Two models for earthquake forerunners

Mjachkin, V. I.; Brace, W. F.; Соболев, Г. А.; Dieterich, James H.

doi:10.1007/bf01592908

Cited by 213 publications

(40 citation statements)

References 14 publications

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“…Several mechanisms have been proposed, which could explain the relationship between radon anomalies and earthquake. Two models of earthquake precursors are discussed by Mjachkin et al (1975), with a common principle: at a certain preparation stage, a region of many cracks is formed. According to the dilatancy-diffusion model (Martinelli, 1991;Mjachkin et al, 1975), the increase in tectonic stress causes the extension and opening of favourably-oriented cracks in a porous, cracked, saturated rock.…”

Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

“…Two models of earthquake precursors are discussed by Mjachkin et al (1975), with a common principle: at a certain preparation stage, a region of many cracks is formed. According to the dilatancy-diffusion model (Martinelli, 1991;Mjachkin et al, 1975), the increase in tectonic stress causes the extension and opening of favourably-oriented cracks in a porous, cracked, saturated rock. Water flows into the opened cracks, drying the rock near each pore and finally resulting in a decrease of pore pressure in the total earthquake preparation zone.…”

Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

“…At the end of the diffusion period, the appearance of pore pressure and the increased number of cracks leads to the main rupture. According to the crack-avalanche model (Mjachkin et al, 1975), the increasing tectonic stress leads to the formation of a cracked focal rock zone, with slowly altering volume and shape. At a certain stage -when the whole focal zone becomes unstable -the cracks quickly concentrate near the fault surface, triggering the main rupture.…”

Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

See 2 more Smart Citations

Radon as an Earthquake Precursor – Methods for Detecting Anomalies

Gregorič¹,

Zmazek²,

Džeroski³

et al. 2012

Earthquake Research and Analysis - Statistical Studies, Observations and Planning

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Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

Section: Anomalous Radon Concentration and Seismicitymentioning

confidence: 99%

See 1 more Smart Citation

Radon as an Earthquake Precursor – Methods for Detecting Anomalies

Gregorič¹,

Zmazek²,

Džeroski³

et al. 2012

Earthquake Research and Analysis - Statistical Studies, Observations and Planning

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“…Although this is only -10 cm, it took place during only 41 years (or less), suggesti•':g significant stress transfer onto the nearby asperity. These ooservations could be explained by strain softening models such as those proposed by Brady [1974], Stuart [1974Stuart [ , 1979, Mjachkin et al [1975]. Although these models differ in many regards, they all suggest that earthquakes may occur after a period of stress changes in the focal zone, and may imply that the upper crust is stiff enough to allow decrease of the driving stress by accelerated precursory slip along all or part of the future rupture plane.…”

Section: Leveling Datamentioning

confidence: 99%

Pre‐seismic slip on the 26 September 1997, Umbria‐Marche Earthquake fault? Unexpected clues from the analysis of 1951–1992 elevation changes

Martini

Valensise

1999

Geophysical Research Letters

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Abstract.We studied 1951-1992 elevation changes recorded by a first order leveling line that intercepts the surface projection of the 26 Sep. 1997, M w 6.0, Umbria-Marche earthquake causative fault. The line documents 1951-1992 localized subsidence along a 12 km section above the fault. We calculated the expected 1997 coseismic elevation changes along the line using standard dislocation modeling and found that their trend has an amplitude three times larger than the trend of the observed pre-1997 signal but with a similar shape. We suggest that this signal is the result of 10 cm of pre-1992 slip along the northernmost 5 km of the 1997 earthquake fault, where coseismic slip was found to be less than the average estimated for the entire fault. This result implies unusually fast slip along this section of the fault and may suggest slip acceleration in preparation tbr the impending failure.

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“…The differences in terms of resistivity variations between the wet and dry models of dilatancy are clearly considerable. Myachkin et al (1975) discuss methods of differentiating between the possible wet and dry mechanisms of dilatancy. In addition we should acknowledge that there can be a total absence of any precursory phenomena in some shallow earthquakes (Kerr, 1979).…”

Section: Correlations Of the Time Variations Of Response Functionsmentioning

confidence: 99%

The time-dependence of electromagnetic response functions

Beamish¹

1982

Geophysical Surveys

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Abstract. Dynamic processes within the Earth axe capable of modifying many of its physical properties. This review considers the modification of electrical resistivity mainly by time-changes in the stressfield experienced by crustal materials. Laboratory experiments indicate that certain rock types, whose resistivity is controlled by the volume and geometry of microcracks, can undergo large resistivity variations in response to the typical strain accumulation and release that accompanies major earthquakes. Electromagnetic response functions axe reviewed with regard to their ability to monitor timechanges of resistivity in active regions. Some examples of the different experimental techniques used to investigate precursory changes in response functions prior to earthquakes are noted. The problems and successes of the subsequent correlation and interpretation of the derived response as a function of time are then discussed. Only relatively few controlled and integrated studies of time-dependent electromagnetic response functions exist. Those which are available, however, emphasise that changing stress-differentials occurring before major earthquakes can be monitored using suitable electromagnetic techniques.

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Two models for earthquake forerunners

Cited by 213 publications

References 14 publications

Radon as an Earthquake Precursor – Methods for Detecting Anomalies

Radon as an Earthquake Precursor – Methods for Detecting Anomalies

Pre‐seismic slip on the 26 September 1997, Umbria‐Marche Earthquake fault? Unexpected clues from the analysis of 1951–1992 elevation changes

The time-dependence of electromagnetic response functions

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