Search

Tagoro is one of the few submarine volcanoes in the world that has been monitored since its early eruptive stage in 2011 to present day. After six multidisciplinary oceanographic cruises conducted between 2014 and 2023 to gather a comprehensive dataset of georeferenced video-imagery and in situ measurements of hydrothermal flow velocities and hydrothermal fluid samples, we provide a robust characterization of the ongoing hydrothermal fluid velocity, heat flux, and nutrient release, along with an accurate delimitation of the hydrothermal field area. Our results reveal that Tagoro hydrothermal system extends from the main hydrothermal crater up to the summit, covering an area of 7600 m2. This hydrothermal field comprises thousands of small individual vents, displaying diverse morphologies such as crevices and delicate chimney-like structures, irregularly scattered across the dominant diffuse venting surface. Hydrothermal fluid temperatures and velocities at the substratum level reveal a clustered spatial distribution, ranging from 21.0 to 33.3 °C and 1.6–26.8 cm min−1, respectively. Furthermore, our findings indicate a discernible correlation between hydrothermal fluid temperature and vent density, while significant differences were observed between velocities from diffuse and focused areas. Additionally, heat fluxes exceed 200 MW across the entire active region, with heat flux values ranging from 6.06 to 146.87 kW m−2 and dissolve inorganic nutrient concentrations exhibit significant enrichments, comparable to the magnitude of important nutrient sources in the area as upwelling systems or mesoscale structures.

[EN] This work presents a compilation of the place names in the Spanish marine subdivisions (North Atlantic, South Atlantic, Estrecho and Alborán, Levantine-Balearic and Canary). By systematically identifying these features across the subdivisions, an extensive bibliographic and database research was conducted to assign appropriate place names to each element. Ten main toponym types have been recognized: geographic, personal, shape description, commemorative, cultural, fisher name, vessels and expeditions, others and unknows. The most common names are geographic locations followed by names of historical personalities. This work evidences the variability of the types depending on the marine subdivisions. This new database is open allowing modifications and new names could be added in the future., [ES] Este trabajo presenta una recopilación de los topónimos en las subdivisiones marinas españolas (Atlántico Norte, Atlántico Sur, Estrecho y Alborán, Levantino-Balear y Canarias). Mediante la identificación sistemática de estas características en las subdivisiones, se llevó a cabo una extensa investigación bibliográfica y de bases de datos para asignar nombres de lugar adecuados a cada elemento. Se han reconocido diez tipos principales de topónimos: geográficos, personales, descripciones de forma, conmemorativos, culturales, nombres de pescadores, nombres de embarcaciones y expediciones, otros y desconocidos. Los nombres más comunes son ubicaciones geográficas, seguidos de nombres de personalidades históricas. Este trabajo evidencia la variabilidad de los tipos según las subdivisiones marinas. Esta nueva base de datos está abierta a modificaciones y nuevos nombres que podrían agregarse en el futuro.

Multibeam bathymetry, sub-bottom parametric profiler, multichannel seismic reflection data and sediment cores were used to detail the nature, morpho-sedimentary and internal structure of five newly discovered submarine mud volcanoes (MVs) in the Moroccan margin of the Gulf of Cadiz. The Henriet and Subvent MVs are located at 300–400 m water depth, while Chueca, Demetrio de Armas and Puerto Real MVs are at 1100–1800 m water depth. Two main types of morphologies are identified: regular cone-shaped edifices (Subvent MV) with a pronounced crater (Henriet MV) in the eastern province; and ridge-attached oval-shaped conical edifices (Chueca, Demetrio de Armas and Puerto Real MVs) in the western province. The overall seismic architecture of these MVs is the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. The Henriet and Subvent MV system is composed of stacked bicones and intrusive complexes, which penetrated upper Miocene-Quaternary sedimentary units rooted in the Gulf of Cadiz wedge. Major phases of mud extrusion and outbuilding took place since the Late Pliocene with re-activation during mid-Pleistocene. Mud breccias interbedded with hemipelagic/contourite sediments were collected for all MVs. Cores attest to recent periods of mud outflows lasting from the Late Pleistocene (180 ky) whereas the end of MV extrusion could date back to historic times (the last 0.6 ky), giving rise to the onset of a new quiescent activity. The most active MV points out to the Subvent MV. These new MVs are formed in response to the extensional and compressional system within the Gibraltar Arc. In the eastern side, MVs are related to extensional faults forming deep sedimentary basins and forcing overpressured fluids to migrate upwards coeval with thick contourite deposits. On the western side, MVs are related to compressional ridges at the front of fold-thrust systems which act, as pathways to deep-seated fluids to ascent to seafloor.

