ORCID Profile
0000-0003-4142-227X
Current Organisation
Electricité de France
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Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-5754
Abstract: & & Cape Verde is an intraplate archipelago located in the Atlantic Ocean about 560 km west of Senegal, on top of a ~130 Ma sector of the African oceanic lithosphere. Until recently, due to the lack of broadband seismic stations, the upper-mantle structure beneath the islands was poorly known. In this study we used data from two temporary deployments across the archipelago, measuring the phase velocities of Rayleigh-waves fundamental-modes in a broad period range (8& #8211 s), by cross-correlating teleseismic earthquake data between pairs of stations. Deriving a robust average, phase-velocity curve for the Cape Verde region, we inverted it for a shear-wave velocity profile using non-linear gradient search.& & & & Our results show anomalously low velocities of & #8764 .2 km/s in the asthenosphere, indicating the presence of high temperatures and, eventually, partial melting. This temperature anomaly is probably responsible for the thermal rejuvenation of the oceanic lithosphere to an age as young as about 30 Ma, which we inferred from the comparison of seismic velocities beneath Cape Verde and the ones representing different ages in the Central Atlantic.& & & & The present results, together with previously detected low-velocity anomalies in the lower mantle and relatively He-unradiogenic isotopic ratios, also suggest a hot plume deeply rooted in the lower mantle, as the origin of the Cape Verde hotspot.& & & & & span& The author& /span& & span& s& /span& & span& would like to acknowledge the financial support FCT through project& /span& & span& UIDB/50019/2020& /span& & span& & #8211 IDL& /span& & span& and FIRE project Ref. PTDC/GEO- GEO/1123/2014.& /span& & &
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-11754
Abstract: & & Spatial resolution, as the ability to distinguish different features that are close together, is a fundamental concept in seismic tomography and other imaging fields. In contrast with microscopy or telescopy, seismic tomography& #8217 s images are computed, and their resolution has a complex, non-linear dependence on the data s ling and errors. Linear inverse theory provides a useful resolution-analysis approach, defining resolution in terms of the closeness of the resolution matrix to the identity matrix. This definition is similar to the universal, multi-disciplinary one in some contexts but erges from it markedly in others. In this work, we adopt the universal definition of resolution (the minimum distance at which two spike anomalies can be resolved). The highest achievable resolution of a tomographic model then varies spatially and depends on the data s ling and errors in the data. We show that the propagation of systematic errors is resistant to data redundancy and results in models dominated by noise if the target resolution is too high. This forces one to look for smoother models and effectively limits the resolution. Here, we develop a surface-wave tomography method that finds optimal lateral resolution at every point by means of error tracking.& br& We first measure interstation phase velocities at simultaneously recording station pairs and compute phase-velocity maps at densely, logarithmically spaced periods. Multiple versions of the maps with varying smoothness are computed, ranging from very rough to very smooth. Phase-velocity curves extracted from the maps at every point are then inverted for shear-velocity (V& sub& S& /sub& ) profiles. As we show, errors in these phase-velocity curves increase nearly monotonically with the map roughness. Very smooth V& sub& S& /sub& models computed from very smooth phase-velocity maps will be the most accurate, but at a cost of a loss of most structural information. At the other extreme, models that are too rough will be dominated by noise. We define the optimal resolution at a point such that the error of the local phase-velocity curve is below an empirical threshold. The error is estimated by isolating the roughness of the phase-velocity curve that cannot be explained by any Earth structure.& br& A 3D V& sub& S& /sub& model is then computed by the inversion of the phase-velocity maps with the optimal resolution at every point. The estimated optimal resolution shows smooth lateral variations, confirming the robustness of the procedure. Importantly, optimal resolution does not scale with the density of the data coverage: some of the best-s led locations require relatively low lateral resolution, probably due to systematic errors in the data.& br& We apply the method to image the lithosphere and underlying mantle beneath Ireland and Britain, using 11238 newly measured, broadband, inter-station dispersion curves. The lateral resolution of the 3D model is computed explicitly and varies from 39 km in central Ireland to over 800 km at the region boundaries, where the data coverage declines. Our tomography reveals pronounced, previously unknown variations in the lithospheric thickness beneath the region, with implications for the Caledonian assembly of the islands& #8217 landmass and the mechanism of the magmatism of the British Tertiary Igneous Province.& &
Publisher: EDP Sciences
Date: 2015
DOI: 10.2113/GSSGFBULL.186.1.3
Abstract: The aim of the SI-Hex project (acronym for « Sismicité Instrumentale de l’Hexagone ») is to provide a catalogue of seismicity for metropolitan France and the French marine economic zone for the period 1962–2009 by taking into account the contributions of the various seismological networks and observatories from France and its neighbouring countries. The project has been launched jointly by the Bureau Central Sismologique Français (CNRS-University/BCSF) and the Laboratoire de Détection et de Géophysique (CEA-DAM/LDG). One of the main motivations of the project is to provide the end user with the best possible information on location and magnitude of each earthquake. So far, due to the various procedures in use in the observatories, the different locations and magnitudes of earthquakes located in the SI-Hex zone were presenting large discrepancies. In the 2014 version of the catalogue, 1D localizations of hypocentres performed with a unique computational scheme and covering the whole 1962–2009 period constitute the backbone of the catalogue (SI-Hex solutions). When available, they are replaced by more precise localizations made at LDG or, for recent times, by the regional observatories within: 1) the French Alps, 2) the southernmost Alps and the Mediterranean domain including Corsica, 3) the Pyrenees, and 4) the Armorican massif. Moment magnitudes Mw are systematically reported in the SI-Hex catalogue. They are computed from coda-wave analysis of the LDG records for most Mw& .4 events, and are converted from local magnitudes ML for smaller magnitude events. Finally, special attention is paid to the question of discrimination between natural and artificial seismic events in order to produce a catalogue for direct use in seismic hazard analysis and seismotectonic investigations. The SI-Hex catalogue is accessible on the web site www.franceseisme.fr and contains 38,027 earthquake hypocentres, together with their seismic moment magnitudes Mw.
Publisher: Elsevier BV
Date: 10-2015
Publisher: American Geophysical Union (AGU)
Date: 07-2011
DOI: 10.1029/2011GL047971
Publisher: Seismological Society of America (SSA)
Date: 13-05-2014
DOI: 10.1785/0120130222
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-11942
Abstract: & & The maximum achievable resolution of a tomographic model varies spatially and depends on the data s ling and errors in the data. Adaptive parameterization schemes match the spatial variations in data s ling but do not address the effects of the errors. The propagation of systematic errors, however, is resistant to data redundancy and results in models dominated by noise if the target resolution is too high. This forces us to look for smoother models and thus limits the imaging resolution.& br& & br& We develop a surface-wave tomography method that finds optimal lateral resolution at every point by means of error tracking. We first measure inter-station phase-velocities at simultaneously recording station pairs and compute phase-velocity maps at densely, logarithmically spaced periods. Unlike in the classical approach, multiple versions of the maps with varying smoothness constraints are computed, so that the maps range from very rough to very smooth. Phase-velocity curves extracted from the maps at every point can then be inverted for shear-velocity (V& sub& s& /sub& ) profiles. As we show, errors in these phase-velocity curves increase nearly monotonically with the map roughness. Very smooth V& sub& s& /sub& models computed from very smooth phase-velocity maps will be the most robust, but at a cost of a loss of most structural information. At the other extreme, models that are too rough will be dominated by noise. We define the optimal resolution at a point such that the error of the local phase-velocity curve is below an empirical threshold. The error is estimated by isolating the roughness of the phase-velocity curve that cannot be explained by any Earth structure. A 3D V& sub& s& /sub& model is then computed by the inversion of the phase-velocity maps with the optimal resolution at every point. The estimated optimal resolution shows smooth lateral variations, confirming the robustness of the procedure. Importantly, optimal resolution does not scale with the density of the data coverage: some of the best-s led locations require relatively low lateral resolution, probably due to systematic data errors. We apply the method to image the Ireland& #8217 s and Britain& #8217 s upper mantle, using our large, new regional dataset. We report a pronounced thinning of the lithosphere beneath the British Tertiary Igneous Province, with important implications for the Paleogene uplift and volcanism in the region.& &
Publisher: Oxford University Press (OUP)
Date: 12-04-2012
Publisher: Seismological Society of America (SSA)
Date: 26-04-2023
DOI: 10.1785/0120220227
Abstract: We present an analytical solution for the evaluation of timing errors at seismological stations. The method makes use of differential P- and S-wave arrival time measurements demeaned over a network that recorded a set of densely located seismic events. In this configuration, one can assume coincident P and S ray paths between sources and receivers, and cancel out dependencies associated with absolute event origin times, event locations, and P- or S-wave velocities in the problem. Relative timing errors can be obtained by linear inversion, using only a limited amount of input data: differential P- and S-wave arrival times, and a local VP/VS ratio. By setting at least one reference station in the network, supposed to be devoid of any timing error, one can retrieve reliable timing errors for other stations. We validate the approach against synthetic and real data. We also analyze the sensitivity of results on errors in the input data. Although picking uncertainties do affect the variability of estimates, we also identified a significant bias when an incorrect VP/VS ratio is used. However, this bias can be reduced if one uses the optimal VP/VS value that minimizes the root mean square of travel-time residuals. Application of the method to a collection of manually picked arrival times for the 2002–2003 Tricastin, France, earthquake, swarm allowed us to identify nonstationary timing errors from tenth to tens of seconds during the monitoring c aign.
