|
|
|
|
|
| Tsang-hin-sun, Eve; Royer, Jean-yves; Perrot, Julie. |
| Volcanic and tectonic events are the main processes involved in the generation of the oceanic crust and responsible for the seismicity associated with seafloor spreading. To monitor this activity, usually not or poorly detected by land-based seismological stations, we deployed from February 2012 to February 2013 a network of autonomous hydrophones to compare the behaviour of the ultraslow-spreading Southwest (SWIR) with that of the intermediate-spreading Southeast Indian ridges (SEIR). The rate of seismicity is similar for both ridges, suggesting that there is no systematic relationship between seismicity and spreading rates. The along-axis distribution of the seismic events, however, does differ, reflecting the rate-dependence of accretion modes.... |
| Tipo: Text |
Palavras-chave: Seismicity and tectonics; Acoustic properties; Mid-ocean ridge processes; Indian Ocean. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00340/45165/44559.pdf |
| |
|
|
| Douillet, G. A.; Taisne, B.; Tsang-hin-sun, Eve; Mueller, S. K.; Kueppers, U.; Dingwell, D. B.. |
| Soft-sediment deformation structures can provide valuable information about the conditions of parent flows, the sediment state and the surrounding environment. Here, examples of soft-sediment deformation in deposits of dilute pyroclastic density currents are documented and possible syn-eruptive triggers suggested. Outcrops from six different volcanoes have been compiled in order to provide a broad perspective on the variety of structures: SoufriSre Hills (Montserrat), Tungurahua (Ecuador), Ubehebe craters (USA), Laacher See (Germany), and Tower Hill and Purrumbete lakes (both Australia). The variety of features can be classified in four groups: (1) tubular features such as pipes; (2) isolated, laterally oriented deformation such as overturned or... |
| Tipo: Text |
|
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00639/75156/75425.pdf |
| |
|
| |
|
|
| Tsang-hin-sun, Eve; Evain, Mikael; Julia, J; Lamarque, G; Schnurle, Philippe. |
| This study investigates the seismic structure and anisotropy in the crust beneath Madagascar and south-eastern Africa, using receiver functions. The understanding of seismic anisotropy is essential for imaging past and present deformation in the lithosphere-asthenosphere system. In the upper mantle, seismic anisotropy mainly results from the orientation of olivine, which deforms under tectonic (fossil anisotropy) or flow processes (in the asthenosphere). In the crust, the crystallographic alignment of amphiboles, feldspars(plagioclase) or micas or the alignment of heterogeneities such as fractures, add to a complex geometry, which results in challenges to understanding the Earth's shallow structure. The decomposition of receiver functions into back-azimuth... |
| Tipo: Text |
Palavras-chave: Crustal seismic anisotropy; Inherited structural heterogeneities; Crustal stress; Receiver function harmonics; Madagascar; Africa; EARS. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00686/79843/82668.pdf |
| |
|
|
|
