scholarly journals Regional and teleseismic event detection capability of the small-aperture Tripoli seismic array, Greece

2018 ◽  
Vol 40 (3) ◽  
pp. 1246
Author(s):  
M. Pirli ◽  
J. Schweitzer
Keyword(s):  
Seismic Array ◽  
Detection Capability ◽  
Small Aperture ◽  
Slowness Vector ◽  
Reference Event ◽  
On Line ◽  
Detection Capabilities ◽  
Teleseismic Event ◽  
Teleseismic Events ◽  
Of Greece

The Tripoli Seismic Array (TRISAR) is a small-aperture array designed to monitor and locate the seismicity in the area of Greece. In this study, its detection capabilities are discussed for regional and teleseismic events. A reference event list is compiled, consisting of events ofmb>5.0for regional and teleseismic distances (A>6°), according to the ISC On-line Bulletin. TRISAR automatically detected approximately 25% of these events over the entire investigated distance range. Although TRISAR slowness vector residuals are rather large, as expected for an array of such small aperture, the benefits resulting from the use of such a system for reporting regional and teleseismic activity is obvious.

scholarly journals INSTALLATION AND PRELIMINARY RESULTS FROM A SMALL APERTURE SEISMIC ARRAY IN TRIPOLI, GREECE

2004 ◽  
Vol 36 (3) ◽  
pp. 1499 ◽  
Author(s):  
M. Pirli ◽  
Ν. Voulgaris ◽  
J. Alexopoulos ◽  
K. Makropoulos
Keyword(s):  
Body Wave ◽  
Seismic Array ◽  
Small Aperture ◽  
Preliminary Results ◽  
Seismic Waveforms ◽  
Equipment Safety ◽  
Array Calibration ◽  
Array Performance ◽  
The University ◽  
Of Greece

A small aperture seismic array was installed by the University of Athens, in the area of Tripoli, Greece, on July 16th 2003, in order to test the performance of seismic array processing in the area of Greece and assess its contribution to earthquake location, especially in offshore areas not azimuthally covered by the existing, conventional seismological networks. The array consists of four three-component seismological stations, one of them in the middle of a small, almost equilateral triangle, formed by the deployment of the other three stations. Despite the fact that array siting is a compromise of array installation criteria, equipment safety and logistics, the test character of the experiment can be served successfully. The array transfer function depicts good azimuthal coverage nonetheless the existence of side-lobes and a rather wide main lobe is characteristic of spatial aliasing and low resolution in the two-dimensional wavenumber domain. The resolvable wavenumber passband of the array permits the determination of most of the common seismic body wave phases (Pn, Pg, Sn, Sg, etc.) for local and regional events in the area of Greece. Location of recorded events was performed using slowness and backazimuth data, calculated by f-k analysis of the seismic waveforms. Preliminary results have been compared to epicentres calculated by the Geodynamic Institute of the National Observatory of Athens. Although some differences are observed, these are not significant and location results as well as overall array performance can be improved by array calibration and travel-time, azimuth and slowness correction calculations.

Detection of ultraweak signals on the Mikhnevo small-aperture seismic array by using cross-correlation of waveforms

2015 ◽  
Vol 460 (2) ◽  
pp. 189-191 ◽  
Author(s):  
V. V. Adushkin ◽  
I. O. Kitov ◽  
N. L. Konstantinovskaya ◽  
K. S. Nepeina ◽  
M. A. Nesterkina ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Seismic Array ◽  
Small Aperture

P-wave backazimuth anomalies observed by a small-aperture seismic array at Pinyon Flat, southern California: Implications for structure and source location

1996 ◽  
Vol 86 (2) ◽  
pp. 470-476 ◽  
Author(s):  
Cheng-Horng Lin ◽  
S. W. Roecker
Keyword(s):  
Southern California ◽  
Seismic Array ◽  
P Wave ◽  
Small Aperture ◽  
Data Set ◽  
Single Interface ◽  
Seismic Networks ◽  
Dense Seismic Array ◽  
Beamforming Technique

Abstract Seismograms of earthquakes and explosions recorded at local, regional, and teleseismic distances by a small-aperture, dense seismic array located on Pinyon Flat, in southern California, reveal large (±15°) backazimuth anomalies. We investigate the causes and implications of these anomalies by first comparing the effectiveness of estimating backazimuth with an array using three different techniques: the broadband frequency-wavenumber (BBFK) technique, the polarization technique, and the beamforming technique. While each technique provided nearly the same direction as a most likely estimate, the beamforming estimate was associated with the smallest uncertainties. Backazimuth anomalies were then calculated for the entire data set by comparing the results from beamforming with backazimuths derived from earthquake locations reported by the Anza and Caltech seismic networks and the Preliminary Determination of Epicenters (PDE) Bulletin. These backazimuth anomalies have a simple sinelike dependence on azimuth, with the largest anomalies observed from the southeast and northwest directions. Such a trend may be explained as the effect of one or more interfaces dipping to the northeast beneath the array. A best-fit model of a single interface has a dip and strike of 20° and 315°, respectively, and a velocity contrast of 0.82 km/sec. Application of corrections computed from this simple model to ray directions significantly improves locations at all distances and directions, suggesting that this is an upper crustal feature. We confirm that knowledge of local structure can be very important for earthquake location by an array but also show that corrections computed from simple models may not only be adequate but superior to those determined by raytracing through smoothed laterally varying models.

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.

Detection capabilities of the Yellowknife seismic array and regional seismicity

1971 ◽  
Vol 61 (4) ◽  
pp. 993-1008
Author(s):  
F. M. Anglin
Keyword(s):  
Seismic Array ◽  
Detection Level ◽  
Array Data ◽  
Regional Variations ◽  
Regional Seismicity ◽  
The Third ◽  
Detection Capabilities ◽  
The Mean

abstract Detection statistics from a search of 99 days of Yellowknife Array data have been obtained. The mean 50 and 90 per cent cumulative detection levels are found to be m 3.9 and m 4.2 for the third zone from Yellowknife. Regional variations in the detection levels have been found. The 50 per cent cumulative detection level ranges from m 3.8 for Asia to m 4.3 for the Aleutians. Regional values of the slopes of the recurrence curves for log N versus magnitude have been obtained, the mean slope for the third zone from Yellowknife being −0.99.

Monitoring the West Bohemian earthquake swarm in 2008/2009 by a temporary small-aperture seismic array

2011 ◽  
Vol 16 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Stefan Hiemer ◽  
Dirk Roessler ◽  
Frank Scherbaum
Keyword(s):  
Earthquake Swarm ◽  
Seismic Array ◽  
The West ◽  
Small Aperture

A Semiautomatic Calibration Method Applied to a Small-Aperture Alaskan Seismic Array

2007 ◽  
Vol 97 (1B) ◽  
pp. 100-113 ◽  
Author(s):  
K. G. Lindquist ◽  
I. M. Tibuleac ◽  
R. A. Hansen
Keyword(s):  
Calibration Method ◽  
Seismic Array ◽  
Small Aperture
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