Articles | Volume 7, issue 6
https://doi.org/10.5194/se-7-1591-2016
© Author(s) 2016. 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-7-1591-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
29 Nov 2016
Research article |
| 29 Nov 2016
The imprint of crustal density heterogeneities on regional seismic wave propagation
Department of Earth Sciences, Utrecht University, Utrecht, the Netherlands
Nienke Blom
Department of Earth Sciences, Utrecht University, Utrecht, the Netherlands
Andreas Fichtner
Department of Earth Sciences, ETH Zurich, Zurich, Switzerland
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Maren Böse, Laurentiu Danciu, Athanasios Papadopoulos, John Clinton, Carlo Cauzzi, Irina Dallo, Leila Mizrahi, Tobias Diehl, Paolo Bergamo, Yves Reuland, Andreas Fichtner, Philippe Roth, Florian Haslinger, Frédérick Massin, Nadja Valenzuela, Nikola Blagojević, Lukas Bodenmann, Eleni Chatzi, Donat Fäh, Franziska Glueer, Marta Han, Lukas Heiniger, Paulina Janusz, Dario Jozinović, Philipp Kästli, Federica Lanza, Timothy Lee, Panagiotis Martakis, Michèle Marti, Men-Andrin Meier, Banu Mena Cabrera, Maria Mesimeri, Anne Obermann, Pilar Sanchez-Pastor, Luca Scarabello, Nicolas Schmid, Anastasiia Shynkarenko, Bozidar Stojadinović, Domenico Giardini, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 583–607, https://doi.org/10.5194/nhess-24-583-2024, https://doi.org/10.5194/nhess-24-583-2024, 2024
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Seismic hazard and risk are time dependent as seismicity is clustered and exposure can change rapidly. We are developing an interdisciplinary dynamic earthquake risk framework for advancing earthquake risk mitigation in Switzerland. This includes various earthquake risk products and services, such as operational earthquake forecasting and early warning. Standardisation and harmonisation into seamless solutions that access the same databases, workflows, and software are a crucial component.
Emma Pearce, Dimitri Zigone, Coen Hofstede, Andreas Fichtner, Joachim Rimpot, Sune Olander Rasmussen, Johannes Freitag, and Olaf Eisen
EGUsphere, https://doi.org/10.5194/egusphere-2023-2192, https://doi.org/10.5194/egusphere-2023-2192, 2023
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Our seismic study near EastGRIP camp in Greenland reveals varying firn properties by direction, crucial for studying ice stream stability, structure, surface mass balance and past climate conditions. We used dispersion curve analysis of Love and Rayleigh waves to show firn is non-uniform along and across flow of an ice stream due to wind patterns, seasonal variability and the proximity to the edge of the ice stream. This approach better informs firn structure advancing ice stream understanding.
Laura Ermert, Jonas Igel, Korbinian Sager, Eléonore Stutzmann, Tarje Nissen-Meyer, and Andreas Fichtner
Solid Earth, 11, 1597–1615, https://doi.org/10.5194/se-11-1597-2020, https://doi.org/10.5194/se-11-1597-2020, 2020
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We present an open-source tool to model ambient seismic auto- and cross-correlations with spatially varying source spectra. The modeling is based on pre-computed databases of seismic wave propagation, which can be obtained from public data providers. The aim of this tool is to facilitate the modeling of ambient noise correlations, which are an important seismologic observable, with realistic wave propagation physics. We present a description and benchmark along with example use cases.
Nienke Blom, Alexey Gokhberg, and Andreas Fichtner
Solid Earth, 11, 669–690, https://doi.org/10.5194/se-11-669-2020, https://doi.org/10.5194/se-11-669-2020, 2020
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We have developed a model of the Earth's structure in the upper 500 km beneath the central and eastern Mediterranean. Within this model, we can see parts of the African tectonic plate that have sunk underneath the European plate over the past tens of millions of years. This model was constructed using seismic waveform tomography by matching the seismograms from many earthquakes recorded at the surface to synthetic seismograms that were generated by simulating earthquake wave propagation.