The Spanish Institute of Oceanography has realized nineteen oceanographic cruises in order to monitor the geomorphological changes during the submarine eruption of the Tagoro volcano and later evolution. The major geomorphological features were achieved fundamentally by the use of Multibeam EM710 echosounder data. Eruption was characterized by two main phases, the first one alternate stages of vertical growth and denudation by development of basal and southern flank collapses of the main edifice took place; the second phase was characterized by a fissure growth with a NNW-SSE trend. The eruption produced a main volcanic edifice rising from 400 to 88 m water depth. The edifice consists of four attached cones extended and at least fifteen emission vents. This edifice has a quasi-circular base and its final morphology was modulated by the activity of emission vents during the second phase which produced a NNW-SSE elongated summit line. Both vertical growth and instability phases were conditioned by preexistent southwestwards gradient of the seafloor slope and its initial location into a gully on the southern submarine island flank. In the proximal area, morphology is also characterized in by four ridges that correspond to semi-buried residual scars of different collapse phases. On the SW flank an apron of mixed lavas, pyroclastic and debris flows were deposited along more than 5 km length. These deposits were channeled throughout the previous gully and three parts are differentiated: proximal apron from the cone to an intermediate ravine located at 2.5 km away from the base of the main edifice where its maximum thickness occur in an accumulation front, the intermediated ravine and the distal apron fan deposits from the mouth of the ravine to 1800 m depth. The Tagoro volcano was built during a monogenetic eruption dominated by pyroclastic and lava balloon emissions, with lava emissions in the deepest vents. Its evolution alternating constructive and destructive stages a

Several water masses are involved in the circulation of oceans, their bottom layers impacting on sedimentation through contourites. The majority of palaeoceanographic studies on regional contourites are performed for one water mass despite that their joint study would offer relevant clues to understand past ocean and climate interaction. This works presents for the first time a an analysis about the impact of the Light Intermediate Mediterranean (LMW) and Dense Deep Mediterranean (DMW) bottom currents on the sedimentation in the Alboran Sea (SW Mediterranean) and its paleoceanographic significance in response to climatic oscillations from the last glacial period to the Holocene. To do this, an integration of chronostratigraphical, sedimentological, and compositional data is carried out from contourites formed by those water masses. That integration enable us to define three distinct contourite stratigraphic models. (I) The contourite terrace model, characterized by coarse-grained contourites, which is an archive of the interplay between the high-energy Atlantic Water-LMW interface and glacioeustasy from the Younger Dryas (YD) to the Holocene. (II) The contourite drift models, which are archives of rapid ocean-climate coupled fluctuations since 29.5 kyr. They comprise coarse-grained contourites formed by a relatively fast LMW and fine-grained contourites formed by a relatively weak DMW, except for the Heinrich Stadials HS3 to HS1 and YD when coarse-grained contourites were deposited. (III) The contourite/turbidite mixed model represents another archive of DMW and glacioeustasy interplay from the end of the late Pleistocene to Holocene. That contourite stratigraphy allows us to infer for the first time the relative variability of the LMW versus DMW flow regimes, which records differences and similarities. The similarities indicate that the LMW and DMW fluctuations occur in parallel at millennial and centennial time scales. The differences refer to the overall higher v

