Induced Seismicity Keranen, Katie M; Weingarten, Matthew
Annual review of earth and planetary sciences,
05/2018, Letnik:
46, Številka:
1
Journal Article
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The ability of fluid-generated subsurface stress changes to trigger earthquakes has long been recognized. However, the dramatic rise in the rate of human-induced earthquakes in the past decade has ...created abundant opportunities to study induced earthquakes and triggering processes. This review briefly summarizes early studies but focuses on results from induced earthquakes during the past 10 years related to fluid injection in petroleum fields. Study of these earthquakes has resulted in insights into physical processes and has identified knowledge gaps and future research directions. Induced earthquakes are challenging to identify using seismological methods, and faults and reefs strongly modulate spatial and temporal patterns of induced seismicity. However, the similarity of induced and natural seismicity provides an effective tool for studying earthquake processes. With continuing development of energy resources, increased interest in carbon sequestration, and construction of large dams, induced seismicity will continue to pose a hazard in coming years.
Reinjection of saltwater, co-produced with oil, triggered thousands of widely felt and several damaging earthquakes in Oklahoma and Kansas. The future seismic hazard remains uncertain. Here, we ...present a new methodology to forecast the probability of damaging induced earthquakes in space and time. In our hybrid physical-statistical model, seismicity is driven by the rate of injection-induced pressure increases at any given location and spatial variations in the number and stress state of preexisting basement faults affected by the pressure increase. If current injection practices continue, earthquake hazards are expected to decrease slowly. Approximately 190, 130 and 100 widely felt M ≥ 3 earthquakes are anticipated in 2018, 2019 and 2020, respectively, with corresponding probabilities of potentially damaging M ≥ 5 earthquakes of 32, 24 and 19%. We identify areas where produced-water injection is more likely to cause seismicity. Our methodology can be used to evaluate future injection scenarios intended to mitigate seismic hazards.
Given the rapid growth of the
industry, developing practices for producing young plants with limited genetic variation and efficient growth is crucial to achieving reliable and successful cultivation ...results. This study presents a multi-faceted experiment series analyzing propagation techniques for evaluating proficiency in the growth and development of
vegetative cuttings. This research encompasses various (1) soilless propagation methods including aeroponics, horticultural (phenolic) foam, and rockwool; (2) transplant timings; (3) aeroponic spray intervals; and (4) aeroponic reservoir nutrient concentrations, to elucidate their impact on rooting and growth parameters amongst two
cultivars. Aeroponics was as effective as, and in some cases more effective than, soilless propagation media for root development and plant growth. In aeroponic systems, continuous spray intervals, compared to intermittent, result in a better promotion of root initiation and plant growth. Moreover, raised nutrient concentrations in aeroponic propagation demonstrated greater rooting and growth. The effects of experimental treatment were dependent on the cultivar and sampling day. These findings offer valuable insights into how various propagation techniques and growth parameters can be tailored to enhance the production of vegetative cuttings. These results hold critical implications for cultivators intending to achieve premium harvests through efficient propagule methods and optimization strategies in the competitive
industry. Ultimately, our findings suggest that aeroponic propagation, compared to alternative soilless methods, is a rapid and efficient process for cultivating vegetative cuttings of
and offers sustainable advantages in resource conservation and preservation.
Groundwater observations in Ash Meadows, Nevada are dedicated to protect its unique ecosystem and to manage groundwater resources. The groundwater levels are sensitive to natural factors such as ...earth tides and earthquakes, allowing us to study dynamic hydrologic properties. During the 2019 M6.4 and M7.1 Ridgecrest earthquakes, Ash Meadows groundwater levels declined in the fractured carbonate aquifer by 7-9 cm, whereas no coseismic groundwater level response was observed in the overlying (∼280 m) alluvial aquifer. We analyzed the static and dynamic stresses produced by the earthquake, and found static stresses should have produced only coseismic water level increases in the Ash Meadows region. At the same time, dynamic stresses were large enough to induce coseismic water level response and are likely the driving force for groundwater level reductions in the carbonate aquifer. Although tidal analysis does not show an observable long-term change in hydraulic parameters, we observed a temporary diffusivity enhancement in the 6 days following the M6.4 foreshock. In addition, we did not observe a postseismic recovery of water level in the carbonate aquifer. Instead, a subsequent 2-year observation of water levels indicates a persistent decline at a rate of 1.7−4.6×10−5 m/day, which is in direct contrast to a generally increasing water level before the earthquake. As of August 2021, water levels in the carbonate aquifer have declined between 1.4-3.7 cm since the earthquake. Persistent water level declines induced by the passage of seismic waves may modify aquifer properties in the short (days) and long-term (months to years). High resolution groundwater monitoring is needed to better understand the postseismic response in hydrologically sensitive aquifers such as Ash Meadows.
