Article
Geochemistry & Geophysics
Itzhak Lior, Anthony Sladen, Diane Rivet, Jean-Paul Ampuero, Yann Hello, Carlos Becerril, Hugo F. Martins, Patrick Lamare, Camille Jestin, Stavroula Tsagkli, Christos Markou
Summary: The novel technique of distributed acoustic sensing (DAS) has great potential for underwater seismology by transforming standard telecommunication cables into dense arrays of seismo-acoustic sensors. Recording transient ground deformations by analyzing ambient noise, earthquakes, and phase velocities on DAS records is crucial for seismic monitoring. The apparent velocities play a significant role in detecting seismic deformations and phases, with DAS capabilities found to be similar to nearby broadband sensors underwater.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Energy & Fuels
Zhuoheng Chen, Stephen E. Grasby, Wanju Yuan, Xiaojun Liu
Summary: This study investigates the potential of using a ground surface temperature (GST) monitoring network as a tool in geothermal resource exploration. The results show that GST time series contain information indicative of subsurface geothermal anomalies and that a GST monitoring network could be an effective tool for geothermal resource exploration in high latitude and/or elevation areas with seasonal snow cover.
Article
Geosciences, Multidisciplinary
Patrick Paitz, Nadja Lindner, Pascal Edme, Pierre Huguenin, Michael Hohl, Betty Sovilla, Fabian Walter, Andreas Fichtner
Summary: Avalanches and other hazardous mass movements in alpine areas pose a threat to the population and critical infrastructure. This study proposes the use of Distributed Acoustic Sensing (DAS) to measure strain rate and characterize ground deformation caused by avalanches. By analyzing the DAS recordings, a Bayesian Gaussian Mixture Model is trained to automatically classify avalanche-induced ground deformations. Furthermore, the study demonstrates the potential of DAS as a research and early warning tool for hazardous mass movements.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geochemistry & Geophysics
Xiaowei Chen
Summary: In this study, the author demonstrates that DAS raw strain rate data can be used to estimate spectral source parameters without converting to particle velocities. The study applies spectral analysis to a geothermal field using joint DAS and seismic Nodal array, and the results are consistent with similar features. The observations suggest the potential for using DAS arrays for earthquake source characterizations.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
John J. Wellik, Stephanie G. Prejean, Devy K. Syahbana
Summary: This study found that the evolution of earthquake families provided evidence that Mount Agung was progressing toward eruption, despite overall earthquake rates and seismic energy release declining. The dominant earthquake families during the crisis ceased before the onset of tremor, with characteristics commonly observed during eruptions appearing days before the actual eruptions began. This suggests that the time history of earthquake families can provide valuable insight into the evolution of volcanic activity and improve eruption forecasts.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Destin Nziengui-Ba, Olivier Coutant, Ludovic Moreau, Pierre Boue
Summary: We investigated the potential of fibre optics coupled with distributed acoustic sensing (DAS) for measuring ice layer thickness and Young's modulus using guided seismic waves. Through field measurements and Bayesian inversion, we obtained accurate results for ice thickness and Young's modulus, which were consistent with field observations. The use of DAS to record guided seismic waves could be a valuable tool for monitoring environments such as floating ice shelves and sea ice.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Evgeniia Martuganova, Manfred Stiller, Ben Norden, Jan Henninges, Charlotte M. Krawczyk
Summary: By utilizing seismic exploration techniques and fiber-optic cables to record data in deep geothermal boreholes, we successfully created a detailed three-dimensional image that revealed small-scale features in the reservoir, which is crucial for future geothermal exploration.
