Article
Geochemistry & Geophysics
Taeho Kim, Jean-Philippe Avouac
Summary: Induced seismicity during Enhanced Geothermal Stimulation in Otaniemi, Finland was modeled using statistical and physical approaches. The physical model, assuming rate-and-state friction, produced simulations closest to the observations, highlighting the importance of a time-dependent earthquake nucleation process in reproducing the spatial pattern of seismicity. A statistical model, estimating seismicity rate based on convolution of the injection history with a kernel approximating earthquake triggering by fluid diffusion, also fit the observations well and had superior computational efficiency. The Kaiser effect, however, was not clearly observed in the data from Otaniemi.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
R. De Matteis, V Convertito, F. Napolitano, O. Amoroso, T. Terakawa, P. Capuano
Summary: Focal mechanisms of selected earthquakes in the Mount Pollino region from 2010 to 2014 were used to infer pore fluid pressure at hypocenter depths, revealing a fluid-filled volume with values reaching 35 MPa. The study found that seismicity distribution was actually driven by pore-pressure diffusion mechanism with relatively low diffusivity value, which can also explain the delayed triggering of larger events.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Lea Perrochet, Giona Preisig, Benoit Valley
Summary: Seismicity following heavy rainfall events in karst areas is influenced by direct hydraulic connection through karst conduits, rather than pressure diffusion, highlighting the importance of considering karst's intrinsic properties and spatial distribution.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Ameha A. Muluneh, Derek Keir, Giacomo Corti
Summary: Lower crustal earthquakes at plate boundaries and intraplate settings occur at depth where deformation is normally expected to occur in a ductile manner. Our models suggest that the depth distribution of earthquakes in the lower crust is best explained by strong mafic lower crustal rheology and hydrostatic fluid pore pressure conditions in areas away from the Main Ethiopian Rift beneath the NW plateau. In the central MER, the lower crust has no long-term strength and seismicity is likely induced by a combination of near-lithostatic pore fluid pressure and high strain rates due to fluid movement.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Energy & Fuels
Jannes L. Kinscher, Matsen Broothaers, Jean Schmittbuhl, Francesca De Santis, Ben Laenen, Emmanuelle Klein
Summary: This study presents the main features of geothermal production history and seismic data at the Balmatt geothermal doublet in Mol, Belgium. It identifies a hidden fault zone not found during exploration and provides new constraints on seismic activity and hazard.
Article
Multidisciplinary Sciences
Pasan Herath, Januka Attanayake, Kalpna Gahalaut
Summary: Anomalous seismic activity exceeding the national background seismic rate was observed around the Victoria Reservoir in Sri Lanka. The study detected a previously unnoticed seismic swarm and established a causal relationship between the reservoir-induced stresses and the earthquake swarm. The study also provided a low-cost workflow for monitoring reservoir-induced seismicity in developing countries.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Kai Zhao, Xiaoyun Wang, Yongcun Feng, Wei Gao, Wenjie Song, Liangbin Dou, Hailong Jiang
Summary: Due to the complexity of the fault activation mechanism in hot dry rock injection and production, a thermal-hydraulic-mechanical coupling mathematical model is established to evaluate the fault activation risk. The results show that the risk of fault activation increases with greater well spacing and injection flow, and with lower reservoir permeability and higher initial reservoir temperature. Different fault occurrences lead to different risks of fault activation. These findings are important for the safe and efficient development of hot dry rock reservoirs.
Article
Geosciences, Multidisciplinary
Timothy Chapman, Luke Milan, Julie Vry
Summary: This study investigates the relationship between tectonic tremor, hydrofracturing, and fluid migration under the actively forming Southern Alps in New Zealand. It combines predictions from phase equilibria and mechanical modeling to analyze the links between these processes. The study finds that the production of water during metamorphism along active plate boundaries contributes to tectonic tremor.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Alfio Vigano, Giorgio Ranalli, Daniele Andreis, Silvana Martin
Summary: The friction coefficient is an important parameter for describing the strength of seismic faults, and it is related to the properties of rocks and pore fluid pressures. By using an iterative inversion procedure and analyzing datasets, the average static friction coefficient of seismic faults can be obtained, which is crucial for further understanding the behavior and stability models of seismic faults.
JOURNAL OF GEODYNAMICS
(2021)
Article
Geochemistry & Geophysics
Harsh K. Gupta
Summary: Under certain geological conditions, human-induced seismicity can occur due to activities such as gold/coal mining, geothermal and natural gas/oil production, filling of artificial water reservoirs, and high-pressure fluid injection. Reservoir-triggered seismicity (RTS) is the most prominent, with reported earthquakes exceeding M 6 and causing casualties and property destruction. The height of water column in the reservoir is the most important factor for RTS to occur.
