Assessing post-failure mobility of submarine landslides from seismic geomorphology and physical properties of mass transport deposits: An example from seaward of the Kumano Basin, Nankai Trough, offshore Japan

2016 ◽  
Vol 374 ◽  
pp. 73-84 ◽  
Author(s):  
Zachary T. Moore ◽  
Derek E. Sawyer
Keyword(s):  
Mass Transport ◽  
Physical Properties ◽  
Nankai Trough ◽  
Submarine Landslides ◽  
Seismic Geomorphology ◽  
Kumano Basin ◽  
Mass Transport Deposits

scholarly journals IODP Expedition 333: Return to Nankai Trough Subduction Inputs Sites and Coring of Mass Transport Deposits

2012 ◽  
Vol 14 ◽  
pp. 4-17 ◽  
Author(s):  
P. Henry ◽  
T. Kanamatsu ◽  
K. T. Moe ◽  
M. Strasser ◽  
Keyword(s):  
Heat Flow ◽  
Mass Transport ◽  
Nankai Trough ◽  
Seismogenic Zone ◽  
Ocean Drilling Program ◽  
Flow Measurements ◽  
Integrated Ocean Drilling Program ◽  
Shikoku Basin ◽  
Lower Temperature ◽  
Mass Transport Deposits

Integrated Ocean Drilling Program (IODP) Expedition 333 returned to two sites drilled during IODP Expedition 322 on the ocean side of the Nankai Trough to pursue the characterization of the inputs to the Nankai subduction and seismogenic zone, as part of the Nankai Trough Seismogenic Experiment (NanTroSEIZE) multi-expedition project. Site C0011 is located at the seaward edge of the trench and Site C0012 on a basement high, Kashinozaki Knoll (Fig. 1). The main objectives of drilling again at these sites were to fill coring gaps in the upper part (<350 m) of the sedimentary sequence, to measure heat flow, and to core the oceanic basement to a greater depth on the Knoll. New results include the observation of a diagenetic boundary within the Shikoku Basin sediments that may be compared to one documented further west by ODP Legs 131, 190 and 196 but occurs here at a lower temperature. Borehole heat flow measurements confirm spatial variations in the Shikoku Basin that were indicated by short probe surveys. Heat flow variations between topographic highs and lows may be related to fluid convection within the basement. This expedition also included the objectives of the Nankai Trough Submarine LandSLIDE history (NanTroSLIDE) Ancillary Project Letter (APL) and cored at Site C0018 a pile of mass transport deposits on the footwall of the megasplay fault, a major out of sequence thrust that presumably slips coseismically during large subduction earthquakes. This brought new insight on the timing of these mass wasting events and on the deformation within the sliding slope sediments. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.14.01.2012" target="_blank">10.2204/iodp.sd.14.01.2012</a>

Tectonic and geomorphic controls on the distribution of submarine landslides across active and passive margins, eastern New Zealand

2020 ◽  
Author(s):  
Sally Watson ◽  
Joshu Mountjoy ◽  
Gareth Crutchley
Keyword(s):  
New Zealand ◽  
Mass Transport ◽  
Submarine Landslide ◽  
Sediment Supply ◽  
Submarine Landslides ◽  
Mass Wasting ◽  
Active Margin ◽  
Eastern Margin ◽  
Marine Habitats ◽  
Mass Transport Deposits

&lt;p&gt;Submarine landslides occur on continental margins globally and can have devastating consequences for marine habitats, offshore infrastructure and coastal communities due to potential tsunamigenic consequences. Evaluation of the magnitude and distribution of submarine landslides is central to marine and coastal hazard planning. Despite this, there are few studies that comprehensively quantify the occurrence of submarine landslides on a margin-wide scale.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;We present the first margin-wide submarine landslide database along the eastern margin of New Zealand comprising &gt;2200 landslide scars and associated mass-transport deposits. Analysis of submarine landslide distribution reveals 1) locations prone to mass-failure, 2) spatial patterns of landslide scale and occurrence, and 3) the potential preconditioning factors and triggers of mass wasting across different geologic settings.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Submarine landslides are widespread on the eastern margin of New Zealand, occurring in water depths from ~300 m to ~4,000 m. Landslide scars and mass transport deposits are more prevalent, and on average larger, on the active margin, compared the passive margin. We attribute higher concentrations of landslides on the active margin to the prevalence of deforming thrust ridges, related to active margin processes including oversteepening, faulting and seamount subduction. Higher sediment supply on the northernmost active margin is also likely to be a key preconditioning factor resulting in the concentration of large landslides in this region.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;In general, submarine landslide scars are concentrated around canyon systems and close to canyon thalwegs. This suggests that not only does mass wasting play a major role in canyon evolution, but also that slope undercutting in canyons may be a fundamental preconditioning factor for slope failure.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Results of this study offer unique insights into the spatial distribution, magnitude and morphology of submarine landslides across different geologic settings, providing a better understanding of the causative factors for mass wasting in New Zealand and around the world.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Indonesian Throughflow as a preconditioning mechanism for submarine landslides in the Makassar Strait