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Laura A. Ermert, Enrique Cabral-Cano, Estelle Chaussard, Darío Solano-Rojas, Luis Quintanar, Diana Morales Padilla, Enrique A. Fernández-Torres, and Marine A. Denolle
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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.
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Jordi Díaz, Sergi Ventosa, Martin Schimmel, Mario Ruiz, Albert Macau, Anna Gabàs, David Martí, Özgenç Akin, and Jaume Vergés
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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
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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.
Marcel Paffrath, Wolfgang Friederich, and the AlpArray and AlpArray-SWATH D Working Groups
Solid Earth, 12, 1635–1660, https://doi.org/10.5194/se-12-1635-2021, https://doi.org/10.5194/se-12-1635-2021, 2021
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Using the AlpArray seismic network, we have determined highly accurate travel times of P waves from over 370 major global earthquakes between 2015 and 2019, which shall be used for a tomography of the mantle beneath the greater Alpine region.
Comparing with theoretical travel times of a standard reference earth model, we receive very stable patterns of travel-time differences across the network which provide evidence of varying subduction behaviour along the strike of the Alpine orogen.
Itzhak Lior, Anthony Sladen, Diego Mercerat, Jean-Paul Ampuero, Diane Rivet, and Serge Sambolian
Solid Earth, 12, 1421–1442, https://doi.org/10.5194/se-12-1421-2021, https://doi.org/10.5194/se-12-1421-2021, 2021
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The increasing use of distributed acoustic sensing (DAS) inhibits the transformation of optical fibers into dense arrays of seismo-acoustic sensors. Here, DAS strain records are converted to ground motions using the waves' apparent velocity. An algorithm for velocity determination is presented, accounting for velocity variations between different seismic waves. The conversion allows for robust determination of fundamental source parameters, earthquake magnitude and stress drop.
Sarah Mader, Joachim R. R. Ritter, Klaus Reicherter, and the AlpArray Working Group
Solid Earth, 12, 1389–1409, https://doi.org/10.5194/se-12-1389-2021, https://doi.org/10.5194/se-12-1389-2021, 2021
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The Albstadt Shear Zone, SW Germany, is an active rupture zone with sometimes damaging earthquakes but no visible surface structure. To identify its segmentations, geometry, faulting pattern and extension, we analyze the continuous earthquake activity in 2011–2018. We find a segmented N–S-oriented fault zone with mainly horizontal and minor vertical movement along mostly NNE- and some NNW-oriented rupture planes. The main horizontal stress is oriented NW and due to Alpine-related loading.
Gesa Maria Petersen, Simone Cesca, Sebastian Heimann, Peter Niemz, Torsten Dahm, Daniela Kühn, Jörn Kummerow, Thomas Plenefisch, and the AlpArray and AlpArray-Swath-D working groups
Solid Earth, 12, 1233–1257, https://doi.org/10.5194/se-12-1233-2021, https://doi.org/10.5194/se-12-1233-2021, 2021
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The Alpine mountains are known for a complex tectonic history. We shed light onto ongoing tectonic processes by studying rupture mechanisms of small to moderate earthquakes between 2016 and 2019 observed by the temporary AlpArray seismic network. The rupture processes of 75 earthquakes were analyzed, along with past earthquakes and deformation data. Our observations point at variations in the underlying tectonic processes and stress regimes across the Alps.
Azam Jozi Najafabadi, Christian Haberland, Trond Ryberg, Vincent F. Verwater, Eline Le Breton, Mark R. Handy, Michael Weber, and the AlpArray and AlpArray SWATH-D working groups
Solid Earth, 12, 1087–1109, https://doi.org/10.5194/se-12-1087-2021, https://doi.org/10.5194/se-12-1087-2021, 2021
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This study achieved high-precision hypocenters of 335 earthquakes (1–4.2 ML) and 1D velocity models of the Southern and Eastern Alps. The general pattern of seismicity reflects head-on convergence of the Adriatic Indenter with the Alpine orogenic crust. The relatively deeper seismicity in the eastern Southern Alps and Giudicarie Belt indicates southward propagation of the Southern Alpine deformation front. The derived hypocenters form excellent data for further seismological studies, e.g., LET.