Since Tagoro volcano erupted in 2011, several impacts have been associated to the volcano formation process, some of which are still present to date. This chapter is a review of the marine environmental perturbations caused by Tagoro volcano as a new geological structure, but thoroughly onto the partly annihilated benthic and demersal pre-existing biota, and the colonizing dynamics during the recovery process. Shallow recent volcanic activity in the NE Atlantic is uncommon, thus, Tagoro provides a unique opportunity to study, from the very beginning, the evolution of the unusual shallow hydrothermal systems, and the establishment of new marine habitats and associated biota. Distinct habitat types, with different associated deposit products (volcaniclastic aprons, lava balloons, lava ponds, etc.), have been described, and a description of the colonizing biota has been made from the available published works as well as from underwater imagery and benthic dredge samples taken during several field expeditions (Vulcano0313, 1013, 0314 and Vulcana0417). Those habitats included hard (rocky) and mixed (loose) substrate habitats, but also extreme habitats with hydrothermal vents and bacterial mats, accompanied by significant physical and chemical anomalies. Habitat preference by the observed taxa among the volcanic edifice has been explored through nMDS analyses, and a comparative analysis with published data of the typical fauna of the region (La Restinga, Mar de Las Calmas, Marine Reserve, El Hierro Island), permitted to foresee the very first steps and direction of the recovery of the benthic and demersal communities. The impact caused by Tagoro onto the nearest littoral benthic communities, the ichthyofauna and the local fisheries have been described as well. Finally, some recommendations and further steps are given in order to adequately monitor the successional trend and environmental status of the benthic and demersal communities

[EN] The Strait of Gibraltar is a first-order physiographic feature between southern Iberia and northern Africa. It has been excavated over the Arc of Gibraltar in favor of a conjugated ENE-WSW and WNW-ESE fault system that have acted as weakness structures. The Strait was generated by erosive processes of the water masses coming from the Atlantic Ocean in the lower Pliocene, due to the rude and rapid flooding of the Alboran Sea basin. Once the flood stabilized the exchange and interaction of the Atlantic and Mediterranean water masses began as we know it today; the Atlantic water that circulates on the surface of the Strait towards the Alborán Sea, and the Mediterranean water masses that circulate in depth towards the Atlantic Ocean. The acceleration of the Atlantic and Mediterranean water masses in the Strait corridor has favored the development of erosive processes.These processeshave allowed the outcrops of the rocky substratum, the development of sedimentary instabilities and the generation of paleochannels, carbonate crusts and cold-water coral formations during the Pliocene and Quaternary. Likewise, the acceleration of the Mediterranean water masses on their way in and out of the Strait and their interaction with the sea floor have controlled sedimentation both in the Alborán Sea basin and in the Gulf of Cádiz, forming contouritic depositional systems, [ES] El estrecho de Gibraltar es un rasgo fisiográfico de primer orden entre el sur de Iberia y el norte de África. Ha sido excavado sobre el Arco de Gibraltar a favor de un sistema de fallas conjugadas de direcciones ENE-OSO y ONO-ESE que han actuado como estructuras de debilidad. El Estrecho fue generado por procesos erosivos de las masas de agua procedentes del océano Atlántico en el Plioceno inferior, al producirse de forma brusca y rápida la inundación de la cuenca del mar de Alborán. Una vez estabilizada la inundación comenzó el intercambio y la interacción de las masas de agua atlántica y mediterránea tal y como hoy la conocemos: el agua atlántica que circula en la superficie del Estrecho hacia el mar de Alborán, y las masas de agua mediterráneas que transitan en profundidad hacia el océano Atlántico. La aceleración de las masas de agua atlántica y mediterránea en el corredor del Estrecho ha favorecido el desarrollo de procesos erosivos. Estos procesos han permitido los afloramientos del substrato rocoso, el desarrollo de inestabilidades sedimentarias, generación de paleocanales, costras carbonatas y formaciones coralígenas de aguas frías durante el Plioceno y el Cuaternario.Asimismo, la aceleración de las masas de agua mediterráneas en su camino de entrada y salida del Estrecho y su interacción con el suelo marino han controlado la sedimentación tanto en la cuenca del mar de Alborán como en el golfo de Cádiz, formando sistemas deposicionales contorníticos

