Mass-wasting processes along the margins of the Ulleung Basin, East Sea: insights from multichannel seismic reflection and multibeam echosounder data

2018 ◽  
Vol 477 (1) ◽  
pp. 107-119 ◽  
Author(s):  
Senay Horozal ◽  
Jang-Jun Bahk ◽  
Sang Hoon Lee ◽  
Deniz Cukur ◽  
Roger Urgeles ◽  
...  
Keyword(s):  
Large Scale ◽  
Sediment Supply ◽  
Ulleung Basin ◽  
Small Scale ◽  
Sedimentation Rates ◽  
Submarine Landslides ◽  
Slope Failures ◽  
Mass Wasting ◽  
Western Margin ◽  
Southern Margin

AbstractSubmarine landslides represent a major, previously little recognized, geological hazard to the coastal communities. This study investigates the size, depth and degree of submarine landslides along the margins of the Ulleung Basin and examines how the shelf morphology and sediment supply affect the style and occurrence of slope failures. The slopes have experienced at least 38 episodes of submarine failures, which have left clear arcuate-shaped scarps that initiate at water depths of 150–1120 m. Individual landslides comprise volumes over the range 0.1–340 km3, cover 20–800 km2 on the seafloor and have runout distances of up to 50 km from the source. The headwall scarps are observed as being in excess of 500 m high. The height of scarps in the southern margin is significantly larger than in the western margin. Moreover, the volume of mass-transport deposits in the southern margin is also much higher compared to those from the western margin. The occurrence of the broad shelf (30–150 km wide) and high sedimentation rates in the southern margin might have led to large-scale slope failures. In contrast, the narrow shelf (<20 km) and low sedimentation rates in the western margin would only have promoted small-scale mass-wasting events.

Submarine landslides in the western margin of the Ulleung Basin, East Sea

2016 ◽  
pp. 715-720
Author(s):  
D Cukur ◽  
G Kong ◽  
J Bahk ◽  
Senay Horozal ◽  
Y Yoon ◽  
...  
Keyword(s):  
East Sea ◽  
Ulleung Basin ◽  
Submarine Landslides ◽  
Western Margin

scholarly journals SUBSTRATE ENTRAINMENT, DEPOSITIONAL RELIEF, AND SEDIMENT CAPTURE: IMPACT OF A SUBMARINE LANDSLIDE ON FLOW PROCESS AND SEDIMENT SUPPLY

2021 ◽  
Author(s):  
Ander Martínez-Doñate ◽  
Aurelia Privat ◽  
David Hodgson ◽  
Chris Jackson ◽  
Ian Kane ◽  
...  
Keyword(s):  
Large Scale ◽  
Submarine Landslide ◽  
Sediment Supply ◽  
Submarine Landslides ◽  
Dispersal Patterns ◽  
Flow Process ◽  
Growth Strata ◽  
Shallow Marine ◽  
Depositional Processes ◽  
Stratal Architecture

Submarine landslides can generate complicated patterns of seafloor relief that influence subsequent flow behaviour and sediment dispersal patterns. While the large-scale morphology of submarine landslide deposits, or mass transport deposits (MTDs), can be resolved in seismic data, the nature of their upper surface, and its impact on facies distributions and stratal architecture of overlying deposits, is rarely resolvable. MTD is a commonly used term in subsurface studies, covering a range of processes and resultant deposits that can not be resolved in seismic or core-based datasets. However, field-based studies often allow a more detailed characterisation of the deposit. The early post-rift Middle Jurassic deep-water succession of the Los Molles Formation is exceptionally well-exposed along a dip-orientated WSW-ENE outcrop belt in the Chacay Melehue depocentre, Neuquén Basin, Argentina. We correlate 27 sedimentary logs constrained by marker beds to document the sedimentology and architecture of a >47 m thick and at least 9.6 km long mud-rich debrite. The debrite overlies ramps and steps, indicating erosion and substrate entrainment. Megaclasts sourced from shallow-marine environments support a shallow marine origin of the mass failure. Two distinct sandstone-dominated units overlie the debrite. The lower sandstone unit is characterised by: i) abrupt thickness changes, wedging and progressive rotation of laminae in sandstone beds associated with growth strata; and ii) detached sandstone load balls within the underlying debrite. The combination of these features suggests syn-sedimentary foundering processes due to density instabilities at the top of the fluid-saturated mud-rich debrite. The debrite relief controlled the spatial distribution of foundered sandstones. The upper sandstone unit is characterised by thin-bedded deposits, locally overlain by medium- to thick-bedded lobe axis/off-axis deposits. The thin-beds show local thinning and onlapping onto the debrite, where it develops its highest relief. Facies distributions and stacking patterns record the progradation of submarine lobes and their complex interaction with long-lived debrite-related topography. These characteristics can help us understand post-depositional processes above MTDs and predict facies distributions and palaeoenvironments in subsurface datasets. The emplacement of a kilometre-scale debrite in an otherwise mud-rich basinal setting and accumulation of overlying sand-rich deposits suggests a genetic link between the mass-wasting event and transient coarse clastic sediment supply to an otherwise sand-starved part of the basin.