•Coseismic groundwater level declines were observed in the carbonate aquifer, but not in the overlying valley-fill aquifer.•Groundwater level declines are triggered by dynamic stresses and cannot be explained by static stress changes.•Transient changes in groundwater tidal response suggest a short-term diffusivity increase.•Persistent groundwater level decline is observed for 2 years after the earthquake in the fractured carbonate aquifer.
We present an overview of the current status of unconventional energy development, particularly of shale gas, and underground CO
2
storage as a measure to mitigate greenhouse gas increase in the ...atmosphere. We review their potential to induce seismicity, which has caused debates among related energy enterprises, engineers, researchers, and environmental and public communities regarding their potential hazards. Studies show that fracking can be a problem in that it consumes abundant water, but the seismicity induced by fracking has not yet been observed to induce many felt earthquakes. However, massive wastewater injection, a part of the unconventional energy development process has caused
M
5.0+ earthquakes in the past as well as several recent and ongoing cases of induced seismicity. Large-scale CO
2
injection as a part of carbon sequestration efforts in the near future has a high risk of inducing large earthquakes. Therefore, injection operations related to both unconventional energy development and carbon sequestration should be optimized and managed to mitigate the likelihood of an induced seismic event.
We studied the 24 year record of water level responses in Devils Hole, Death Valley National Park, NV, to dynamic crustal stresses from earthquakes. The continuous water level record exhibited 219 ...responses from earthquakes around the world, displaying hydroseismogram and coseismic offset types of response. We found that the water level in Devils Hole is extremely sensitive to earthquakes, and the seismic energy density required to initiate both hydroseismogram and coseismic offset responses is e ~ 10−6 J/m3, 2 orders of magnitude smaller than previously documented. Multiple mechanisms at Devils Hole may be responsible for observed water level responses to distant earthquakes. The hydroseismogram‐type responses are best explained by poroelastic deformation, while coseismic offset responses are likely the result of localized permeability changes. This study could have implication to studying dynamic triggering of earthquakes, as remote earthquakes can lead to pore pressure changes and consequently effective stress changes in fluid‐filled fault zones.
Key Points
Devils Hole sets new threshold of water level sensitivity to remote earthquakes
Water level response frequency is characteristic of Rayleigh wave triggering
Several mechanisms, both dilatation and permeability change, operate at one site
Wastewater reinjection increases pore fluid pressure and can make faults frictionally unstable, triggering earthquakes. Little is known, however, about how regional geomechanical properties influence ...the likelihood that disposal will induce seismicity. We investigate the impact of preinjection conditions on the proportion of possible fault orientations destabilized by a specified pore pressure increase. Stress state is the most important factor, with 7 times as many planes unstable in extension than contraction—indeed, normal or strike‐slip faulting environments characterize most injection‐induced seismicity—and additional fivefold increases in transitional stress states. Geomechanical susceptibility depends inversely on overburden density and depth, consistent with the shallow hypocenters of most induced events. The coefficient of friction and initial pore pressure have little impact: Faults initially below hydrostatic pressure can slip during gravity‐fed injection. Combining these factors, site‐specific geomechanical analyses could determine 300‐fold variations in the likelihood of induced seismicity before disposal, offering a proactive way to manage hazard.
Plain Language Summary
We investigate what factors influence the likelihood that industrial activities will trigger earthquakes. The initial pore‐fluid pressure is unimportant, meaning that gravity‐fed injection can readily cause seismicity. By contrast, readily known properties of the region (stress state, depth to bedrock faults, and density of the overlying sedimentary rock units) produce 300‐fold variations in the likelihood of injection‐induced earthquakes. Conducting simple analyses prior to injection could mitigate seismic hazard.
