Case 14: Electromagnetic radiations from shallow earthquakes observed in the LF range

1991 ◽  
pp. 77-77
Author(s):  
K. Oike ◽  
T. Ogawa
Keyword(s):  
Shallow Earthquakes ◽  
Electromagnetic Radiations

Enhanced shielding of electromagnetic radiations with flexible, light‐weight, and conductive Ag‐Cu / MWCNT / rGO architected PVDF nanocomposite films

2021 ◽  
Author(s):  
Kumaran Rengaswamy ◽  
Vinaya Kumar Asapu ◽  
Alagar Muthukaruppan ◽  
Dinesh Kumar Sakthivel ◽  
Subramanian Venkatachalam ◽  
...  
Keyword(s):  
Nanocomposite Films ◽  
Light Weight ◽  
Electromagnetic Radiations

Seismic moment catalog of large shallow earthquakes, 1900 to 1989

1992 ◽  
Vol 82 (3) ◽  
pp. 1306-1349 ◽  
Author(s):  
Javier F. Pacheco ◽  
Lynn R. Sykes
Keyword(s):  
Seismic Moment ◽  
Subduction Zones ◽  
B Value ◽  
Reference List ◽  
Transform Faults ◽  
Shallow Earthquakes ◽  
Seismicity Rates ◽  
Chile Earthquake ◽  
The Moment ◽  
Earthquake Process

Abstract We compile a worldwide catalog of shallow (depth < 70 km) and large (Ms ≥ 7) earthquakes recorded between 1900 and 1989. The catalog is shown to be complete and uniform at the 20-sec surface-wave magnitude Ms ≥ 7.0. We base our catalog on those of Abe (1981, 1984) and Abe and Noguchi (1983a, b) for events with Ms ≥ 7.0. Those catalogs, however, are not homogeneous in seismicity rates for the entire 90-year period. We assume that global rates of seismicity are constant on a time scale of decades and most inhomogeneities arise from changes in instrumentation and/or reporting. We correct the magnitudes to produce a homogeneous catalog. The catalog is accompanied by a reference list for all the events with seismic moment determined at periods longer than 20 sec. Using these seismic moments for great and giant earthquakes and a moment-magnitude relationship for smaller events, we produce a seismic moment catalog for large earthquakes from 1900 to 1989. The catalog is used to study the distribution of moment released worldwide. Although we assumed a constant rate of seismicity on a global basis, the rate of moment release has not been constant for the 90-year period because the latter is dominated by the few largest earthquakes. We find that the seismic moment released at subduction zones during this century constitutes 90% of all the moment released by large, shallow earthquakes on a global basis. The seismic moment released in the largest event that occurred during this century, the 1960 southern Chile earthquake, represents about 30 to 45% of the total moment released from 1900 through 1989. A frequency-size distribution of earthquakes with seismic moment yields an average slope (b value) that changes from 1.04 for magnitudes between 7.0 and 7.5 to b = 1.51 for magnitudes between 7.6 and 8.0. This change in the b value is attributed to different scaling relationships between bounded (large) and unbounded (small) earthquakes. Thus, the earthquake process does have a characteristic length scale that is set by the downdip width over which rupture in earthquakes can occur. That width is typically greater for thrust events at subduction zones than for earthquakes along transform faults and other tectonic environments.

scholarly journals Relative stability of planar clusters B11, B12, and B13 in neutral- and charged-states

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Levan Chkhartishvili
Keyword(s):  
Binding Energy ◽  
Relative Stability ◽  
Energy Criterion ◽  
Nanostructured Coating ◽  
Neutron Absorption ◽  
Coating Materials ◽  
Boron Cluster ◽  
Boron Clusters ◽  
Planar Structures ◽  
Electromagnetic Radiations

Theoretically, within the diatomic model, there is studied the relative stability of most abundant boron clusters B11, B12, and B13 with planar structures in neutral, positively and negatively charge-states. According to the specific (pet atom) binding energy criterion, B12+ (6.49 eV) is found to be the most stable boron cluster, while B11– + B13+ (5.83 eV) neutral pair is expected to present the preferable ablation channel for boron-rich solids. Obtained results would be applicable in production of boron-clusters-based nanostructured coating materials with super-properties such as lightness, hardness, conductivity, chemically inertness, neutron-absorption, etc. making them especially effective for protection against cracking, wear, corrosion, neutron- and electromagnetic-radiations, etc.

scholarly journals Trichel Pulse in Negative DC Corona discharge and Its Electromagnetic Radiations

2015 ◽  
Vol 10 (3) ◽  
pp. 1174-1180 ◽  
Author(s):  
Yu Zhang ◽  
Li-Juan Liu ◽  
Jin-Song Miao ◽  
Zu-Lin Peng ◽  
Ji-Ting Ouyang
Keyword(s):  
Corona Discharge ◽  
Electromagnetic Radiations

scholarly journals Amplitudes of surface waves and magnitudes of shallow earthquakes*

1945 ◽  
Vol 35 (1) ◽  
pp. 3-12
Author(s):  
B. Gutenberg
Keyword(s):  
Absorption Coefficient ◽  
Surface Waves ◽  
Epicentral Distance ◽  
Pacific Basin ◽  
Depth Of Focus ◽  
Intermediate Depth ◽  
Station Corrections ◽  
The Pacific ◽  
Shallow Earthquakes

Summary. A study of amplitudes of surface waves having periods of about 20 seconds is employed to improve the calculation of magnitudes of distant shallow earthquakes. Table 3 gives station corrections; table 4, revised figures for the effect of epicentral distance. It is found that for epicentral distances between about 20° and 175° the average observed amplitudes correspond closely to those calculated with an absorption coefficient k = 0.0003 per km. For paths completely outside or inside the Pacific Basin, k = 0.0002± per km., while for paths tangent to its boundary the amplitudes of surface waves with periods of about 20 seconds may be reduced by two-thirds or more (in extreme cases by almost nine-tenths) through reflection or refraction of energy; such seismograms of shallow shocks may be taken as indicating intermediate depth of focus.

scholarly journals Amplitudes of P, PP, and S and magnitude of shallow earthquakes*

1945 ◽  
Vol 35 (2) ◽  
pp. 57-69
Author(s):  
B. Gutenberg
Keyword(s):  
Absorption Coefficient ◽  
Shallow Earthquake ◽  
Transverse Waves ◽  
Longitudinal Waves ◽  
Longitudinal And Transverse Waves ◽  
The Core ◽  
The Earth ◽  
Shallow Earthquakes

Summary It is found that the absorption coefficient for longitudinal and transverse waves in the mantle of the earth as well as for longitudinal waves through the core is 0.00012 per km. In the average shallow earthquake about equal amounts of energy go into longitudinal and transverse waves. Equation (18), together with tables 2 and 4, permits the calculation of the magnitude of a shallow earthquake from the amplitudes of P, PP, or S.

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