Submarine landslides in the western margin of the Ulleung Basin, East Sea

2018 ◽  
pp. 715-720
Author(s):  
D. Cukur ◽  
G.-S. Kong ◽  
J.-J. Bahk ◽  
Horozal Senay ◽  
Y. Yoon ◽  
...  
Keyword(s):  
East Sea ◽  
Ulleung Basin ◽  
Submarine Landslides ◽  
Western Margin

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;

A sedimentary record of Holocene surface runoff events and earthquake activity from Lake Iseo (Southern Alps, Italy)

The Holocene ◽  
2012 ◽  
Vol 22 (7) ◽  
pp. 749-760 ◽  
Author(s):  
Stefan Lauterbach ◽  
Emmanuel Chapron ◽  
Achim Brauer ◽  
Matthias Hüls ◽  
Adrian Gilli ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Large Scale ◽  
Sediment Supply ◽  
Small Scale ◽  
Earthquake Activity ◽  
Erosion Processes ◽  
Seismic Surveying ◽  
Matter Flux ◽  
Event Layers ◽  
Runoff Events

This study presents a record of Holocene surface runoff events and several large earthquakes, preserved in the sediments of pre-Alpine Lake Iseo, northern Italy. A combination of high-resolution seismic surveying, detailed sediment microfacies analysis, non-destructive core-scanning techniques and AMS 14C dating of terrestrial macrofossils was used to detect and date these events. Based on this approach, our data shed light on past seismic activity in the vicinity of Lake Iseo and the influence of climate variability and human impact on allochthonous detrital matter flux into the lake. The 19 m long investigated sediment sequence of faintly layered lake marl contains frequent centimetre- to decimetre-scale sandy-silty detrital layers. During the early to mid Holocene, these small-scale detrital layers, reflecting sediment supply by extreme surface runoff events, reveal a distinct centennial-scale recurrence pattern. This is in accordance with regional lake-level highstands and minima in solar activity and thus apparently mainly climate-controlled. After c. 4200 cal. yr BP, intervals of high detrital flux occasionally also correlate with periods of enhanced human settlement activity. In consequence, deposition of small-scale detrital layers during the late Holocene apparently reflects a rather complex interplay between climatic and anthropogenic influences on catchment erosion processes. Besides the small-scale detrital layers, five up to 2.40 m thick large-scale detrital event layers, composed of basal mass-wasting deposits overlain by large-scale turbidites, were identified, which are supposed to be triggered by strong earthquakes. The uppermost large-scale event layer can be correlated to a documented Mw=6.0 earthquake in ad 1222 in Brescia. The four other large-scale event layers are supposed to correspond to previously undocumented local earthquakes. These occurred around 350 bc, 570 bc, 2540 bc and 6210 bc and most probably also reached magnitudes in the order of Mw = 5.0–6.5.

scholarly journals Mass wasting along the NW African continental margin

2018 ◽  
Vol 477 (1) ◽  
pp. 151-167 ◽  
Author(s):  
S. Krastel ◽  
W. Li ◽  
M. Urlaub ◽  
A. Georgiopoulou ◽  
R. B. Wynn ◽  
...  
Keyword(s):  
Continental Margin ◽  
Large Scale ◽  
Current Knowledge ◽  
Special Focus ◽  
Submarine Landslides ◽  
Mass Wasting ◽  
Recurrence Rates ◽  
Volcanic Debris ◽  
Rising Sea Level ◽  
Over Time

AbstractThe NW African continental margin is well known for the occurrence of large-scale but infrequent submarine landslides. The aim of this paper is to synthesize the current knowledge on submarine mass wasting off NW Africa with a special focus on the distribution and timing of large landslides. The described area reaches from southern Senegal to the Agadir Canyon. The largest landslides from south to north are the Dakar Slide, the Mauritania Slide, the Cap Blanc Slide, the Sahara Slide and the Agadir Slide. Volumes of individual slides reach several hundreds of cubic kilometres; run-outs are up to 900 km. In addition, giant volcanic debris avalanches are widespread on the flanks of the Canary Islands. All headwall areas are complex with clear indications of multiple failures. The most prominent similarity between all investigated landsides is the existence of widespread glide planes that follow the stratigraphy, which points to weak layers as most important preconditioning factor for the failures. Landslides with volumes larger than 100 m3 are close to being evenly distributed over time, contradicting previous suggestions that landslides off NW Africa occur at periods of low or rising sea level. The risk associated with the landslides off NW Africa, however, is relatively low due to their long recurrence rates.

