Underwater Explosives: Scaling of Source Spectra

1981 ◽  
pp. 87-91 ◽  
Author(s):  
R. Hughes
Keyword(s):  
Source Spectra

P-wave spectra of nevada test site events at near and very near distances: Implications for a near-regional body wave-surface wave discriminant

1976 ◽  
Vol 66 (3) ◽  
pp. 803-825
Author(s):  
William A. Peppin
Keyword(s):  
Scaling Laws ◽  
Body Wave ◽  
Test Site ◽  
P Wave ◽  
Spectral Amplitude ◽  
Source Spectrum ◽  
Wave Spectra ◽  
Nevada Test Site ◽  
Field Source ◽  
Source Spectra

abstract Some 140 P-wave spectra of explosions, earthquakes, and explosion-induced aftershocks, all within the Nevada Test Site, have been computed from wide-band seismic data at close-in (< 30 km) and near-regional (200 to 300 km) distances. Observed near-regional corner frequencies indicate that source corner frequencies of explosions differ little from those of earthquakes of similar magnitude for 3 < ML < 5. Plots of 0.8 to 1.0 Hz Pg spectral amplitude versus 12-sec Rayleigh-wave amplitude show a linear trend with unit slope over three orders of magnitude for explosions; earthquakes fail to be distinguished from explosions on such a plot. These spectra also indicate similar source spectra for explosions in different media (tuff, alluvium, rhyolite) which corroborates Cherry et al. (1973). Close-in spectra of three large explosions indicate that: (1) source corner frequencies of explosions scale with yield in a way significantly different from previously published scaling laws; (2) explosion source spectra in tuff are flat from 0.2 to 1.0 Hz (no overshoot); (3) the far-field source spectrum decays at least as fast as frequency cubed. Taken together, these data indicate that the following factors are not responsible for Peppin and McEvilly's (1974) near-regional discriminant: (a) source dimension, (b) source rise time, or (c) shape of the source spectrum.

Rupture Characteristics and Bedrock Structural Control of the 2016 Mw 6.0 Intraplate Earthquake in the Petermann Ranges, Australia

2020 ◽  
Vol 110 (3) ◽  
pp. 1037-1045 ◽  
Author(s):  
Januka Attanayake ◽  
Tamarah R. King ◽  
Mark C. Quigley ◽  
Gary Gibson ◽  
Dan Clark ◽  
...  
Keyword(s):  
Structural Control ◽  
P Wave ◽  
Corner Frequency ◽  
Intraplate Earthquake ◽  
Wave Source ◽  
Rupture Plane ◽  
Australian Continent ◽  
Vertical Displacements ◽  
Source Spectra ◽  
Surface Observations

ABSTRACT The 20 May 2016 surface-rupturing intraplate earthquake in the Petermann Ranges is the largest onshore earthquake to occur in the Australian continent in 19 yr. We use in situ and Interferometric Synthetic Aperture Radar surface observations, aftershock distribution, and the fitting of P-wave source spectra to determine source properties of the Petermann earthquake. Surface observations reveal a 21-km-long surface rupture trace (strike=294°±29°) with heterogeneous vertical displacements (<0.1–0.96  m). Aftershock arrays suggest a triangular-shaped rupture plane (dip  ≈  30°) that intersects the subsurface projection of the major geophysical structure (Woodroffe thrust [WT]) proximal to the preferred location of the mainshock hypocenter, suggesting the mainshock nucleated at a fault junction. Footwall seismicity includes apparent southwest-dipping Riedel-type alignments, including possible activation of the deep segment of the WT. We estimate a moment magnitude (Mw) of 6.0 and a corner frequency (fc) of 0.2 Hz, respectively, from spectral fitting of source spectra in the 0.02–2 Hz frequency band. These translate into a fault area of 124  km2 and an average slip of 0.36 m. The estimated stress drop of 2.2 MPa is low for an intraplate earthquake; we attribute this to low-frictional slip (effective coefficient of friction >0.015) along rupture-parallel phyllosilicate-rich surfaces within the host rock fabric with possible additional contributions from elevated pore-fluid pressures.

Effect of optical filters and light source spectra on the spectral luminous efficiency function measurement

2020 ◽  
Vol 27 (2) ◽  
pp. 149-155
Author(s):  
Yajing Ji ◽  
Wenyi Li ◽  
Muqing Liu ◽  
Haiping Shen
Keyword(s):  
Light Source ◽  
Optical Filters ◽  
Luminous Efficiency ◽  
Function Measurement ◽  
Efficiency Function ◽  
Source Spectra

3D Statistical Parametric Mapping of EEG Source Spectra by Means of Variable Resolution Electromagnetic Tomography (VARETA)

2001 ◽  
Vol 32 (2) ◽  
pp. 47-61 ◽  
Author(s):  
J. Bosch-Bayard ◽  
P. Valdés-Sosa ◽  
T. Virues-Alba ◽  
E. Aubert-Vázquez ◽  
E. Roy John ◽  
...  
Keyword(s):  
Statistical Parametric Mapping ◽  
Variable Resolution ◽  
Parametric Mapping ◽  
Electromagnetic Tomography ◽  
Source Spectra

Source spectra and site-response estimates using the Coda of Lg waves in western Europe

1996 ◽  
Vol 23 (13) ◽  
pp. 1605-1608 ◽  
Author(s):  
S. Chevrot ◽  
Y. Cansi
Keyword(s):  
Western Europe ◽  
Site Response ◽  
Source Spectra
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