 222 industrial explosions and 543 earthquakes. During the year, the "Mikhnevo" array records about 5000 events, of which about 1000 are earthquakes at teleseismic and regional distances, and about 900 are identified as industrial explosions. Mutual processing of observed data on the temporary network and on the "Mikhnevo" in some cases (17%) made it possible to specify the results of the location of industrial explosions obtained previously at the "Mikhnevo" over 10 km.

scholarly journals Seismogenic ancient structures of the central and northern part of the East European platform

2019 ◽  
Vol 489 (4) ◽  
pp. 405-408
Author(s):  
V. V. Adushkin ◽  
I. A. Sanina ◽  
G. N. Ivanchenko ◽  
E. M. Gorbunova ◽  
I. P. Gabsatarova ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Seismic Activity ◽  
East European Platform ◽  
Historical Earthquakes ◽  
Seismic Array ◽  
Small Aperture ◽  
Seismic Stations ◽  
East European

The analysis of the location of the epicenters of earthquakes that occurred in the central and northern part of the East European platform in 2009-2016, recorded by the seismic stations of the GS RAS and the small aperture seismic array of IGD RAS Mikhnevo was performed. The results obtained indirectly indicate the seismic activity of the Riphean structures of the region, disturbing the surface of the basement, and their possible activation at the present time. Available data on historical earthquakes also confirm their relevance to paleorifts. It seems important to take into account the position of the ancient aulacogens in assessing the seismic hazard of the East European platform.

National Seismological Network in India for Real-Time Earthquake Monitoring

2021 ◽  
Author(s):  
Brijesh K. Bansal ◽  
Ajeet P. Pandey ◽  
Ajay P. Singh ◽  
Gaddale Suresh ◽  
Ravi K. Singh ◽  
...  
Keyword(s):  
Real Time ◽  
Source Parameters ◽  
Focal Depth ◽  
Streaming Data ◽  
Small Aperture ◽  
Earthquake Parameters ◽  
Seismic Stations ◽  
National Network ◽  
Earthquake Source Parameters ◽  
Seismological Network

Abstract The National Seismological Network (NSN) of India has a history of more than 120 yr. During the last two decades, the NSN has gone through a significant modernization process, involving installation of seismic stations equipped with a broadband seismograph (BBS) and a strong-motion accelerograph (SMA). Each station has a very-small-aperture terminal connectivity for streaming data in real time to the central receiving station (CRS) in New Delhi. Seismic data recorded by the network are analyzed continuously on 24×7 basis to monitor the earthquakes in India and its adjoining regions. In this article, we present details of BBS and SMA network configurations; data streaming from the field seismic stations to the CRS for analysis; and the automatic and manual publication of the earthquake parameters including location coordinates, focal depth, time of occurrence, and magnitude, etc. Details of historically significant analog seismic charts and the seismic catalog, which includes more than 34,000 events with magnitude Mw 1.7–9.3 since 1505, are provided. The national network of India has been strengthened over the years and is now capable of estimating the main earthquake source parameters within ∼5–10min with an average of about 8.0 min. The spatial analysis of minimum magnitude of completeness further indicates a significant enhancement in minimum threshold magnitude detection capability of the network in recent decades.

2D velocity profiles along south- and northwestern Norway: An approach using receiver function analysis and Markov chains

2020 ◽  
Author(s):  
Marco Brönner ◽  
Claudia Pavez
Keyword(s):  
Deep Structure ◽  
Receiver Function ◽  
Function Analysis ◽  
Velocity Model ◽  
Reversible Jump ◽  
Moho Discontinuity ◽  
Mantle Transition Zone ◽  
Temporary Network ◽  
Receiver Function Analysis ◽  
Teleseismic Events