scholarly journals Morphology of small-scale submarine mass movement events across the northwest United Kingdom

2021 ◽  
Author(s):  
Gareth Carter ◽  
Rhys Cooper ◽  
Joana Gafeira ◽  
John Howe ◽  
David Long
Keyword(s):  
United Kingdom ◽  
Large Scale ◽  
Slope Failure ◽  
Mass Movement ◽  
Morphometric Parameters ◽  
Single Type ◽  
Small Scale ◽  
Mass Movements ◽  
Submarine Landslides ◽  
Coastal Inlets

&lt;p&gt;Given the potentially devastating consequences of shallow submarine landslides on infrastructure and human lives, it is imperative that we understand potential slope stability issues within marine coastal regions. In Scottish waters, our lack of knowledge regarding the nature of the seabed within the fjords and coastal inlets is concerning given that these sea lochs have similar morphological features and settings to global examples (e.g. Norway) where recent slope failures have had such highly devastating results. Global examples from similar physiographic settings also demonstrate the temporal aspect of these events, highlighting that they are caused by active modern processes and therefore represent contemporary geohazards. In addition, previous studies have highlighted that there tends to be a scale bias towards the mapping and reporting of large-scale events, and there is a requirement for studies that focus on small-scale (&amp;#8804;1 km&lt;sup&gt;3&lt;/sup&gt;) mass movements which can still have damaging consequences on seafloor and coastal (both nearshore and onshore) infrastructure.&lt;/p&gt;&lt;p&gt;In this study, a review of multibeam echo sounder (MBES) survey datasets from five locations around the United Kingdom northwest coast has led to the identification of a total of 14 separate submarine mass movement scars and deposits within the fjords (sea lochs) and coastal inlets of mainland Scotland, and the channels between the islands of the Inner Hebrides. In these areas, Quaternary sediment deposition was dominated by glacial and glaciomarine processes. Analysis of the morphometric parameters of each submarine mass movement has revealed that they fall into four distinct groups of subaqueous landslides; Singular Slumps, Singular Translational, Multiple Single-Type, and Complex (translational &amp; rotational) failures. The Singular Slump Group includes discrete, individual subaqueous slumps that exhibit no evidence of modification through the merging of several scars. The Singular Translational Group comprise a single slide that displays characteristics associated with a single translational (planar) failure with no merging of multiple events. The Multiple Single-Type Group incorporates scars and deposits that displayed morphometric features consistent with the amalgamation of several failure events of the same type (e.g. debris flows or slumps). Finally, the Complex (translational &amp; rotational) Group comprises landslides that exhibited complex styles of failures, including both translational and rotational mechanisms controlling the same slide. The submarine mass movements that comprise this dataset are then discussed in relation to global fjordic and glaciomarine nearshore settings, and slope failure trigger mechanisms associated with these environments are described with tentative links to individual submarine landslides from the database, where appropriate. It is acknowledged that additional MBES data are needed not only to expand this database but also to create a more statistically robust study. However, this initial study provides the basis for a much wider investigation of submarine mass movements and correlations between their morphometric parameters.&lt;/p&gt;

scholarly journals Substrate Entrainment, Depositional Relief, and Sediment Capture: Impact of a Submarine Landslide on Flow Process and Sediment Supply

2021 ◽  
Vol 9 ◽  
Author(s):  
A. Martínez-Doñate ◽  
A. M-L. J. Privat ◽  
D. M. Hodgson ◽  
C. A-L. Jackson ◽  
I. A. Kane ◽  
...  
Keyword(s):  
Large Scale ◽  
Submarine Landslide ◽  
Sediment Supply ◽  
Submarine Landslides ◽  
Dispersal Patterns ◽  
Flow Process ◽  
Seismic Reflection Data ◽  
Growth Strata ◽  
Reflection Data ◽  
Stratal Architecture