Article
Geochemistry & Geophysics
Gene A. Ichinose, Robert J. Mellors, Justin G. Barno, Rengin Gok
Summary: From a direct comparison between array derived dynamic strain rate (ADDS) and distributed acoustic sensing (DAS) strain rate, it was found that they are coherent for frequencies less than or equal to 1 Hz, but this correlation decays quickly for higher frequencies.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Sven Peter Nasholm, Kamran Iranpour, Andreas Wuestefeld, Ben D. E. Dando, Alan F. Baird, Volker Oye
Summary: Distributed Acoustic Sensing (DAS) involves the transmission of laser pulses along a fiber-optic cable, measuring strain through backscattered pulses. DAS has differences from conventional sensors but has the potential for array processing algorithms.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
F. Hormozzade Ghalati, J. A. Craven, D. Motazedian, S. E. Grasby, E. Roots, V. Tschirhart, Z. Chen, X. Liu
Summary: In this study, the relationship between electrical resistivity and fluid flow in a geothermal reservoir was investigated by combining 3-D resistivity models derived from AMT data with rock properties and fluid sample data. The results showed that 3-D inversion of AMT data can map the fluid pathways at the study site, which are correlated with loss circulation zones in boreholes and can account for a porosity of up to 8.5% and a permeability of approximately 0.249 mD.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Multidisciplinary Sciences
Philippe Jousset, Gilda Currenti, Benjamin Schwarz, Athena Chalari, Frederik Tilmann, Thomas Reinsch, Luciano Zuccarello, Eugenio Privitera, Charlotte M. Krawczyk
Summary: Understanding physical processes prior to and during volcanic eruptions has improved significantly in recent years, but uncertainties about subsurface structures and undetected processes within the volcano prevent volcanologists from inferring subtle triggering mechanisms of volcanic phenomena. This article demonstrates that distributed acoustic sensing (DAS) with optical fibers allows for remote identification of volcanic events and imaging of hidden near-surface volcanic structural features, providing the basis for improved volcano monitoring and hazard assessment.
NATURE COMMUNICATIONS
(2022)
Article
Geosciences, Multidisciplinary
Gongbo Zhang, Zhenghong Song, Abayomi Gaius Osotuyi, Rongbing Lin, Benxin Chi
Summary: This study deploys fiber-optic cables as vibration sensors using Distributed Acoustic Sensing technology to monitor train-induced ground motion signals. With optimized algorithms, the position, speed, and quantity of trains can be accurately tracked. By reducing the array aperture and moving subarrays, reliable train speed curves/motion tracks are obtained.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Energy & Fuels
Jerome Azzola, Katja Thiemann, Emmanuel Gaucher
Summary: To accelerate the energy transition, the exploitation of deep geothermal reservoirs for district heating networks is a priority. Sustainable development requires minimizing risks, such as induced seismicity, while optimizing operational processes. Distributed Acoustic Sensing (DAS) is an effective component of seismic monitoring, particularly in urban environments, and has shown potential for real-time monitoring and risk mitigation in the geothermal field.
Article
Geosciences, Multidisciplinary
Ardianto Ardianto, Andri Dian Nugraha, Haunan Afif, Devy Kamil Syahbana, David P. Sahara, Zulfakriza Zulfakriza, Sri Widiyantoro, Awali Priyono, Shindy Rosalia, Asep Saepuloh, Kasbani Kasbani, Faiz Muttaqy, Puput P. Rahsetyo, Imam C. Priambodo, Martanto Martanto
Summary: Local seismic tomography was applied to investigate the subsurface structure of Mt. Agung, revealing anomalous regions related to potential shallow magma reservoirs and sub-vertical dyke complexes. This study provides new insights for improving eruption forecasting through better understanding of the magma plumbing system beneath Mt. Agung.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Geochemistry & Geophysics
Feng Cheng, Jonathan B. Ajo-Franklin, Avinash Nayak, Veronica Rodriguez Tribaldos, Robert Mellors, Patrick Dobson
Summary: We utilize distributed acoustic sensing (DAS) and ambient noise interferometry to image the geothermal reservoirs in Imperial Valley, California, using unlit fiber-optic telecommunication infrastructure (dark fiber). By applying ambient noise interferometry to DAS records, we obtain a high-resolution two-dimensional (2D) S wave velocity (V-s) structure to a depth of 3 km. We discover a high V-s and low V-p/V-s ratio feature beneath the Brawley geothermal system, indicating hydrothermal mineralization and lower porosity.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Surya Pachhai, Mingming Li, Michael S. Thorne, Jan Dettmer, Hrvoje Tkalcic
Summary: Studies reveal that ultralow-velocity zones beneath the Coral Sea exhibit stratified density increases and shear-wave velocity decreases, which may be related to remnants of Earth's early differentiation.