SURVEYS IN GEOPHYSICS
(2022)
Article
Multidisciplinary Sciences
Marcello Gori, Vito Rubino, Ares J. Rosakis, Nadia Lapusta
Summary: This study reveals that fast fluid injection rates lead to dynamic ruptures at lower pressure levels and smaller spatial scales, while slow injection rates result in gradual nucleation processes consistent with accelerating slow slip behaviors. The presence of fluids influences friction properties and pore-pressure increase rate needs to be considered in nucleation processes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Geochemistry & Geophysics
Man Zhang, Shemin Ge, Qiang Yang, Xiaodong Ma
Summary: This study focuses on the seismic impact near four newly built large hydropower stations downstream the Jinsha River in Southwestern China. The research finds that impoundment of these reservoirs may lead to changes in pore pressure and an increase in Coulomb stress on nearby faults, triggering seismic activity. Earthquakes occurring after reservoir impoundment may be related to changes in pore pressure and fault stress.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Zoe Braden, Whitney M. Behr
Summary: The study focuses on the deformation structures and conditions of mafic oceanic crust during subduction in the Chugach accretionary complex of south-central Alaska. It reveals that basalt disintegrates into chlorite-rich fault gouge under lithostatic pore fluid pressures, leading to weakening through cataclasis, dilatational shear fracturing, and slip on shear bands. This process occurs in a narrower fault zone with higher stress and pore fluid pressure fluctuations compared to sediment-hosted megathrusts.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Yuyang Tan, Jiawei Qian, Jun Hu, Haijiang Zhang, Huilin Xing, Junlun Li, Jian Xu, Wen Yang, Ning Gu, Siyu Miao
Summary: Seismic activity near shale gas fields in the Sichuan Basin of China has increased significantly, but it is difficult to directly link it with hydraulic fracturing stimulation due to the lack of public industrial stimulation data. Understanding subsurface fluid distribution can help address this issue. This study uses seismic tomography methods to build three-dimensional models and characterizes fluid distributions beneath the shale gas field.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Energy & Fuels
Geoffrey Mibei, Bjorn S. Hardarson, Hjalti Franzson, Eniko Bali, Halldor Geirsson, Gudmundur H. Gudfinnsson, Charles Lichoro, John Lagat
Summary: Trachytic and basaltic volcanic materials erupted from around 390,000 years ago to the Holocene, forming the 136 km(2) active volcanic edifice of Paka. The geothermal system of Paka mainly manifests as surface fumaroles and hot altered grounds. Fluid inclusion analysis and temperature data from exploration wells indicate that the most suitable area for geothermal development lies within a 12 km2 area in the summit area and Northeast of the Paka caldera.
Article
Geochemistry & Geophysics
V Durand, A. Gualandi, S. Ergintav, G. Kwiatek, M. Haghshenas, M. Motagh, G. Dresen, P. Martinez-Garzon
Summary: In this study, we analyze and characterize a slow slip event that occurred in the Sea of Marmara in 2016. By combining different types of geodetic data and seismicity, we propose two interpretations to explain the observations. Our results indicate that the slow event may have initiated on different sections of the Armutlu fault and triggered seismicity on a neighboring fault.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Geochemistry & Geophysics
Fatih Turhan, Digdem Acarel, Vladimir Plicka, Marco Bohnhoff, Remzi Polat, Jiri Zahradnik
Summary: Turkish seismologists studied the 2019 Silivri earthquake to predict the future major earthquake in Istanbul, and found that this earthquake involved both strike-slip and thrust faulting. The simultaneous occurrence of these faulting types may have implications for tsunami hazard.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Grzegorz Kwiatek, Patricia Martinez-Garzon, Jorn Davidsen, Peter Malin, Aino Karjalainen, Marco Bohnhoff, Georg Dresen
Summary: We investigated induced seismicity caused by hydraulic stimulation in a geothermal well near Helsinki, Finland. The seismicity was monitored and analyzed, and it was found that there was no correlation between earthquake magnitudes during the stimulation. The interevent time statistics followed a Poisson distribution. The study suggests that the hydraulic stimulation did not result in earthquake interaction or prolonged seismic events.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Aglaja Blanke, Carolin M. Boese, Georg Dresen, Marco Bohnhoff, Grzegorz Kwiatek
Summary: The controlled hydraulic stimulation experiments in Underground Research Laboratories (URLs) have been studied through active and passive seismic monitoring. Microseismic monitoring is used to characterize the stimulated reservoir volume, while active seismic sources provide stronger signals and a broader frequency range for better analysis of damage evolution in the rock mass. The coda analysis of active Ultrasonic Transmission (UT) measurements complements established imaging methods, providing valuable information for imaging georeservoirs.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
P. Martinez-Garzon, G. C. Beroza, G. M. Bocchini, M. Bohnhoff
Summary: Research finds that small stress changes, such as sea level fluctuations, can trigger earthquakes. High-resolution seismic catalogs with low detection thresholds are best suited to study this phenomenon.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Yinlin Ji, Lei Wang, Hannes Hofmann, Grzegorz Kwiatek, Georg Dresen
