Pierre Arroucau

• Électricité de France (EDF)

Earthquake hazard analyses rely on seismogenic source models. These are designed in various fashions, such as point sources or area sources, but the most effective is the three-dimensional representation of geological faults. We here refer to such models as fault sources. This study presents the European Fault-Source Model 2020 (EFSM20), which was...

Earthquake hazard analyses rely on the availability of seismogenic source models. These are designed in different fashions, such as point sources or area sources, but the most effective is the three-dimensional representation of geological faults. We here refer to such models as fault sources. This study presents the European Fault-Source Model 202...

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 und...

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,...

Localisés à distance des grandes limites de plaques lithosphériques, les domaines intraplaques présentent de faibles vitesses de déformation géologique, se traduisant par des niveaux de sismicité faibles à modérés, avec des temps de retour longs entre deux séismes significatifs. Dans ces régions, les processus de surface sont plus rapides que les p...

The 2019-11-1, Mw4.9 Le Teil earthquake occurred within the NE termination of the Cévennes faults system (CFS) in southern France, along the La Rouvière fault (LRF), an Oligocene normal fault which was not known to be potentially active. This shallow moderate magnitude reversefaulting event produced a 5 km-long surface rupture and strong ground sha...

The classical Backus–Gilbert method seeks localized Earth-structure averages at the shortest length scales possible, given a data set, data errors, and a threshold for acceptable model errors. The resolving length at a point is the width of the local averaging kernel, and the optimal averaging kernel is the narrowest one such that the model error i...

A common deviation from typical subduction models occurs when thrust sheets of oceanic crust and upper‐mantle rocks are emplaced over more buoyant continental lithosphere. The archetypal example of ophiolite obduction is the Semail ophiolite in the United Arab Emirates (UAE)‐Oman orogenic belt, formed and obducted onto the Arabian continental margi...

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, an...

We present PRISM3D, a three-dimensional (3D) 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 o W to 5 o E in longitude, 34 o N to 46 o N in latitude, and vertically from 3.5 km above to...

Cape Verde is an intraplate archipelago located in the Atlantic Ocean about 560 km west of Senegal, on an ~ 130 Ma old oceanic lithosphere. The upper-mantle structure beneath the islands was poorly known, until recently, in large part due to the lack of broadband seismic stations. In this study we used data from two temporary deployments across the...

Linearised least-square inversions are commonly used to locate small-magnitude earthquakes, as they are fast and simple to implement. These methods are based on minimising the root-mean-square (RMS) of travel time residuals to find the best-fitting location coordinates and origin time. There are two well-known problems that affect location estimate...

Independent models of P wave and S wave velocity anomalies in the mantle derived from seismic tomography help to distinguish thermal signatures from those of partial melt, volatiles, and compositional variations. Here we use seismic data from SW Europe and NW Africa, spanning the region between the Pyrenees and the Canaries, in order to obtain a ne...

Intraplate Iberia is a region of slow lithopsheric deformation (<1 mm/yr) with significant historical earthquake activity. Recent high-quality instrumental data has shown that small-magnitude earthquakes collapse along clusters and lineaments, which however do not bear a clear relationship to geologically mapped active structures. In this article,...

The mechanisms of continental growth are a crucial part of plate tectonic theory, yet a clear understanding of the processes involved remains elusive. Here we determine seismic Rayleigh wave phase anisotropy variations in the crust beneath the southern Tasmanides of Australia, a Paleozoic accretionary margin. Our results reveal a complex, thick-ski...

At 01:36 UTC (03:36 local time) on August 24th 2016, an earthquake Mw 6.0 struck an extensive sector of the central Apennines (coordinates: latitude 42.70° N, longitude 13.23° E, 8.0 km depth). The earthquake caused about 300 casualties and severe damage to the historical buildings and economic activity in an area located near the borders of the Um...

At 01:36 UTC (03:36 local time) on August 24th 2016, an earthquake Mw 6.0 struck an extensive sector of the central Apennines (coordinates: latitude 42.70° N, longitude 13.23° E, 8.0 km depth). The earthquake caused about 300 casualties and severe damage to the historical buildings and economic activity in an area located near the borders of the Um...