The shallow Tagoro submarine volcano monitoring represents a unique opportunity not only for improving our sparse understanding of submarine volcanic processes in specific scientific fields as physical and chemical oceanography or marine geology but also its interactions over the marine biology in one of the richest marine ecosystems in Europe. This chapter aims to summarize the most relevant physical–chemical, geological and biological changes that occurred in the marine ecosystem of El Hierro island, at the Marine Reserve Punta de La Restinga—El Mar de Las Calmas, due to the genesis of the new underwater volcano Tagoro (27º37′07″N–017º59′28″W) in October 2011. During the first six months of the eruption, extreme physical–chemical perturbations caused by this event, comprising thermal increase from up to + 18.8 °C, water acidification with a pH decrease of 2.9 units, deoxygenation to anoxic levels and extremely high metal enrichment among others, resulted in significant and dramatic alterations of the marine ecosystem. After March 2012, once the eruptive phase was finished, the new submarine volcano entered an active hydrothermal phase involving the release of heat with smaller but still significant and important thermal anomalies of up to + 2.55 °C around the craters, density decrease of − 1.43 kg m−3, pH decrease of − 1.25 units, and high concentrations of metals and inorganic nutrients similar to upwelling zones. These enrichments are still active up to date, producing clear signs of marine recovery not only in the benthonic strata but also in the whole water column compared with pre-eruptive data. Since its eruption ten years ago, an unprecedented monitoring effort has turned into the longest and most complete multidisciplinary time-series for the study of a shallow submarine volcano, with the realization of 31 oceanographic multidisciplinary expeditions that systematically measure more than 40 different physical–chemical and biological variables. All this info

Active volcanoes are key laboratories to carry out detailed research -and monitoring- about the history of magmas before, during and after eruptions. Tagoro, the submarine active vol- cano at El Hierro Island (Canary archipelago), is a highly favorable case to assess and monitor its daily ongoing behaviour, as well as to study the links between the processes of magma genesis occurring at depth and their derived eruptive events at the surface. In this interdisciplinary research we combine new results of classical petrology (petrography, geochemistry, and thermodynamics) on the volcanic products expelled by Tagoro during the 2011–2012 eruption, with a high- resolution (5 m grid) bathymetry model car- ried out during 2017, and recent data from magnetometry, to refine the current knowl- edge of this eruption. Our results mainly reveal (i) slight magma differentiation and mixing processes at c. 12 km depth during a continuous eruptive pulse; (ii) a similar mag- matic evolution and residence times at depth between previous and 2011–2012 eruptions on the island; (iii) an insignificant interaction of external fluids with the magma at depth or within the ascent conduit; (iv) a present-day magnetometric anomaly under the Tagoro’s area; (v) a minimum volume estimate for the magma withdrawn from the plumbing system at depth.

The bamboo coral Isidella elongata is often associated with a diverse community, including commercial fish species, playing an important role in the deep-sea Mediterranean as a biodiversity hotspot. There has been a drastic decrease of the populations of this species since the twentieth century, mainly related to impacts of fishing, leading to its inclusion in the Barcelona Convention and the list of Mediterranean vulnerable marine ecosystems. However, the knowledge on its local scale distribution is still very limited. In this study, habitat suitability models were performed based on a dense population of I. elongata, located in the Mallorca Channel (western Mediterranean), to contribute to fill this knowledge gap. Generalized additive models, Maximum entropy models and Random Forest were combined into an ensemble model. Models showed that habitat is most suitable on smooth plains surrounding the seamounts of Ses Olives and Ausiàs March present in the study area. Furthermore, two models out of three showed a preference of the coral for flat areas. The predictions of the habitat suitability models presented in this study can be useful to design protection measures for this critically endangered species to contribute to the species’ and deep-sea fisheries management.