Submarine landslides can generate complicated patterns of seafloor relief that influence subsequent flow behaviour and sediment dispersal patterns. In subsurface studies, the term mass transport deposits (MTDs) is commonly used and covers a range of processes and resultant deposits. While the large-scale morphology of submarine landslide deposits can be resolved in seismic reflection data, the nature of their upper surface and its impact on both facies distributions and stratal architecture of overlying deposits is rarely resolvable. However, field-based studies often allow a more detailed characterisation of the deposit. The early post-rift Middle Jurassic deep-water succession of the Los Molles Formation is exceptionally well-exposed along a dip-orientated WSW-ENE outcrop belt in the Chacay Melehue depocentre, Neuquén Basin, Argentina. We correlate 27 sedimentary logs constrained by marker beds to document the sedimentology and architecture of a &gt;47 m thick and at least 9.6 km long debrite, which contains two different types of megaclasts. The debrite overlies ramps and steps, indicating erosion and substrate entrainment. Two distinct sandstone-dominated units overlie the debrite. The lower sandstone unit is characterised by: 1) abrupt thickness changes, wedging and progressive rotation of laminae in sandstone beds associated with growth strata; and 2) detached sandstone load balls within the underlying debrite. The combination of these features suggests syn-sedimentary foundering processes due to density instabilities at the top of the fluid-saturated mud-rich debrite. The debrite relief controlled the spatial distribution of foundered sandstones. The upper sandstone unit is characterised by thin-bedded deposits, locally overlain by medium-to thick-bedded lobe axis/off-axis deposits. The thin-beds show local thinning and onlapping onto the debrite, where it develops its highest relief. Facies distributions and stacking patterns record the progradation of submarine lobes and their complex interaction with long-lived debrite-related topography. The emplacement of a kilometre-scale debrite in an otherwise mud-rich basinal setting and accumulation of overlying sand-rich deposits suggests a genetic link between the mass-wasting event and transient coarse clastic sediment supply to an otherwise sand-starved part of the basin. Therefore, submarine landslides demonstrably impact the routing and behaviour of subsequent sediment gravity flows, which must be considered when predicting facies distributions and palaeoenvironments above MTDs in subsurface datasets.

scholarly journals SUBSTRATE ENTRAINMENT, DEPOSITIONAL RELIEF, AND SEDIMENT CAPTURE: IMPACT OF A SUBMARINE LANDSLIDE ON FLOW PROCESS AND SEDIMENT SUPPLY

2021 ◽  
Author(s):  
Ander Martínez-Doñate ◽  
Aurelia Privat ◽  
David Hodgson ◽  
Chris Jackson ◽  
Ian Kane ◽  
...  
Keyword(s):  
Large Scale ◽  
Submarine Landslide ◽  
Sediment Supply ◽  
Submarine Landslides ◽  
Dispersal Patterns ◽  
Flow Process ◽  
Growth Strata ◽  
Shallow Marine ◽  
Depositional Processes ◽  
Stratal Architecture

Submarine landslides can generate complicated patterns of seafloor relief that influence subsequent flow behaviour and sediment dispersal patterns. While the large-scale morphology of submarine landslide deposits, or mass transport deposits (MTDs), can be resolved in seismic data, the nature of their upper surface, and its impact on facies distributions and stratal architecture of overlying deposits, is rarely resolvable. MTD is a commonly used term in subsurface studies, covering a range of processes and resultant deposits that can not be resolved in seismic or core-based datasets. However, field-based studies often allow a more detailed characterisation of the deposit. The early post-rift Middle Jurassic deep-water succession of the Los Molles Formation is exceptionally well-exposed along a dip-orientated WSW-ENE outcrop belt in the Chacay Melehue depocentre, Neuquén Basin, Argentina. We correlate 27 sedimentary logs constrained by marker beds to document the sedimentology and architecture of a >47 m thick and at least 9.6 km long mud-rich debrite. The debrite overlies ramps and steps, indicating erosion and substrate entrainment. Megaclasts sourced from shallow-marine environments support a shallow marine origin of the mass failure. Two distinct sandstone-dominated units overlie the debrite. The lower sandstone unit is characterised by: i) abrupt thickness changes, wedging and progressive rotation of laminae in sandstone beds associated with growth strata; and ii) detached sandstone load balls within the underlying debrite. The combination of these features suggests syn-sedimentary foundering processes due to density instabilities at the top of the fluid-saturated mud-rich debrite. The debrite relief controlled the spatial distribution of foundered sandstones. The upper sandstone unit is characterised by thin-bedded deposits, locally overlain by medium- to thick-bedded lobe axis/off-axis deposits. The thin-beds show local thinning and onlapping onto the debrite, where it develops its highest relief. Facies distributions and stacking patterns record the progradation of submarine lobes and their complex interaction with long-lived debrite-related topography. These characteristics can help us understand post-depositional processes above MTDs and predict facies distributions and palaeoenvironments in subsurface datasets. The emplacement of a kilometre-scale debrite in an otherwise mud-rich basinal setting and accumulation of overlying sand-rich deposits suggests a genetic link between the mass-wasting event and transient coarse clastic sediment supply to an otherwise sand-starved part of the basin.

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale
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