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.

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.

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 >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 Channel incision into a submarine landslide: an exhumed Carboniferous example from the Paganzo Basin, San Juan, Argentina

2021 ◽  
Author(s):  
David Hodgson ◽  
Jeff Peakall ◽  
Charlotte Allen ◽  
Luz Gomis Cartesio ◽  
Juan Pablo Milana
Keyword(s):  
Sediment Transport ◽  
Large Scale ◽  
Submarine Landslide ◽  
Geological Mapping ◽  
Transport Systems ◽  
Submarine Landslides ◽  
Dispersal Patterns ◽  
Paganzo Basin ◽  
Mass Transport Deposits ◽  
Erosion Surface

Emplacement of submarine landslides, or mass transport deposits, can radically reshape the physiography of continental margins, and strongly influence subsequent sedimentary processes and dispersal patterns. The irregular relief they generate creates obstacles that force reorganisation of sediment transport systems. Subsurface and seabed examples show that channels can incise directly into submarine landslides. Here, we use high-resolution sedimentological analysis, geological mapping and photogrammetric modelling to document the evolution of two adjacent, and partially contemporaneous, sandstone-rich submarine channel-fills (NSB and SSB) that incised deeply (>75 m) with steep lateral margins (up to 70°) into a 200 m thick debrite. The stepped erosion surface mantled by clasts, ranging from gravels to cobbles, points to a period of downcutting and sediment bypass. A change to aggradation is marked by laterally-migrating sandstone-rich channel bodies that is coincident with prominent steps in the large-scale erosion surface. Two types of depositional terrace are documented on these steps: one overlying an entrenchment surface, and another located in a bend cut-off. Above a younger erosion surface, mapped in both NSB and SSB, is an abrupt change to partially-confined tabular sandstones with graded caps, interpreted as confined lobes. The lobes are characterised by a lack of compensational stacking and increasingly thick hybrid bed deposits, suggesting progradation of a lobe complex confined by the main erosion surface. The incision of adjacent and partially coeval channels into a thick submarine landslide, and sand-rich infill including development of partially confined lobes, reflects the complicated relationships between evolving relief and changes in sediment gravity flow character, which can only be investigated at outcrop. The absence of channel-fills in bounding strata, and the abrupt and temporary presence of coarse sediment infilling the channels, indicates that the submarine landslide emplacement reshaped sediment transport systems, and established conditions that effectively separated sand- from mud-dominated deposits.

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

<p>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.</p><p> </p><p>We present the first margin-wide submarine landslide database along the eastern margin of New Zealand comprising >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.</p><p> </p><p>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.</p><p> </p><p>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.</p><p> </p><p>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.</p><p> </p>

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.

Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula

1998 ◽  
Vol 135 (4) ◽  
pp. 519-535 ◽  
Author(s):  
B. HATHWAY ◽  
D. I. M. MACDONALD ◽  
J. B. RIDING ◽  
D. J. CANTRILL
Keyword(s):  
Antarctic Peninsula ◽  
Large Scale ◽  
Upper Cretaceous ◽  
Source Area ◽  
Weddell Sea ◽  
Sediment Supply ◽  
Shallow Marine ◽  
Magmatic Arc ◽  
James Ross Island ◽  
The Antarctic

