Measurements of Ground Movement on Mount Etna, Sicily: A Systematic Plan to Record Different Temporal and Spatial Components of Ground Movement Associated with Active Volcanism

International audienc

Dissipation of Ultrasonic and Audible Sound Waves in Liquid Foams

International audienc

The 1986 Kalamata (South Peloponnesus) Earthquake: Detailed Study of a Normal Fault, Evidences for East-West Extension in the Hellenic Arc

International audienceTectonic and seismological data collected in the field following the September 13, 1986, Kalamata earthquake (south Peloponnesus) are presented and analyzed to discuss the earthquake rupture process and the regional tectonics. The event occurred on the Kalamata normal fault whose trace was mapped with SPOT images and topographic and field observations. This fault is part of an approximately NNW-SSE en •chelon system cutting through the Hellenic nappes. The fault striking N15°E on the average, with a dip of about 50°, has a minimum cumulated Quaternary throw of the order of 1 km. The measured coseismic slip is 6-18 cm over a length of 6 km. The main shock focal mechanism obtained from long-period waveform modeling (strike=201° (+ 10 °, -20°), dip=45°+/- 5°, rake= 283° (+ 10°, -25°)) represents almost pure east-west extension and is in good agreement with tectonic observations. The centroid depth is constrained to 5+/-3 km and the seismic moment to 7.0 +/- 2.5 x 10+17 N m. Over 700 aftershocks, located by a 16-station network installed after the earthquake for a period of 2 weeks, define two clusters separated by a "gap" of aftershock activity, from the surface to a depth of about 10 km. The main cluster, to the south, defines a 45° west dipping plane which lies on the downward extension of the fault mapped at the surface. Focal mechanisms of aftershocks on this fault plane are homogeneous and represent E-W extension as the main shock. In contrast, the majority of focal mechanisms in the uppermost part of the footwall show more or less E-W compression, probably corresponding to postseismic stress release. The northern cluster of aftershocks is very dense and located away from the surface rupture, within a relay zone between the Kalemate and the next en échelon faults to the NW, the Thouria faults. There focal mechanisms represent extension from about N115° to N70° and N20°, corresponding mostly to fault reactivation in an area where nonrigid deformations prevail. The main shock probably initiated in this relay zone 3-4 s before the rupture front reached the main fault plane and released most of the energy there, the rupture presumably propagating southward. The focal mechanism of the Kalamata earthquake and that of the April 27, 1965, earthquake located to the northwest of Crete, as well as the regional active normal fault pattern, imply that E-W extension oblique to the Hellenic arc is presently the dominant tectonic regime. E-W stretching occurs partly on reactivated NW-SE faults parallel to the Hellenic structures but mostly on newly formed N-S normal faults across those structures. The latter faults are responsible for the apparent segmentation of the Hellenic belt from southern Peloponnesus to Crete. The existence of active E-W extension in this region implies a recent change in the tectonic regime and consequently a change in boundary conditions at the subduction zone, probably in response to the incoming margin of Africa

Acoustic absorption of solid foams with thin membranes

International audienceWe measured the acoustic absorption, in the 0.5–6 kHz frequency range, of polyurethane foams with mean pore diameters between 0.6 and 3.2 mm. Two types of foams were investigated: classical open-cell ones versus membrane foams, in which thin polyurethane membranes were preserved during solidification. Interestingly, the latter presented better absorption abilities, indicating that membranes could be an asset for sound absorption

Regiospecific solid-phase strategy to N7-substituted purines and its application to 8-azapurines and [i]-condensed purines

10.1021/cc7000919Journal of Combinatorial Chemistry95804-810JCCH

Microseismicity surveys of the fault-systems of S. E. Spain

Three microseismicity surveys were carried out in 1982, 1984 and 1985 in south-east Spain. The main survey was in 1984 with 24 seismic recording stations installed during 41 days. A total of 103 earthquakes were recorded with magnitudes between 0.5 and 3.9. Epicenters can be associated to faults in the area, which are shown to be seismically active. Larger activity is concentrated at the southern part of the area. Joint fault plane solutions show mecanism of fault with vertical motion of normal and reverse character.Part of this work has been supported by the DGICT, project PB-86-0431-C05 and the Comité Conjunto Hispano-Norteamericano para la cooperación cientifica y tecnologíca project CCA-8309/009.Peer reviewe

BRAF inhibitors based on an imidazo[4,5]pyridin-2-one scaffold and a meta substituted middle ring

We recently reported on the development of a novel series of BRAF inhibitors based on a tripartite A-B-C system characterized by a para-substituted central aromatic core connected to an imidazo[4,5]pyridin-2-one scaffold and a substituted urea linker. Here, we present a new series of BRAF inhibitors in which the central phenyl ring connects to the hinge binder and substrate pocket of BRAF with a meta-substitution pattern. The optimization of this new scaffold led to the development of lownanomolar inhibitors that permits the use of a wider range of linkers and terminal C rings while enhancing the selectivity for the BRAF enzyme in comparison to the para series. © 2010 American Chemical Society