Javier Ojeda and Sergio Ruiz
Solid Earth, 12, 1075–1085, https://doi.org/10.5194/se-12-1075-2021, https://doi.org/10.5194/se-12-1075-2021, 2021
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In Santiago, Chile, the lockdown imposed due to COVID-19 was recorded by seismological instruments. This analysis shows temporal changes in the surface vibrations controlled by lockdown phases, mobility, and epidemiological factors. Our findings suggest that
dynamic lockdownand the early deconfinement in April 2020 caused an increase in mobility and therefore virus transmission. We propose that seismic networks could be used to monitor urban mobility as a new proxy in public policies.
Jiří Kvapil, Jaroslava Plomerová, Hana Kampfová Exnerová, Vladislav Babuška, György Hetényi, and AlpArray Working Group
Solid Earth, 12, 1051–1074, https://doi.org/10.5194/se-12-1051-2021, https://doi.org/10.5194/se-12-1051-2021, 2021
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This paper presents a high-resolution 3-D shear wave velocity (vS) model of the Bohemian Massif crust imaged from high-density data and enhanced depth sensitivity of tomographic inversion. The dominant features of the model are relatively higher vS in the upper crust than in its surrounding, a distinct intra-crustal interface, and a velocity decrease in the lower part of the crust. The low vS in the lower part of the crust is explained by the anisotropic fabric of the lower crust.
Martijn P. A. van den Ende and Jean-Paul Ampuero
Solid Earth, 12, 915–934, https://doi.org/10.5194/se-12-915-2021, https://doi.org/10.5194/se-12-915-2021, 2021
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Distributed acoustic sensing (DAS) is an emerging technology that measures stretching of an optical-fibre cable. This technology can be used to record the ground shaking of earthquakes, which offers a cost-efficient alternative to conventional seismometers. Since DAS is relatively new, we need to verify that existing seismological methods can be applied to this new data type. In this study, we reveal several issues by comparing DAS with conventional seismometer data for earthquake localisation.
Rebecca O. Salvage and David W. Eaton
Solid Earth, 12, 765–783, https://doi.org/10.5194/se-12-765-2021, https://doi.org/10.5194/se-12-765-2021, 2021
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Small earthquakes in Alberta and north-east British Columbia have been previously ascribed to industrial activities. The COVID-19 pandemic forced almost all these activities to stop for ~ 4 months. However, unexpectedly, earthquakes still occurred during this time. Some of these earthquakes may be natural and some the result of earthquakes > M6 occurring around the world. However, ~ 65 % of the earthquakes detected may be the remnants of previous fluid injection in the area (
latent seismicity).
Jordi Diaz, Mario Ruiz, and José-Antonio Jara
Solid Earth, 12, 725–739, https://doi.org/10.5194/se-12-725-2021, https://doi.org/10.5194/se-12-725-2021, 2021
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During the COVID-19 pandemic lockdown, the city of Barcelona was covered by a network of 19 seismometers. The results confirm that the quieting of human activity during lockdown has resulted in a reduction of seismic vibrations. The different lockdown phases in Barcelona are recognized consistently at most of the seismic stations. Our contribution demonstrates that seismic noise can be used as a free and reliable tool to monitor human activity in urban environments.
Raphael S. M. De Plaen, Víctor Hugo Márquez-Ramírez, Xyoli Pérez-Campos, F. Ramón Zuñiga, Quetzalcoatl Rodríguez-Pérez, Juan Martín Gómez González, and Lucia Capra
Solid Earth, 12, 713–724, https://doi.org/10.5194/se-12-713-2021, https://doi.org/10.5194/se-12-713-2021, 2021
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COVID-19 pandemic lockdowns in countries with a dominant informal economy have been a greater challenge than in other places. This motivated the monitoring of the mobility of populations with seismic noise throughout the various phases of lockdown and in the city of Querétaro (central Mexico). Our results emphasize the benefit of densifying urban seismic networks, even with low-cost instruments, to observe variations in mobility at the city scale over exclusively relying on mobile technology.
