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| Tang, Genyang; Barton, Penny J.; Mcneill, Lisa C.; Henstock, Timothy J.; Tilmann, Frederik; Dean, Simon M.; Jusuf, Muhammad D.; Djajadihardja, Yusuf S.; Permana, Haryadi; Klingelhoefer, Frauke; Kopp, Heidrun. |
| We present a detailed 3-D P-wave velocity model obtained by first-arrival travel-time tomography with seismic refraction data in the segment boundary of the Sumatra subduction zone across Simeulue Island, and an image of the top of the subducted oceanic crust extracted from depth-migrated multi-channel seismic reflection profiles. We have picked P-wave first arrivals of the air-gun source seismic data recorded by local networks of ocean-bottom seismometers, and inverted the travel-times for a 3-D velocity model of the subduction zone. This velocity model shows an anomalous zone of intermediate velocities between those of oceanic crust and mantle that is associated with raised topography on the top of the oceanic crust. We interpret this feature as a... |
| Tipo: Text |
Palavras-chave: Active-source tomography; Sumatra subduction zone; Segmentation; Plate interface. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00137/24834/22916.pdf |
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| Goswami, Bedanta K.; Weitemeyer, Karen A.; Minshull, Timothy A.; Sinha, Martin C.; Westbrook, Graham; Chabert, Anne; Henstock, Timothy J.; Ker, Stephan. |
| We acquired coincident marine controlled-source electromagnetic (CSEM), high-resolution seismic reflection and ocean-bottom seismometer (OBS) data over an active pockmark in the crest of the southern part of the Vestnesa Ridge, to estimate fluid composition within an underlying fluid-migration chimney. Synthetic model studies suggest resistivity obtained from CSEM data can resolve gas or hydrate saturation greater than 5% within the chimney. Acoustic chimneys imaged by seismic reflection data beneath the pockmark and on the ridge flanks, were found to be associated with high-resistivity anomalies (+2-4 m). High-velocity anomalies (+0.3 km/s), within the gas hydrate stability zone (GHSZ) and low-velocity anomalies (-0.2 km/s) underlying the GHSZ, were also... |
| Tipo: Text |
Palavras-chave: Gas hydrate; Svalbard; CSEM; Saturation; Pockmark; Vestnesa. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00283/39458/37928.pdf |
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