The mechanisms of continental growth are a crucial part of plate tectonic theory, yet a clear understanding of the processes involved remains elusive. Here, we determine seismic Rayleigh-wave phase anisotropy variations in the crust beneath the southern Tasmanides of Australia, a Paleozoic accretionary margin. Our results reveal a complex, thick-sk...

The eastern Tennessee seismic zone (ETSZ) is the second most seismically active area in the central and eastern United States after the New Madrid seismic zone, but the relatively weak seismicity and the absence of correlation between the seismicity distribution and the surface geology make its seismogenic potential controversial. In this work we i...

Seismic network performance plays an important role in the operation of seismological observatories and temporary network deployments. The event detection magnitude threshold of a network is frequently derived from the observed magnitude of completeness or from measured noise amplitudes in conjunction with theoretically derived ground displacements...

Portugal lies on the south-westernmost tip of Europe, next to the boundary between Eurasia and Africa. The slow oblique convergence between Iberia and Nubia is accommodated along a broad region of diffuse deformation rather than along a single plate boundary. Individual faults have low loading rates, which results in long time intervals between ear...

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...

For nearly half a century, a number of conflicting tectonic models have been postulated to explain the enigmatic geological relationship between Tasmania and Victoria, with a view to unifying our understanding of the evolution of the eastern margin of Gondwana in Australia. In this study, ambient noise data from an array of 24 broadband seismometer...

We use ambient noise recordings from the largest transportable seismic array in the Southern Hemisphere to image azimuthal variations in Rayleigh wave phase anisotropy in the crust beneath southeast Australia. This region incorporates a transition from the Precambrian shield region of Australia in the west to younger Phanerozoic terranes in the eas...

This study investigates crustal anisotropy in the New Madrid Seismic Zone (NMSZ) by analyzing shear-wave splitting measurements from local earthquake data. In addition to the waveforms provided by the Center for Earthquake Research and Information (CERI) for over 3000 events, seismograms recorded by the portable array for numerical data acquisition...

Online Material: Additional Kraljevo sequence data, details. An M w 5.4 earthquake occurred on 3 November 2010 (Fig. 1) near the city of Kraljevo, Serbia, the population of which is more than 100,000 people. By the end of March 2011, the earthquake had been followed by a sequence of more than 650 aftershocks of magnitude greater than 1.0. Despite...

Portugal lies on the south-westernmost tip of Europe, next to the boundary between Eurasia and Africa. The slow oblique convergence between Iberia and Nubia is accommodated along a broad region of diffuse deformation rather than along a single plate boundary. Individual faults have low loading rates, which result in long time intervals between eart...

[1] We present three-dimensional P- and S-wave velocity models for the active eastern Tennessee seismic zone (ETSZ) using arrival time data from more than 1000 local earthquakes. A nonlinear tomography method is used that involves sequential inversion for model and hypocenter parameters. We image several velocity anomalies that persist through most...

Ambient seismic noise data from the ongoing WOMBAT transportable seismic array in southeast Australia, the largest deployment of its kind in the Southern Hemisphere, are used to produce a high-resolution 3-D shear wave velocity model of the region. We apply a two-stage, transdimensional, hierarchical Bayesian inversion approach to recover phase vel...

The Eastern Tennessee Seismic Zone (ETSZ) is an intraplate seismic region characterized by frequent but low magnitude earthquakes and is the second most active seismic area in the United States east of the Rocky Mountains. One key question in the ETSZ is the actual relationship between earthquake distribution and geological structure at depth. Seis...

Bayesian travel-time inversion for Earthquake hypocentral location in 1D layered media. (2012) The earthquake location algorithms routinely used in the seismological community generally rely on a linearized inverse approach in which the objective function measuring the difference between observed and calculated arrival times is minimized through an...

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 uncer...

A limitation of most forms of passive seismic tomography using distant earthquakes lies in the fact that crustal structure is poorly resolved. An attempt is made here to address this issue by modelling teleseismic receiver functions (RFs) and dispersion curves derived from ambient noise through a multistep approach. The SEAL3 experiment in central...

The lithosphere beneath eastern Australia was formed during a protracted period of Palaeozoic orogeny that began in the Early Cambrian and terminated in the Middle Triassic. Accretion of new and reworked lithosphere occurred outboard of the proto-Pacific margin of Gondwana, which at that time extended some 20,000 km along the east margin of Precamb...