Cited articles
Aki, K. and Richards, P.: Quantitative Seismology, University Science Books, 2002.
Anderson, D. L., Schreiber, E., Lieberman, R. C., and Soga, N.: Some elastic constant data on minerals relevant to geophysics, Rev. Geophys. Space Phys., 6, 491–524, 1968.
Backus, G. E. and Gilbert, F.: The resolving power of gross Earth data, Geophys, J. Roy. Astr. Soc., 16, 169–205, 1968.
Backus, G. E. and Gilbert, F.: Uniqueness in the inversion of inaccurate gross Earth data, Philos. T. R. Soc. A, 266, 123–192, 1970.
Becker, T. W. and Boschi, L.: A comparison of tomographic and geodynamic mantle models, Geochem. Geophys. Geosys., 3, 1525–2027, https://doi.org/10.1029/2001GC000168, 2002.
Bernauer, M., Fichtner, A., and Igel, H.: Optimal observables for multi-parameter seismic tomography, Geophys. J. Int., 198, 1241–1254, 2014.
Bozdağ, E., Trampert, J., and Tromp, J.: Misfit functions for full waveform inversion based on instantaneous phase and envelope measurements, Geophys. J. Int., 185, 845–870, 2011.
Brocher, T. M.: Empirical relations between elastic wavespeeds and density in the Earth's crust, Bull. Seis. Soc. Am., 95, 2081–2092, 2005.
Bunge, H.-P., Hagelberg, C. R., and Travis, B. J.: Mantle circulation models with variational data assimilation: Inferring past mantle flow and structure from plate motion histories and seismic tomography, Geophys. J. Int., 152, 280–301, 2003.
Cerveny, V.: Seismic ray theory, Cambridge University Press, 2001.
Chen, P., Zhao, L., and Jordan, T. H.: Full 3-D tomography for the crustal structure of the Los Angeles region, Bull. Seismol. Soc. Am., 97, 1094–1120, 2007.
Chen, M., Niu, F., Liu, Q., Tromp, J., and Zheng, X.: Multi-parameter adjoint tomography of the crust and upper mantle beneath East Asia – Part I: Model construction and comparisons, J. Geophys. Res., 120, 1762–1786, 2015.
Christensen, N. I. and Mooney, W. D.: Seismic velocity structure and composition of the continental crust: a global view, J. Geophys. Res., 1000, 9761–9788, 1995.
Cupillard, P., Delavaud, E., Burgos, G., Festa, G., Vilotte, J.-P., Capdeville, Y., and Montagner, J.-P.: RegSEM: A versatile code based on the spectral element method to compute seismic wave propagation at the regional scale, Geophys. J. Int., 188, 1203–1220, 2012.
Dahlen, F., Hung, S.-H., and Nolet, G.: Fréchet kernels for finite-frequency traveltimes – I. Theory, Geophys. J. Int., 141, 157–174, 2000.
Dahlen, F. A. and Tromp, J.: Theoretical Global Seismology, Princeton University Press, NJ, 1998.
Dalton, C. A., Ekström, G., and Dziewonski, A. M.: The global attenuation structure of the upper mantle, J. Geophys. Res., 113, B09303, https://doi.org/10.1029/2007JB005429, 2008.
Dziewoński, A. M., Hager, B. H., and O'Connell, R. J: Large-scale heterogeneities in the lower mantle, J. Geophys. Res., 82, 239-255, 1977.
Dziewoński, A. M. and Anderson, D. L.: Preliminary reference Earth model, Phys. Earth Planet. Int., 25, 297–356, 1981.