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 10-2018
Publisher: American Geophysical Union (AGU)
Date: 04-2010
DOI: 10.1029/2009GL041974
Publisher: Oxford University Press (OUP)
Date: 08-05-2023
DOI: 10.1093/GJI/GGAD194
Abstract: Ireland and neighbouring Britain share much of their tectonic history and are both far from active plate boundaries at present. Their seismicity shows surprising lateral variations, with very few earthquakes in Ireland but many low-to-moderate ones in the adjacent western Britain. Understanding the cause of these variations is important for our understanding of the basic mechanisms of the intraplate seismicity distributions and for regional hazard assessment. The distribution of microseismicity within Ireland and its underlying causes have been uncertain due to the sparsity of the data s ling of the island, until recently. Here, we use the data from numerous recently deployed seismic stations in Ireland and map its seismicity in greater detail than previously. The majority of detectable seismic events are quarry and mine blasts. These can be discriminated from tectonic events using a combination of the waveform data, event origin times, and the epicentres’ proximity to quarries and mines, catalogued or identified from the satellite imagery. Our new map of natural seismicity shows many more events than known previously but confirms that the earthquakes are concentrated primarily in the northernmost part of the island, with fewer events along its southern coast and very few deeper inland. Comparing the seismicity with the recently published surface wave tomography of Ireland and Britain, we observe a strong correspondence between seismicity and the phase velocities at periods s ling the lithospheric thickness. Ireland has relatively thick, cold and, by inference, mechanically strong lithosphere and has very few earthquakes. Most Irish earthquakes are in the north of the island, the one place where its lithosphere is thinner, warmer and, thus, weaker. Western Britain also has relatively thin lithosphere and numerous earthquakes. By contrast, southeastern England and, probably, eastern Scotland have thicker lithosphere and, also, few earthquakes. The distribution of earthquakes in Ireland and Britain is, thus, controlled primarily by the thickness and mechanical strength of the lithosphere. The thicker, colder, stronger lithosphere undergoes less deformation and features fewer earthquakes than thinner, weaker lithosphere that deforms more easily. Ireland and Britain are tectonically stable and the variations in the lithospheric thickness variations across them are estimated to be in a 75–110 km range. Our results thus indicate that moderate variations in the lithospheric thickness within stable continental interiors can exert substantial control on the distributions of seismicity and seismic hazard—in Ireland, Britain and elsewhere around the world.