This paper explains the current seafloor morphology and processes that affect the formation and evolution of three mud volcanoes and one mud volcano/mud diapir complex in the deepest sector of the Spanish margin of the Gulf of Cádiz. The present study provides novel results and interpretations based on an extensive multidisciplinary data set. New high resolution bathymetric and backscatter data from multibeam echosounders enabled a detailed geomorphological analysis aimed at identifying diverse seafloor features in the different edifices studied and their adjacent bottoms. These features are mainly related to fluid escape (e.g., mud volcanoes, mud flows and depressions), gravitational (e.g., slide deposits and scars), and tectonic (e.g., faults and uplifted antiforms) processes. Very high-resolution parametric profiles and single channel seismic reflection profiles were interpreted for further analysis of the internal structures, demonstrating their important interplay with diapiric processes. Box-corer and gravity-corer have been used to identify different sediment types that have been correlated with backscatter values. The dominant benthic species associated with fluid venting and also with different types of substrates (hard and soft) were characterized using submarine images obtained with an underwater camera deep-towed sled. The benthic species observed were contrasted, and added to those collected with beam trawl and box-corer for characterisation of the benthic and demersal communities. Different geological and biological indicators have been used as proxies of the interaction of these features with the geological processes (such as fluid-escape-related, gravitational, or structural) to characterise the environmental conditions that determine the geomorphology, substrates, habitats and their associated biota. Multivariate analyses combining faunistic and environmental data resulted in the presence of 3 main faunistic assemblages linked to different levels of

The Tajogaite volcanic eruption took place on the southwestern flank of La Palma Island between September 19th and December 13th, 2021. An oceanographic study of the area was carried out to control the effects of the submarine lava flow on the seabed, developed in three-time windows during the eruption. Changes in morphology, extent, and thickness, have been studied by combining pre and successive post-bathymetric datasets, with 1m of spatial resolution, using an MB710 multibeam echosounder. To characterize the lava flow facies and different substrate types it has been used an ROV-Liropus 2000. The first bathymetric survey was carried out in the most probable arrival zone of lava flow to the sea to establish the pre-eruption characteristics of the insular shelf and slope where several gullies and their head-scarps were located. On September 28th, the lava flow arrived at the ocean forming two lava deltas: the northern and smaller one located to the south of the Tazacorte harbor, and the southern and main one attached to the north side of the lava delta generated during the 1949¿s eruption. The new volcanic materials have been identified at least to a depth of 360 m and approximately 1.2 km from the initial shoreline, occupying an estimated submarine area of 35 ha. The northern lava delta has been emplaced on the inner shelf but in the southern one, the subaerial part reaches the old shelf edge where they have rested on a rocky platform and the submarine lava flow has been channeled into shelf depressions and submarine gullies that intersect the shelf border and the upper slope, totally transforming the relief. Lava flows advanced along the seabed both as ¿aa¿ and block flows in the proximal area, also forming megapillows of different sizes on the upper slope. The monitoring of this eruption allowed studying, in real-time, the arrival of a lava flow to the sea and the associated modification of the coast and seabed. Results provide additional information on the devel

Active volcanoes are key laboratories to carry out detailed research -and monitoring- about the history of magmas before, during and after eruptions. Tagoro, the submarine active volcano at El Hierro Island (Canary archipelago), is a highly favorable case to assess and monitor its daily ongoing behaviour, as well as to study the links between the processes of magma genesis occurring at depth and their derived eruptive events at the surface. In this interdisciplinary research we combine new results of classical petrology (petrography, geochemistry, and thermodynamics) on the volcanic products expelled by Tagoro during the 2011–2012 eruption, with a high-resolution (5 m grid) bathymetry model carried out during 2017, and recent data from magnetometry, to refine the current knowledge of this eruption. Our results mainly reveal (i) slight magma differentiation and mixing processes at c. 12 km depth during a continuous eruptive pulse; (ii) a similar magmatic evolution and residence times at depth between previous and 2011–2012 eruptions on the island; (iii) an insignificant interaction of external fluids with the magma at depth or within the ascent conduit; (iv) a present-day magnetometric anomaly under the Tagoro’s area; (v) a minimum volume estimate for the magma withdrawn from the plumbing system at depth.

