Comparison of Mass Wasting Processes on the Slopes of the Rockall Trough, Northeast Atlantic

Georgiopoulou, Aggeliki; Benetti, Sara; Shannon, Patrick M.; Sacchetti, Fabio; Haughton, Peter D. W.; Comas-Bru, Laia; Krastel, Sebastian

doi:10.1007/978-3-319-00972-8_42

Cited by 5 publications

(2 citation statements)

References 19 publications

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“…Here, these erosion processes are highlighted by high suitability for bedrock to occur in the canyon's head, either in Whittard Canyon or on the northern and southern Porcupine Bank canyons (Figures 7-9). Large-scale sediment slumps and block failure (Leynaud et al, 2009;Carter et al, 2018) appear to be direct erosion processes affecting the Whittard Canyon walls as well as the Rockall Bank and the northern Porcupine Bank (Faugeres et al, 1981;Elliott et al, 2006;Georgiopoulou et al, 2014). These processes are highlighted here by areas of high BSI overprinting on headwall scar locations and parts of canyon walls (Figures 5A, B, 9).…”

Section: Bedrock Outcrop Type and Associated Processesmentioning

confidence: 77%

Large-scale bedrock outcrop mapping on the NE Atlantic Irish continental margin

Recouvreur,

Wheeler,

Strachan

et al. 2024

Front. Mar. Sci.

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The Irish continental margin (ICM) encompasses many complex sedimentary basins and diverse geomorphological features displaying bedrock outcrops where a large variety of habitats can be observed. This large area of seabed extends over >400,000 km2 and cannot be mapped manually or in a standardized way. Novel bedrock suitability mapping is applied to the entire ICM to determine potential bedrock outcrop from shallow to deep settings and to improve on the regional near-surface geology of the Irish margin. With the use of ROV video transects covering all the ICM and multibeam echosounder dataset, key terrain variables diagnostic of bedrock outcrop have been derived from bathymetry. A reclassification of each terrain variable was created by identifying the suitable ranges for outcrop occurrence in the variables, corresponding to the most common values occurring where the bedrock is located. Suitable bedrock location in non-surveyed areas have been calculated using these variables with map algebra to develop the novel Bedrock Suitability Index. This high-resolution (25 m2) model indicates that the main features where outcrop could be observed are canyon heads, terraces, or failure scarps, especially noticeable on the Whittard Canyon system. The Bedrock Suitability Index model is validated by video observations of bedrock exposures and is established with 58% level of confidence with 25 m2 resolution on the overall margin over >400,000 km2. The BSI mapping suggests a structural control on bedrock outcrop occurrences, with high BSI correlating with deep structural fabrics of the margin as bedrock outcrop can be found in areas where previously mapped faults have been identified. Bedrock and hard substratum mapping are important components to improve habitat identification and mapping. This less-invasive, low-cost method can be applied with open source software in a relatively simple way of determining where bedrock could be found. It can also be used to refine areas where there will be simply too much data for use to manually classify. Potential bedrock outcrop mapping can be included in a species distribution model.

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Section: Bedrock Outcrop Type and Associated Processesmentioning

confidence: 77%

Large-scale bedrock outcrop mapping on the NE Atlantic Irish continental margin

Recouvreur,

Wheeler,

Strachan

et al. 2024

Front. Mar. Sci.

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“…The authors also found a high correlation between length and area of MTDs. A study of MTDs in the Rockall trough (west of Ireland the UK) also related MTD geometry to slope morphology and sediment supply (Georgiopoulou et al, 2014). The relationship between length and area of an MTD was also identified by Katz et al, (2015) in an analysis of over 400 MTDs on the continental slope of Israel, with MTD deposits comprising 20%of the studied continental slope.…”

Section: Introductionmentioning

confidence: 98%

Unpredictable geometry and depositional stacking patterns of mass-transport complexes in salt minibasins

Biancardi

Alves

Martins-Ferreira

2020

Marine and Petroleum Geology

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Mass-transport complexes in a salt minibasin of the Espírito Santo Basin (SE Brazil) are investigated using a high-quality 3D seismic volume and borehole data. A series of six (6), stacked MTCs were identified from the sea floor down to an approximate depth of 1.5 kilometres. These MTCs exhibit a high variability in size and internal structures. Three of the MTCs contain single, discrete landslide deposits while the other three MTCs contain multiple, contemporaneous landslides that merge to span the entire salt minibasin. The data in this work show that Area/Length relationships and the number of contemporaneous landslide deposits within an MTC are random, revealing no obvious relationship with relative location or depth. As such, there are no clear stacking patterns for the MTCs in this minibasin. This implies that landslide deposits can be encountered anywhere within a salt minibasin and, furthermore, the extent of the slope failure and its internal structure are unpredictable. This work concludes that slope instability can be the dominant process of sediment filling Miocene salt minibasins on the continental slope of Espírito Santo. Moreover, there is a strong link between halokinesis and the triggering of landslides in the salt minibasins, but the identification of MTCs 2 becomes challenging with increasing depth and there is the potential for them to be misrepresented.The identification of basal ramps therefore becomes critical in any analysis; except for the youngest MTC 1, all other complexes show clear basal ramps, and for one of the MTCs the basal ramp is its sole identifying character.

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Mass transport deposits in the Donegal Barra Fan and their association with British–Irish Ice Sheet dynamics

Roy

Georgiopoulou

Benetti

et al. 2020

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This study analyses seismic data to investigate the kinematic indicators within the mass transport deposits (MTDs) of the Donegal Barra Fan complex in the Rockall Trough, along the NW European continental margin. Five episodes of mega-scale MTDs (DBF-01, -02, -03, -04 and -05) are identified. DBF-01 is the largest MTD in the NW British continental margin, comprising 1907 km3 of sediments. Fold-and-thrusts were identified within the MTDs where they attain maximum thickness of c. 300–380 ms TWT, but not at the toe region. This indicates that local erosion and deceleration caused bulking up of the MTD volume, but the MTD was not fully arrested due to the high mobility of the mass flow. MTD thickness distribution and thrust fault orientations indicate source areas and flow direction of MTD. The MTDs show a compensational stacking pattern with earlier deposits influencing the position and flow direction of succeeding slides, suggesting that glaciogenic debris flows are sensitive to topographic variability. We propose that increased sediment input associated with at least five expansions of the British–Irish Ice Sheet to the shelf edge led to the development of these MTDs and that the youngest of them, DBF-05, corresponds to the Last Glacial Maximum.

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Comparison of Mass Wasting Processes on the Slopes of the Rockall Trough, Northeast Atlantic

Cited by 5 publications

References 19 publications

Large-scale bedrock outcrop mapping on the NE Atlantic Irish continental margin

Large-scale bedrock outcrop mapping on the NE Atlantic Irish continental margin

Unpredictable geometry and depositional stacking patterns of mass-transport complexes in salt minibasins

Mass transport deposits in the Donegal Barra Fan and their association with British–Irish Ice Sheet dynamics

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