Theory of Magnetic Location of a Possible Earthquake Epicenter Area

2019 ◽  
pp. 15-33
Author(s):  
Oleg Novik ◽  
Feodor Smirnov ◽  
Maxim Volgin
Keyword(s):  
Earthquake Epicenter

scholarly journals Multi-point ground-based ULF magnetic field observations in Europe during seismic active periods in 2004 and 2005

2008 ◽  
Vol 8 (3) ◽  
pp. 501-507 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Intensity ◽  
Seismic Activity ◽  
Magnetic Field Intensity ◽  
Field Measurements ◽  
Fluxgate Magnetometer ◽  
Vertical Magnetic Field ◽  
Earthquake Epicenter ◽  
Electromagnetic Noise ◽  
Horizontal Magnetic Field

Abstract. We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of <σ>=10−3 S/m and a certain distance of the observatory to the earthquake epicenter.

Magnitude thresholds and spatial footprints of damage from induced earthquakes

2020 ◽  
Vol 36 (4) ◽  
pp. 1995-2018 ◽  
Author(s):  
Bridger W Baird ◽  
Abbie B Liel ◽  
Robert E Chase
Keyword(s):  
United States ◽  
Ground Motions ◽  
Geographic Area ◽  
Earthquake Epicenter ◽  
Induced Earthquakes ◽  
Injection Wells ◽  
Building Models ◽  
Central United States ◽  
First Onset ◽  
Moderate Magnitude

The rise in the number of anthropogenic small- to moderate-magnitude earthquakes in the central United States raises questions about the damageability of the built environment in such events. This study examines the performance of modern light-frame wood buildings, including single, multifamily, and commercial constructions, in earthquakes with moment magnitudes of 3–6, using dynamic analysis of building models subjected to ground motions recorded in past induced events in North America. We focus on first onset of damage, for example, wallboard or wallpaper cracking, and nails popping out. The results show that earthquakes with magnitudes less than 4–4.25 are unlikely to cause damage to modern constructions. However, moderate-magnitude events can cause damage over a wide geographic area (more than 30 mi from the earthquake epicenter, or 40 or more miles from a wastewater injection well). These results can be used to suggest setback distances between injection wells and certain neighborhoods or facilities, and magnitude thresholds for post-earthquake inspections.

scholarly journals Ionospheric variations before some large earthquakes over Sumatra

2011 ◽  
Vol 11 (2) ◽  
pp. 597-611 ◽  
Author(s):  
A. M. Hasbi ◽  
M. A. Mohd Ali ◽  
N. Misran
Keyword(s):  
Electron Density ◽  
Earthquake Epicenter ◽  
Equatorial Anomaly ◽  
Density Data ◽  
Density Measurements ◽  
Champ Satellite ◽  
Density Analysis ◽  
Large Earthquakes ◽  
Electron Density Analysis ◽  
Champ Data

Abstract. The paper investigates the ionospheric variations before some large earthquakes that occurred during 2004–2007 in Sumatra using GPS and CHAMP data. The TEC shows the occurrence of positive and negative anomalies detected within a few hours to 6 days before the earthquakes. These anomalies mostly occur during the daytime hours between 4 and 17 LT. The TEC anomalies are mostly consistent with the CHAMP satellite electron density data. The electron density analysis over the 28 March 2005 earthquake epicenter shows that an equatorial anomaly modification took place a few days before the event. The modification took shape in the form of crest amplification during the daytime. The comparison between the TEC and electron density measurements during very quiet geomagnetic conditions is shown to be a useful indicator of a forthcoming earthquake.

Strategies to Prepare Emergency Management Personnel to Integrate Geospatial Tools into Emergency Management

2011 ◽  
pp. 245-261
Author(s):  
Tricia Toomey ◽  
Eric Frost ◽  
Murray E. Jennex
Keyword(s):  
Emergency Management ◽  
Disaster Management ◽  
Work Experience ◽  
Earthquake Epicenter ◽  
Management Personnel ◽  
Emergency Managers ◽  
Diverse Field ◽  
Mitigation Planning ◽  
Geospatial Tools ◽  
Response And Recovery

Emergency management is a diverse field. Effective disaster management involves knowledge of various subjects as well as work experience in all aspects related to mitigation, planning, response, and recovery efforts. One field not being fully exploited by disaster management is the use of geospatial tools in the form of Geographic Information Systems (GIS), cartography, and geovisualization. One reason for this is that many emergency managers are not fully aware of the assistance GIS can lend to effectively manage disaster situations. All functions of emergency management have a strong geographic component. Where is the earthquake epicenter? Where is the damage? Where does the dam inundation run and who/what is in that path? Where is the area of road closures? The questions asking “where” are endless in effective emergency management and range from the mitigation stage through to the recovery stage. For example, a tsunami may inundate only a certain portion of the region, therefore, it is important to have mitigation and planning efforts concentrated in those regions. It is also important to know what businesses, housing, and populations are in the affected areas. The integration of geospatial tools for risk assessment, mitigation, planning, response, and recovery efforts is emerging as an effective and potentially invaluable resource for answering such questions in regards to emergency management.

The tsunami of March 9, 1957, on the Island of Hawaii

1959 ◽  
Vol 49 (1) ◽  
pp. 79-90
Author(s):  
George D. Fraser ◽  
Jerry P. Eaton ◽  
Chester K. Wentworth
Keyword(s):  
Empirical Data ◽  
Produced Water ◽  
Earthquake Epicenter ◽  
Local Conditions ◽  
Precise Evaluation ◽  
Before And After ◽  
Wave Heights ◽  
Average Wave ◽  
Different Parts

Abstract The Aleutian-born tsunami of March 9, 1957, produced water heights on the island of Hawaii between those produced by the 1946 and 1952 tsunamis. The tsunami-generating mechanism, although poorly understood, permits a hypothesis of multiple waves generated near the source (or the same wave traveling different paths) which eventually interfere to produce contrasting intensities in different parts of the broad Hawaiian area. Comparisons suggest that each tsunami is unique and unpredictable in some respects and predictable in others. Water heights depend in part on location and orientation of coastlines with respect to the earthquake epicenter and the presumed line along which the tsunami was generated. Local conditions of seiche and coastline configuration further modify average wave heights. Local conditions are effectively constant with respect to Aleutian tsunamis, and empirical data on water heights and danger areas are available. A program of improving tsunami and earthquake observations, together with additional tide-observation stations, may eventually permit more precise evaluation of a tsunami both before and after its arrival.

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