Article
Geochemistry & Geophysics
Solvi Thrastarson, Dirk-Philip Van Herwaarden, Lion Krischer, Christian Boehm, Martin van Driel, Michael Afanasiev, Andreas Fichtner
Summary: This paper presents a new method of global-scale full-waveform inversion (FWI) that significantly reduces computational cost without sacrificing rigor. The method utilizes data-adaptation and application-oriented specialization on both simulation and measurement levels. The authors also demonstrate the effectiveness of the method by inverting seismic waveforms for 3-D whole-mantle structure and constructing a global FWI model.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geochemistry & Geophysics
Maria Koroni, Anselme Borgeaud, Andreas Fichtner, Frederic Deschamps
Summary: The core-mantle boundary (CMB) is a significant internal boundary in the Earth that strongly influences its dynamics. However, there is currently a lack of agreement between models of CMB topographic variations. This study analyzes seismic waves interacting with the CMB to understand the difficulties in inferring CMB topography and provides sensitivity kernels to explain the behavior of measured traveltimes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Wenyong Pan, Luping Qu, Kristopher A. Innanen, Jan Dettmer, Marie Macquet, Donald Lawton, Yanfei Wang
Summary: Distributed acoustic sensing (DAS) technology is widely evaluated as a cost-effective and nonintrusive seismic monitoring tool for CO2 sequestration. Optical fibers deployed in surface trenches can record high-quality surface waves, and full-waveform inversion (FWI) is applied to image the S-wave velocity (VS) and attenuation (quality factor QS) models. The low-frequency components in DAS recordings help overcome FWI's cycle-skipping problem. The inversion results provide valuable information for characterizing near-surface environments and support seismic imaging in deeper CO2 injection zones.
Article
Geochemistry & Geophysics
Carlos Herrera, John F. Cassidy, Jan Dettmer, Efrain Rivera, Sergio Ruiz, Hannes Vasyura-Bathke
Summary: On September 10, 2008, a M-w 5.7 earthquake occurred in the Central Valley of northern Chile near the town of Pica. The earthquake had a high stress-drop and generated unusually high ground accelerations. The source properties indicate reverse-oblique fault motion on a plane dipping to the northeast, consistent with the dominant style of faulting in the region. Despite the lower occurrence rate of crustal events compared to interplate and inslab events, similar or larger magnitude crustal events have occurred approximately once every three years in northern Chile, posing a significant hazard to nearby populations or critical infrastructure.
SEISMOLOGICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Andreas Fichtner, Coen Hofstede
Summary: This paper presents a basic algorithm for optimal experimental design in distributed fibre-optic sensing. The algorithm takes into account various factors such as cable length, points of interest, obstacles, and topographic variations, allowing for flexibility in different applications.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geochemistry & Geophysics
Jonas K. H. Igel, Daniel C. C. Bowden, Andreas Fichtner
Summary: Seismic ambient noise sources have gained increasing attention as they offer new possibilities to study the Earth's subsurface and the atmosphere-ocean-solid Earth coupling. Methodological developments such as pre-computed wavefields and spatially variable grids have made it feasible to locate and analyze these noise sources. By utilizing Matched Field Processing (MFP) to obtain a starting model, the inversion process can be guided towards acceptable global noise source models, ultimately improving the final results. The provided web framework, seismic ambient noise sources (SANS), allows the public to access daily regional-to-global-scale SANS maps of secondary microseisms, enabling the implementation of time-variable noise source distributions and serving as a reference for larger scale studies.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Saule Simute, Christian Boehm, Lion Krischer, Alexey Gokhberg, Martin Vallee, Andreas Fichtner
Summary: This study presents probabilistic centroid-moment tensor solutions using a combination of Hamiltonian Monte Carlo sampling and 3-D full-waveform inversion, with a focus on the Japanese islands. The results demonstrate the importance of considering 3-D Earth structure in estimating earthquake parameters, particularly for shorter-period data.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geosciences, Multidisciplinary
Jincheng Ma, Hans-Peter Bunge, Andreas Fichtner, Sung-Joon Chang, You Tian
