scholarly journals SOURCE PARAMETERS of STRONG EARTHQUAKES of the EARTH

2019 ◽  
pp. 292-298 ◽  
Author(s):  
L. Chepkunas ◽  
L. Malyanova
Keyword(s):  
Seismic Moment ◽  
Source Parameters ◽  
Dynamic Parameters ◽  
Strong Earthquakes ◽  
The Earth ◽  
The World ◽  
Stress Drops ◽  
Digital Equipment

For the 19 strongest earthquakes of Russia and the world the dynamic parameters: seismic moments, lengths of ruptures, stress drops, the values of motion in the source are brought. The spectra of Р-wave were calculated on records of IRIS-IDA digital equipment at stations Obninsk-OBN, Talay-TLY, Kislovodsk-KIV in the range of epitsentralny distances of =25–82°. On the basis of the values of seismic moment Мo received on digital records at stations Obninsk-OBN, Talay-TLY, Kislovodsk-KIV, the momentny magnitude Mw (Kana-mori) are presented.

scholarly journals SOURCE PARAMETERS of STRONG EARTHQUAKES of the EARTH

2020 ◽  
pp. 244-249
Author(s):  
L. Chepkunas ◽  
L. Malyanova
Keyword(s):  
Seismic Moment ◽  
Source Parameters ◽  
P Wave ◽  
Apparent Stress ◽  
Dynamic Parameters ◽  
Strong Earthquakes ◽  
Rupture Length ◽  
The Earth ◽  
The World ◽  
The Moment

For nine strongest earthquakes in Russia and the World, dynamic parameters were determined. They were calculated from the P-wave spectra recorded by IRIS-IDA digital equipmentat Obninsk (OBN), Talaya (TLY) and Arti (ARU) stations at the epicentral distances =30–80°.The following parameters are given: seismic moment, rupture length, stress drop and apparent stress, average displacement during rupture of earthquake. The moment magnitude Mw obtained from seismic moment M0 at Obninsk, Talaya, and Arti stations was calculate by the formula of H. Kanamori.A comparison of the obtained parameters M0 and Mw with the data of the GCMT international center showed their proximity.

Source parameters and scaling relationships of small earthquakes in the northeastern Caribbean

1981 ◽  
Vol 71 (4) ◽  
pp. 1173-1190
Author(s):  
Arthur Frankel
Keyword(s):  
Seismic Moment ◽  
Dynamic Stress ◽  
Source Parameters ◽  
Earthquake Swarm ◽  
Fold Increase ◽  
Virgin Islands ◽  
Scaling Relationships ◽  
Short Period ◽  
Relative Stress ◽  
Stress Drops

abstract The seismic moments and stress drops of 23 earthquakes (1.1 ≦ M ≦ 2.4) that occurred during an earthquake swarm in the Virgin Islands were determined from the analysis of their P waveforms. The data consist of digitally recorded seismograms collected by a short-period seismic network operating in the northeastern Caribbean. The events of the swarm are particularly useful for comparing the relative stress drops of small earthquakes, because their source to receiver paths and focal mechanisms are very similar. The static stress drops calculated for these earthquakes varied from about 0.2 to 2 bars. The data clearly illustrate that the static and dynamic stress drops of these earthquakes generally increased with the size (moment) of the events. The fault radii for these shocks increased with seismic moment, but only by a factor of 2 for a 100-fold increase in seismic moment. The velocity waveforms of the larger events were systematically more impulsive than those of the smaller earthquakes. These observations imply that, for this set of earthquakes, the final fault radius is a function of the stress drop that occurs during the rupture process.

scholarly journals GLOBAL EARTHQUAKES

2019 ◽  
Author(s):  
Svetlana Poygina ◽  
Nataliya Petrova ◽  
N. Boldyreva
Keyword(s):  
Upper Mantle ◽  
Seismic Energy ◽  
Focal Mechanisms ◽  
Strong Earthquakes ◽  
Tectonic Plates ◽  
Plate Movement ◽  
The Earth ◽  
The Pacific ◽  
The World ◽  
Maximum Earthquake

