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| Mazzullo, Alessandro; Stutzmann, Eleonore; Montagner, Jean-paul; Kiselev, Sergey; Maurya, Satish; Barruol, Guilhem; Sigloch, Karin. |
| In the western Indian Ocean, the Reunion hot spot is one of the most active volcanoes on Earth. Temporal interactions between ridges and plumes have shaped the structure of the zone. This study investigates the mantle structure using data from the Reunion Hotspot and Upper Mantle-Reunions Unterer Mantel (RHUM-RUM) project, which significantly increased the seismic coverage of the western part of the Indian Ocean. For more than 1year, 57 ocean bottom seismometer stations and 23 temporary land stations were deployed over this area. For each earthquake station path, the Rayleigh wave fundamental mode phase velocities were measured for the periods from 30s to 300s and group velocities for the period from 16s to 250s. A three-dimensional model of the shear... |
| Tipo: Text |
Palavras-chave: Tomography; Indian Ocean; Seismic anisotropy; Hot spot ridge; Upper mantle. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00600/71180/69533.pdf |
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| Hable, Sarah; Sigloch, Karin; Stutzmann, Eleonore; Kiselev, Sergey; Barruol, Guilhem. |
| We use seismic noise cross-correlations to obtain a 3-D tomography model of SV-wave velocities beneath the western Indian Ocean, in the depth range of the oceanic crust and uppermost mantle. The study area covers 2000×2000 km2 between Madagascar and the three spreading ridges of the Indian Ocean, centred on the volcanic hotspot of La Réunion. We use seismograms from 38 ocean bottom seismometers (OBSs) deployed by the RHUM-RUM project and 10 island stations on La Réunion, Madagascar, Mauritius, Rodrigues, and Tromelin. Phase cross-correlations are calculated for 1119 OBS-to-OBS, land-to-OBS, and land-to-land station pairs, and a phase-weighted stacking algorithm yields robust group velocity measurements in the period range of 3-50 s. We demonstrate that OBS... |
| Tipo: Text |
Palavras-chave: Crustal imaging; Seismic instruments; Seismic interferometry; Seismic noise; Seismic tomography. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00508/61988/66099.pdf |
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| Hable, Sarah; Sigloch, Karin; Barruol, Guilhem; Staehler, Simon C.; Hadziioannou, Celine. |
| Many applications in seismology rely on the accurate absolute timing of seismograms. However, both seismological land stations and ocean bottom seismometers (OBSs) can be affected by clock errors, which cause the absolute timing of seismograms to deviate from a highly accurate reference time signal, usually provided by GPS satellites. Timing problems can occur in land stations when synchronization with a GPS signal is temporarily or permanently lost. This can give rise to complicated, time-dependent clock drifts relative to GPS time, due to varying environmental conditions. Seismometers at the ocean bottom cannot receive GPS satellite signals, but operate in more stable ambient conditions than land stations. The standard protocol is to synchronize an OBS... |
| Tipo: Text |
Palavras-chave: Time-series analysis; Seismic instruments; Seismic interferometry; Seismic noise. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00444/55599/57230.pdf |
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| Barruol, Guilhem; Sigloch, Karin. |
| Whether volcanic intraplate hot spots are underlain by deep mantle plumes continues to be debated 40 years after the hypothesis was proposed by Morgan [1972]. Arrivals of buoyant plume heads may have been among the most disruptive agents in Earth's history, initiating continental breakup, altering global climate, and triggering mass extinctions. Further, with the temporary shutdown of European air traffic in 2010 caused by the eruption of Eyjafjallajökull, a geologically routine eruption in the tail end of the presumed Iceland plume, the world witnessed an intrusion of hot spot activity into modern-day life. |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00273/38465/36874.pdf |
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