Publisher: American Geophysical Union (AGU)
Date: 02-2012
DOI: 10.1029/2011JB008560
Publisher: Copernicus GmbH
Date: 28-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-8652
Abstract: & & Seismic event locations are usually performed by means of iterative, linearized arrival time inversion considering 1D velocity models with fixed data errors. Both the use of inaccurate velocity structure or data error estimates may however affect the quality of event location and uncertainty evaluation. Here, we test a 3D P- and S-wave velocity model built in a previous work for Metropolitan France (the part of France located in Europe) and we compare it with the & #8220 Auvergne& #8221 1D velocity model used by BCSF-R& #233 NaSS (Bureau Central Sismologique Fran& #231 ais - R& #233 seau National de Surveillance Sismique) using quarry blast data. The reason for using quarry blast data is that, to some extent, their epicentral location and depth are known, which is not the case for earthquakes. We first identify potential active quarries over the territory of Metropolitan France by comparing catalog quarry blast locations with those from quarries visible from satellite images. Relocation is achieved by means of a Hierarchical Bayesian inversion procedure in which not only the hypocentral parameters (longitude, latitude, depth, origin time) are inverted for, but also P- and S-wave arrival time errors. The area of interest is a 1& #176 by 1& #176 zone located between 4& #176 E and 5& #176 E in longitude and 44& #176 N and 45& #176 N in latitude, the region where the Le Teil earthquake occurred (Mw 4.9, 2019/11/11). We first demonstrate the ability of the algorithm to properly determine hypocentral parameters and data noise using two simple synthetic experiments. Then we apply it to real data and relocate 147 quarry blasts that occurred in the region between 1980 and 2020 and that were located wit the & #8220 Auvergne& #8221 1D velocity model. Relocations obtained with the 1D and 3D model are rather similar. Estimated data errors are larger, in both cases, than the litude of picking uncertainties, meaning that both models could be improved, by seismic arrival time tomography for instance. They are larger in the 3D case, suggesting that, from that point of view, the 1D model is in better agreement with the data. Distances between relocated hypocenters and the closest known quarry are comparable but relocations with the 3D model are characterized by shallower hypocenters than those obtained with the 1D model, so they appear more consistent with the fact that events are quarry blasts. In both cases, some events are quite far away from the closest quarry, suggesting that some of them might be natural events.& &
Publisher: Seismological Society of America (SSA)
Date: 07-2013
DOI: 10.1785/0220120158
Publisher: Elsevier BV
Date: 10-2016
Publisher: American Geophysical Union (AGU)
Date: 2014
DOI: 10.1002/2013JB010433
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-9542
Abstract: In this work, we present a new earthquake catalogue for metropolitan France (i.e. the part of France located in Europe), which can be used to derive parameters of interest for seismic hazard modeling in that region. The catalogue is built from the amalgamation of existing catalogues for France but also neighboring countries, for both historical (here, ante-1965) and instrumental times. It covers a period ranging from 250 to 2020. Magnitudes are homogenized as moment magnitudes (Mw) using adequate conversion laws when needed. Uncertainties on location and magnitude are also provided so they can be used to realistically quantify epistemic uncertainties in hazard models. This catalogue somehow represents an updated version of the catalogue used in Drouet et al. (2020), augmented from recently published information. It extends from -8.1& #176 E to 11.& #176 E in longitude and from 38& #176 N to 51& #176 N in order to encompass the three area source models that were used in that study. The core of this catalogue is FCAT-17 (Manchuel et al., 2018), completed using the most recent ESHM2020 catalogue, FCAT-17 being given priority on the French territory plus a 20 km buffer beyond its borders and exclusive economic zone. Then, national catalogues for neighboring countries (Portugal, Spain, United Kingdom, Ireland, Belgium, Netherlands, Luxembourg, Germany, Austria, Switzerland, Italy) are also incorporated and are given full priority over their territory. The final model contains more than 45,000 events with magnitudes as low as Mw=2.0. Such low magnitudes were considered in order to provide as much constraint as possible to recurrence models, despite the fact low magnitude events are -per se- of little interest for seismic hazard models.
