Articles | Volume 4, issue 2
https://doi.org/10.5194/se-4-543-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/se-4-543-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Study on the limitations of travel-time inversion applied to sub-basalt imaging
I. Flecha
Departament de Estructura i Dinàmica de la Terra, Institut de Ciències de la Terra Jaume Almera-ICTJA-CSIC, C/ Lluís Solé i Sabarís s/n, 08028, Barcelona, Spain
R. Carbonell
Departament de Estructura i Dinàmica de la Terra, Institut de Ciències de la Terra Jaume Almera-ICTJA-CSIC, C/ Lluís Solé i Sabarís s/n, 08028, Barcelona, Spain
R. W. Hobbs
Department of Earth Sciences, University of Durham, Durham DH1 3LE, UK
Related subject area
Seismology
The 3D QP model of the China Seismic Experimental Site (CSES-Q1.0) and its tectonic implications
Understanding seismic anisotropy in the Rotondo granite: investigating stress as a potential source
A new look at reflection seismic data from the Central Caledonian Transect across the Scandinavian Peninsula
Quaternary surface ruptures of the inherited mature Yangsan Fault: implications for intraplate earthquakes in southeastern Korea
Seismic noise characterisation for the Buddusò – Ala dei Sardi wind park (Sardinia, Italy) and its impact on the Einstein Telescope candidate site
Earthquakes triggered by the subsurface undrained response to reservoir impoundment at Irapé, Brazil
Accretionary prism deformation and fluid migration caused by slow earthquakes in the Nankai subduction zone
Coda-derived source properties estimated using local earthquakes in the Sea of Marmara, Türkiye
Extraction of pre-earthquake anomalies from borehole strain data using Graph WaveNet: a case study of the 2013 Lushan earthquake in China
Highlights on mantle deformation beneath the Western Alps with seismic anisotropy using CIFALPS2 data
Frequency-dependent shear wave attenuation across the Central Anatolia region, Türkiye
Thermal structure of the southern Caribbean and northwestern South America: implications for seismogenesis
Linked and fully coupled 3D earthquake dynamic rupture and tsunami modeling for the Húsavík–Flatey Fault Zone in North Iceland
Global seismic energy scaling relationships based on the type of faulting
Earthquake monitoring using deep learning with a case study of the Kahramanmaras Turkey earthquake aftershock sequence
Reference seismic crustal model of the Dinarides
The 2022 MW 6.0 Gölyaka–Düzce earthquake: an example of a medium-sized earthquake in a fault zone early in its seismic cycle
Offshore seismicity clusters in the West Iberian Margin illustrated by 2 decades of events
A new seismicity catalogue of the eastern Alps using the temporary Swath-D network
The impact of seismic noise produced by wind turbines on seismic borehole measurements
A borehole trajectory inversion scheme to adjust the measurement geometry for 3D travel-time tomography on glaciers
Probing environmental and tectonic changes underneath Mexico City with the urban seismic field
Quantifying gender gaps in seismology authorship
Mapping the basement of the Cerdanya Basin (eastern Pyrenees) using seismic ambient noise
Ocean bottom seismometer (OBS) noise reduction from horizontal and vertical components using harmonic–percussive separation algorithms
Towards real-time seismic monitoring of a geothermal plant using Distributed Acoustic Sensing
Constraints on fracture distribution in the Los Humeros geothermal field from beamforming of ambient seismic noise
Upper-lithospheric structure of northeastern Venezuela from joint inversion of surface-wave dispersion and receiver functions
A study on the effect of input data length on a deep-learning-based magnitude classifier
Multi-array analysis of volcano-seismic signals at Fogo and Brava, Cape Verde
Reflection imaging of complex geology in a crystalline environment using virtual-source seismology: case study from the Kylylahti polymetallic mine, Finland
Radial anisotropy and S-wave velocity depict the internal to external zone transition within the Variscan orogen (NW Iberia)
The damaging character of shallow 20th century earthquakes in the Hainaut coal area (Belgium)
Distributed acoustic sensing as a tool for subsurface mapping and seismic event monitoring: a proof of concept
Seismic monitoring of the STIMTEC hydraulic stimulation experiment in anisotropic metamorphic gneiss
Two subduction-related heterogeneities beneath the Eastern Alps and the Bohemian Massif imaged by high-resolution P-wave tomography
One-dimensional velocity structure modeling of the Earth's crust in the northwestern Dinarides
A functional tool to explore the reliability of micro-earthquake focal mechanism solutions for seismotectonic purposes
Changepoint detection in seismic double-difference data: application of a trans-dimensional algorithm to data-space exploration
Imaging structure and geometry of slabs in the greater Alpine area – a P-wave travel-time tomography using AlpArray Seismic Network data
3D crustal structure of the Ligurian Basin revealed by surface wave tomography using ocean bottom seismometer data
Basin inversion: reactivated rift structures in the central Ligurian Sea revealed using ocean bottom seismometers
Moho and uppermost mantle structure in the Alpine area from S-to-P converted waves
The effect of 2020 COVID-19 lockdown measures on seismic noise recorded in Romania
Elastic anisotropies of deformed upper crustal rocks in the Alps
COVID-19 lockdown effects on the seismic recordings in Central America
A revised image of the instrumental seismicity in the Lodi area (Po Plain, Italy)
Seismic radiation from wind turbines: observations and analytical modeling of frequency-dependent amplitude decays
Accelerating Bayesian microseismic event location with deep learning
Present-day geodynamics of the Western Alps: new insights from earthquake mechanisms
Mengqiao Duan, Lianqing Zhou, Ying Fu, Yanru An, Jingqiong Yang, and Xiaodong Zhang
Solid Earth, 16, 391–408, https://doi.org/10.5194/se-16-391-2025, https://doi.org/10.5194/se-16-391-2025, 2025
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We obtain the highest-resolution three-dimensional P-wave attenuation model in the China Seismic Experimental Site to date. The P-wave attenuation value anomalies along large fault zones, some basin areas, and the Tengchong volcanic area are low, reflecting the high degree of medium fragmentation in these areas with thick sedimentary layers or rich in fluids.