Summary: The study finds that high injection rates in low-permeability granite samples can shorten the nucleation length of earthquakes, increasing the seismic hazard.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Geological
Valerian Schuster, Erik Rybacki, Audrey Bonnelye, Grzegorz Kwiatek, Anja M. Schleicher, Georg Dresen
Summary: This study investigates the influence of pressure and mineral composition on the deformation behavior during fault reactivation in the Opalinus Clay formation. The results show a transition from brittle to semi-brittle behavior with increasing pressure, characterized by non-linear strain hardening and delocalization of deformation.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Geochemistry & Geophysics
J. M. Holmgren, G. Kwiatek, M. J. Werner
Summary: The rupture behavior of microseismicity in fluid-injection settings is influenced by pore pressure and shows a certain degree of predictability. Through the analysis of directivity patterns and focal mechanisms, this study identifies rupture planes and directions of 10 events recorded during the 2018 St1 Deep Heat geothermal project in Finland. Unlike previous studies, the events in this project exhibit varied rupture directions, with some rupturing towards, away from, or parallel to the injection well. These findings contribute to the understanding of rupture growth in pore-pressure dominated settings.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Simon Guerin-Marthe, Grzegorz Kwiatek, Lei Wang, Audrey Bonnelye, Patricia Martinez-Garzon, Georg Dresen
Summary: Aseismic slip during the preparatory stage prior to earthquakes is poorly understood. This study investigated the influence of load point velocity and surface roughness on slow slip. Friction experiments were conducted on granite samples with different surface roughness, with varying load point velocities. The results showed that aseismic slip during the preparatory stage increased with roughness, while the duration of precursory slip decreased with increased load point velocity, revealing a complex slip pattern on rough faults leading to dynamic ruptures at high load point velocities.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Sadegh Karimpouli, Danu Caus, Harsh Grover, Patricia Martinez-Garzon, Marco Bohnhoff, Gregory C. Beroza, Georg Dresen, Thomas Goebel, Tobias Weigel, Grzegorz Kwiatek
Summary: This study pioneers in time to failure (TTF) prediction based on machine learning using acoustic emission (AE) records from laboratory stick-slip experiments. The regression voting ensemble of Long-Short Term Memory (LSTM) networks predicts TTF with a coefficient of determination (R2) of 70% on the test dataset. Feature importance analysis reveals that AE rate, correlation integral, event proximity, and focal mechanism-based features are the most important features for TTF prediction.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Amandine Amemoutou, Patricia Martinez-Garzon, Virginie Durand, Grzegorz Kwiatek, Marco Bohnhoff, Georg Dresen
Summary: The Main Marmara Fault (MMF) is a part of the North Anatolian Fault Zone (NAFZ) in Turkey, posing a seismic threat to the Istanbul area. By comparing seismic strain rates and coupling estimates from historical and instrumental records, it is found that major earthquakes have similar strain rates to tectonic strain rates, while seismic energy released in off-fault areas is significantly smaller. A significant portion of shear strain in the Sea of Marmara is currently accommodated by seismic deformation. The seismic coupling varied before and after the 1999 Izmit earthquake, indicating different contributions of aseismic slip during different stages of the seismic cycle.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Geological
Carolin M. Boese, Grzegorz Kwiatek, Katrin Plenkers, Thomas Fischer, Georg Dresen
Summary: In the STIMTEC and STIMTEC-X hydraulic stimulation experiments, acoustic emission (AE) sensors were installed in the Reiche Zeche mine to record picoseismicity. The sensors were placed in boreholes without a coupling system or cementing, and their performance measures such as frequency bandwidth, sensitivity, first motion polarity, coupling, and placement quality were investigated. The hydrophone-like acoustic emission (HAE) sensors can be paired with hydraulic equipment to improve seismic event detection and location quality during hydraulic stimulations. They can adequately record the wavefield for first-arrival identification and amplitude characteristics, but are less suitable for detecting S-waves.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Physics, Fluids & Plasmas
Andrew Patton, Thomas Goebel, Grzegorz Kwiatek, Joern Davidsen
Summary: In this study, it is found that large-scale stress heterogeneities induced by a notch fundamentally change the characteristics of the failure point in triaxial compression experiments on Westerly granite samples. Accelerated seismic release without a critical point and no change in power-law exponent e of the AE size distribution are observed. This suggests that large-scale heterogeneities play a significant role in predicting compressive failure in rock.
Article
Geochemistry & Geophysics
Carolin M. Boese, Grzegorz Kwiatek, Thomas Fischer, Katrin Plenkers, Juliane Starke, Felix Blumle, Christoph Janssen, Georg Dresen
Summary: The STIMTEC experiment involved hydraulic stimulation testing and high-resolution seismic monitoring to study the relationship between rock damage and hydraulic enhancement. Results showed structural anisotropy and seismic activity. Various sensors were used to explore the impact of different velocity models on the accuracy of earthquake event localization.