Publisher: Elsevier BV
Date: 07-2006
Publisher: Geological Society of America
Date: 09-2014
DOI: 10.1130/G35766.1
Publisher: Copernicus GmbH
Date: 27-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-4477
Abstract: & & The maximum achievable resolution of a tomographic model varies spatially and depends on the data s ling and errors in the data. The significant and continual measurement-error decreases in seismology and data-redundancy increases have reduced the impact of random errors on tomographic models. Systematic errors, however, are resistant to data redundancy and their effect on the model is difficult to predict often this results in models dominated by noise if the target resolution is too high. Here, we develop a method for finding the optimal resolving length at every point, implementing it for surface-wave tomography. As in the Backus-Gilbert method, every solution at a point results from an entire-system inversion, and the model error is reduced by increasing the model-parameter averaging. The key advantage of our method consists in its direct, empirical evaluation of the posterior model error at a point.& & & & We first measure interstation phase velocities at simultaneously recording station pairs and compute phase-velocity maps at densely, logarithmically spaced periods. Numerous versions of the maps with varying smoothness are then computed, ranging from very rough to very smooth. Phase-velocity curves extracted from the maps at every point can be inverted for shear-velocity (V& sub& S& /sub& ) profiles. As we show, errors in these phase-velocity curves increase nearly monotonically with the map roughness. We evaluate the error by isolating the roughness of the phase-velocity curve that cannot be explained by any Earth structure and determine the optimal resolving length at a point such that the error of the local phase-velocity curve is below a threshold.& & & & A 3-D V& sub& S& /sub& model is then computed by the inversion of the composite phase-velocity maps with an optimal resolution at every point. Importantly, the optimal resolving length does not scale with the density of the data coverage: some of the best-s led locations display relatively low lateral resolution, due to systematic errors in the data.& & & & We apply this method to image the lithosphere and underlying mantle beneath Ireland and Britain. Our very large data produces a total of 11238 inter-station dispersion curves, spanning a very broad total period range (4& #8211 s), yielding unprecedented data coverage of the area and providing state-of-the-art regional resolution from the crust to the deep asthenosphere. Our tomography reveals pronounced, previously unknown variations in the lithospheric thickness beneath Ireland and Britain, with implications for their Caledonian assembly and for the mechanisms of the British Tertiary Igneous Province magmatism.& &
Publisher: American Geophysical Union (AGU)
Date: 15-12-2016
DOI: 10.1002/2016GL071201
Publisher: American Geophysical Union (AGU)
Date: 02-2019
DOI: 10.1029/2018JB016531
Publisher: Oxford University Press (OUP)
Date: 12-01-2021
DOI: 10.1093/GJI/GGAB005
Abstract: We present PRISM3D, a 3-D reference seismic model of P- and S-wave velocities for Iberia and adjacent areas. PRISM3D results from the combination of the most up-to-date earth models available for the region. It extends horizontally from 15°W to 5°E in longitude, 34°N to 46°N in latitude and vertically from 3.5 km above to 200 km below sea level, and is modelled on a regular grid with 10 and 0.5 km of grid node spacing in the horizontal and vertical directions, respectively. It was designed using models inferred from local and teleseismic body-wave tomography, earthquake and ambient noise surface wave tomography, receiver function analysis and active source experiments. It includes two interfaces, namely the topography/bathymetry and the Mohorovičić (Moho) discontinuity. The Moho was modelled from previously published receiver function analysis and deep seismic sounding results. To that end we used a probabilistic surface reconstruction algorithm that allowed to extract the mean of the Moho depth surface along with its associated standard deviation, which provides a depth uncertainty estimate. The Moho depth model is in good agreement with previously published models, although it presents slightly sharper gardients in orogenic areas such as the Pyrenees or the Betic-Rif system. Crustal and mantle P- and S-wave wave speed grids were built separately on each side of the Moho depth surface by weighted average of existing models, thus allowing to realistically render the speed gradients across that interface. The associated weighted standard deviation was also calculated, which provides an uncertainty estimation on the average wave speed values at any point of the grid. At shallow depths (& km), low P and S wave speeds and high VP/VS are observed in offshore basins, while the Iberian Massif, which covers a large part of western Iberia, appears characterized by a rather flat Moho, higher than average VP and VS and low VP/VS. Conversely, the Betic-Rif system seems to be associated with low VP and VS, combined with high VP/VS in comparison to the rest of the study area. The most prominent feature of the mantle is the well known high wave speed anomaly related to the Alboran slab imaged in various mantle tomography studies. The consistency of PRISM3D with previous work is verified by comparing it with two recent studies, with which it shows a good general agreement.The impact of the new 3-D model is illustrated through a simple synthetic experiment, which shows that the lateral variations of the wave speed can produce traveltime differences ranging from –1.5 and 1.5 s for P waves and from –2.5 and 2.5 s for S waves at local to regional distances. Such values are far larger than phase picking uncertainties and would likely affect earthquake hypocentral parameter estimations. The new 3-D model thus provides a basis for regional studies including earthquake source studies, Earth structure investigations and geodynamic modelling of Iberia and its surroundings.