The information on the Earth seismicity in 2013 at the level of strong earthquakes with M≥6 is provided according to the Seismological Bulletin of the Geophysical Survey of RAS (GS RAS). The initial Seismo-logical Bulletin for 2013 contains parameters of 4212 earthquakes in the world, versus 4845 in 2012. This article analyzes parameters of 160 strong earthquakes of the Earth in 2013 with M≥6, including 24 strongest earthquakes with M≥7 and the maximum earthquake of the Earth with Mw8.3 occurred in Okhotsk Sea, as well as four earthquakes with M6.0–6.8, which resulted in significant sacrifices and destructions. The location of earthquake epicenters and seismic stations, whose data were used to deter-mine the main parameters of earthquake foci, are shown, as well as a comparative analysis of the number of earthquakes and seismic energy released within the Earth's seismic regions is given. The information on focal mechanisms and consequences of 28 strongest earthquakes, including macroseismic effect, number of victims, landslides, tsunamis, etc. is given. The epicenters of most of them are confined to the boundaries of the largest tectonic plates of the Earth, and their focal mechanisms correspond to the basic laws of plate movement. The hypocenters of most of the strongest earthquakes are located within the Earth's crust, with the exception of earthquakes in Colombia, the Kuril Islands and south of the Fiji Is-lands, which had intermediate depths (h=98–171 km), and the strongest in 2013 Okhotsk earthquake, the source of which lay in the upper mantle at the depth of h=617 km. The movement in the source of the Okhotsk earthquake corresponds to the subduction process of the Pacific plate under the continent and indicates that the subducted plate is at the depth of 617 km.

Scaling relations between seismic moment and rupture area of earthquakes in stable continental regions

2021 ◽  
pp. 875529302098802
Author(s):  
Paul Somerville
Keyword(s):  
Seismic Moment ◽  
Source Parameters ◽  
Scaling Relations ◽  
Scale Invariant ◽  
Intraplate Earthquakes ◽  
Rupture Area ◽  
Earthquake Source Parameters ◽  
Stable Continental Regions ◽  
Self Similar ◽  
Stress Drops

This article describes the development of scaling relations between seismic moment and rupture area of earthquakes in stable continental regions (SCRs). The article reviews the relations developed by Somerville and compares them with relations developed by other investigators. It also compares the scaling relations of SCR earthquakes with those in tectonically active continental regions (TCRs). Three different methods of estimating rupture area, based on aftershocks, slip models, and duration methods were used by Somerville to analyze the relation between seismic moment and rupture area, using earthquake source parameters compiled from published literature. For each category of data, the relations obtained were not significantly different from those obtained by constraining them to be self-similar (scale-invariant), so self-similar relations were adopted. The stress drops corresponding to these scaling relations range from 51 to 86 bars, with an average of 65 bars. This value is comparable with the value of 58 bars obtained by Leonard, and it is recommended that the Leonard scaling relations for SCR earthquakes be used for the NGA East Project. To a first approximation, the results of Somerville and those of Somerville et al. indicate that the rupture areas of SCR earthquakes are about half those of TCR earthquakes, and their stress drops are about 2.8 times higher. Allmann and Shearer find less of a difference, presumably because their intraplate category includes some earthquakes that we would assign to TCR instead of SCR. Their study indicates that the rupture areas of intraplate earthquakes are about two-thirds those of TCR earthquakes, and their stress drops are about 2 times higher.

scholarly journals Strong earthquakes in the Globe and Russia in the first half of 2020 according to the GS RAS

2020 ◽  
Vol 2 (3) ◽  
pp. 7-21
Author(s):  
Yuri Vinogradov ◽  
Mariya Ryzhikova ◽  
Svetlana Poygina ◽  
Natalia Petrova ◽  
Marina Kolomiets
Keyword(s):  
Seismic Energy ◽  
Caribbean Sea ◽  
Focal Mechanisms ◽  
Material Damage ◽  
Strong Earthquakes ◽  
Catastrophic Earthquake ◽  
The Earth ◽  
The World ◽  
The Caribbean ◽  
The Kuril Islands

The data on the seismicity of the Earth in the first half of 2020 at the level of strong earthquakes with mb6 are presented according to the Earthquake Early Alert Service (EEAS) of the Geo-physical Survey RAS. The review also includes information on weaker but destructive earth-quakes in the world and tangible earthquakes in Russia. In total, 64 earthquakes with mb6 were registered in the first half of the year, including four events in Russia. For 18 strong earthquakes, the EEAS published Informational messages within one or two days after their occurrence, for 16 of them the information on focal mechanisms was given. A comparative analysis of the seismic energy released in the territory of the Globe showed that in the first half of 2020 its amount corresponds to the average values for the last three years. The strongest earthquakes with MS=7.7 occurred on January 28 in the Caribbean Sea and on June 23 in Mexico, accompanied by fore- and aftershocks. The largest human casualties and material damage during the study period were caused by the catastrophic earthquake with MS=6.6 that occurred on January 24 in Turkey. As a result of the earthquake, 41 people died, 1607 were injured. On the territory of Russia, the strongest earthquake with MS=7.5 occurred on March 25 east of the Kuril Islands and was felt in Severo-Kurilsk with an intensity Ii=5–6. A total of 47 tangible earthquakes with mb=3.6–7.2 were recorded in Russia.

scholarly journals Seismic Moment, Stress Drop, Strain Energy, Dislocation Radius, and Location of Seismic Acoustic Emissions Associated with a High Alpine Snowpack at Berthoud Pass, Colorado, U.S.A. (Abstract only)