Kathrin Behnen, Marian Hertrich, Hansruedi Maurer, Alexis Shakas, Kai Bröker, Claire Epiney, María Blanch Jover, and Domenico Giardini
Solid Earth, 16, 333–350, https://doi.org/10.5194/se-16-333-2025, https://doi.org/10.5194/se-16-333-2025, 2025
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Several cross-hole seismic surveys in the undisturbed Rotondo granite are used to analyze the seismic anisotropy in the Bedretto Lab, Switzerland. The P and S1 waves show a clear trend of faster velocities in the NE–SW direction and slower velocities perpendicular to it, indicating a tilted transverse isotropic velocity model. The symmetry plane is mostly aligned with the direction of maximum stress, but also the orientation of fractures is expected to influence the velocities.
Christopher Juhlin, Rodolphe Lescoutre, and Bjarne Almqvist
EGUsphere, https://doi.org/10.5194/egusphere-2025-1196, https://doi.org/10.5194/egusphere-2025-1196, 2025
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Reflection seismic data can provide high resolution images of the Earth's crust and allow a better understanding of crustal structure on all continents. In this paper we revisit reflection seismic data that were acquired previously across the central part of the Scandinavian peninsula. Merging of individual components of the data set in a more optimal manner resulted in a new image of the crust below the Scandinavian Caledonides with a revised interpretation of the crustal structure in the west.
Sangmin Ha, Hee-Cheol Kang, Seongjun Lee, Yeong Bae Seong, Jeong-Heon Choi, Seok-Jin Kim, and Moon Son
Solid Earth, 16, 197–231, https://doi.org/10.5194/se-16-197-2025, https://doi.org/10.5194/se-16-197-2025, 2025
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Unlike episodic plate boundary earthquakes, their randomness makes predicting intraplate earthquakes challenging. This study aids in understanding intraplate earthquake behavior by analyzing paleo-earthquake records of the Yangsan Fault in Korea. Five trench sites revealed six Quaternary earthquakes, the latest 3000 years ago, with Mw 6.7–7.1. The right-lateral fault has a 0.13 mm yr-1 slip rate and a recurrence interval of over 13000 years; it has been continuously active since the Quaternary.
Giovanni Diaferia, Carlo Giunchi, Marco Olivieri, Irene Molinari, Fabio Di Felice, Andrea Contu, Domenico D'Urso, Luca Naticchioni, Davide Rozza, Jan Harms, Alessandro Cardini, Rosario De Rosa, Matteo Di Giovanni, Valentina Mangano, Fulvio Ricci, Lucia Trozzo, and Carlo Murineddu
EGUsphere, https://doi.org/10.5194/egusphere-2024-3600, https://doi.org/10.5194/egusphere-2024-3600, 2024
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Wind turbines produce strong seismic noise that can disturb nearby sensitive instruments, like seismic sensors. We examines the noise from one of Italy's largest wind farms, near the proposed site for the Einstein Telescope, a future gravitational wave observatory. We find that the turbines generate noticeable noise peaks, detectable up to 13 km. Despite the excellent noise suppression at borehole sensors, small noise disturbances are detectable when the wind park operates at full capacity.
Haris Raza, George Sand França, Eveline Sayão, and Victor Vilarrasa
Solid Earth, 15, 1407–1417, https://doi.org/10.5194/se-15-1407-2024, https://doi.org/10.5194/se-15-1407-2024, 2024
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Hydropower dams associated with a large reservoir, a key renewable, face challenges like reservoir-triggered seismicity (RTS). Here, rock samples show 6.3 %–14.7 % porosity and a maximum permeability of 0.0098 mD. A 136 m reservoir rise causes a 0.61 MPa pore pressure increase. Vertical stress rises by 0.75 MPa, and horizontal stress falls by 0.48 MPa, which leads to fault destabilization, causing RTS. These facts urge the adoption of sustainable energy strategies and future dam development.
