skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Submarine landslides triggered by destabilization of high-saturation hydrate anomalies: LANDSLIDES CAUSED BY HYDRATE ANOMALIES

Abstract

Submarine landslides occur along continental margins at depths that often intersect the gas hydrate stability zone, prompting suggestions that slope stability may be affected by perturbations that arise from changes in hydrate stability. Here we develop a numerical model to identify the conditions under which the destabilization of hydrates results in slope failure. Specifically, we focus on high-saturation hydrate anomalies at fine-grained to coarse-grained stratigraphic boundaries that can transmit bridging stresses that decrease the effective stress at sediment contacts and disrupt normal sediment consolidation. We evaluate slope stability before and after hydrate destabilization. Hydrate anomalies act to significantly increase the overall slope stability due to large increases in effective cohesion. However, when hydrate anomalies destabilize there is a loss of cohesion and increase in effective stress that causes the sediment grains to rapidly consolidate and generate pore pressures that can either trigger immediate slope failure or weaken the surrounding sediment until the pore pressure diffuses away. In cases where failure does not occur, the sediment can remain weakened for months. In cases where failure does occur, we quantify landslide dynamics using a rate and state frictional model and find that landslides can display either slow or dynamic (i.e., catastrophic) motionmore » depending on the rate-dependent properties, size of the stress perturbation, and the size of the slip patch relative to a critical nucleation length scale. Our results illustrate the fundamental mechanisms through which the destabilization of gas hydrates can pose a significant geohazard.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1]
  1. Univ. of Oregon, Eugene, OR (United States)
Publication Date:
Research Org.:
Univ. of Oregon, Eugene, OR (United States)
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1532978
Grant/Contract Number:  
FE0013565
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Geochemistry, Geophysics, Geosystems
Additional Journal Information:
Journal Volume: 18; Journal Issue: 7; Journal ID: ISSN 1525-2027
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; Geochemistry & Geophysics

Citation Formats

Handwerger, Alexander L., Rempel, Alan W., and Skarbek, Rob M. Submarine landslides triggered by destabilization of high-saturation hydrate anomalies: LANDSLIDES CAUSED BY HYDRATE ANOMALIES. United States: N. p., 2017. Web. doi:10.1002/2016gc006706.
Handwerger, Alexander L., Rempel, Alan W., & Skarbek, Rob M. Submarine landslides triggered by destabilization of high-saturation hydrate anomalies: LANDSLIDES CAUSED BY HYDRATE ANOMALIES. United States. doi:10.1002/2016gc006706.
Handwerger, Alexander L., Rempel, Alan W., and Skarbek, Rob M. Tue . "Submarine landslides triggered by destabilization of high-saturation hydrate anomalies: LANDSLIDES CAUSED BY HYDRATE ANOMALIES". United States. doi:10.1002/2016gc006706. https://www.osti.gov/servlets/purl/1532978.
@article{osti_1532978,
title = {Submarine landslides triggered by destabilization of high-saturation hydrate anomalies: LANDSLIDES CAUSED BY HYDRATE ANOMALIES},
author = {Handwerger, Alexander L. and Rempel, Alan W. and Skarbek, Rob M.},
abstractNote = {Submarine landslides occur along continental margins at depths that often intersect the gas hydrate stability zone, prompting suggestions that slope stability may be affected by perturbations that arise from changes in hydrate stability. Here we develop a numerical model to identify the conditions under which the destabilization of hydrates results in slope failure. Specifically, we focus on high-saturation hydrate anomalies at fine-grained to coarse-grained stratigraphic boundaries that can transmit bridging stresses that decrease the effective stress at sediment contacts and disrupt normal sediment consolidation. We evaluate slope stability before and after hydrate destabilization. Hydrate anomalies act to significantly increase the overall slope stability due to large increases in effective cohesion. However, when hydrate anomalies destabilize there is a loss of cohesion and increase in effective stress that causes the sediment grains to rapidly consolidate and generate pore pressures that can either trigger immediate slope failure or weaken the surrounding sediment until the pore pressure diffuses away. In cases where failure does not occur, the sediment can remain weakened for months. In cases where failure does occur, we quantify landslide dynamics using a rate and state frictional model and find that landslides can display either slow or dynamic (i.e., catastrophic) motion depending on the rate-dependent properties, size of the stress perturbation, and the size of the slip patch relative to a critical nucleation length scale. Our results illustrate the fundamental mechanisms through which the destabilization of gas hydrates can pose a significant geohazard.},
doi = {10.1002/2016gc006706},
journal = {Geochemistry, Geophysics, Geosystems},
issn = {1525-2027},
number = 7,
volume = 18,
place = {United States},
year = {2017},
month = {5}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share: