|
|
|
|
|
| Ioualalen, Mansour; Ratzov, G.; Collot, Jean-yves; Sanclemente, E.. |
| P>Shelf promontories exhibit very specific bathymetric features with regards to tsunamis. Because of their submerged cape morphology, a potential tsunami generated seawards of the promontory will exhibit a specific mode of propagation and coastal impact. To identify this peculiar tsunami signature, the Atacames Promontory, Ecuador, was chosen as a case study (another example is the shelf of the Nile delta, Egypt). The area is tectonically very active, hosts earthquakes among the most powerful recorded, as well as areas of slope instabilities that have triggered significant submarine landslides in the past (several cubic kilometres of volume). Both types of events are likely to be tsunamigenic. To examine the tsunami behaviour at the coastal area of the... |
| Tipo: Text |
Palavras-chave: Tsunamis; Site effects; Wave propagation; Submarine landslides; South America. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00200/31101/29509.pdf |
| |
|
|
| Lamarche, Geoffroy; Joanne, Cathy; Collot, Jean-yves. |
| Four > 100 km(3) mass-transport deposits (MTDs) identified from their morphology and seismic facies across the Matakaoa Margin and Raukumara fore-arc basin, NE New Zealand, constitute the Matakaoa Submarine Instability Complex (MSIC). MSIC originates from a 45-km-wide, 1100-m-high reentrant in the continental slope. The deposits resulted from three mass-failure events: ( 1) The Raukumara Slump is identified from the collapsed NW flank of an anticline at the northern end of the reentrant and imbricate structures at its distal end, overlying a flat decollement over a > 50-km distance. The slump age is roughly estimated between upper Miocene and lower Pleistocene. (2) The Matakaoa Debris Avalanche (MDA) is subdivided into a similar to 260-km(3) blocky... |
| Tipo: Text |
Palavras-chave: Submarine landslide; Debris flow; Slump; Debris avalanche; Raukumara Basin; Hikurangi Margin. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34861/33203.pdf |
| |
|
|
| Collot, Jean-yves; Ratzov, Gueorgui; Silva, P.; Proust, J.‐n.; Migeon, Sebastien; Hernandez, M.‐j.; Michaud, F.; Pazmino, A.; Barba Castillo, D.; Alvarado, A.; Khumara, S.. |
| Deciphering the migration pattern of the Esmeraldas submarine Canyon (EC) and its history of cut‐and‐fill allows constraining the Pliocene‐Pleistocene tectonic evolution of the Ecuador‐Colombia convergent margin. Swath bathymetry, multichannel seismic reflection and chronological data show that the EC is a 143‐km–long, shelf‐incising, river‐connected canyon that started incising slope apron deposits in the Manglares fore‐arc basin ~ 5.3 Ma ago. The EC inception appears contemporaneous with the subduction of the Carnegie Ridge that is believed to have initiated 5‐6 Myr ago and is considered an indirect cause of the EC formation. During its two‐stage left‐lateral migration, the EC upper‐half scoured deep incisions providing evidences for uplift episodes in... |
| Tipo: Text |
Palavras-chave: Convergent margin tectonics; Submarine canyon; Fore-arc basin; Natural hazards; Paleoseismology. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62060/66236.pdf |
| |
|
|
| Collot, Jean-yves; Ribodetti, A.; Agudelo, W.; Sage, F.. |
| Tectonic processes that control the transition from poorly consolidated sediment entering the subduction channel (SC) to the seismogenic zone are documented using seismic imaging. We applied pre-stack depth migration and a post-processing sequence to a seismic reflection line acquired across the Ecuador convergent margin to obtain a 2D-quantitative image of the first similar to 24 km of the SC. Structural interpretation shows that the SC consists of a 630-1150-m-thick, low-velocity, continuous sheet of sediment that dips similar to 6 degrees landward and undergoes shear deformation. The long sheet is bounded at top and bottom by decollement thrusts, and developed over time Riedel shears and basal thrust faulting and folding downdip, pointing to a dynamic... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00200/31096/29514.pdf |
| |
|
|
|
