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In high latitude continental margins, glacio-seismotectonics becomes particularly relevant during postglacial unloading periods and related isostatic rebound. Based on multibeam bathymetry and parametric profiles, an unexpected active 30 km long NNW-SSE fault is imaged for the first time in the inner Storfjorden glacial trough, at the passive continental margin of the Barents Sea. The 10 km southern tip of the fault was surveyed in detail and it is characterised by a total fault throw of 65 m. The fault forms an asymmetric valley with an upraised block to its east (top at 245 m water depth), a downthrown block to the west (at 310 m water depth), and a most recent fault scarp with 8 m relief at the seafloor valley axis. Recent fault activity is evidenced by its morphological expression on the seafloor, the faulting of the glacial, glaciomarine and marine sediments and streamlined landforms formed during the last glacial-interglacial period. Mass flow deposits along the upraised block would also indicate recent fault activity. This fault may trigger earthquakes of up to MW 6.2, based on the magnitude/length ratio of the detailed surveyed segment, which is similar in magnitude to those that occurred in the nearby northeastern regions during 2008–2012. In any case, earthquakes may reach up to MW 6.8 if the entire fault length is activated. Rather than the expected normal fault on the passive margin, this fault seems to be reversed and dipping eastwards. The integration of the Storfjorden glacial trough reverse fault with regional structures suggests that the fault activated the southwestward front of a wide, continental crustal block. These results are in accordance with a change in the stresses in the passive continental margin since the rifting stage, from extension to post-rift compression, and suggest that postglacial unloading may have favoured the fault development

The coexistence of shortening and extensional tectonic regimes is a common feature in orogenic belts. The westernmost end of the Western Mediterranean is an area undergoing shortening related to the 5 mm/yr NNW‒SSE convergence of the Nubia and Eurasia Plates. In this region, the Central Betic Cordillera shows a regional ENE‒WSW extension. Here, we present GNSS-derived geodetic data along a 170 km-long transect orthogonal to the main active normal faults of the Central Betic Cordillera. Our data indicate that the total extension rate along the Central Betic Cordillera is 2.0 ± 0.3 mm/yr. Extension is accommodated in the eastern (0.8 ± 0.3 mm/yr in the Guadix-Baza Basin) and western (1.3 ± 0.3 mm/yr in the Granada Basin) parts of the Central Betic Cordillera, while no extension is recorded in the central part of the study area. Moreover, our data permit us to quantify, for the first time, short-term fault slip rates of the Granada Fault System, which is one of the main seismogenic sources of the Iberian Peninsula. We deduce a fault slip rate of ∼1.3 ± 0.3 mm/yr for the whole Granada Basin, with 0.9 ± 0.3 mm/yr being accommodated in the Granada Fault System and 0.4 ± 0.3 mm/yr being accommodated in the southwestern sector of the Granada Basin, where no active faults have been previously described at the surface. The heterogeneous extension in the Central Betic Cordillera could be accommodated by shallow high-angle normal faults that merge with a detachment at depth. Part of the active extension could be derived from gravitational instability because of underlying over-thickened crust.

Uno de los peligros geológicos más comunes en las laderas submarinas de los márgenes continentales del Ártico son los deslizamientos de tierra. Estos ocurren cuando se desploma el suelo y se mueven gran cantidad de sedimentos desde las zonas más someras hasta las profundidades del océano.

Purpose: High latitude continental margins undergone the effects of global climatic change and ocean warming, that are key factors that may induce future landslides. This is because the increase of water temperature may contribute to gas hydrates breakdown which leads to increase pore pressure of sediments. Other important factor is the seismicity related to glacio-isostatic adjustments; the isostatic uplift decreases the confining pressure and induce fault activity and hence seismicity. Therefore, a modelling approach to understand the tsunamigenic potentiality of submarine landslides will provide new perspectives on tsunami hazard threat in these regions. Methods: Here, we use the Landslide L-ML-HySEA numerical model to analyze the tsunamigenic potential of the Storfjorden SL-1 landslide (Southwestern Svalbard), and thus evaluate the hazards of similar structures that may develop in the future. Results: This landslide extends from the shelf-edge at 420-480 m down to > 1900 m water depth, is ~ 60 km in length and covers an area > 1300 km2. Modelling results show that the tsunami waves present low amplitude values in open sea, reaching several meters at the coastal area where arrival times start at 50 min. Tsunami waves comprise two initial wave dipoles, with troughs to the northeast (Spitsbergen and towards the continent) and humps to the south (seawards) and southwest (Bear Island), reaching more than 3 m of amplitude above the landslide, and finally merging into a single wave dipole. The formation of dipoles is related to the evacuation area at the slide scar by the instantaneous landslide displacement, and by the uneven landslide deformation having different velocities during its runout. In fact, a new wave dipole is formed, opposite to the initial ones, when the faster moving body reaches the slower one, and both merge increasing the thickness of the Storfjorden SL-1 landslide. The local bathymetry of the continental shelf, characterized by glacial troughs and