1983 ◽  
Vol 4 ◽  
pp. 304-304
Author(s):  
Charles Cleland Rosé
Keyword(s):  
Stress Drop ◽  
Seismic Moment ◽  
Source Parameters ◽  
Acoustic Emissions ◽  
Body Waves ◽  
P Wave ◽  
Dissipated Energy ◽  
Fracture Area ◽  
Stress Drops ◽  
Predictive Indicator

The monitoring of the number of acoustic seismic impulses arising from snow instabilities is regarded as a relative indicator of an unstable snow slope but has not yielded a qualitative, predictive indicator. Until now, the source parameters (fracture area and length), seismic moment, energy released, stress drop, and location of acoustic seismic emissions arising from the snowpack have been neglected. A comprehension of these parameters leads to a better understanding of the event and may help in avalanche prediction.The location of a seismic event is derived from time differences between P-wave arrivals at four sensors located at the snow-ground interface. Three methods confirm the location of an acoustic seismic snow event to within 2 to 4 cm when the event is inside a seismic net.Spectral analyses of body waves from seismic snow events yield estimates of source parameters, stress drop and energy released. Equivalent dislocation surface radii range from 4.8 to 9.0 cm, which give stress drops of 0.20 to 0.29 bar, with a dissipated energy in the range of 0.0205 to 0.0632 J.Spectral analysis of the acoustic seismic snow event with application of dislocation theory provides several likely methods to predict avalanches of a climax type.

scholarly journals Seismic Moment, Stress Drop, Strain Energy, Dislocation Radius, and Location of Seismic Acoustic Emissions Associated with a High Alpine Snowpack at Berthoud Pass, Colorado, U.S.A. (Abstract only)

1983 ◽  
Vol 4 ◽  
pp. 304
Author(s):  
Charles Cleland Rosé
Keyword(s):  
Stress Drop ◽  
Seismic Moment ◽  
Source Parameters ◽  
Acoustic Emissions ◽  
Body Waves ◽  
P Wave ◽  
Dissipated Energy ◽  
Fracture Area ◽  
Stress Drops ◽  
Predictive Indicator

The monitoring of the number of acoustic seismic impulses arising from snow instabilities is regarded as a relative indicator of an unstable snow slope but has not yielded a qualitative, predictive indicator. Until now, the source parameters (fracture area and length), seismic moment, energy released, stress drop, and location of acoustic seismic emissions arising from the snowpack have been neglected. A comprehension of these parameters leads to a better understanding of the event and may help in avalanche prediction. The location of a seismic event is derived from time differences between P-wave arrivals at four sensors located at the snow-ground interface. Three methods confirm the location of an acoustic seismic snow event to within 2 to 4 cm when the event is inside a seismic net. Spectral analyses of body waves from seismic snow events yield estimates of source parameters, stress drop and energy released. Equivalent dislocation surface radii range from 4.8 to 9.0 cm, which give stress drops of 0.20 to 0.29 bar, with a dissipated energy in the range of 0.0205 to 0.0632 J. Spectral analysis of the acoustic seismic snow event with application of dislocation theory provides several likely methods to predict avalanches of a climax type.

Exiting Socialism Challenges

2006 ◽  
pp. 114-125 ◽  
Author(s):  
G. Popov
Keyword(s):  
Social Challenges ◽  
The Earth ◽  
The World ◽  
Science And Culture ◽  
Municipal Economy

Exiting socialism by almost a third of the earth population appears to be the most prominent event of the late XX century. The author makes an attempt to formulate some challenges of this process and thus a theory of exiting socialism. First, he inquires into the concept of exiting socialism as it exists in the world. Then he analyzes real experiences in this field. The research enables the author to outline the main economic, governmental and social challenges of such exit - from municipal economy to science and culture.

Slavery and the Trumpocene: It's Not the End of the World

2019 ◽  
Vol 41 (1) ◽  
pp. 40-50
Author(s):  
Claire Colebrook
Keyword(s):  
Living System ◽  
Racial Violence ◽  
First Century ◽  
The West ◽  
The Earth ◽  
The World ◽  
End Of The World ◽  
Twenty First Century ◽  
Geological Period

There is something more catastrophic than the end of the world, especially when ‘world’ is understood as the horizon of meaning and expectation that has composed the West. If the Anthropocene is the geological period marking the point at which the earth as a living system has been altered by ‘anthropos,’ the Trumpocene marks the twenty-first-century recognition that the destruction of the planet has occurred by way of racial violence, slavery and annihilation. Rather than saving the world, recognizing the Trumpocene demands that we think about destroying the barbarism that has marked the earth.

Sign in / Sign up

Export Citation Format

Share Document