The northern, James Ross Island region of the Larsen Basin, on the eastern, back-arc margin of the Antarctic Peninsula magmatic arc, includes one of the thickest and most complete Upper Cretaceous sedimentary successions exposed in the Southern Hemisphere. However, the southern part of the basin remains poorly known, mainly owing to inaccessibility and lack of exposure. Table Nunatak, an isolated, 1-km-long, 400-m-wide outcrop at the tip of Kenyon Peninsula, is the only known exposure of Upper Cretaceous or younger strata in this region. The 62-m-thick succession exposed there is assigned to the newly defined Table Nunatak Formation. It consists mainly of sharp-based, amalgamated beds of fine-grained sandstone up to 2.8 m thick, with subordinate intervals of intensely bioturbated mudstone. Wave ripples are present at some levels, and locally developed swaley cross-stratification provides evidence for storm-generated combined-flow deposition. However, most sandstone beds appear to be internally structureless apart from normal grading, and are interpreted as the direct suspension deposits of highly sediment-charged storm- and/or flood-related flows. The succession represents relatively nearshore deposition, probably at the mouth of a river or deltaic distributary channel. Charcoalified plant debris, abundant at the tops of some sandstone beds, suggests a periodically wildfire-swept hinterland forested largely by coniferous trees. Dinoflagellate cyst assemblages indicate a late Santonian age, and suggest correlation with the basal part of the Lachman Crags Member of the Santa Marta Formation (Marambio Group) on James Ross Island. Palaeocurrents, sandstone petrography and the high sediment supply rate proposed for the Table Nunatak Formation, suggest a relatively high-relief source area to the west, with large-scale erosion of granitoid plutons and metamorphic rocks, possibly related to arc uplift during a mid-Cretaceous compressional episode. The formation is evidence of a major southward extension of the Upper Cretaceous strata exposed in the northern Larsen Basin, and suggests lateral continuity of shallow-marine deposition for at least 500–600 km along the Weddell Sea margin of the Antarctic Peninsula in Santonian times.

Line length balancing to evaluate multi-phase submarine landslide development: an example from the Storegga Slide, Norway

2019 ◽  
Vol 500 (1) ◽  
pp. 531-549 ◽  
Author(s):  
Suzanne Bull ◽  
Joseph A. Cartwright
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Line Length ◽  
Proximal Region ◽  
Submarine Landslide ◽  
Landslide Development ◽  
Multi Phase ◽  
Storegga Slide ◽  
2D And 3D ◽  
3D Seismic Data

AbstractThis study shows how simple structural restoration of a discrete submarine landslide lobe can be applied to large-scale, multi-phase examples to identify different phases of slide-lobe development and evaluate their mode of emplacement. We present the most detailed analysis performed to date on a zone of intense contractional deformation, historically referred to as the compression zone, from the giant, multi-phase Storegga Slide, offshore Norway. 2D and 3D seismic data and bathymetry data show that the zone of large-scale (>650 m thick) contractional deformation can be genetically linked updip with a zone of intense depletion across a distance of 135 km. Quantification of depletion and accumulation along a representative dip-section reveals that significant depletion in the proximal region is not accommodated in the relatively mild amount (c. 5%) of downdip shortening. Dip-section restoration indicates a later, separate stage of deformation may have involved removal of a significant volume of material as part of the final stages of the Storegga Slide, as opposed to the minor volumes reported in previous studies.

Simulation of tsunami waves generated by submarine landslides in the Black Sea

2015 ◽  
Vol 30 (4) ◽  
Author(s):  
Gayaz S. Khakimzyanov ◽  
Oleg I. Gusev ◽  
Sofya A. Beizel ◽  
Leonid B. Chubarov ◽  
Nina Yu. Shokina
Keyword(s):  
Surface Waves ◽  
Black Sea ◽  
Numerical Technique ◽  
Submarine Landslide ◽  
The Black Sea ◽  
Submarine Landslides ◽  
Hydrodynamic Approximation ◽  
Tsunami Waves ◽  
Dispersive Model ◽  
Shallow Water Models

AbstractNumerical technique for studying surface waves appearing under the motion of a submarine landslide is discussed. This technique is based on the application of the model of a quasi-deformable landslide and two shallow water models, namely, the classic (dispersion free) one and the completely nonlinear dispersive model of the second hydrodynamic approximation. Numerical simulation of surface waves generated by a large model landslide on the continental slope of the Black Sea near the Russian coast is performed. It is shown that the dispersion has a significant impact on the picture of propagation of tsunami waves on sufficiently long paths.