El Moudnib, L., Villaseñor, A., Harnafi, M., Gallart, J., Pazos, A., Serrano, I., nd J. A. Pulgar, D. C., Ibarra, P., Himmi, M. M., and Chourak, M.: Crustal structure of the Betic-Rif system, western Mediterranean, from local earthquake tomography, Tectonophysics, 643, 94–105, 2015.
Faccioli, E., Maggio, F., Quarteroni, A., and Tagliani, A.: Spectral-domain decomposition methods for the solution of acoustic and elastic wave equations, Geophysics, 61, 1160–1174, 1996.
Fichtner, A., Kennett, B. L. N., Igel, H., and Bunge, H.-P.: Theoretical background for continental- and global-scale full-waveform inversion in the time-frequency domain, Geophys. J. Int., 175, 665–685, 2008.
Fichtner, A., Kennett, B. L. N., Igel, H., and Bunge, H.-P.: Full seismic waveform tomography for upper-mantle structure in the Australasian region using adjoint methods, Geophys. J. Int. , 179, 1703–1725, 2009.
Fichtner, A., Kennett, B. L. N., Igel, H., and Bunge, H.-P.: Spectral-element simulation and inversion of seismic waves in a spherical section of the Earth, J. Num. An. Ind. Appl. Math., 4, 11–22, 2009.
Fichtner, A.: Full Seismic Waveform Modelling and Inversion, Springer, Heidelberg, 2010.
Fichtner, A., Saygin, E., Taymaz, T., Cupillard, P., Capdeville, Y., and Trampert, J.: The deep structure of the North Anatolian Fault Zone, Earth Planet. Sc. Lett., 373, 109–117, 2013.
Fichtner, A. and Villaseñor, A.: Crust and upper mantle of the western Mediterranean - Constraints from full-waveform inversion, Earth Planet. Sc. Lett., 428, 52–62, 2015.
Fichtner, A., Trampert, J., Cupillard, P., Saygin, E., Taymaz, T., Capdeville, Y.. and Villaseñor, A.: Multi-scale full waveform inversion, Geophys. J. Int., 194, 534–556, 2013.
Frankel, A.: A review of numerical experiments on seismic wave scattering, Pure Appl. Geophys., 4, 639–685, 1989.
Frankel, A. and Clayton, R.: Finite-difference simulations of seismic scattering: implications for the propagation of short period seismic waves in the crust and models of crustal heterogeneity, J. Geophys. Res., 91, 6465–6489, 1986.
Furumura, T. and Kennett, B. L. N.: Subduction zone guided waves and the heterogeneity structure of the subducted plate – intensity anomalies in northern Japan, J. Geophys. Res., 110, B10302, https://doi.org/10.1029/2004JB003486, 2005.
Gaite, B., Villaseñor, A., Iglesias, A., Herraiz, M. and Jiménez-Munt, I.: A 3-D shear velocity model of the southern North American and Caribbean plates from ambient noise and earthquake tomography, Solid Earth, 6, 271-284, 2015.
Gardner, G. H. F., Gardner, L. W., and Gregory, A. R.: Formation velocity and density – the diagnostic basics for stratigraphic traps, Geophysics, 39, 770–780, 1974.
Gokhberg, A. and Fichtner, A.: Full-waveform inversion on heterogeneous HPC systems, Comput. Geosci., 89, 260–268, https://doi.org/10.1016/j.cageo.2015.12.013, 2016.
Groenenboom, J. and Snieder, R.: Attenuation, dispersion and anisotropy by multiple scattering of transmitted waves through distributions of scatterers, J. Acoust. Soc. Am., 98, 3482–3492, 1995.
Haberland, C. and Rietbrock, A.: Attenuation tomography in the western central Andes: A detailed insight into the structure of a magmatic arc, J. Geophys. Res., 106, 11151–11167, 2001.
Igel, H. and Gudmundsson, O.: Frequency-dependent effects on travel times and waveforms of long-period S and SS waves, Phys. Earth. Planet. Int., 104, 229–246, 1997.
Ishii, M. and Tromp, J.: Normal-mode and free-air gravity constraints on lateral variations in velocity and density of Earth's mantle, Science, 285, 1231–1236, 1999.