Summary: Knowledge of lithospheric structure is crucial to comprehend how continental collision and oceanic subduction affect surface tectonic configurations. By using full-waveform tomographic images, scientists have discovered lateral heterogeneities and anisotropy in the lithosphere and asthenosphere of Asia. Estimations of lithospheric thickness based on seismic velocity reductions have shown significant variations among different tectonic units. The thickest cratonic roots are found beneath the Sichuan, Ordos, and Tarim basins, as well as central India. Radial anisotropy signatures from 11 representative tectonic provinces reveal the diverse nature and geodynamic processes of their past and present deformations. The extensive deformation of the continental lithosphere is characterized by low-velocity anomalies stretching from the Himalayan Orogen to the Baikal rift zone in central Asia, accompanied by crustal thickening after collision. The presence of a horizontal low-velocity layer at depths of approximately 100-300 km beneath the lithosphere suggests the existence of the asthenosphere beneath East and Southeast Asia, with varying anisotropy indicative of channel flows.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Patrick Paitz, Nadja Lindner, Pascal Edme, Pierre Huguenin, Michael Hohl, Betty Sovilla, Fabian Walter, Andreas Fichtner
Summary: Avalanches and other hazardous mass movements in alpine areas pose a threat to the population and critical infrastructure. This study proposes the use of Distributed Acoustic Sensing (DAS) to measure strain rate and characterize ground deformation caused by avalanches. By analyzing the DAS recordings, a Bayesian Gaussian Mixture Model is trained to automatically classify avalanche-induced ground deformations. Furthermore, the study demonstrates the potential of DAS as a research and early warning tool for hazardous mass movements.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geochemistry & Geophysics
Dirk-Philip van Herwaarden, Solvi Thrastarson, Vaclav Hapla, Michael Afanasiev, Jeannot Trampert, Andreas Fichtner
Summary: In this study, a seismic model of the Africa Plate is constructed using the full-waveform inversion technique. The model is used for geodynamic and geochemical interpretation, earthquake-induced ground motion predictions, and earthquake source inversion. The data from 397 earthquakes and 184,356 source-receiver pairs are inverted to image the tectonic features of the Africa Plate. A new strategy to assess model uncertainty is proposed.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Andreas Fichtner, Coen Hofstede, Lars Gebraad, Andrea Zunino, Dimitri Zigone, Olaf Eisen
Summary: Ice streams play a significant role in ice sheet mass loss and sea level rise. In this study, a distributed acoustic sensing experiment was conducted to investigate the dynamic behavior of the Northeast Greenland Ice Stream. The results showed that the wave speeds and reflectivity of the ice can be determined through a combination of nonlinear traveltime tomography and firn modeling. The differences in wave speeds suggest anisotropy related to crystal orientation fabric, while the reflectivity image indicates climatic variations caused by changes in grain size. However, improving the resolution requires addressing issues such as signal bandwidth, signal-to-noise ratio, and systematic errors.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
S. H. McKean, J. A. Priest, J. Dettmer, G. Fradelizio, D. Eaton
Summary: A Bayesian quantile regression method is used to separate microseismic events related to hydraulic fractures from induced events. This method allows for optimization of hydraulic treatments and mitigation of induced seismicity. A case study demonstrates the successful differentiation of faults connected to hydraulic fractures and faults solely related to induced seismicity.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
Hannes Vasyura-Bathke, Jan Dettmer, Katherine Biegel, Rebecca O. Salvage, David Eaton, Nicolas Ackerley, Sergey Samsonov, Torsten Dahm
Summary: A joint analysis of InSAR and seismic data reveals that long-term saltwater disposal in western Canada triggers resurgent earthquakes by reactivating a complex fault system. The mainshock of the earthquake sequence occurred at a depth of about 5 km and propagated towards the injection source, stopping at a depth of about 2 km. The reactivated faults are part of a regional, basement-rooted graben system and appear to be truncated by a fault that is misoriented for slip in the present-day stress regime.
COMMUNICATIONS EARTH & ENVIRONMENT
(2023)
Article
Environmental Sciences
Susanne M. M. Ouellet, Jan Dettmer, Gerrit Olivier, Tjaart DeWit, Matthew Lato
Summary: In this study, ambient noise interferometry is used to monitor the performance of a tailings dam and is correlated with water level changes. A one-dimensional model is obtained, showing good results. This method provides important advances and implications for understanding changes in dam performance by directly measuring soil stiffness and inferring other geotechnical design parameters.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)