The recent sedimentological properties of contouritic features (terrace and drift) developed between the Guadiaro and Baños submarine canyons (NW Alboran Sea) have been characterised using sedimentological (texture, median grain size, sorting, terrigenous UP10 fraction), compositional (sand fraction composition and Zr/Rb ratio), and chronostratigraphic ( 18O and AMS 14C) data. Ten sediment cores retrieved from 319 to 914 m water depth across the margin (from the upper slope to basin environment) sampled a contourite terrace, and plastered, sheeted and elongated separated contourite drifts formed under the influence of intermediate and deep Mediterranean water masses (MWs). Integration of this data reveals that the terrace and Guadiaro-Baños drift deposits have comprised mainly mud, silt, sandy-silt and silty-sand contourite facies for the last 29 kyr. The vertical distribution of these facies allows us to identify mainly bi-gradational sequences composed of a coarsening up and a fining up sub-sequence which are clearly reflected in the Zr/Rb ratio. Correlation of physical and chemical palaeocurrent proxies after core chronostratigraphy reveals comparable millennial and centennial patterns with maximum peaks at Heinrich Events H3, H2, H1, and the Younger Dryas. This implies a concomitant deposition of a uniform layer of coarse-grained sediments on the drifts located on the lower slope and in the basin during those cold periods. The differences in sedimentation rate (SR) and facies among the regional contourite sequences from the upper continental slope to the basin allow us to establish two depositional models: Model 1, on the slope, involves silty contourites with a low SR (< 9 cm/kyr) and the singular presence of glauconite on the upper slope; Model 2, at the base of slope and in the basin, is characterised by muddy contourites with a higher SR (up to 37.4 cm/kyr). These models seem to be controlled mainly by the spatial and temporal dynamics of intermediate and de

El Cañón de Algeciras se localiza en el eje de una bahía en forma de herradura (Bahía de Algeciras),está excavado sobre un sustrato rocoso (Unidades del Flysch del Campo de Gibraltar) y afectado por la dinámica de intercambio de masas de agua en el Estrecho de Gibraltar.Por sus características geomorfológicas y el contexto oceanográfico en el que se encuentra, este cañón es un excelente ejemplo para comprender mejor los procesos sedimentarios mixtos. Esta zona se ha estudiado en base a un mosaico de batimetría multihaz (EM710) y perfiles del subsuelo con sonda paramétrica(TOPASPS18). El cañón discurre a lo largo de 19 km de longitud en dirección NNO-SSE,estando constituido por segmentos menores de dirección NNE-SSO, ENE-WSWy NNO-SSE, su anchura varía de 1,2 a 3,6 km y los flancos tienen desniveles comprendidos entre90y560 m. En las paredes del cañón se han caracterizado elementos morfosedimentarios gravitacionales y contorníticos. Los gravitacionales comprenden deslizamientos y cárcavas en las paredes del cañón, así como un talweg turbidítico; los contorníticos incluyen parches de sedimentos adosados en sus paredes que localmente llegan a extenderse hasta el talweg, así como escarpes y superficies erosivas.La variabilidad espacial de estos elementos indica la coexistencia de procesos gravitacionales y contorníticos en los sectores proximal (cabecera, 60-390 m de profundidad) y medio(390-550 de profundidad), mientras que en el sector distal(550-890 de profundidad)se observa únicamente la acción de procesos gravitacionales. Asimismo, indican una sedimentación contornítica preferencial tanto en el flanco oriental del sector proximal como en el flanco occidental en el sector medio.Estos datos sugieren que el factor de control principal de los procesos mixtos es la interacción entre la propia morfología del cañón y la dinámica de avance y retroceso a lo largo del mismo de las masas de agua Atlántica superficial y la Mediterránea profunda, en función de la marea

