Seismogenic width of a fault zone

Kocharyan, G. G.; Кишкина, С. Б.; Остапчук, А. А.

doi:10.1134/s1028334x11030147

Cited by 10 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Выполненные исследования, с одной стороны, не охватывают всю ширину зоны возможного влияния разлома, которая может достигать десятка километров. С другой стороны, активные и аномальные деформационные процессы локализуются именно в узких областях разломных зон, ширина которых в диапазоне длин разломов L=10-100 км может составлять порядка L•10 -2 [Kocharyan et al, 2011]. В таком случае протяженность геодинамической сети (~3.5 км) можно считать оптимальной для изучения локальных деформационных процессов.…”

Section: результаты и их обсуждениеunclassified

Contemporary Geodynamics of the Garomai Active Fault (Sakhalin Island)

Vasilenko

Prytkov

2019

Geodin. tektonofiz.

View full text Add to dashboard Cite

In the northern Sakhalin Island, the tectonic activity of the fault zones is a potential threat to the industrial infrastructure of the petroleum fields. Recently, the background seismicity has increased at the Hokkaido‐Sakhalin fault that consists of several segments, including the Garomai active fault. In the studies of the regional deformation processes, it is important not only to analyze the seismic activity, but also to quantitatively assess the dynamics of deformation accumulation in the fault zones. In order to study the contemporary geodynamics of the Garomai fault, a local GPS/GLONASS network has been established in the area wherein trunk oil and gas pipelines are installed across the fault zone. Based on the annual periodic measurements taken in 2006–2016, we study the features of surface deformation and calculate the rates of displacements caused by the tectonic activity in the fault zone. During the survey period, no significant displacement of the fault wings was revealed. In the immediate vicinity of the fault zone, multidirectional horizontal displacements occur at a rate up to 1.6 mm/yr, and uplifting of the ground surface takes place at a rate of 3.4 mm/yr. This pattern of displacements is a reflection of local deformation processes in the fault zone. At the western wing of the fault, a maximum deformation rate amounts to 1110–6 per year. The fault is a boundary mark of a transition from lower deformation rates at the eastern wing to higher ones at the west wing. In contrast to the general regional compression setting that is typical of the northern Sakhalin Island, extension is currently dominant in the Garomai fault zone. The estimated rates of relative deformation in the vicinity of the Garomai fault give grounds to classify it as ‘hazardous’.

show abstract

Section: результаты и их обсуждениеunclassified

Contemporary Geodynamics of the Garomai Active Fault (Sakhalin Island)

Vasilenko

Prytkov

2019

Geodin. tektonofiz.

View full text Add to dashboard Cite

show abstract

“…Отдельно должно быть обращено внимание на относительное ослабление прочности протяженной межблоковой зоны разлома с увеличением ее длины [Kocharyan, Spivak, 2003;Kocharyan et al, 2011]. В данных работах показано, что величина нормальной жесткости межблоковой границы нелинейно снижается по мере увеличения ее длины.…”

Section: способствующие формированию очагов катастрофических землетряunclassified

“…Это означает, что протяженные разломы оказываются относительно более чувствительными к вариациям напряженного состояния по сравнению с рядом расположенными более короткими разрывами. Предложено уравнение [Kocharyan et al, 2011], связывающее жесткость K* (МПа/м) межблоковой разломной зоны с ее длиной L (км):…”

Section: способствующие формированию очагов катастрофических землетряunclassified

Tectonophysical Signs of the Formation of Strong Earthquake Foci in Seismic Zones of Central Asia

Шерман¹

2016

Geodin. tektonofiz.

View full text Add to dashboard Cite

Vibrations of the Earth crust and variations in the physical fields of the Earth atmosphere and ionosphere are continuously monitored by a variety of techniques and specialized facilities across the world. Nevertheless, most catastrophic earthquakes even in this century have occurred in "incidental" or "unexpected" places in "unpredicted" time. Earthquake predictions have errors as the current knowledge of focal mechanisms of strong (M≥8) earthquakes is still insufficient. It is believed today that the most common source of earthquakes is movement of rock blocks along a fault/megafracture. Such movements take place in a stepwise pattern with high or reduced friction, depending on the presence of fluids, hitches on the fault planes and other factors. Modern seismic forecasting is based on the concept of precursors.The author considers geological and geophysical settings in areas of dynamic influence of faults, wherein 8>М>7.5 earthquakes took place. Based on earthquake recurrence curves constructed for such areas, four tectonic criteria for formation of strong earthquake sources are identified: structural (large seismically active faults), kinematic (large amplitudes of the fault wing's displacements), rheological (physical properties of the fault infill material, such as low viscosity of the intra-fault medium) and dynamic (high rates of the fault wing's displacements) criteria. These criteria should be in the focus of quantitative studies in order to provide a solid scientific basis for long-term forecasting of strong earthquakes. Curves constructed for the criteria can show changes in the physics of earthquake foci in case of strong seismic events.With account of the tectonophysical features of faults associated with strong seismic events, the following conclusions are drawn. (1) In the continental lithosphere, catastrophic earthquakes (M≥8) occur in areas of dynamic influence of the major faults in the lithosphere in case of relatively high amplitudes of displacements of boundary blocks (i.e. fault wings). (2) In the relatively stable stress field, high amplitude displacements take place in case of reduced viscosity/quasi-viscosity of the medium comprising the internal structure of faults. (3) Reduced viscosity of the intrafault medium is related to the physical conditions of transition of rocks in fault zones (mainly along the fault planes) in the state of quasi-plastic or plastic flow (unilateral pressure in excess of hydrostatic pressure, and relatively decreasing strength properties of the intra-fault medium with increasing length of the fault wings). (4) Reduced viscosity of the fault zone leads to an increase in the displacement rate of the fault wings in the constant stress field. The latter factor is the main one, transforming seismically active faults with M≤7.5 seismic events into faults of similar characteristics, but with earthquakes of higher energy, M≥8. Focal mechanisms of such earthquakes are associated with conditions for a potential increase of the displacement amplitude regardless of the pre...

show abstract

Hydraulic fracturing operation for oil and gas production and associated earthquake activities across the USA

Villa

Singh

2020

Environ Earth Sci

View full text Add to dashboard Cite

Seismogenic width of a fault zone

Cited by 10 publications

References 5 publications

Contemporary Geodynamics of the Garomai Active Fault (Sakhalin Island)

Contemporary Geodynamics of the Garomai Active Fault (Sakhalin Island)

Tectonophysical Signs of the Formation of Strong Earthquake Foci in Seismic Zones of Central Asia

Hydraulic fracturing operation for oil and gas production and associated earthquake activities across the USA

Contact Info

Product

Resources

About