Three-dimensional seismic analysis of the morphology and spatial distribution of chimneys beneath the Nyegga pockmark field, offshore mid-Norway

摘要: Three-dimensional (3D) seismic data analysis has identified 415 chimneys in the Nyegga area, on mid-Norwegian continental margin. The majority of connect with pockmarks at modern seafloor, suggesting that represent acoustic imprint highly focused, cross-stratal fluid flow. A semi-quantitative spatial chimney complex, measuring parameters describing dimension, geometry and root zone, provides constraints geological controls formation. Most region descriptively fall into categories ‘blowout chimneys’, because they diagnostically link to topography-controlled leakage locations within strata showing indications free gas. We find approximately 60% fluid-escape emanate from gas layers below hydrate stability zone. timing focused expulsion through formation pockmark field postdate last glacial maximum 25 000 years before present.