Takashi Tonegawa, Takeshi Akuhara, Yusuke Yamashita, Hiroko Sugioka, Masanao Shinohara, Shunsuke Takemura, and Takeshi Tsuji
EGUsphere, https://doi.org/10.5194/egusphere-2024-3405, https://doi.org/10.5194/egusphere-2024-3405, 2024
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This study demonstrates that for slow earthquakes in the shallow Nankai subduction zone, (1) the velocity reductions in the accretionary prism reflect the stress field changes due to the slow earthquakes, and (2) the temporal variations in the heterogeneous structure correspond to upward fluid migrations from the source region of the slow earthquakes.
Berkan Özkan, Tuna Eken, Peter Gaebler, and Tuncay Taymaz
Solid Earth, 15, 1303–1317, https://doi.org/10.5194/se-15-1303-2024, https://doi.org/10.5194/se-15-1303-2024, 2024
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This study estimates source properties by analyzing seismic data of 303 earthquakes (2018–2020) in the Marmara Region, Turkey, and finds a strong correlation between moment-derived coda magnitude (Mw-coda) and moment magnitude (ML). Moreover, the scaled energy increases with seismic moment estimates and shows non-self-similar scaling in earthquake sources.
Chenyang Li, Yu Duan, Ying Han, Zining Yu, Chengquan Chi, and Dewang Zhang
Solid Earth, 15, 877–893, https://doi.org/10.5194/se-15-877-2024, https://doi.org/10.5194/se-15-877-2024, 2024
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This study advances the field of earthquake prediction by introducing an extraction method for pre-seismic anomalies based on the structure of Graph WaveNet networks. We believe that our study makes a significant contribution to the literature as it not only demonstrates the effectiveness of this innovative approach in integrating borehole strain data from multiple stations but also reveals distinct temporal and spatial correlations preceding earthquake events.
Silvia Pondrelli, Simone Salimbeni, Judith M. Confal, Marco G. Malusà, Anne Paul, Stephane Guillot, Stefano Solarino, Elena Eva, Coralie Aubert, and Liang Zhao
Solid Earth, 15, 827–835, https://doi.org/10.5194/se-15-827-2024, https://doi.org/10.5194/se-15-827-2024, 2024
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We analyse and interpret seismic anisotropy from CIFALPS2 data that fill the gaps in the Western Alps and support a new hypothesis. Instead of a continuous mantle flow parallel to the belt, here we find a N–S mantle deformation pattern that merges first with a mantle deformed by slab steepening beneath the Central Alps and then merges with an asthenospheric flow sourced beneath the Massif Central. This new sketch supports the extinction of slab retreat beneath the Western Alps.
Gizem Izgi, Tuna Eken, Peter Gaebler, Tülay Kaya-Eken, and Tuncay Taymaz
Solid Earth, 15, 657–669, https://doi.org/10.5194/se-15-657-2024, https://doi.org/10.5194/se-15-657-2024, 2024
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In this manuscript, we investigate the complexity of the upper-crustal block of the Central Anatolia region, Türkiye. We present the results of seismic attenuation by examining 1509 local earthquakes recorded at 72 broadband stations and deployed within the framework of a passive seismic experiment. We emphasize the detailed 2D maps of intrinsic and scattering attenuation within the area where two devastating earthquakes (M1 7.8 and M1 7.5 Kahramanmaraş Earthquake Sequence) happened in 2023.
Ángela María Gómez-García, Álvaro González, Mauro Cacace, Magdalena Scheck-Wenderoth, and Gaspar Monsalve
Solid Earth, 15, 281–303, https://doi.org/10.5194/se-15-281-2024, https://doi.org/10.5194/se-15-281-2024, 2024
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We compute a realistic three-dimensional model of the temperatures down to 75 km deep within the Earth, below the Caribbean Sea and northwestern South America. Using this, we estimate at which rock temperatures past earthquakes nucleated in the region and find that they agree with those derived from laboratory experiments of rock friction. We also analyse how the thermal state of the system affects the spatial distribution of seismicity in this region.
Fabian Kutschera, Alice-Agnes Gabriel, Sara Aniko Wirp, Bo Li, Thomas Ulrich, Claudia Abril, and Benedikt Halldórsson
Solid Earth, 15, 251–280, https://doi.org/10.5194/se-15-251-2024, https://doi.org/10.5194/se-15-251-2024, 2024
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We present a suite of realistic 3D dynamic rupture earthquake–tsunami scenarios for the Húsavík–Flatey Fault Zone in North Iceland and compare one-way linked and fully coupled modeling workflows on two fault system geometries. We find that our dynamic rupture simulation on a less segmented strike-slip fault system causes local tsunami wave heights (crest to trough) of up to ~ 0.9 m due to the large shallow fault slip (~ 8 m), rake rotation (± 20°), and coseismic vertical displacements (± 1 m).