We present a novel method for joint inversion of receiver functions and surface wave dispersion data, using a transdimensional Bayesian formulation. This class of algorithm treats the number of model parameters (e.g. number of layers) as an unknown in the problem. The dimension of the model space is variable and a Markov chain Monte Carlo (McMC) sc...

The seismicity of intraplate continental interiors is one of the most challenging -though a bit overlooked- research topics in seismology. The most famous of those is undoubtedly the New Madrid seismic zone (NMSZ), named after the city of New Madrid, Missouri, that was destroyed by one of the three M>7.0 earthquakes that occurred in central United...

The earthquake location algorithms routinely used in the seismological community generally rely on a linearized inverse approach in which the objective function measuring the difference between observed and calculated arrival times is minimized through an iterative procedure with a fixed 1D velocity model. Markov chain Monte Carlo (MCMC) inversion...

The Eastern Tennessee Seismic Zone (ETSZ) is an intraplate seismic region characterized by frequent but low magnitude earthquakes and is the second most active seismic area in the United States east of the Rocky Mountains. Since the middle of the seventies, the Center for Earthquake Research and Information (CERI) has installed and maintained sever...

A Mw=5.4 earthquake occurred on November 3, 2010 near the City of Kraljevo, Serbia (lat. 43.765 N, long. 20.713 E) and was followed by a sequence of more than 650 aftershocks with magnitude greater than 1.0. Despite the moderate magnitude of the event, two people were killed, many other were injured, and the total damage to the city is estimated to...

The Mw=7.0 earthquake that occurred in the vicinity of Port-au-Prince, Haiti on january 12th, 2010 caused significant damage to the infrastructures of the country and resulted in more than 200,00 casualties. The Republic of Haiti is part of the island of Hispaniola and is located at the boundary between the North American and Caribbean tectonic pla...

The Eastern Tennessee Seismic Zone (ETSZ) is the second most active seismic region in the eastern United States and is located in the southern Appalachian fold-and-thrust belt. The earthquakes mostly occur between 5 and 25 km depth, below the decollement surface, and tend to align along the New York Alabama magnetic lineament, a linear feature attr...

Two methods of Digital Elevation Model (DEM) analysis (the Slope/Area relationship and the Stream Length Index (SL)) are tested for selected drainage areas in the eastern Tennessee seismic zone (ETSZ), the second most active region of the eastern and central United States. Previous studies have shown that DEM analysis could be used to quantify surf...

Since 2004 more than 7000 km of full-crustal reflection profiles have been collected across Australia to give a total of more than 11 000 km, providing valuable new constraints on crustal structure. A further set of hitherto unexploited results comes from 150 receiver functions distributed across the continent, mostly from portable receiver sites....

The island of Tasmania, at the southeast tip of Australia, is an ideal natural laboratory for ambient noise tomography, as the surrounding oceans provide an energetic and relatively even distribution of noise sources. We extract Rayleigh wave dispersion curves from the continuous records of 104 stations with ∼15 km separation. Unlike most passive e...

More than 100 years ago it was predicted that the distribution of first digits of real world observations would not be uniform, but instead follow a trend where measurements with lower first digit (1,2,...) occur more frequently than those with higher first digits (...,8,9). This result has long been known by mathematicians but regarded as mere mat...

The eastern Tennessee seismic zone (ETSZ) is the second most seismically active region of the United States east of the Rocky Mountains. Located at the southern edge of the Appalachian Range, in an intraplate continental setting, it can be described as a northeast trending, 300 km long by 100 km wide belt of diffuse seismicity. Although no major ea...

The New Madrid Seismic Zone (NMSZ) of the central Mississippi river valley is currently the most seismically active region in the central and eastern United States. A number of earthquakes occurred in NMSZ between 1811 and 1812, of which three major earthquakes with magnitudes greater than 7 destroyed the town of New Madrid, Missouri. Intraplate se...

In contrast to the ancient Proterozoic and Archean terranes of central and western Australia, eastern Australia consists of an outward stepping series of fold belts that largely formed between the Middle Cambrian and Triassic as a result of convergence along the proto-Pacific margin of east Gondwana. In southeast Australia, the Delamerian Orogen ab...

We present three-dimensional P- and S-wave (Vp and Vs) velocity models and hypocenter relocations for the active eastern Tennessee seismic zone (ETSZ) based upon arrival time data from more than 1000 local earthquakes. The most striking result is the change in hypocenter density on either side of a pronounced, NE-SW trending, linear magnetic anomal...