Ishii, M. and Tromp, J.: Even-degree lateral variations in the Earth's mantle constrained by free oscillations and the free-air gravity anomaly, Geophys. J. Int., 145, 77–96, 2001.
Ishii, M. and Tromp, J.: Constraining large-scale mantle heterogeneity using mantle and inner-core sensitive normal modes, Phys. Earth Planet. Inter., 146, 113–124, 2004.
Jahnke, G., Thorne, M. S., Cochard, A., and Igel, H.: Global SH-wave propagation using a parallel axisymmetric spherical finite-difference scheme: application to whole-mantle scattering, Geophys. J. Int., 173, 815–826, 2008.
Jordan, T. H.: The continental tectosphere, Rev. Geophys., 13, 1–12, 1975.
Jordan, T. H.: Composition and development of the continental tectosphere, Nature, 274, 544–548, 1978.
Kennett, B. L. N.: The seismic wavefield I. – Introduction and theoretical development, Cambridge University Press, 2001.
Kennett, B. L. N. and Furumura, T.: Stochastic waveguide in the lithosphere: Indonesian subduction zone to Australian craton, Geophys. J. Int., 172, 363–382, 2008.
Kennett, B. L. N. and Bunge, H.-P.: Geophysical Continua, Cambridge University Press, 2008.
Kennett, B. L. N. and Abdullah, A.: Seismic wave attenuation beneath the Australasian region, Austr. J. Earth Sci., 58, 285–295, 2011.
Klimeš, L.: Correlation functions of random media, Pure Appl. Geophys., 159, 1811–1831, 2002.
Koelemeijer, P., Deuss, A. , and Ritsema, J.: Density structure of Earth's lowermost mantle from stoneley mode splitting observations, Nat. Commun., under review, 2016.
Komatitsch, D. and Tromp, J.: Introduction to the spectral element method for three-dimensional seismic wave propagation, Geophys. J. Int., 139, 806–822, 1999.
Komatitsch, D. and Vilotte, J. P.: The spectral element method: an effective tool to simulate the seismic response of 2-D and 3-D geological structures, Bull. Seismol. Soc. Am, 88, 368–392, 1998.
Kristekova, M., Kristek, J., and Moczo, P.: Time-frequency misfit and goodness-of-fit criteria for quantitative comparison of time signals, Geophys. J. Int., 178, 813–825, 2009.
Kristekova, M., Kristek, J., Moczo, P., and Day, S. M.: Misfit criteria for quantitative comparison of seismograms, Bull. Seismol. Soc. Am., 96, 1836–1850, 2006.
Kuo, C. and Romanowicz, B.: On the resolution of density anomalies in the Earth's mantle using spectral fitting of normal mode data, Geophys. J. Int., 150, 162–179, 2002.
Lin, F.-C. and Tsai, B. S. V. C.: Joint inversion of Rayleigh wave phase velocity and ellipticity using USArray: Constraining velocity and density structure in the upper crust, Geophy Res. Lett., 39, L12303, https://doi.org/10.1029/2012GL052196, 2012.
Lin, F.-C., Tsai, V. C., and Ritzwoller, M. H.: The local amplification of surface waves: A new observable to constrain elastic velocities, density, and anelastic attenuation, J. Geophys. Res., 117, B06302, https://doi.org/10.1029/2012JB009208, 2012.
Liu, L. and Gurnis, M.: Simultaneous inversion of mantle properties and initial conditions using an adjoint of mantle convection, J. Geophys. Res., 113, B08405, https://doi.org/10.1029/2008JB005594, 2008.
Ludwig, W. J., Nafe, J. E., and Drake, C. L.: Seismic refraction, edited by: Maxwell, A. E., The Sea, Wiley-Interscience, New York, 1970.
Maceira, M. and Ammon, C. J.: Joint inversion of surface wave velocity and gravity observations and its application to central asian basins shear velocity structure, J. Geophys. Res., 114, B02314, https://doi.org/10.1029/2007JB005157, 2009.