Quetzalcoatl Rodríguez-Pérez and F. Ramón Zúñiga
Solid Earth, 15, 229–249, https://doi.org/10.5194/se-15-229-2024, https://doi.org/10.5194/se-15-229-2024, 2024
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The behavior of seismic energy parameters and their possible dependence on the type of fault for globally detected earthquakes were studied. For this purpose, different energy estimation methods were used. Equations were obtained to convert energies obtained in different ways. The dependence of the seismic energy on the focal mechanism was confirmed up to depths close to 180 km. The results will help to explain the seismic rupture of earthquakes generated at greater depth.
Wei Li, Megha Chakraborty, Jonas Köhler, Claudia Quinteros-Cartaya, Georg Rümpker, and Nishtha Srivastava
Solid Earth, 15, 197–213, https://doi.org/10.5194/se-15-197-2024, https://doi.org/10.5194/se-15-197-2024, 2024
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Seismic phase picking and magnitude estimation are crucial components of real-time earthquake monitoring and early warning. Here, we test the potential of deep learning in real-time earthquake monitoring. We introduce DynaPicker, which leverages dynamic convolutional neural networks for event detection and arrival-time picking, and use the deep-learning model CREIME for magnitude estimation. This workflow is tested on the continuous recording of the Turkey earthquake aftershock sequences.
Katarina Zailac, Bojan Matoš, Igor Vlahović, and Josip Stipčević
Solid Earth, 14, 1197–1220, https://doi.org/10.5194/se-14-1197-2023, https://doi.org/10.5194/se-14-1197-2023, 2023
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Presently there is no complete crustal model of the Dinarides. Using the compilations of previous studies, we have created vertically and laterally varying crustal models defined on a regular grid for the wider area of the Dinarides, also covering parts of the Adriatic Sea and the SW part of the Pannonian Basin. In addition to the seismic velocities and density, we also defined three interfaces: sedimentary deposit bottom, carbonate rock thickness and crustal thickness.
Patricia Martínez-Garzón, Dirk Becker, Jorge Jara, Xiang Chen, Grzegorz Kwiatek, and Marco Bohnhoff
Solid Earth, 14, 1103–1121, https://doi.org/10.5194/se-14-1103-2023, https://doi.org/10.5194/se-14-1103-2023, 2023
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We analyze the 2022 MW 6.0 Gölyaka sequence. A high-resolution seismicity catalog revealed no spatiotemporal localization and lack of immediate foreshocks. Aftershock distribution suggests the activation of the Karadere and Düzce faults. The preferential energy propagation suggests that the mainshock propagated eastwards, which is in agreement with predictions from models, where the velocity in the two sides of the fault is different.
Gabriela Fernández-Viejo, Carlos López-Fernández, and Patricia Cadenas
Solid Earth, 14, 1083–1101, https://doi.org/10.5194/se-14-1083-2023, https://doi.org/10.5194/se-14-1083-2023, 2023
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The seismic activity of the last 20 years within the West Iberian Margin away from the plate boundaries has been analyzed through the Spanish and Portuguese seismic network public databases. Previously defined as diffuse, the study reveals two distinct clusters in the NW–SE direction. Based on the characteristics of the events, some hypotheses for this activity are put forward and discussed, indicating the need for ocean-bottom seismometer data and high-resolution fault mapping.
Laurens Jan Hofman, Jörn Kummerow, Simone Cesca, and the AlpArray–Swath-D Working Group
Solid Earth, 14, 1053–1066, https://doi.org/10.5194/se-14-1053-2023, https://doi.org/10.5194/se-14-1053-2023, 2023
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We present an earthquake catalogue for the eastern and southern Alps based on data from a local temporary monitoring network. The methods we developed for the detection and localisation focus especially on very small earthquakes. This provides insight into the local geology and tectonics and provides an important base for future research in this part of the Alps.
Fabian Limberger, Georg Rümpker, Michael Lindenfeld, and Hagen Deckert
Solid Earth, 14, 859–869, https://doi.org/10.5194/se-14-859-2023, https://doi.org/10.5194/se-14-859-2023, 2023
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Wind turbines that are located close to a seismometer produce ground tremors that can increase the noise level at the seismic station. Using numerical models, we analyse the effectivity of borehole installations to reduce this impact. We study effects of geophysical parameters on the borehole effectivity and validate our modelling approach with data from real boreholes. Boreholes are effective in reducing the impact of wind turbines; however, this depends on the wavelength of the seismic wave.
Sebastian Hellmann, Melchior Grab, Cedric Patzer, Andreas Bauder, and Hansruedi Maurer
Solid Earth, 14, 805–821, https://doi.org/10.5194/se-14-805-2023, https://doi.org/10.5194/se-14-805-2023, 2023
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Acoustic waves are suitable to analyse the physical properties of the subsurface. For this purpose, boreholes are quite useful to deploy a source and receivers in the target area to get a comprehensive high-resolution dataset. However, when conducting such experiments in a subsurface such as glaciers that continuously move, the boreholes get deformed. In our study, we therefore developed a method that allows an analysis of the ice while considering deformations.
