It was proposed that erosion of subsea ridges on the Hikurangi margin may be linked to a
fluctuating level of the top of gas hydrate stability in the ocean. Since publication of this
hypothesis, three field campaigns were conducted in the study area. Here we summarize relevant
results from these cruises. We found that water temperature fluctuations occur at lower
frequencies and higher amplitudes than previously thought, making it more likely that
temperature changes reach sub-seafloor gas hydrates. Dredge samples encountered numerous
consolidated mudstones. We speculate that gas hydrate “freeze-thaw” cycles may lead to dilation
of fractures in mudstones due to capillary forces, weakening the seafloor. Ubiquitous gas pockets
beneath the ridge may lead to overpressure that may also contribute to seafloor fracturing.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/1551 |
| Date | 07 1900 |
| Creators | Pecher, Ingo A., Henrys, Stuart A., Ellis, Susan, Crutchley, Gareth, Fohrmann, Miko, Gorman, Andrew R., Greinert, Jens, Chiswell, Stephen M., TAN0607 Scientific Party, SO191 Scientific Party |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Rights | Pecher, Ingo A. |
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