scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2011 ◽  
Vol 2(11)2011 (2(11)) ◽  
pp. 275-277
Author(s):  
І. Sanina ◽  
◽  
S.B. Kishkina ◽  
D.M. Loktiev ◽  
M.A. Nesterkina ◽  
...  
Keyword(s):  
Power Plants ◽  
Small Aperture ◽  
Aperture Arrays ◽  
Atomic Power Plants

The results of mobile small aperture arrays application for control of geological state stability in time of atomic power plants construction in Leningrad and Nizhniy Novgorod regions are presented.

Detection and source parameterization of small-energy fireball events in Western Alps with ground-based infrasonic arrays

2021 ◽  
Author(s):  
Giacomo Belli ◽  
Emanuele Pace ◽  
Emanuele Marchetti
Keyword(s):  
Western Alps ◽  
Apparent Velocity ◽  
Array Analysis ◽  
Small Energy ◽  
Small Aperture ◽  
Energy Estimation ◽  
Trajectory Reconstruction ◽  
Tnt Equivalent ◽  
Back Azimuth ◽  
Aperture Arrays

Summary We present infrasound signals generated by four fireball events occurred in Western Alps between 2016 and 2019 and that were recorded by small aperture arrays at source-to receiver distances < 300 km. Signals consist in a series of short-lived infrasonic arrivals that are closely spaced in time. Each arrival is identified as a cluster of detections with constant wave parameters (back-azimuth and apparent velocity), that change however from cluster to cluster. These arrivals are likely generated by multiple infrasonic sources (fragmentations or hypersonic flow) along the entry trajectory. We developed a method, based on 2D ray-tracing and on the independent optically determined time of the event, to locate the source position of the multiple arrivals from a single infrasonic array data and to reconstruct the 3D trajectory of a meteoroid in the Earth's atmosphere. The trajectories derived from infrasound array analysis are in excellent agreement with trajectories reconstructed from eyewitnesses reports for the four fireballs. Results suggest that the trajectory reconstruction is possible for meteoroid entries located up to ∼300 km from the array, with an accuracy that depends on the source-to-receiver distance and on the signal-to-noise level. We also estimate the energy of the four fireballs using three different empirical laws, based both on period and amplitude of recorded infrasonic signals, and discuss their applicability for the energy estimation of small energy fireball events ($\le 1{\rm{kt\,\,TNT\,\,equivalent}}$).

All-union Conference on the Preparation of Operating Personnel for Atomic Power Plants

1977 ◽  
Vol 42 (6) ◽  
pp. 587-588
Author(s):  
L. M. Voronin ◽  
G. N. Ushakov ◽  
V. M. Gordina
Keyword(s):  
Power Plants ◽  
Operating Personnel ◽  
Union Conference ◽  
Atomic Power Plants

Radiation safety of atomic power plants in the USSR

1983 ◽  
Vol 54 (4) ◽  
pp. 290-301
Author(s):  
E. I. Vorob'ev ◽  
L. A. Il'in ◽  
V. D. Turovskii ◽  
L. A. Buldakov ◽  
N. G. Gusev ◽  
...  
Keyword(s):  
Power Plants ◽  
Radiation Safety ◽  
Atomic Power Plants

A seismic passive imaging step beyond SPAC and ReMi

Geophysics ◽  
2013 ◽  
Vol 78 (5) ◽  
pp. KS63-KS72 ◽  
Author(s):  
Francesco Mulargia ◽  
Silvia Castellaro
Keyword(s):  
Passive Imaging ◽  
Small Aperture ◽  
Simple Geometry ◽  
Recording Station ◽  
Refraction Microtremor ◽  
A New Technique ◽  
Statistical Mode ◽  
The One ◽  
Aperture Arrays ◽  
The Waves

The basic property of passive imaging is that, given any two points, one of them can be taken as the source of the waves and the other as the recording station. This property can be derived from the statistical self-alignment of the rays along the vector joining the two points, and applies also to nondiffuse wavefields like seismic tremor. It provides a statistical basis for the use of the stationary phase integral, allowing passive interferometry under the mild constraint of mechanical homogeneity at a local scale. Combined with the tremor’s large spectral bandwidth, it allows one to recover the local Green’s function from spatial correlation. Furthermore, combining this property also with the azimuthal isotropy of either the wavefield or the array, and using the statistical mode as the estimator, provides a new technique to measure the local velocity dispersion in the subsoil. This technique exploits the potential of spatial autocorrelation (SPAC) and refraction microtremor (ReMi), allowing one (1) to use sparse small-aperture arrays with simple geometry, (2) to dispense with the fitting of Bessel functions, and (3) to measure, in a few minutes, the local (phase and group) wave velocity as a function of frequency of potentially all the wave-propagation modes — body and surface — and not just of the one prevailing at each frequency.

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