Showing papers by "Jürgen Mienert published in 2010"
TL;DR: The P-Cable 3D seismic system allows for high-resolution seismic imaging to characterize upper geosphere geological features focusing on geofluid expressions (gas chimneys), shallow gas and gas hydrate reservoirs as mentioned in this paper.
158 citations
TL;DR: In this article, travel-time inversion of wide-angle ocean-bottom seismic (OBS) data results in detailed P-wave velocity models of the shallow sub-seabed beneath the Nyegga pockmark field.
63 citations
TL;DR: A series of en echelon cracks run nearly parallel to the outer shelf edge of the mid-Norwegian margin this paper, where up to 10m-deep cracks developed in the seabed at 400-550m water depth.
Abstract: A series of en echelon cracks run nearly parallel to the outer shelf edge of the mid-Norwegian margin. The features can be followed in a ~60-km-long and ~5-km-wide zone in which up to 10-m-deep cracks developed in the seabed at 400–550 m water depth. The time of the seabed cracking has been dated to 7350 14C years BP (8180 cal years BP), which corresponds with the main Storegga Slide event (8100 ± 250 cal. years BP). Reflection seismic data suggest that the cracks do not appear to result from deep-seated faults, but it cannot be ruled out completely that tension crevices were created in relation to past movements on the headwall of the Storegga slide. The cracking zone corresponds well to the zone where the base of the hydrate stability zone (BHSZ) outcrops. Evidence of fluid release in the BHSZ outcrop zone comes from an extensive pockmark field. We suggest that post-glacial ocean warming triggered the dissociation of gas hydrates while the interplay between dissociation, overpressure, and sediment fracturing on the outer shelf remains to be understood.
23 citations
TL;DR: In this paper, an integrated study of the Nyegga site offshore mid-Norway, where a gas hydrate prospect is defined on the basis of a multitude of geophysical models and one shallow geotechnical borehole, is presented.
Abstract: Gas hydrates have lately received increased attention as a potential future energy source, which is not surprising given their global and widespread occurrence. This article presents an integrated study of the Nyegga site offshore mid-Norway, where a gas hydrate prospect is defined on the basis of a multitude of geophysical models and one shallow geotechnical borehole. This prospect appears to hold around 625GSm3 (GSm3 = 109 standard cubic metres) of gas. The uncertainty related to the input parameters is dealt with through a stochastic calculation, giving a spread of in-place volumes of 183GSm3 (P90) to 1431GSm3 (P10). The resource density for Nyegga is found to be comparable to published resource assessments of other global hydrate provinces.
15 citations
TL;DR: In this article, the role of sub seabed topographically controlled fluid migration is assessed to improve the understanding of distributions of acoustic chimneys at the Nyegga pockmark field on the mid-Norwegian continental margin.
12 citations
14 Jun 2010
TL;DR: In this article, two high resolution P-Cable 3D seismic cubes have been acquired in the Barents Sea in 2007 and 2009 to image shallow gas and fluid escape structures.
Abstract: Two high resolution P-Cable 3D seismic cubes have been acquired in the Barents Sea in 2007 and 2009 to image shallow gas and fluid escape structures. The cubes show that the technology is able to provide images of very high quality above the seabed multiple, comparable or even better than high resolution 2D but with the added benefit of 3D structural control. The new data are useful to map shallow geohazards and petroleum accumulations, and to understand the processes and implications of massive leakage of sediment-bound greenhouse gases.
3 citations