Role of Gas Hydrate and its Migration Pathways in Submarine Slope Failures: East Indian Margin

Gas hydrates are icelike compounds composed of water and methane gas in very compact form. There is substantial evidence from case histories that links gas hydrate dissociation to submarine slope failures and other geohazards. Theoretical analyses have also shown that upon dissociation gas hydrates will cause an increase in fluid pressure and a reduction in effective stress and thus result in loss of the soil strength. This paper presents a preliminary quantification of the effects of gas hydrate dissociation through development of a pore-pressure model that was incorporated into one- and two-dimensional slope stability analyses. The ensuing numerical study investigated submarine slope stability through parametric studies and application to two important case histories and found that dissociation of even small amounts of hydrate can have a significant destabilizing effect. Yet whether gas hydrate dissociation can alone cause large-scale slope failures has still to be demonstrated as there are often many destabilizing processes; however, this research highlights the importance of assessing the effects of gas hydrate dissociation on the behaviour of submarine slopes.Key words: gas hydrates, slope stability, marine, offshore, methane gas, instability.

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Potential role of compressional structures in generating submarine slope failures in the Niger Delta

Marine Geology ◽

10.1016/j.margeo.2006.11.002 ◽

2007 ◽

Vol 237 (3-4) ◽

pp. 169-190 ◽

Cited By ~ 33

Author(s):

N. Sultan ◽

M. Voisset ◽

B. Marsset ◽

T. Marsset ◽

E. Cauquil ◽

...

Keyword(s):

Niger Delta ◽

Potential Role ◽

Slope Failures ◽

Submarine Slope

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Self-Preservation of Gas Hydrate Particles Suspended in Crude Oils and Liquid Hydrocarbons: Role of Preparation Method, Dispersion Media, and Hydrate Former

Energy & Fuels ◽

10.1021/acs.energyfuels.6b01531 ◽

2016 ◽

Vol 30 (11) ◽

pp. 9014-9021 ◽

Cited By ~ 12

Author(s):

Andrey S. Stoporev ◽

Andrey Yu. Manakov ◽

Lubov’ K. Altunina ◽

Larisa A. Strelets

Keyword(s):

Gas Hydrate ◽

Preparation Method ◽

Crude Oils ◽

Liquid Hydrocarbons ◽

Dispersion Media

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Numerical Study of Tsunami Generated by Multiple Submarine Slope Failures in Resurrection Bay, Alaska, during the M w 9.2 1964 Earthquake

Tsunami Science Four Years after the 2004 Indian Ocean Tsunami ◽

10.1007/978-3-0346-0064-4_8 ◽

2009 ◽

pp. 131-152 ◽

Cited By ~ 1

Author(s):

Elena Suleimani ◽

Roger Hansen ◽

Peter J. Haeussler

Keyword(s):

Numerical Study ◽

Slope Failures ◽

Submarine Slope

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Along-Strike Migration of Intermittent Submarine Slope Failures at Subduction Margins: Geological Evidence from the Chikura Group, Central Japan

Submarine Mass Movements and Their Consequences - Advances in Natural and Technological Hazards Research ◽

10.1007/978-3-319-00972-8_49 ◽

2013 ◽

pp. 551-560 ◽

Cited By ~ 5

Author(s):

Yuzuru Yamamoto ◽

Shunsuke Kawakami

Keyword(s):

Slope Failures ◽

Central Japan ◽

Geological Evidence ◽

Submarine Slope

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Investigating the controls of submarine landslides and associated hazards in Pangnirtung Fiord, Eastern Baffin Island (Nunavut)

10.5194/egusphere-egu21-13364 ◽

2021 ◽

Author(s):

Philip Sedore ◽

Alexandre Normandeau ◽

Vittorio Maselli

Keyword(s):

High Latitude ◽

Debris Flows ◽

Slope Failure ◽

Recurrence Time ◽

High Recurrence Rate ◽

Baffin Island ◽

Submarine Landslides ◽

Slope Failures ◽

Near Surface ◽

Submarine Slope

High-latitude fiords are susceptible to hazardous subaerial and submarine slope failures. Recent investigations have shown that past slope failures in fiords of Greenland and Alaska have generated devastating landslide induced tsunamis. Since coastal communities inhabit these high-latitude fiords, it is critical to understand the slope failure recurrence time, their distribution, potential triggers, and ability to generate tsunamis. In this study, we identified > 50 near-surface submarine landslides in Pangnirtung Fiord, eastern Baffin Island, Nunavut, using multibeam bathymetric and sub-bottom profiler data, along with sediment gravity-cores collected in 2019. Morphometric and morphological analyses, along with sedimentological analyses, were carried out on submarine landslide deposits to quantify their spatial and temporal distribution throughout the fiord and to evaluate the factors that may have triggered the slope failures.Combining bathymetric with topographic data from unmanned aerial vehicle imagery, we found that most of these landslide deposits are relatively small (~ 0.08 km2) and are associated with outwash fans and steep fiord sidewalls. However, since most slope failure head scarps lie between the intertidal zone and ~30 m water depth, they could not be mapped, which makes it challenging to determine the triggers of the submarine slope failures. Radiocarbon dating reveals that most of these surficial landslide deposits are younger than 500 years old and that they were most likely triggered at different times. This finding highlights a high recurrence rate of slope failures within the fiord, suggesting that localised triggers are responsible for slope failures within the fiord, as opposed to widespread, seismically induced triggers which do not occur as frequently in the study area. In addition, the elongated morphology of the landslide deposits and the varying degrees of landslide deposit surface roughness supports localised point-source triggers. Since most landslides are associated with subaerial outwash fans and deltas, we suggest that triggers of these relatively frequent submarine landslides within Pangnirtung Fiord include rapid floodwater input, subaerial debris flows, and sea-ice loading during low tide.This research shows that slope failures in a high-latitude fiord are affected by the interaction of numerous subaerial and submarine processes, leading us to speculate that a potential increase in the frequency of subaerial debris flows and river floods due to climate change may increase the recurrence of submarine landslides.

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