Laura A. Ermert, Enrique Cabral-Cano, Estelle Chaussard, Darío Solano-Rojas, Luis Quintanar, Diana Morales Padilla, Enrique A. Fernández-Torres, and Marine A. Denolle
Solid Earth, 14, 529–549, https://doi.org/10.5194/se-14-529-2023, https://doi.org/10.5194/se-14-529-2023, 2023
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Mexico City is built on a unique ground containing the clay-rich sediments of the ancient lake Texcoco. Continuous imperceptible shaking of these deposits by city traffic and other sources allows us to monitor changes in the subsurface seismic wave speed. Wave speed varies seasonally, likely due to temperature and rain effects; it temporarily drops after large earthquakes then starts to recover. Throughout the studied period, it increased on average, which may be related to soil compaction.
Laura Anna Ermert, Maria Koroni, and Naiara Korta Martiartu
Solid Earth, 14, 485–498, https://doi.org/10.5194/se-14-485-2023, https://doi.org/10.5194/se-14-485-2023, 2023
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We investigate women's representation in seismology to raise awareness of existing gender disparities.
By analysing the authorship of peer-reviewed articles, we identify lower representation of women among single authors, high-impact authors, and highly productive authors. Seismology continues to be a male-dominated field, and trends suggest that parity is decades away. These gaps are an obstacle to women’s career advancement and, if neglected, may perpetuate the leaky-pipeline problem.
Jordi Díaz, Sergi Ventosa, Martin Schimmel, Mario Ruiz, Albert Macau, Anna Gabàs, David Martí, Özgenç Akin, and Jaume Vergés
Solid Earth, 14, 499–514, https://doi.org/10.5194/se-14-499-2023, https://doi.org/10.5194/se-14-499-2023, 2023
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We assess the capability of multiple methods based on the interpretation of seismic noise to map the basement of the Cerdanya Basin, located in the eastern Pyrenees. Basement depth estimations retrieved from the different approaches are consistent, with maximum depths reaching 700 m close to the Têt fault bounding the basin to the east. Our results prove that seismic noise analysis using high-density networks is an excellent tool to improve the geological characterization of sedimentary basins.
Zahra Zali, Theresa Rein, Frank Krüger, Matthias Ohrnberger, and Frank Scherbaum
Solid Earth, 14, 181–195, https://doi.org/10.5194/se-14-181-2023, https://doi.org/10.5194/se-14-181-2023, 2023
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Investigation of the global Earth's structure benefits from the analysis of ocean bottom seismometer (OBS) data that allow an improved seismic illumination of dark spots of crustal and mantle structures in the oceanic regions of the Earth. However, recordings from the ocean bottom are often highly contaminated by noise. We developed an OBS noise reduction algorithm, which removes much of the oceanic noise while preserving the earthquake signal and does not introduce waveform distortion.
Jerome Azzola, Katja Thiemann, and Emmanuel Gaucher
EGUsphere, https://doi.org/10.5194/egusphere-2022-1417, https://doi.org/10.5194/egusphere-2022-1417, 2022
Preprint archived
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Distributed Acoustic Sensing is applied to the micro-seismic monitoring of a geothermal plant. In this domain, the feasibility of managing the large flow of generated data and their suitability to monitor locally induced seismicity was yet to be assessed. The proposed monitoring system efficiently managed the acquisition, processing and saving of the data over a 6-month period. This testing period proved that the monitoring concept advantageously complements more classical monitoring networks.
Heather Kennedy, Katrin Löer, and Amy Gilligan
Solid Earth, 13, 1843–1858, https://doi.org/10.5194/se-13-1843-2022, https://doi.org/10.5194/se-13-1843-2022, 2022
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The energy transition is an important topic for benefiting the future; thus renewable energy is required to reach net-zero carbon emission goals. Geothermal energy, heat from the ground, can be used in this transition. Therefore, geothermal fields need to be characterized as much as possible to allow for increased productivity within these fields. This study involves and looks at potential fractures within a geothermal field at depth to help increase the overall understanding of this field.
Roberto Cabieces, Mariano S. Arnaiz-Rodríguez, Antonio Villaseñor, Elizabeth Berg, Andrés Olivar-Castaño, Sergi Ventosa, and Ana M. G. Ferreira
Solid Earth, 13, 1781–1801, https://doi.org/10.5194/se-13-1781-2022, https://doi.org/10.5194/se-13-1781-2022, 2022
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This paper presents a new 3D shear-wave velocity model of the lithosphere of northeastern Venezuela, including new Moho and Vp / Vs maps. Data were retrieved from land and broadband ocean bottom seismometers from the BOLIVAR experiment.
Megha Chakraborty, Wei Li, Johannes Faber, Georg Rümpker, Horst Stoecker, and Nishtha Srivastava
Solid Earth, 13, 1721–1729, https://doi.org/10.5194/se-13-1721-2022, https://doi.org/10.5194/se-13-1721-2022, 2022
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Earthquake magnitude is a crucial parameter in defining its damage potential, and hence its speedy determination is essential to issue an early warning in regions close to the epicentre. This study summarises our findings in an attempt to apply deep-learning-based classifiers to earthquake waveforms, particularly with respect to finding an optimum length of input data. We conclude that the input length has no significant effect on the model accuracy, which varies between 90 %–94 %.