The coexistence of shortening and extensional tectonic regimes is a common feature in orogenic belts. The westernmost end of the Western Mediterranean is an area undergoing shortening related to the 5 mm/yr NNW‒SSE convergence of the Nubia and Eurasia Plates. In this region, the Central Betic Cordillera shows a regional ENE‒WSW extension. Here, we present GNSS-derived geodetic data along a 170 km-long transect orthogonal to the main active normal faults of the Central Betic Cordillera. Our data indicate that the total extension rate along the Central Betic Cordillera is 2.0 ± 0.3 mm/yr. Extension is accommodated in the eastern (0.8 ± 0.3 mm/yr in the Guadix-Baza Basin) and western (1.3 ± 0.3 mm/yr in the Granada Basin) parts of the Central Betic Cordillera, while no extension is recorded in the central part of the study area. Moreover, our data permit us to quantify, for the first time, short-term fault slip rates of the Granada Fault System, which is one of the main seismogenic sources of the Iberian Peninsula. We deduce a fault slip rate of ∼1.3 ± 0.3 mm/yr for the whole Granada Basin, with 0.9 ± 0.3 mm/yr being accommodated in the Granada Fault System and 0.4 ± 0.3 mm/yr being accommodated in the southwestern sector of the Granada Basin, where no active faults have been previously described at the surface. The heterogeneous extension in the Central Betic Cordillera could be accommodated by shallow high-angle normal faults that merge with a detachment at depth. Part of the active extension could be derived from gravitational instability because of underlying over-thickened crust.

This article offers an overview of the main sedimentary systems defining the geomorphology of deep sea environments from low to high latitudes. Mass-transport deposits, turbidite systems, contourites, volcaniclastic aprons, glacial trough mouth systems, carbonate mounds and other bathyal systems, such as pelagites, hemipelagites, mid-ocean channels and polymetallic mineral deposits, are presented with special attention to their morphology, sediments, processes and controlling factors. The integration of the main systems on the continental margins and adjacent abyssal plains in the North Atlantic and westernmost Mediterranean allows to characterize different sedimentation models

A modelling approach to understand the tsunamigenic potentiality of submarine landslides will provide new perspectives on tsunami hazard threat, mostly in polar margins where global climatic change and its related ocean warming may induce future landslides. Here, we use the L-ML-HySEA (Landslide Multilayer Hyperbolic Systems and Efficient Algorithms) numerical model, including wave dispersion, to provide new insights into factors controlling the tsunami characteristics triggered by the Storfjorden LS-1 landslide (southwestern Svalbard). Tsunami waves, determined mainly by the sliding mechanism and the bathymetry, consist of two initial wave dipoles, with troughs to the northeast (Spitsbergen and towards the continent) and crests to the south (seawards) and southwest (Bear Island), reaching more than 3 m of amplitude above the landslide and finally merging into a single wave dipole. The tsunami wave propagation and its coastal impact are governed by the Storfjorden and Kveithola glacial troughs and by the bordering Spitsbergen Bank, which shape the continental shelf. This local bathymetry controls the direction of propagation with a crescent shape front, in plan view, and is responsible for shoaling effects of amplitude values (4.2 m in trough to 4.3 m in crest), amplification (3.7 m in trough to 4 m in crest) and diffraction of the tsunami waves, as well as influencing their coastal impact times