Marquering, H., Dahlen, F. A. , and Nolet, G.: Three-dimensional sensitivity kernels for finite-frequency traveltimes: the banana-doughnut paradox, Geophys. J. Int., 137, 805–815, 1999.
Meschede, M. and Romanowicz, B.: Non-stationary spherical random media and their effect on long-period mantle waves, Geophys. J. Int., 203, 1605–1625, 2015.
Mitchell, J. B.: Anelastic structure and evolution of the continental crust and upper mantle from seismic surface wave attenuation, Rev. Geophys., 33, 441–462, 1995.
Mosca, I., Cobden, L., Deuss, A., Ritsema, J., and Trampert, J.: Seismic and mineralogical structures of the lower mantle from probabilistic tomography, J. Geophys. Res., 117, B06304, https://doi.org/10.1029/2011JB008851, 2012.
Nataf, H. C. and Ricard, Y.: 3SMAC: an a priori tomographic model of the upper mantle based on geophysical modelling, Phys. Earth. Planet. Int., 95, 101–122, 1996.
Peter, D., Komatitsch, D., Luo, Y., Martin, R., Le Goff, N., Casarotti, E., Le Loher, P., Magnoni, F., Liu, Q., Blitz, C., Nissen-Meyer, T., Basini, P., and Tromp, J.: Forward and adjoint simulations of seismic wave propagation on fully unstructured hexahedral meshes, Geophys. J. Int., 186, 721–739, 2011.
Płonka, A.: The imprint of crustal density heterogeneities on regional seismic wave propagation – dataset, https://doi.org/10.5281/zenodo.168576, 2016.
Resovsky, J. and Ritzwoller, M.: Regularisation uncertainty in density models estimated from normal mode data, Geophys. Res. Lett., 26, 2319–2322, 1999.
Resovsky, J. and Trampert, J.: Reliable mantle density error bars: an application of the Neighbourhood Algorithm to normal-mode and surface wave data, Geophys. J. Int., 150, 665–672, 2002.
Richards, M. and Lithgow-Bertelloni, C.: A geodynamic model of mantle density heterogeneity, J. Geophys. Res., 98, 21–895, 1993.
Rickers, F., Fichtner, A., and Trampert, J.: Imaging mantle plumes with instantaneous phase measurements of diffracted waves, Geophys. J. Int., 19, 650–664, 2012.
Rickers, F., Fichtner, A., and Trampert, J.: The Iceland – Jan Mayen plume system and its impact on mantle dynamics in the North Atlantic region: Evidence from full-waveform inversion, Earth Planet. Sc. Lett., 367, 39–51, 2013.
Romanowicz, B.: A global tomographic model of shear attenuation in the upper mantle, J. Geophys. Res., 100, 12375–12394, 1995.
Romanowicz, B.: Can we resolve 3-D density heterogeneity in the lower mantle?, Geophys. Res. Lett., 28, 1107–1110, 2001.
Romanowicz, B. and Mitchell, B. J.: Deep Earth structure – Q of the Earth from Crust to Core, edited by: Schubert, G., Treatise on Geophysics, 731–774, Elsevier 2007.
Selby, N. D. and Woodhouse, J. H.: The Q structure of the upper mantle: Constraints from Rayleigh wave amplitudes, J. Geophys. Res., 107, ESE 5-1–ESE 5-11, https://doi.org/10.1029/2001JB000257, 2002.
Shapiro, N. M., Campillo, M., Stehly, L., and Ritzwoller, M.: High resolution surface wave tomography from ambient seismic noise, Science, 307, 1615–1618, 2005.
Sieminski, A., Trampert, J., and Tromp, J.: Principal component analysis of anisotropic finite-frequency kernels, Geophys. J. Int., 179, 1186–1198, 2009.
Simmons, N. A., Forte, A. M., Boschi, L., and Grand, S. P.: GyPSuM: A joint tomography model of mantle density and seismic wave speeds, J. Geophys. Res., 115, B12310, https://doi.org/10.1029/2010JB007631, 2001.
