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Nodder, Scott D.; Lamarche, Geoffroy; Proust, Jean-noel; Stirling, Mark. |
[1] Seafloor fault scarps and near-surface deformation of late Quaternary seismic reflectors occur along the eastern margin of the Wanganui Basin, 200 km behind the active Hikurangi subduction front, southern North Island, New Zealand. The offshore scarps are associated with the low-strain, compressional Kapiti-Manawatu Fault System (KMFS), which comprises high-angle (> 60 degrees) reactivated reverse and normal faults oriented NE-SW, highly oblique to the coast. Seafloor scarps range from < 10 to 50 km in length with vertical seafloor offsets of 2 to 30 m. The longest structure is the Mascarin Fault, with maximum late Quaternary vertical slip rates of 3 mm a(-1) (where a is years). Other faults in the KMFS have typical rates of < 1 mm a(-1),... |
Tipo: Text |
Palavras-chave: Hikurangi subduction zone; Active normal fault; Wanganui basin; Surface rupture; North island; Seismic hazard; Wellington region; Taranaki basin; Ohariu fault; Cook strait. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00207/31839/30253.pdf |
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Courboulex, Francoise; Mercerat, E. Diego; Deschamps, Anne; Migeon, Sebastien; Baques, Marion; Larroque, Christophe; Rivet, Diane; Hello, Yann. |
A broadband seismological station (PRIMA) installed offshore Nice airport (southeastern France) reveals a strong amplification effect of seismic waves. PRIMA station was in operation for 2 years (9/2016 to 10/2018) on the outer shelf at a water depth of 18 m. Situated at the mouth of the Var River, this zone is unstable and prone to landslides. A catastrophic landslide and tsunami already occurred in 1979, causing 10 casualties. Given the level of seismicity of the area, it is important to infer the impact of an earthquake on this zone. We analyze the recordings of earthquakes and seismic noise at the PRIMA station by comparing them to nearby inland stations. We find that the seismic waves are strongly amplified at PRIMA at some specific frequencies (with... |
Tipo: Text |
Palavras-chave: Earthquakes; Site effects; Landslides; Offshore seismometer; Seismic hazard. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77081/78405.pdf |
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Gasperini, Luca; Stucchi, Massimiliano; Cedro, Vincenzo; Meghraoui, Mustapha; Ucarkus, Gulsen; Polonia, Alina. |
A new analysis of high-resolution multibeam and seismic reflection data, collected during several oceanographic expeditions starting from 1999, allowed us to compile an updated morphotectonic map of the North Anatolian Fault below the Sea of Marmara. We reconstructed kinematics and geometries of individual fault segments, active at the time scale of 10 ka, an interval which includes several earthquake cycles, taking as stratigraphic marker the base of the latest marine transgression. Given the high deformation rates relative to sediment supply, most active tectonic structures have a morphological expression at the seafloor, even in presence of composite fault geometries and/or overprinting due to mass-wasting or turbidite deposits. In the frame of the... |
Tipo: Text |
Palavras-chave: North Anatolian fault; Sea of Marmara; Earthquakes; Active fault segments; Marine geophysics; Seismic hazard. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00684/79575/82244.pdf |
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