[EN] The Storfjorden Trough Mouth Fan is affected by a huge submarine landslide mapped based on multibeam bathymetry and very high-resolution seismic profiles. The Storfjorden landslide covers an area of 1200 km2 with a volume of 40 km3. The Landslide-HySEA numerical modelling has simulated the hypothetical tsunami (Gonzalez-Vida et al., 2019). The model related landslide evidences the presence of two interacting sediment volumes, which are slumping simultaneously. Wave trains values are one meter with N-S propagation direction and run-up value ~ 2m in Spitsbergen and Bear Islands. Sedimentary instability would be related to i) the interplay between the over-steeping of the continental slope (4º), ii) the high sedimentation rates of clays during interglacial periods, which are intercalated with glaciogenic sediments deposited during the glacial periods building a stratigraphy with over-consolidated clay levels, iii) and the seismic activity (Faleide et al, 1996). It contributes to increase the knowledge and the evaluation about the potential tsunamigenic of submarine landslides in similar scenarios, where the environmental changes by impact of climatic changes may favour submarine landslide triggering, [ES] El abanico de Storfjorden está afectado por un gran deslizamiento submarino identificado en la batimetría multihaz y perfiles sísmicos de muy alta resolución. El deslizamiento de Storfjorden cubre un área de 1200 km2 con un volumen de 40 km 3. Se ha realizado la simulación del deslizamiento mediante el modelo numérico Landslide-HySEA (González-Vida et al., 2019). El análisis del deslizamiento proporciona evidencia de la presencia de dos volúmenes de sedimentos interactivos, que se desploman simultáneamente. El tsunami comprende trenes de olas de 1 m de amplitud que se dispersan hacia N-S, afectando las costas de Spitsbergen y la Isla del Oso con olas ~ 2 m. La inestabilidad sedimentaria que desencadena el tsunami podría estar relacionada con varios factores: i) las pendientes del talud (4º); ii) la rápida deposición de arcillas durante los periodos inter-glaciares alternados con sedimentos glaciogénicos en eventos glaciares, favoreciendo la sub-consolidación de las arcillas; y iii) la ocurrencia de terremotos (Faleide et al, 1996). Ello contribuye al estudio y evaluación del potencial tsunamigénico de deslizamientos submarinos en escenarios similares, donde los cambios ambientales debido al impacto del cambio climático pueden favorecer el desarrollo de procesos de inestabilidad sedimentaria submarina

Climate variations control sediment supply to the continental slope as well as glacial advances and retreats, which (a) cause significant stress changes in the sedimentary column and redistribution of interstitial fluids, (b) induce a particular margin stratigraphic pattern and permeability architecture and (c) are at the origin of isostatic adjustments that may reactivate faults. We test this hypothesis using a combination of geophysical and geotechnical data from the Storfjorden Trough Mouth Fan, off southern Svalbard. The results of compressibility and permeability testing are used together with margin stratigraphic models obtained from seismic reflection data, as input for numerical finite elements models to understand focusing of interstitial fluids in glaciated continental margins and influence on timing and location of submarine slope failure. Available results indicate values of overpressure of 0.23–0.5 (slope-shelf) that persist to present-day. This overpressure started to develop in response to onset of Pleistocene glaciations and reduced by half the factor of safety of the continental slope

Climate variations control sediment supply to the continental slope as well as glacial advances and retreats, which (a) cause significant stress changes in the sedimentary column and redistribution of interstitial fluids, (b) induce a particular margin stratigraphic pattern and permeability architecture and (c) are at the origin of isostatic adjustments that may reactivate faults. We test this hypothesis using a combination of geophysical and geotechnical data from the Storfjorden Trough Mouth Fan, off southern Svalbard. The results of compressibility and permeability testing are used together with margin stratigraphic models obtained from seismic reflection data, as input for numerical finite elements models to understand focusing of interstitial fluids in glaciated continental margins and influence on timing and location of submarine slope failure. Available results indicate values of overpressure of 0.23-0.5 (slope-shelf) that persists to present-day. This overpressure started to develop in response to onset of Pleistocene glaciations and reduced by half the factor of safety of the continental slope

Relatively recent, shallow landslides are imaged both on swath bathymetry, sub-bottom and multichannel seismic reflection (MCS) data from the upper-middle continental slope on the Storfjorden and Kveithola Trough Mouth Fans, NW Barents Sea margin. Giant paleo-landslide deposits, detected only by MCS profiles, are characterized by chaotic acoustic units up to about 250 m thick on the lower continental slope. The thickest, oldest landslide, dated between 1 and 0.8 Ma, took place just after the large-scale intensification of glaciation in the Barents Sea. The apparent spatial coincidence of landslides and channels with the boundary between the two fan systems, that are generated due to huge quantities of sediments transported to the continental slope by paleo-ice streams, suggests a common controlling climatic process for their development. Most probably the slides are related to the abundance of basal meltwater beneath the ice sheet, which in addition to determining ice stream motion and lubrication also influences the behavior of mass wasting processes