<p>A receiver function analysis was carried out along two profiles located in north- and southwestern Norway. We selected and processed 801 teleseismic events registered by twelve seismic stations belonging to the 2002-2005 Geofon/Aarhus temporary network. The HK (depth vs Vp/Vs) stacking procedure and a Reversible jump Markov chain Monte Carlo (Rj-McMC) inversion were applied independently with the objective to reveal new crustal and crust-mantle transitional contrasts gaining a better understanding of the geology. In the southern profile, the most noticeable feature corresponds to a Moho offset of about ~5 km ca. 85 km to the east of the Norwegian coast: That feature was previously observed in several occasions and is also well-supported from this research. Furthermore, a very deep Moho discontinuity – at between 45 – 50 km depth - was found beneath the northern profile, approximately 70 km inland from the coast, and dipping about 30° to the northwest. Even when this deep structure was previously inferred through other methods, its presence was not certainly confirmed and so far, the origin of this feature is still disputed. We discuss two hypotheses, which are valid to explain the occurrence of the noticeable anomaly. First, a gradual and wide crust-mantle transition zone, which is also reflected in the velocity model or second, the presence of a paleo-slab of Fennoscandian basement subducted and deformed during the Caledonian Orogen (490-390 Ma).</p>

The deep structure of the Grenville Front: a new perspective from western Quebec

1994 ◽  
Vol 31 (2) ◽  
pp. 282-292 ◽  
Author(s):  
R. L. Kellett ◽  
A. E. Barnes ◽  
M. Rive
Keyword(s):  
Upper Mantle ◽  
Seismic Reflection ◽  
Deep Structure ◽  
Leading Edge ◽  
Electrical Anisotropy ◽  
Data Sets ◽  
Seismic Section ◽  
Grenville Province ◽  
New Perspective ◽  
Tectonic Boundary

The Grenville Front is a major tectonic boundary exposed on the Canadian Shield. The front is defined as the northwestern limit of Grenvillian deformation, on the basis of geochronological and metamorphic data. This boundary is also evident in some geophysical data sets. The Lithoprobe Abitibi–Grenville transect crosses the Grenville Front near Lac Témiscamingue in western Quebec. A new 114 km long deep seismic reflection line shows a crustal structure quite different from that seen on previous surveys across the Grenville Front. The Archean foreland (Pontiac Subprovince) has a pattern of reflectivity similar to that seen in most of the Superior Province. This pattern continues for some 30 km south of the surface exposure of the Grenville Front. There is no evidence for a band of dipping reflectors truncating the horizontal Pontiac reflectors; in fact, the leading edge of the Grenville Province is difficult to identify on the seismic section. The Moho is well defined and reveals that the crust thins under the Grenville Front. The magnetotelluric survey shows that the upper crust is resistive across the entire profile, but the resistivity is higher within a Grenvillian allochthonous terrane at the southern end of the profile. The mid-crustal low-resistivity layer and the upper mantle electrical anisotropy are also continuous across the Grenville Front. The Grenville Front is highly variable in its character along the Grenville Orogen, and this character may be strongly controlled by the nature of the foreland to the northwest.

scholarly journals Deep Structure of the Eastern Himalayan Collision Zone: Evidence for Underthrusting and Delamination in the Postcollisional Stage

Tectonics ◽  
2019 ◽  
Vol 38 (10) ◽  
pp. 3614-3628 ◽  
Author(s):  
Chun‐Yong Wang ◽  
W. D. Mooney ◽  
L. Zhu ◽  
X. Wang ◽  
H. Lou ◽  
...  
Keyword(s):  
Deep Structure ◽  
Collision Zone

scholarly journals Results of the reinterpretation of materials of IV geotraverse of NHS (PK 295- 400) in the central part of the Holovanivsk suture zone

2021 ◽  
pp. 58-64
Author(s):  
O.A. Trypolsky ◽  
◽  
O.V. Topoliuk ◽  
O.O. Trypolska ◽  
O.B. Gintov ◽  
...  
Keyword(s):  
Shear Zone ◽  
Fault Zone ◽  
Deep Structure ◽  
Suture Zone ◽  
The Body ◽  
Intrusive Body ◽  
Seismic Section ◽  
Supply Channel ◽  
Host Rocks ◽  
The Given