The Gulf of Cadiz and the Alboran Sea are characterized by tectonic activity due to oblique convergence at the boundary between the Eurasian and Nubian plates. This activity has favoured a variety of tsunamigenic sources: basically, seismogenic faults and submarine landslides. The main tsunamigenic faults in the Gulf of Cadiz would comprise the thrust systems of Gorringe Ridge, Marquês de Pombal, São Vicente Canyon, and Horseshoe faults with a high susceptibility; meanwhile in the Alboran Sea would be the thrust system of the northern Alboran Ridge with high susceptibility, and the thrust systems of north Xauen and Adra margin, the transpressive segment of Al Idrissi fault, and the Yusuf-Habibas and Averroes faults, with moderate to high susceptibility. The areas with the greatest potential to generate tsunamigenic submarine landslides are in the Gulf of Cadiz, the São Vicente Canyon, Hirondelle Seamount, and Gorringe Ridge; and in the Alboran Sea are the southern and northern flanks of Alboran Ridge. Both sources are likely to generate destructive tsunamis in the Gulf of Cadiz, given its history of bigger earthquakes (>7 Mw) and larger landslides. To fully assess tsunamigenic sources, further work needs to be performed. In the case of seismogenic faults, research focuses on geometry, offsets, timing, paleoearthquakes, and recurrence, and in landslides on early post-failure evolution, age, events, and recurrence. In situ measurements, paleotsunami records, and long-term monitoring, in addition to major modelling developments, will be also necessary.

We present a multidisciplinary study of morphology, stratigraphy, sedimentology, tectonic structure, and physical oceanography to report that the complex geomorphology of the Palomares continental margin and adjacent Algerian abyssal plain (i.e., Gulf of Vera, Western Mediterranean), is the result of the sedimentary response to the Aguilas Arc continental tectonic indentation in the Eurasian–Africa plate collision. The inden tation is imprinted on the basement of the margin with elongated metamorphic antiforms that are pierced by igneous bodies, and synforms that accommodate the deformation and create a complex physiography. The basement is partially covered by Upper Miocene deposits sealed by the regional Messinian Erosive Surface characterized by palaeocanyons that carve the modern margin. These deposits and outcropping basement highs are then covered and shaped by Plio-Quaternary contourites formed under the action of the Light Intermediate and Dense Deep Mediterranean bottom currents. Even though bottom currents are responsible for the primary sedimentation that shapes the margin, 97% of this region's seafloor is affected by mass-movements that modified contourite sediments by eroding, deforming, faulting, sliding, and depositing sediments. Mass-movement processes have resulted in the formation of recurrent mass-flow deposits, an enlargement of the submarine canyons and gully incisions, and basin-scale gravitational slides spreading above the Messinian Salinity Crisis salt layer. The Polopo, Aguilas and Gata slides are characterized by an extensional upslope domain that shapes the continental margin, and by a downslope contractional domain that shapes the abyssal plain with diapirs piercing (hemi)pelagites/sheet-like turbidites creating a seafloor dotted by numerous crests. The mass movements were mostly triggered by the interplay of the continental tectonic indentation of the Aguilas Arc with sedimentological factors over time. The indentation, which involves t

This paper integrates sedimentary, tectonic and volcanic geological processes inside a model of volcano-tectonic activity in oceanic intraplate domains related to rifted continental margins. The study case, the eastern Canary Basin (NE Atlantic), is one of the few places in the world where giant MDTs and Quaternary volcanic and hydrothermal edifices take place in intraplate domains. In this paper, we analyse how two structural systems (WNW-ESE and NNE-SSW) matching with the oceanic fabric control the location of volcanic systems, seafloor tectonic reliefs and subsequently the distribution of main sedimentary systems. Linear turbidite channels, debris flow lobes and the lateral continuity of structural and volcanic reliefs follow a WNW-ESE trend matching the tracks of the oceanic fracture zones. Furthermore, escarpments, anticline axes and volcanic ridges follow a NNE-SSW trend matching normal faults delimiting blocks of oceanic basement. The morpho-structural analysis of all the above geomorphological features shows evidence of a volcanic and tectonic activity from the middle–upper Miocene to the Lower–Middle Pleistocene spread over the whole of the eastern Canary Basin that reached the western Canary Islands. This reactivation changes the paradigm in the seamount province of Canary Islands reported inactive since Cretaceous. A tecto-sedimentary model is proposed for this period of time that can be applied in other intraplate domains of the world. A tectonic uplift in the study area with a thermal anomaly triggered volcanic and hydrothermal activity and the subsequent flank collapse and emplacement of mass transport deposits on the Western Canary Slope. Furthermore, this uplift reactivated the normal basement faults, both trending WNW-ESE and NNE-SSW, generating folds and faults that control the location of turbidite channels, escarpments, mass transport deposits and volcanic edifices.