Key Points
Three hundred‐fold variations in the likelihood of induced seismicity can be estimated prior to injection
Extensional and strike‐slip settings, and especially transitional stress regimes, are the most susceptible
Preinjection pore pressure is unimportant, so underpressured basins are not insulated from hazard
In June 2019, an earthquake sequence comprising five M > 5 events occurred in a region of southwest China with fluid injection for both hydraulic fracturing and salt mining, which raised an extensive ...controversy on the cause. Here we use interferometric synthetic aperture radar (InSAR) observations to determine the source parameters of the sequence and to investigate the relationship with local injection activities. Both Sentinel‐1 and Advanced Land Observing Satellite 2 SAR images are collected to measure coseismic and preseismic surface deformation. Geodetic inversions with coseismic observations show that the sequence ruptured a previously unmapped southwest‐dipping thrust fault above 3 km depth, which intersects with the open‐hole sections of wells for solution mining of salt. In the 4 months before the sequence, cumulative line‐of‐sight displacements near the wells are around 1–2 cm after correcting seasonal‐like deformation. Our results indicate that water injection likely enhanced pore pressure within the fault zone and thus contributed to inducing the sequence.
Plain Language Summary
Earthquakes are seldom reported in relation to fluid injection for salt mining. Here, we present a unique case of an earthquake sequence probably induced by such human activity in Changning (southwest China). The sequence began with a Ms 6.0 earthquake, which is an unprecedented magnitude and larger than the historical records of earthquakes induced by wastewater disposal and hydraulic fracturing. Due to the sparse distribution of seismic stations and the failure of a key station closest to injection wells for salt mining before the Ms 6.0 earthquake, available seismic data are not enough to constrain the spatial locations of events in the earthquake sequence. Here we instead use high spatial‐resolution interferometric synthetic aperture radar observations of coseismic surface deformation to image the causative fault of the sequence. We find that the open‐hole sections of injection wells intersect the seismogenic fault. Moreover, the cumulative surface displacements near the salt mine in the ~4 months before the sequence are 1–2 cm, which was mainly caused by ground uplift. Accordingly, we hypothesize that fluid injection increased pore pressure within the fault zone and brought it to rupture. Our interferometric synthetic aperture radar observations and inversion results present significant evidence toward the causality between salt mining and the earthquake sequence.
Key Points
InSAR observations show significant ground deformation due to the Changning earthquake sequence near the salt mine
InSAR inversions reveal that the Changning earthquake sequence ruptured a southwest‐dipping thrust fault above the depth of 3 km
The open‐hole sections of wells injecting for solution mining of salt intersect the InSAR‐inferred seismogenic fault
Given the rapid growth of the Cannabis industry, developing practices for producing young plants with limited genetic variation and efficient growth is crucial to achieving reliable and successful ...cultivation results. This study presents a multi-faceted experiment series analyzing propagation techniques for evaluating proficiency in the growth and development of Cannabis vegetative cuttings. This research encompasses various (1) soilless propagation methods including aeroponics, horticultural (phenolic) foam, and rockwool; (2) transplant timings; (3) aeroponic spray intervals; and (4) aeroponic reservoir nutrient concentrations, to elucidate their impact on rooting and growth parameters amongst two Cannabis cultivars. Aeroponics was as effective as, and in some cases more effective than, soilless propagation media for root development and plant growth. In aeroponic systems, continuous spray intervals, compared to intermittent, result in a better promotion of root initiation and plant growth. Moreover, raised nutrient concentrations in aeroponic propagation demonstrated greater rooting and growth. The effects of experimental treatment were dependent on the cultivar and sampling day. These findings offer valuable insights into how various propagation techniques and growth parameters can be tailored to enhance the production of vegetative cuttings. These results hold critical implications for cultivators intending to achieve premium harvests through efficient propagule methods and optimization strategies in the competitive Cannabis industry. Ultimately, our findings suggest that aeroponic propagation, compared to alternative soilless methods, is a rapid and efficient process for cultivating vegetative cuttings of Cannabis and offers sustainable advantages in resource conservation and preservation.
A single tracing component embedded into a high-frequency processor may produce up to 1 GB/s of trace data or more. These data are vital in debugging, monitoring, verification, and performance ...analysis in System-on-chip and heterogeneous system development. Hardware trace decoders and analyzers have emerged to support online processing of trace data for real-time applications. However, the existing hardware trace decoders designed for the Embedded Trace Macrocell version 4 (ETMv4), a standard feature in most modern ARM processors, can only process trace data at a maximum rate of 250 MB/s. This paper proposes an optimized and parallelized trace decoder for the ETMv4 specification implemented on a Xilinx Ultrascale+ processing up to 1 GB/s of trace data from a single ETM.
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