This work provides the reinterpretation results of the research outcomes with the DSS method on geotraverse IV on section PK 295-400 in order to clarify a seismic section in the Holovanivsk area of high gravity. A number of points of diffraction and seismic sites have been identified in Earth’s crust (at a depth of 2-60 km), which gives an opportunity to considerably specify the data on the deep structure of the studied area. The position in a section of the Talnivska fault zone is clarified due to the identification of additional points of diffraction and a large number of short reflective elements at a depth of 2-8 km. In the central part of the section (PK 338-355), horizontal and inclined elements (at the depths of 2-9 km and 24-44 km) and a series of short steeply inclined reflective elements (at depths of 8-26 km) form the area of the medium which at the depth of 2-44 km differs in its characteristics from the host rocks. This allowed tracing the listriс shear zone that stretches continuously from a depth of 8 km on PK 355 to 44 km on PK 304. All this, as well as available seismotomographic data, allows us to suppose that the Talnivska fault zone is traced up to depths of 100-600 km as a boundary between blocks with different Vp velocities and degrees and gaps in the Golitsyn—Geiko layer. The listriс shear zone is connected to the main part of the Talnivska fault zone near the surface. According to the given re-interpretation of GSS data on geotraverse IV, the supply channel of the intrusive body of hyperbasites is rather narrow at depths of 60-33 km, and starting only from depth of 30 km and almost to the surface the body expands up to 15 km in width. Focusing on the area of increased Vp velocities at a depth of 2-33 km, one can assume that the main intrusive body that consists of hyperbasites and basite-Dunites, peridotites, pyroxenites, gabbro, and amphibolites, the density of which exceeds the density of rocks by 0.1-0.22 g/cm3, is located at these depths along the axis of the central part of the Holovanivsk suture zone.

scholarly journals SEISMICITY of the RUSSIAN PART of EAST EUROPEAN PLATFORM and ADJACENT TERRITORIES in 2015

2021 ◽  
pp. 182-191
Author(s):  
I. Gabsatarova ◽  
B. Assinovskaya ◽  
S. Baranov ◽  
V. Karpinsky ◽  
Ya. Konechnaya ◽  
...  
Keyword(s):  
Noise Level ◽  
East European Platform ◽  
Focal Mechanisms ◽  
Seismic Stations ◽  
East European ◽  
Russian Territory ◽  
Kandalaksha Bay ◽  
Kaliningrad Region ◽  
Macroseismic Survey ◽  
Natural Seismicity

It is reported that 41 stationary seismic stations, 2 arrays, and 7 temporary seismic stations, located in the area of Novovoronezh and Kursk nuclear stations, monitored seismicity of the Russian territory of the East European Platform (EEP) in 2015. The registration capabilities of the seismic network at the EEP as a whole were estimated based on the average station noise level and the equation for the energy decay of seismic phases. Zones with the best capabilities have been allocated. A feature of seismicity in 2015 is the manifestation of earthquakes of moderate magnitudes (ML=2.7–3.9) in the peripheral regions (in the southwest, west, and northwest) and in zones associated with paleorift structures: in the southwest – with the Dnieper Donetsk and in the northeast – with the Kirov-Kazhim and Soligalich (Central Russian) aulacogenes. The results of the macroseismic survey are given for the earthquake in Poltava on February 2, 2015, with M=3.7; focal mechanisms of two earthquakes (03.02.2015 and 12.06.2015) are constructed. According to the data of the Latvian Center, an earthquake was recorded in the region of Lithuania bordering the Kaliningrad region. Weaker natural seismicity with ML≤2.5 was recorded in Karelia and the regions bordering with Finland, near the Kandalaksha Bay, near the Khibiny, and Lovozersky massifs on the Kola Peninsula, and on the territory of the Voronezh crystalline massif.

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