COURBOULEX , Françoise

Small earthquakes are not destructive but can be very helpful. This HDR thesis describes threw different research studies how small earthquakes can be used for (1) understanding seismic source of larger ones by an inversion using empirical Green's functions (2) imaging active faults using location and relative relocation methods (3) predict the...

International audience

The junction between the Western Alps and the Ligurian basin in the Mediterranean Sea is one of the intraplate areas of Western Europe where strong earthquakes occur. The last of these earthquakes occurred in 1887 activating the Ligurian thrust, the major structure which has controlled most of the deformation in the area for about 5 Ma. The...

International audience

The southern Alps–Ligurian basin junction is one of the most seismically active zone of the western Europe. A constant microseismicity and moderate size events (3.5 < M < 5) are regularly recorded. The last reported historical event took place in February 1887 and reached an estimated magnitude between 6 and 6.5, causing human losses and...

We evaluate the non-linear site response at the stations of the Japanese Kik-Net network by computing the ratio between the Fourier spectra of the recordings at the surface and at the downhole station. When the amplitude of the input signal increases, we observe a shift of the resonance peaks towards lower frequencies, characteristic of...

While the triggering process of landslides remains are multiple, the importance of seismic waves is well established. The leading approach to study coseismic landslides is through statistical studies or simple models such as the Newmark method. While providing useful information, these approaches fall short at predicting landslide triggering...

A propos des vibrations du sol dues à un séisme Un séisme est dû à une rupture des roches en profondeur qui occasionne un déplacement rapide des deux compartiments d'une faille. C'est un phénomène bref (quelques secondes pour les séismes faibles à modérés à quelques minutes pour les séismes majeurs) qui génère des vibrations appelées ondes...

We develop a new approach to image earthquake rupture from strong motion data. We use a large data set of aftershock waveforms, interpolated over the seismic fault to obtain Green's function approximations. Next we deploy a Bayesian inversion method to characterize the slip distribution, the rupture velocity, the slip duration, and their...

Quito, the capital of Ecuador, with more than 2.5 M inhabitants, is exposed to a high seismic hazard due to its proximity to the Pacific subduction zone and active crustal faults, both capable of generating significant earthquakes. Furthermore, the city is located in an intermontane piggy-back basin prone to seismic wave amplification. To...

International audience

International audience

We investigate the rupture history of the three largest magnitude earthquakes of the 1997 Umbria-Marche sequence by inverting GPS, DInSAR and near-source strong motion waveforms. We use the frequency domain inversion procedure proposed by Cotton and Campillo (1995) and calculate the Green's functions for a layered half-space using the discrete...

The Ubaye Region is the most seismically active region in the Western Alps, with earthquakes that were commonly felt by the population and that even damaged local villages and cities. Since the 18th century, this area has been regularly struck by seismic swarms with high number of events, such as in 2003-2004 or 2012-2016 or by...

International audience

Summary In 1906, an earthquake with a magnitude estimated between Mw 8.4 and 8.8 occurred in the subduction zone along the coast of Ecuador and Colombia. This earthquake caused extensive damage on the coast but had a rather small impact on the capital city of Quito, situated 180 km away. At that time, the city of Quito extended over a small...

The upper part of the Ubaye Valley (French Alps) is characterized by alternating mainshock‐aftershock sequences and swarms. Particularly, during the 2012–2015 crisis, four mainshocks with Ml > 3.5 occurred. We here focus on the aftershocks of the largest one (Ml = 4.8, 7 April 2014), in order to better understand the involved processes behind...

The Ubaye Region is the most seismically active region in the Western Alps, with earthquakesthat were commonly felt by the population and that even damaged local villages and cities. Since thefirst testimonies in 1844, this area has been regularly struck by seismic swarms with a high number ofevents, such as in 2003–2004 or 2012–2015, or by...

The shallow Nice submarine slope is notorious for the 1979 tsunamigenic landslide that caused eight casualties and severe infrastructural damage. Many previous studies have tackled the question whether earthquake shaking would lead to slope failure and a repetition of the deadly scenario in the region. The answers are controversial. In this...