Up to 12 submarine landslides retain a morphological evidence as concave amphitheater-like depressions of various sizes on the middle and upper slope of the Storfjorden and Kveithola Trough-Mouth Fans (TMFs), NW Barents Sea. The largest of them show lateral scarps 35–40 m high that reach the continental shelf edge and cover an area of at least 1,120 km2. Submarine landslides are translational, with headwall and laterals scarps clearly cut into Last Glacial Maximum debris flows deposits. The largest landslides seem to be rooted at the base of a terrigenous/hemipelagic sedimentary unit inferred to be of Middle Weichselian age (Marine Isotopic Stage 3). Stratigraphic, lithological and geotechnical observations suggest that the rapid deposition of a thick sequence of fine-grained, high water content interlaminate plumites is the most important controlling factors in the generation of submarine landslides on the southern Storfjorden and Kveithola TMFs

The mechanisms of sediment transfer from the base of ice sheets to the continental margins determine the stratigraphic architecture and sedimentation style of glaciated continental margins and control the pathways of fluid migration and massive slope failure. The Spanish projects SVAIS and DEGLABAR and the Italian projects EGLACOM and MELTSTORM, all within the frame of International Polar Year (IPY) Activity 367 (NICE -STREAMS; Neogene ice streams and sedimentary processes on high-latitude continental margins) are using a series of geophysical (multibeam mapping, seismic reflection profiling) and geological/geotechnical techniques (sediment coring, dating and physical properties analysis), to unravel the Quaternary glacial and sedimentary history of a polar continental margin in response to ice sheet dynamics: the Storfjorden Trough and Trough Mouth Fan, off southern Svalbard. The build-up of the sedimentary structure of this margin appears to be controlled by short-lived episodes of extreme sedimentation. Deglaciations, when the ice stream is grounded at or near the continental shelf edge, produce terrigenous sediment focusing on the upper continental slope in the form of interlaminated plumite sequences, consequence of the initial subglacial meltwater outbursts. The dating of top and bottom of post-LGM plumites suggests that deposition might have occurred in a few hundred years with an extremely high sedimentation rate of 3.2 cm a-1. Glacial maxima that may last a few thousand years produce tens of m of massive diamictons (Glacigenic Debris Flows; GDF), so that 45 m of deposit would also result in high sediment accumulation rates of 1.1 cm a-1. The Quaternary style of sediment accretion in this margin and its architecture appear to depend on alternation of these two sediment types and their rates of accumulation. We observe that lateral distribution of GDFs and plumites depends on position of ice streams and the history of their retreat from the shelf edge. Physic

At high-latitudes, sediment dynamics and consequent continental margin architecture are deeply affected by grounded ice. Fast-flowing ice streams deliver large quantities of sediments from meltwater plumes and Glacigenic Debris Flows (GDFs) at the mouth of cross-shelf troughs during relatively short time periods (deglaciations and glacial maxima, respectively). Glacigenic sediment dynamics also controls the distribution in time and space of large-scale landslides

This study aims to present an overview of the seafloor morphology and shallow sedimentary structure of the Storfjorden and Kveithola Trough Mouth Fans (TMFs) on the northwestern Barents Sea continental margin. Data have been compiled from two International Polar Year (IPY) cruises (SVAIS, of the BIO Hespérides and EGLACOM of the R/V OGS-Explora) that yielded 15,340 km2 of multi-beam bathymetry and 9500 km of sub-bottom seismic profiles. In this area, the continental shelf edge defines three wide and subdued sedimentary lobes forming Storfjorden TMF, one single lobe on Kveithola TMF, and three inter-TMF areas on the continental slope. The two northernmost lobes of Storfjorden TMF (Lobes I and II) are composed by thick (up to 50 m) sequences of glacially derived debris flow deposits interbedded with thin a few metres de-glacial and interglacial deposits. A network of upper slope gullies incises these debris flow deposits as a consequence of subglacial meltwater release at or near the shelf break. Gullies evolve into channels whose morphologic evidence disappears midslope, leaving place to a subdued chevron-like morphological pattern inherited by the preceeding glacial maximum debris flow deposits. A drastic change occurs on the continental slope of Storfjorden TMF Lobe III and Kveithola TMF, where are several translational submarine landslides mostly originated in the upper slope, the majority of which detach at the contact between Middle Weishelian glacigenic debris flows and the overlying acoustically laminated plumites. Dendritic canyon systems only develop in inter-TMF areas. The data suggest that TMF continental slope progradation depends on short-lived episodes of extreme sedimentation during glacial maxima and during the early deglaciation phase, and that an important controlling factor is the mechanism of ice stream retreat from the continental shelf edge. We suggest that the two northern Storfjorden sub-ice streams were composed of thicker and perhaps faster