Publisher: American Geophysical Union (AGU)
Date: 04-2018
DOI: 10.1002/2017JB015114
Publisher: Oxford University Press (OUP)
Date: 06-2012
DOI: 10.1111/J.1365-246X.2012.05414.X
Abstract: A meaningful interpretation of seismic measurements requires a rigorous quantification of the uncertainty. In an inverse problem, the data noise determines how accurately observations should be fit, and ultimately the level of detail contained in the recovered model. A common problem in seismic tomography is the difficulty in quantifying data uncertainties, and thus the required level of data fit. Traditionally, the complexity of the solution model (defined by both the number of basis functions and the regularization) is defined arbitrarily by the user prior to inversion with only limited use of data errors. In the context of multiscale problems, dealing with multiple data sets that are characterized by different noise variances and that span the Earth at different scales is a major challenge. Practitioners are usually required to arbitrarily weigh the contribution of each data type into the final solution. Furthermore, the basis functions are usually spatially uniform across the velocity field and regularization procedures are global, which prevents the solution model from accounting for the uneven spatial distribution of information. In this work we propose to address these issues with a Hierarchical Bayesian inversion. The new algorithm represents an extension of the transdimensional tomography to account for uncertainties in data noise. This approach has the advantage of treating the level of noise in each data set, as well as the number of model parameters, as unknowns in the inversion. It provides a parsimonious solution that fully represents the degree of knowledge one has about seismic structure (i.e. constraints, resolution and trade-offs). Rather than being forced to make decisions on parametrization, level of data fit and weights between data types in advance, as is often the case in an optimization framework, these choices are relaxed and instead constrained by the data themselves. The new methodology is presented in a synthetic ex le where both the data density and the underlying structure contain multiple length scales. Three ambient noise data sets that span the Australian continent at different scales are then simultaneously inverted to infer a multiscale tomographic image of Rayleigh wave group velocity for the Australian continent. The procedure turns out to be particularly useful when dealing with multiple data types with different unknown levels of noise as the algorithm is able to naturally adjust the fit to the different data sets and provide a velocity map with a spatial resolution adapted to the spatially variable information present in the data.
Publisher: Copernicus GmbH
Date: 28-03-2022
DOI: 10.5194/EGUSPHERE-EGU22-10503
Abstract: & & Stable continental areas& #8212 those largely unaffected by currently active plate-boundary processes& #8212 undergo little deformation and feature low seismicity rates. Notable exceptions, such as the well-known large earthquakes in the central United States or the Fennoscandian Craton, are rare but highlight the importance of understanding the seismicity in low-strain regions. One long-standing question, debated for over a century, relates to the seismicity of Ireland. Why is it much lower than that in the neighbouring Britain, even though they were assembled in the same Caledonian orogeny, share many of the ancient tectonic boundaries, and are subjected to similar tectonic stresses? Our new catalogue of Ireland& #8217 s seismicity, produced using the greatly improved seismic station coverage of the island over the last decade, shows many more micro-earthquakes than known previously but confirms the much lower seismicity rates in Ireland compared to Britain.& & & & Comparing the distribution of seismicity with high-resolution, surface-wave tomography (performed using the abundant new data) we observe that areas with thicker, colder lithosphere feature lower seismicity than those with thinner lithosphere. This must be because the thicker and colder lithosphere is mechanically stronger and less likely to deform, compared to the thinner and weaker lithosphere under the same tectonic stress. According to the new tomography, Ireland has thicker lithosphere than most of Britain, which can explain its lower seismicity rates. The thinnest lithosphere in Ireland is found in the north of the island, in Co Donegal, and this is where most of Ireland& #8217 s micro-seismicity occurs. A similar relationship between the lithospheric thickness and seismicity rates is observed in Britain, with the London Platform in the southeast of the island showing thick lithosphere and low seismicity.& & & & Together, lithospheric tomography and seismicity maps thus offer a solution to a seismo-tectonic puzzle first formulated in the 19-th century. Evidence of the lithospheric mantle controls on earthquake occurrence can be seen elsewhere around the world as well. The improving accuracy of the tomographic imaging of the lithosphere presents a useful new line of evidence on the mechanisms that control the regional distributions of intraplate earthquakes.& &
Publisher: Oxford University Press (OUP)
Date: 09-2005
No related grants have been discovered for Pierre Arroucau.