Pre- and Post-Tsunami Depth Changes of Submarine Topography for the Analysis of Submarine Landslide-Induced Tsunami: Proposal of Digitization Method and Application to the Case of the 1923 Great Kanto Earthquake Tsunamis

2021 ◽  
Author(s):  
Kazuki Murata ◽  
Shinji Sassa ◽  
Tomohiro Takagawa ◽  
Toshikazu Ebisuzaki ◽  
Shigenori Maruyama
Keyword(s):  
Large Scale ◽  
Interpolation Method ◽  
Weighted Average ◽  
Tokyo Bay ◽  
Submarine Landslides ◽  
Sagami Bay ◽  
Seabed Topography ◽  
Kanto Earthquake ◽  
Before And After ◽  
Tsunami Event

Abstract We first propose and examine a method for digitizing analog data of submarine topography by focusing on the seafloor survey records available in the literature to facilitate a detailed analysis of submarine landslides and landslide-induced tsunamis. Second, we apply this digitization method to the seafloor topographic changes recorded before and after the 1923 Great Kanto earthquake tsunami event and evaluate its effectiveness. Third, we discuss the coseismic large-scale seafloor deformation at the Sagami Bay and the mouth of the Tokyo Bay, Japan. The results confirmed that the latitude / longitude and water depth values recorded by the lead sounding measurement method can be approximately extracted from the sea depth coordinates by triangulation survey through the overlaying of the currently available GIS map data without geometric correction such as affine transformation. Further, this proposed method allows us to obtain mesh data of depth changes in the sea area by using the interpolation method based on the IDW (Inverse Distance Weighted) average method through its application to the case of the 1923 Great Kanto Earthquake. Finally, we analyzed and compared the submarine topography before and after the 1923 tsunami event and the current seabed topography. Consequently, we found that these large-scale depth changes correspond to the valley lines that flow down as the topography of the Sagami Bay and the Tokyo Bay mouth.

Submarine Landslides and Their Tsunami Hazard

2016 ◽  
Vol 49 (1) ◽  
Author(s):  
David R. Tappin
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Submarine Landslide ◽  
Tsunami Hazard ◽  
Publication Date ◽  
Submarine Landslides ◽  
Critical Importance ◽  
Grand Banks ◽  
Landslide Mechanisms ◽  
Landslide Tsunamis

Most tsunamis are generated by earthquakes, but in 1998, a seabed slump offshore of northern Papua New Guinea (PNG) generated a tsunami up to 15 m high that killed more than 2,200 people. The event changed our understanding of tsunami mechanisms and was forerunner to two decades of major tsunamis that included those in Turkey, the Indian Ocean, Japan, and Sulawesi and Anak Krakatau in Indonesia. PNG provided a context to better understand these tsunamis as well as older submarine landslide events, such as Storegga (8150 BP); Alika 2 in Hawaii (120,000 BP), and Grand Banks, Canada (1929), together with those from dual earthquake/landslide mechanisms, such as Messina (1908), Puerto Rico (1928), and Japan (2011). PNG proved that submarine landslides generate devastating tsunamis from failure mechanisms that can be very different, whether singly or in combination with earthquakes. It demonstrated the critical importance of seabed mapping to identify these mechanisms as well as stimulated the development of new numerical tsunami modeling methodologies. In combination with other recent tsunamis, PNG demonstrated the critical importance of these events in advancing our understanding of tsunami hazard and risk. This review recounts how, since 1998, understanding of the tsunami hazard from submarine landslides has progressed far beyond anything considered possible at that time. ▪ For submarine landslide tsunamis, advances in understanding take place incrementally, usually in response to major, sometimes catastrophic, events. ▪ The Papua New Guinea tsunami in 1998, when more than 2,200 people perished, was a turning point in first recognizing the significant tsunami hazard from submarine landslides. ▪ Over the past 2 to 3 years advances have also been made mainly because of improvements in numerical modeling based on older tsunamis such as Grand Banks in 1929, Messina in 1908, and Storegga at 8150 BP. ▪ Two recent tsunamis in late 2018, in Sulawesi and Anak Krakatau, Indonesia, where several hundred people died, were from very unusual landslide mechanisms—dual (strike-slip and landslide) and volcanic collapse—and provide new motivations for understanding these tsunami mechanisms. ▪ This is a timely, state of the art review of landslide tsunamis based on recent well-studied events and new research on older ones, which provide an important context for the recent tsunamis in Indonesia in 2018. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 49 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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