Group and phase velocity maps of the Tasmanian and Western Australian lithosphere are obtained through the cross-correlation of seismic ambient noise recorded by temporary array deployments. Group velocities of fundamental mode Rayleigh waves are calculated through an automated frequency-time (FTAN) procedure. Phase-matched filters are applied to t...

Eastern Tennessee contains one of the most seismically active regions in the eastern North America. The Eastern Tennessee Seismic Zone (ETSZ) is about 300 kilometers long and extends from northwestern Georgia through eastern Tennessee [Study Area: 34°N to 37°N; 86°W to 82.5°W]. It is the second most active earthquake zone of the United States east...

Trans-dimensional Bayesian inverse methods have been recently introduced in the geosciences to solve a variety of inverse problems. This class of algorithms treat the number of model parameters (e.g. number of layers) as an unknown in the problem. The dimension of the model space is variable and Markov chain Monte Carlo (McMC) schemes are used to p...

The Eastern Tennessee Seismic Zone (ETSZ) is an intraplate continental region located in the eastern part of North America and constitutes, after the New Madrid Seismic Zone, the second most active region of the continent east of the Rocky Mountains. It consists of a NE-trending, 300 km long and 100 km wide, belt of diffuse seismicity and is charac...

Detailed images of Rayleigh wave group velocity are derived from ambient seismic noise recorded by WOMBAT, a large rolling seismic array project in southeast Australia. Group velocity maps sensitive to crustal structure exhibit low velocity anomalies in the presence of sedimentary basins and recent hot-spot volcanism, and high velocities in regions...

Ambient noise cross-correlation is now a well established and powerful tool for studying the structure of the crust and upper mantle. In the past decade, it has given rise to a new class of seismic tomography which has been successfully applied at different scales and in various regions of the world. In this work, we exploit the ambient noise data...

The SEAL3 experiment represents one of the twelve array deployments that so far comprise the large and ambitious WOMBAT project, which aims to cover a significant portion of the Australian continent with a rolling array of seismometers. SEAL3 consists of 55 three-component short-period instruments located in central and southern New South Wales (NS...

Techniques using ambient seismic energy have become powerful tools in the imaging of the Earth's lithosphere. In this work we investigate the potential for using ambient energy to image the upper crust at the highest possible resolution. Such images are sought-after in deducing regional-scale 3D geological structure. They are critical to activities...

Over the last decade, twelve seismic arrays have been sequentially deployed as part of the WOMBAT experiment to cover a large area of southeast Australia at station spacings varying between 15 and 50 km. Each array typically consists of between 30 to 60 short period instruments that continuously record for between five to ten months. Early deployme...

The main result of this work is to show that macroseismic intensity decay with distance strongly depends on the epicentral intensity. An attenuation law that takes this parameter into account is proposed for Metropolitan France, from the analysis of SISFRANCE macroseismic database. Such a model significantly reduces the difference between observed...

The Armorican Massif is an outcropping segment of the Hercynian belt of Western Europe. Nowadays it constitutes an intraplate deformation domain in a passive continental margin context. This deformation finds its expression in a moderate seismic activity characterized by low magnitude earthquakes. The geographical distribution of the seismicity, pr...

A Mw 4.3 earthquake occurred on 2002 September 30, in the Armorican Massif, NW France. Since it was one of the largest events ever recorded in this region, this was the opportunity to improve our seismotectonic knowledge of the Armorican Massif. We performed a post-seismic survey (SISBREIZH), which allowed us to locate accurately 62 aftershocks wit...

S U M M A R Y A Mw 4.3 earthquake occurred on 2002 September 30, in the Armorican Massif, NW France. Since it was one of the largest events ever recorded in this region, this was the opportunity to improve our seismotectonic knowledge of the Armorican Massif. We performed a post-seismic survey (SISBREIZH), which allowed us to locate accurately 62 a...

The Armorican Massif (Western France) is a part of the Paleozoic Hercynian range. Its current seismicity is characterized by a diffuse general pattern and by moderate magnitudes. Indeed the events recorded since the instrumental period rarely exceed a magnitude of 4. The Pouzauges earthquake occured on June, 8th. 2001 in the southern part of the Ar...

INSUE-CNRS, 15-03-2003, 4 p.