Carola Leva, Georg Rümpker, and Ingo Wölbern
Solid Earth, 13, 1243–1258, https://doi.org/10.5194/se-13-1243-2022, https://doi.org/10.5194/se-13-1243-2022, 2022
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The seismicity of Fogo and Brava, Cape Verde, is dominated by volcano-tectonic earthquakes in the area of Brava and volcanic seismic signals, such as hybrid events, on Fogo. We locate these events using a multi-array analysis, which allows the localization of seismic events occurring outside the network and of volcanic signals lacking clear phases. We observe exceptionally high apparent velocities for the hybrid events located on Fogo. These velocities are likely caused by a complex ray path.
Michal Chamarczuk, Michal Malinowski, Deyan Draganov, Emilia Koivisto, Suvi Heinonen, and Sanna Rötsä
Solid Earth, 13, 705–723, https://doi.org/10.5194/se-13-705-2022, https://doi.org/10.5194/se-13-705-2022, 2022
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In passive seismic measurement, all noise sources from the environment, such as traffic, vibrations caused by distant excavation, and explosive work from underground mines, are utilized. In the Kylylahti experiment, receivers recorded ambient noise sources for 30 d. These recordings were subjected to data analysis and processing using novel methodology developed in our study and used for imaging the subsurface geology of the Kylylahti mine area.
Jorge Acevedo, Gabriela Fernández-Viejo, Sergio Llana-Fúnez, Carlos López-Fernández, Javier Olona, and Diego Pérez-Millán
Solid Earth, 13, 659–679, https://doi.org/10.5194/se-13-659-2022, https://doi.org/10.5194/se-13-659-2022, 2022
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The NW Iberian Peninsula provides one of the most complete Variscan sections in Europe, showing the transition between a sedimentary domain with folds and thrust and a metamorphic domain with igneous intrusions. By processing the seismic ambient noise recorded by several seismograph networks in this area, new 3-D S-wave velocity and radial anisotropy models were created. These models reveal the limit between the two domains, delineating the core of the large western European Variscan Belt.
Thierry Camelbeeck, Koen Van Noten, Thomas Lecocq, and Marc Hendrickx
Solid Earth, 13, 469–495, https://doi.org/10.5194/se-13-469-2022, https://doi.org/10.5194/se-13-469-2022, 2022
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Over the 20th century, shallow damaging seismicity occurred in and near the Hainaut coal mining area in Belgium. We provide an overview of earthquake parameters and impacts, combining felt and damage testimonies and instrumental measurements. Shallower earthquakes have a depth and timing compatible with mining activity. The most damaging events occurred deeper than the mines but could still have been triggered by mining-caused crustal changes. Our modelling can be applied to other regions.
Nicola Piana Agostinetti, Alberto Villa, and Gilberto Saccorotti
Solid Earth, 13, 449–468, https://doi.org/10.5194/se-13-449-2022, https://doi.org/10.5194/se-13-449-2022, 2022
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Sensing the Earth is a fundamental operation for the future where georesources, like geothermal energy and CO2 underground storage, will become important tools for addressing societal challenges. The development of networks of optical fibre cables gives the possibility of a sensing grid with an unprecedented spatial coverage. Here, we investigate the potential of using portions of a optical fibre cable as a standard seismometer for exploring the subsurface and monitoring georesources.
Carolin M. Boese, Grzegorz Kwiatek, Thomas Fischer, Katrin Plenkers, Juliane Starke, Felix Blümle, Christoph Janssen, and Georg Dresen
Solid Earth, 13, 323–346, https://doi.org/10.5194/se-13-323-2022, https://doi.org/10.5194/se-13-323-2022, 2022
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Hydraulic stimulation experiments in underground facilities allow for placing monitoring equipment close to and surrounding the stimulated rock under realistic and complex conditions at depth. We evaluate how accurately the direction-dependent velocity must be known for high-resolution seismic monitoring during stimulation. Induced transient deformation in rocks only 2.5–5 m apart may differ significantly in magnitude and style, and monitoring requires sensitive sensors adapted to the frequency.
Jaroslava Plomerová, Helena Žlebčíková, György Hetényi, Luděk Vecsey, Vladislav Babuška, and AlpArray-EASI and AlpArray working
groups
Solid Earth, 13, 251–270, https://doi.org/10.5194/se-13-251-2022, https://doi.org/10.5194/se-13-251-2022, 2022
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We present high-resolution tomography images of upper mantle structure beneath the E Alps and the adjacent Bohemian Massif. The northward-dipping lithosphere, imaged down to ∼200 km beneath the E Alps without signs of delamination, is probably formed by a mixture of a fragment of detached European plate and the Adriatic plate subductions. A detached high-velocity anomaly, sub-parallel to and distinct from the E Alps heterogeneity, is imaged at ∼100–200 km beneath the southern part of the BM.
