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Martigné-Briand, France

Tissoux H.,French Natural History Museum | Tissoux H.,CEA Saclay Nuclear Research Center | Valladas H.,CEA Saclay Nuclear Research Center | Voinchet P.,French Natural History Museum | And 6 more authors.
Quaternary Geochronology | Year: 2010

As part of a chronological study of the famous Upper Pleistocene Nussloch (Germany) loess sequence, three samples were collected to check the applicability of palaeodosimetric dating methods (OSL and ESR) to quartz grains. The ESR-multicentre method showed a partial bleaching of the ESR centers in aeolian sands. This partial bleaching was also observed by OSL. Laminated loess seemed to be sufficiently bleached but showed a large scatter of the doses, which we ascribed to heterogeneous responses of the luminescent grains to the SAR protocol. Ages could nevertheless be calculated for the three samples and were found to be somewhat older than the IRSL and 14C ages obtained for the same layers of the laminated loess. © 2009 Elsevier Ltd. All rights reserved.

Evelpidou N.,French National Center for Scientific Research | Karkani A.,National and Kapodistrian University of Athens | Kazmer M.,Eotvos Lorand University | Pirazzoli P.,Laboratoire Of Geographie Physique
Geologica Acta | Year: 2016

Fossil shorelines produced by recent co-seismic movements were identified through a submarine survey along the coasts of Ithaca and Fiscardo (Greece). In both areas a tidal notch-slightly submerged below present Mean Sea Level (MSL) was observed at various sites. This “modern” notch is known to have been submerged by the global sea-level rise during the 19th and 20th centuries. The depth after tide and air-pressure correction of the vertex of the “modern” notch (that owes its submergence to the current rapid sea level rise) was measured between -20 and -30±5cm at Fiscardo and between -36 and -45±6cm at Ithaca. This “modern” notch at the same depth on east and west sides of the Ionian Thrust suggests that both areas were not affected by the co-seismic vertical movements that occurred in 1953 (in the wider area). On the other hand, a greater depth in Ithaca could be an effect of co-seismic subsidence. Over the long term, the tectonic behavior of Ithaca differs from Fiscardo. At Ithaca no evidence of emergence was found and Holocene vertical movements have been only of subsidence: submerged fossil tidal notches were distinguished below MSL at about -40 (modern), -60, -75, -95, -106, -126, -150 and -220±6cm. On the East coast of Fiscardo peninsula impacts of ancient earthquakes have left some marks of emergence at about +18 and +44±5cm, and of submergence at about -25 (modern), -45, -60, -75, -82, -100 and -230cm, with even some evidence of past uplift and subsidence at the same sites. © 2016, Universitat de Barcelona. All rights reserved.

Jousset P.,Bureau de Recherches Geologiques et Minieres | Pallister J.,U.S. Geological Survey | Boichu M.,University of Cambridge | Buongiorno M.F.,Isituto Nazionale di Geofisica e Vulcanologia | And 14 more authors.
Journal of Volcanology and Geothermal Research | Year: 2012

Merapi volcano (Indonesia) is one of the most active and hazardous volcanoes in the world. It is known for frequent small to moderate eruptions, pyroclastic flows produced by lava dome collapse, and the large population settled on and around the flanks of the volcano that is at risk. Its usual behavior for the last decades abruptly changed in late October and early November 2010, when the volcano produced its largest and most explosive eruptions in more than a century, displacing at least a third of a million people, and claiming nearly 400 lives. Despite the challenges involved in forecasting this 'hundred year eruption', we show that the magnitude of precursory signals (seismicity, ground deformation, gas emissions) was proportional to the large size and intensity of the eruption. In addition and for the first time, near-real-time satellite radar imagery played an equal role with seismic, geodetic, and gas observations in monitoring eruptive activity during a major volcanic crisis. The Indonesian Center of Volcanology and Geological Hazard Mitigation (CVGHM) issued timely forecasts of the magnitude of the eruption phases, saving 10,000-20,000 lives. In addition to reporting on aspects of the crisis management, we report the first synthesis of scientific observations of the eruption. Our monitoring and petrologic data show that the 2010 eruption was fed by rapid ascent of magma from depths ranging from 5 to 30km. Magma reached the surface with variable gas content resulting in alternating explosive and rapid effusive eruptions, and released a total of ~0.44Tg of SO2. The eruptive behavior seems also related to the seismicity along a tectonic fault more than 40km from the volcano, highlighting both the complex stress pattern of the Merapi region of Java and the role of magmatic pressurization in activating regional faults. We suggest a dynamic triggering of the main explosions on 3 and 4 November by the passing seismic waves generated by regional earthquakes on these days. © 2012 Elsevier B.V.

Evelpidou N.,National and Kapodistrian University of Athens | Koutsomichou I.,National and Kapodistrian University of Athens | Pirazzoli P.A.,Laboratoire Of Geographie Physique
Continental Shelf Research | Year: 2013

Through this research relative sea level changes from Late Holocene until the present day were studied, in the area of Skopelos and Alonnisos Islands. The study was accomplished through methodical underwater geomorphological research in both islands and led to the location of six and seven distinct submerged fossil shorelines, in Skopelos and Alonnisos accordingly, along the islands' coastline. Both islands have been affected during the last millennia, by repeated subsidence events, often of coseimic origin. The amount of each subsidence displacement was generally limited to one or a few decimetres, with recurrence intervals of some centuries. © 2013 Elsevier Ltd.

Evelpidou N.,National and Kapodistrian University of Athens | Vassilopoulos A.,Geoenvironmental Institute | Pirazzoli P.A.,Laboratoire Of Geographie Physique
Marine Geology | Year: 2012

Detailed mapping along the northwestern coastline of Euboea has provided new evidence of colonization by Lithophaga lithophaga (L.) reaching about 3.8. m above the present biological MSL. Such marine biological marks, together with morphological notches, correspond to the occurrence of two sequences of Holocene vertical displacements higher than those reported by previous studies, on the central part of the southern coast and along the northern coast of the island. A well developed emerged notch is found at + 1.7 ± 0.1. m above present mean sea level, whereas the uppermost part of the lithophagid holes suggest a former emerged shoreline at least at + 3.8 ± 0.1. m. Radiocarbon AMS dating of Lithophaga shells found in their burrows, showed that the lower uplifted shoreline corresponds to a tectonic event (probably coseismic) apparently dated at 2200 a BP, while the higher shoreline corresponds to an older relative sea-level transgression, possibly of tectonic origin, apparently dated about 5570 a BP. The apparent radiocarbon age of lithophagid shells can be about 350 to 400. years older than the uplift event that exposed them, due to incorporation of host-rock carbon. Nevertheless, the two new paleoshorelines provide evidence that repeated uplift movements, greater than those reported by previous authors, occurred during the late Holocene, uplifting the western part of the island. © 2011 Elsevier B.V.

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