Tanimoto, T.: Waveform inversion for three-dimensional density and S wave structure, J. Geophys. Res., 96, 8167–8189, 1991.
Takeuchi, H. and Saito, M.: Seismic surface waves, in: Methods in Computational Physics, edited by: Bolt, B. A., 11, 217–295, 1972.
Tape, C., Liu, Q., Maggi, A., and Tromp, J.: Seismic tomography of the southern California crust based upon spectral-element and adjoint methods, Geophys. J. Int., 180, 433–462, 2010.
Tarantola, A.: A strategy for nonlinear elastic inversion of seismic reflection data, Geophysics, 51, 1893–1903, 1986.
Tondi, R., Achauer, U., Landes, M., Davi, R., and Besutiu, L.: Unveiling seismic and density structure beneath the Vrancea seismogenic zone, Romania, J. Geophys. Res., 141, B11307, https://doi.org/10.1029/2008JB005992, 2009.
Tondi, R., de Franco, R., and Barzaghi, R.: Sequential inversion of refraction and wide-angle reflection traveltimes and gravity data for two-dimensional velocity structures, Geophys. J. Int., 141, 679–698, 2000.
Tong, J., Dahlen, F. A., Nolet, G., and Marquering, H.: Diffraction effects upon finite-frequency travel times: A simple 2-D example, Geophys. Res. Lett., 25, 1983–1986, 1998.
Trampert, J., Deschamps, F., Resovsky, J. , and Yuen, D.: Probabilistic tomography maps chemical heterogeneities throughout the lower mantle, Science, 306, 853–856, 2004.
Trampert, J. and Fichtner, A.: Global imaging of the Earth's deep interior: seismic constraints on (an)isotropy, density and attenuation, edited by: Karato, S., Physics and Chemistry of the deep Earth, Wiley-Blackwell, 2013.
Tromp, J., Tape, C., and Liu, Q.: Seismic tomography, adjoint methods, time reversal and banana-doughnut kernels, Geophys. J. Int., 160, 195–216, 2005.
Turcotte, D. L. and Schubert, G.: Geodynamics, Cambridge University Press, 2014.
van Leeuwen, T. and Mulder, W. A.: A correlation-based misfit criterion for wave-equation traveltime tomography, Geophys. J. Int., 182, 1383–1394, 2010.
Warners-Ruckstuhl, K. N., Govers, R., and Wortel, R.: Lithosphere-mantle coupling and the dynamics of the Eurasian Plate, Geophys. J. Int., 189, 1253–1276, 2012.
Woodhouse, J. H.: The calculation of eigenfrequencies and eigenfunctions of the free oscillations of the Earth and the Sun, edited by: Doornbos, D. J., Seismological algorithms, Academic Press, New York, 321–370, 1988.
Woodhouse, J. H. and Deuss, A. F.: Theory and Observations- Earth's Free Oscillations, in: Treatise on Geophysics, https://doi.org/10.1016/B978-044452748-6.00002-X, Elsevier 2007.
Wu, R. and Aki, K.: Scattering characteristics of elastic waves by an elastic heterogeneity, Geophysics, 50, 582–595, 1985.
Yuan, Y. O., Simons, F. J., and Bozdag, E.: Multiscale adjoint tomography for surface and body waves, Geophysics, 80, R281–R302, 2015.
Zhu, H., Bozdağ, E., and Tromp, J.: Seismic structure of the European upper mantle based on adjoint tomography, Geophys. J. Int., 201, 18–52, 2015.
Short summary
Imaging the inside of the Earth requires knowledge of how the Earth's properties affect seismic recordings. However, certain properties, such as density, affect seismograms in a way that is not fully known. Using numerical simulations, we can calculate a synthetic seismogram for a medium with and without density heterogeneities, and then compare the two signals. That way, we quantify the density effect on a seismogram. We also show that it is visible and growing as the wavefield gets scattered.
Imaging the inside of the Earth requires knowledge of how the Earth's properties affect seismic...