2020 ◽  
Vol 500 (1) ◽  
pp. 195-217 ◽  
Author(s):  
Rachel E. Brackenridge ◽  
Uisdean Nicholson ◽  
Benyamin Sapiie ◽  
Dorrik Stow ◽  
Dave R. Tappin
Keyword(s):  
Mass Transport ◽  
Conveyor Belt ◽  
Ocean Current ◽  
Indonesian Throughflow ◽  
Submarine Landslides ◽  
Fault Rupture ◽  
The South ◽  
The Pacific ◽  
The Indian Ocean ◽  
Mass Transport Deposits

AbstractThe Makassar Strait is an important oceanic gateway, through which the main branch of the Indonesian Throughflow (ITF) transports water from the Pacific to the Indian Ocean. This study identifies a number of moderate (>10 km3) to giant (up to 650 km3) mass transport deposits within the Makassar North Basin Pleistocene–Recent section. The majority of submarine landslides that formed these deposits originated from the Mahakam pro-delta, with the largest skewed to the south. We see clear evidence for ocean-current erosion, lateral transport and contourite deposition across the upper slope. This suggests that the ITF is acting as an along-slope conveyor belt, transporting sediment to the south of the delta, where rapid sedimentation rates and slope oversteepening results in recurring submarine landslides. A frequency for the >100 km3 failures is tentatively proposed at 0.5 Ma, with smaller events occurring at least every 160 ka. This area is therefore potentially prone to tsunamis generated from these submarine landslides. We identify a disparity between historical fault rupture-triggered tsunamis (located along the Palu-Koro fault zone) and the distribution of mass transport deposits in the subsurface. If these newly identified mass failures are tsunamigenic, they may represent a previously overlooked hazard in the region.

scholarly journals Submarine mass wasting and associated tsunami risk offshore western Thailand, Andaman Sea, Indian Ocean

2012 ◽  
Vol 12 (8) ◽  
pp. 2609-2630 ◽  
Author(s):  
J. M. Schwab ◽  
S. Krastel ◽  
M. Grün ◽  
F. Gross ◽  
P. Pananont ◽  
...  
Keyword(s):  
Mass Transport ◽  
Andaman Sea ◽  
Excess Pore Pressure ◽  
Western Slope ◽  
Shelf Area ◽  
Submarine Landslides ◽  
Mass Wasting ◽  
Recurrence Rates ◽  
Mass Transport Deposits ◽  
Water Depths

Abstract. 2-D seismic data from the top and the western slope of Mergui Ridge in water depths between 300 and 2200 m off the Thai west coast have been investigated in order to identify mass transport deposits (MTDs) and evaluate the tsunamigenic potential of submarine landslides in this outer shelf area. Based on our newly collected data, 17 mass transport deposits have been identified. Minimum volumes of individual MTDs range between 0.3 km3 and 14 km3. Landslide deposits have been identified in three different settings: (i) stacked MTDs within disturbed and faulted basin sediments at the transition of the East Andaman Basin to the Mergui Ridge; (ii) MTDs within a pile of drift sediments at the basin-ridge transition; and (iii) MTDs near the edge of/on top of Mergui Ridge in relatively shallow water depths (< 1000 m). Our data indicate that the Mergui Ridge slope area seems to have been generally unstable with repeated occurrence of slide events. We find that the most likely causes for slope instabilities may be the presence of unstable drift sediments, excess pore pressure, and active tectonics. Most MTDs are located in large water depths (> 1000 m) and/or comprise small volumes suggesting a small tsunami potential. Moreover, the recurrence rates of failure events seem to be low. Some MTDs with tsunami potential, however, have been identified on top of Mergui Ridge. Mass-wasting events that may occur in the future at similar locations may trigger tsunamis if they comprise sufficient volumes. Landslide tsunamis, emerging from slope failures in the working area and affecting western Thailand coastal areas therefore cannot be excluded, though the probability is very small compared to the probability of earthquake-triggered tsunamis, arising from the Sunda Trench.

Formation of excess fluid pressure, sediment fluidization and mass-transport deposits in the Plio-Pleistocene Boso forearc basin, central Japan

2018 ◽  
Vol 477 (1) ◽  
pp. 255-264 ◽  
Author(s):  
Nana Kamiya ◽  
Masayuki Utsunomiya ◽  
Yuzuru Yamamoto ◽  
Junichi Fukuoka ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Mass Transport ◽  
Large Scale ◽  
Fluid Pressure ◽  
High Porosity ◽  
Submarine Landslides ◽  
Forearc Basin ◽  
Central Japan ◽  
Pressure Interval ◽  
The Stability ◽  
Mass Transport Deposits

AbstractAnalyses of consolidation state, fabrics and physical properties were conducted on rock samples from the Plio-Pleistocene Boso forearc basin, central Japan. Consolidation tests identified that the trend in consolidation yield stress was systematically 8 MPa smaller than expected for the overburden from the sediment thickness of the Kazusa Group. An excess fluid pressure interval was also identified in the lower part of the basin fill, where several large-scale (several kilometres in length and several tens of metres thick) mass-transport deposits (MTDs) are intercalated. This interval is characterized by high porosity and small consolidation yield stresses, indicating that consolidation had been retarded by the excess fluid pressure. The estimated excess fluid pressure was c. 5–7 MPa. In addition, outcrop-scale fluidization and minor liquefaction features were identified within and below the high fluid pressure interval. The excess fluid pressure reduced the effective stress in the Boso forearc basin and, subsequently, the stability of the slope, allowing small tectonic events to generate submarine landslides. Therefore, the formation of these large-scale MTDs was probably related to the excess fluid-pressure generation.

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