Gregor Rajh, Josip Stipčević, Mladen Živčić, Marijan Herak, Andrej Gosar, and the AlpArray Working Group
Solid Earth, 13, 177–203, https://doi.org/10.5194/se-13-177-2022, https://doi.org/10.5194/se-13-177-2022, 2022
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We investigated the 1-D velocity structure of the Earth's crust in the NW Dinarides with inversion of arrival times from earthquakes. The obtained velocity models give a better insight into the crustal structure and show velocity variations among different parts of the study area. In addition to general structural implications and a potential for improving further work, the results of our study can also be used for routine earthquake location and for detecting errors in seismological bulletins.
Guido Maria Adinolfi, Raffaella De Matteis, Rita de Nardis, and Aldo Zollo
Solid Earth, 13, 65–83, https://doi.org/10.5194/se-13-65-2022, https://doi.org/10.5194/se-13-65-2022, 2022
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We propose a methodology useful to evaluate (1) the reliability of a focal mechanism solution inferred by the inversion of seismological data and (2) the performance of a seismic network, operated to monitor natural or induced seismicity, to assess focal mechanism solutions. As a test case, we studied the focal mechanism reliability by using synthetic data computed for ISNet, a local seismic network monitoring the Irpinia fault system (southern Italy).
Nicola Piana Agostinetti and Giulia Sgattoni
Solid Earth, 12, 2717–2733, https://doi.org/10.5194/se-12-2717-2021, https://doi.org/10.5194/se-12-2717-2021, 2021
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One of the present-day challenges for geoscientists is tackling the big data revolution. An ever-growing amount of data needs to be processed and data are subjectively handled before using them to make inferences on the Earth’s interior. But imposing subjective decisions on the data might have strong influences on the final outputs. Here we present a totally novel and automatic application for screening the data and for defining data volumes that are consistent with physical hypotheses.
Marcel Paffrath, Wolfgang Friederich, Stefan M. Schmid, Mark R. Handy, and the AlpArray and AlpArray-Swath D Working Group
Solid Earth, 12, 2671–2702, https://doi.org/10.5194/se-12-2671-2021, https://doi.org/10.5194/se-12-2671-2021, 2021
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The Alpine mountain belt was formed by the collision of the Eurasian and African plates in the geological past, during which parts of the colliding plates sank into the earth's mantle. Using seismological data from distant earthquakes recorded by the AlpArray Seismic Network, we have derived an image of the current location of these subducted parts in the earth's mantle. Their quantity and spatial distribution is key information needed to understand how the Alpine orogen was formed.
Felix N. Wolf, Dietrich Lange, Anke Dannowski, Martin Thorwart, Wayne Crawford, Lars Wiesenberg, Ingo Grevemeyer, Heidrun Kopp, and the AlpArray Working Group
Solid Earth, 12, 2597–2613, https://doi.org/10.5194/se-12-2597-2021, https://doi.org/10.5194/se-12-2597-2021, 2021
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The Ligurian Sea opened ~30–15 Ma during SE migration of the Calabrian subduction zone. Using ambient seismic noise from stations on land and at the ocean bottom, we calculated a 3D shear-velocity model of the Ligurian Basin. In keeping with existing 2D studies, we find a shallow crust–mantle transition at the SW basin centre that deepens towards the northeast, Corsica, and the Liguro-Provençal coast. We observe a separation of SW and NE basins. We do not observe high crustal vP/vS ratios.
Martin Thorwart, Anke Dannowski, Ingo Grevemeyer, Dietrich Lange, Heidrun Kopp, Florian Petersen, Wayne C. Crawford, Anne Paul, and the AlpArray Working Group
Solid Earth, 12, 2553–2571, https://doi.org/10.5194/se-12-2553-2021, https://doi.org/10.5194/se-12-2553-2021, 2021
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We analyse broadband ocean bottom seismometer data of the AlpArray OBS network in the Ligurian Basin. Two earthquake clusters with thrust faulting focal mechanisms indicate compression of the rift basin. The locations of seismicity suggest reactivation of pre-existing rift structures and strengthening of crust and uppermost mantle during rifting-related extension. Slightly different striking directions of faults may mimic the anti-clockwise rotation of the Corsica–Sardinia block.
Rainer Kind, Stefan M. Schmid, Xiaohui Yuan, Benjamin Heit, Thomas Meier, and the AlpArray and AlpArray-SWATH-D Working Groups
Solid Earth, 12, 2503–2521, https://doi.org/10.5194/se-12-2503-2021, https://doi.org/10.5194/se-12-2503-2021, 2021
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A large amount of new seismic data from the greater Alpine area have been obtained within the AlpArray and SWATH-D projects. S-to-P converted seismic phases from the Moho and from the mantle lithosphere have been processed with a newly developed method. Examples of new observations are a rapid change in Moho depth at 13° E below the Tauern Window from 60 km in the west to 40 km in the east and a second Moho trough along the boundary of the Bohemian Massif towards the Western Carpathians.
Bogdan Grecu, Felix Borleanu, Alexandru Tiganescu, Natalia Poiata, Raluca Dinescu, and Dragos Tataru
Solid Earth, 12, 2351–2368, https://doi.org/10.5194/se-12-2351-2021, https://doi.org/10.5194/se-12-2351-2021, 2021
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The lockdown imposed in Romania to prevent the spread of COVID-19 has significantly impacted human activity across the country. By analyzing the ground vibrations recorded at seismic stations, we were able to monitor the changes in human activity before and during the lockdown.
The reduced human activity during the lockdown has also provided a good opportunity for stations sited in noisy urban areas to record earthquake signals that would not have been recorded under normal conditions.
Ruth Keppler, Roman Vasin, Michael Stipp, Tomás Lokajícek, Matej Petruzálek, and Nikolaus Froitzheim
Solid Earth, 12, 2303–2326, https://doi.org/10.5194/se-12-2303-2021, https://doi.org/10.5194/se-12-2303-2021, 2021
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Rocks in mountain belts have been deformed during continental collision causing a certain alignment of the minerals referred to as crystallographic preferred orientation (CPO). Minerals have anisotropic properties: the velocity of seismic waves travelling through them is direction dependent. This leads to anisotropy of the rocks. We measured the CPO of common rocks within the Alps. With this data and known anisotropic properties of the minerals we calculated the seismic anisotropy of the rocks.
Mario Arroyo-Solórzano, Diego Castro-Rojas, Frédérick Massin, Lepolt Linkimer, Ivonne Arroyo, and Robin Yani
Solid Earth, 12, 2127–2144, https://doi.org/10.5194/se-12-2127-2021, https://doi.org/10.5194/se-12-2127-2021, 2021
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We present the first seismic noise variation levels during COVID-19 in Central America using 10 seismometers. We study the impact of the seismic noise reduction on the detectability of earthquakes and on the felt reports. Our results show maximum values (~50 % decrease) at seismic stations near airports and densely inhabited cities. The decrease in seismic noise improved earthquake locations and reports. Seismic noise could also be useful to verify compliance with lockdown measures.
Laura Peruzza, Alessandra Schibuola, Maria Adelaide Romano, Marco Garbin, Mariangela Guidarelli, Denis Sandron, and Enrico Priolo
Solid Earth, 12, 2021–2039, https://doi.org/10.5194/se-12-2021-2021, https://doi.org/10.5194/se-12-2021-2021, 2021
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In weakly seismic or poorly monitored areas, the uncritical use of earthquake catalogues can be misleading. This is the case for a central sector in the Po Valley, where the Northern Apennines and Southern Alps collide. We collect and reprocess the available instrumental data of about 300 earthquakes from 1951 to 2019. The seismicity is weak, deeper than expected, and far from some existing human activities carried out underground. The potential tectonic causative sources are still unknown.
Fabian Limberger, Michael Lindenfeld, Hagen Deckert, and Georg Rümpker
Solid Earth, 12, 1851–1864, https://doi.org/10.5194/se-12-1851-2021, https://doi.org/10.5194/se-12-1851-2021, 2021
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Frequency-dependent amplitude decays of seismic signals induced by wind turbines are determined from (up to) 6 months of continuous recordings measured along an 8 km profile located at a wind farm in Bavaria, Germany. The radiation pattern and amplitude decay of the induced signals are accounted for by an analytical approach that includes path and source effects. This approach is generalized to predict the characteristic seismic radiation patterns of arbitrary wind farm configurations.
Alessio Spurio Mancini, Davide Piras, Ana Margarida Godinho Ferreira, Michael Paul Hobson, and Benjamin Joachimi
Solid Earth, 12, 1683–1705, https://doi.org/10.5194/se-12-1683-2021, https://doi.org/10.5194/se-12-1683-2021, 2021
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The localization of an earthquake is affected by many uncertainties. To correctly propagate these uncertainties into an estimate of the earthquake coordinates and their associated errors, many simulations of seismic waves are needed. This operation is computationally very intensive, hindering the feasibility of this approach. In this paper, we present a series of deep-learning methods to produce accurate seismic traces in a fraction of the time needed with standard methods.
Marguerite Mathey, Christian Sue, Colin Pagani, Stéphane Baize, Andrea Walpersdorf, Thomas Bodin, Laurent Husson, Estelle Hannouz, and Bertrand Potin
Solid Earth, 12, 1661–1681, https://doi.org/10.5194/se-12-1661-2021, https://doi.org/10.5194/se-12-1661-2021, 2021
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This work features the highest-resolution seismic stress and strain fields available at the present time for the analysis of the active crustal deformation of the Western Alps. In this paper, we address a large dataset of newly computed focal mechanisms from a statistical standpoint, which allows us to suggest a joint control from far-field forces and from buoyancy forces on the present-day deformation of the Western Alps.
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