El análisis morfotectónico del sector central del Promontorio Balear, entre las islas de Ibiza y Mallorca, mediante batimetría multihaz y perfiles sísmicos de muy alta resolución ha permitido diferenciar varios rasgos morfológicos relacionados con la tectónica a dos escalas. Los elementos de gran escala, de dirección NE-SO, son: i) el escarpe Émile Baudot; ii) el monte submarino Émile Baudot, y iii) la alineación de montes submarinos Ausiàs March y Ses Olives. Los elementos de pequeña escala son: i) dos elevaciones longitudinales (ENE-OSO); ii) escarpes rectilíneos (NO-SE a NE-SO); iii) depresiones tectónicas (NNE SSO a NE-SO); y iv) alineaciones rectilíneas de pockmarks (NO-SE a NNE-SSO). Los elementos de mayor tamaño responden a la configuración estructural neógeno-cuaternaria. El escarpe Émile Baudot limita el Promontorio Balear y la cuenca oceánica del Mediterráneo Occidental. La alineación de montes submarinos Ausiàs March y Ses Olives está generada por una fase extensional, y el monte submarino Émile Baudot forma parte de una alineación volcánica NO-SE asociada a la Zona de Fractura de Ibiza. Los elementos de pequeña escala están relacionados con estructuras tectónicas activas que deforman las unidades sedimentarias del Cuaternario y el fondo marino. Las elevaciones longitudinales están generadas por pliegues anticlinales, mientras que el resto de estructuras están asociadas a la actividad de fallas normales de buzamiento alto., A morphotectonic analysis has been carried out between the islands of Ibiza and Majorca in the central sector of the Balearic Promontory using multibeam bathymetry and very high-resolution seismic profiles. Several morphological features related to tectonics at two different scales have been differentiated. The large-scale features have a NE-SW direction, they are: i) the Émile Baudot Escarpment; ii) the Émile Baudot seamount, and iii) the Ausiàs March and Ses Olives seamounts alignment. The differentiated small-scale elements are i) two longitudinal elevations (ENE-WSW); ii) rectilinear scarps (NW-SE to NE-SW); iii) tectonic depressions limited by one or two scarps (NNE-SSW to NE-SW), and iv) rectilinear pockmarks alignments (NW-SE to NNE-SSW). The largest elements respond to the Neogene-Quaternary structural configuration. The Émile Baudot escarpment is the limit between the Balearic Promontory and the Western Mediterranean oceanic basin. The alignment of the Ausiàs March and Ses Olives seamounts respond to the last extensional phase, and the Émile Baudot seamount forms part of a NW-SE volcanic alignment that could be associated with the Ibiza Fracture Zone. The smaller elements are related to active tectonic structures that deform Quaternary sedimentary units and the seafloor. The longitudinal elevations correspond to anticlinal folds, while the rest of the structures are associated to the activity of near vertical normal faults.

En el margen septentrional del Mar de Alborán, la deformación compresiva relacionada con la convergencia entre las placas de Eurasia y Nubia se resuelve mediante una intensa fracturación según dos grandes sistemas de fallas de dirección NNE-SSO con movimiento sinestro y NO-SE de desplazamiento dextral-normal. El análisis estructural de los elementos geomorfológicos presentes en el fondo marino permite establecer, además, una serie de elementos morfológicos generados por la actividad de pliegues anticlinales y sinclinales que conforman una serie de elevaciones de dirección N050-060ºE. Estos pliegues deforman a las unidades sedimentarias superficiales y han sido activos al menos durante el Cuaternario, como lo demuestra el patrón de espesores de las unidades sísmicas afectadas por el plegamiento y la deformación de la superficie erosiva asociada a una terraza contornítica. Este patrón de estructuras se interpreta como generado por la deformación existente sobre una falla de cabalgamiento, vergente hacia el norte, que asume parte de la deformación compresiva causada por la indentación del bloque de la Dorsal de Alborán., In the northern margin of the Alboran Sea, the compressive deformation related to the convergence between the Nubian and Eurasian plates is resolved by an intense fracturing along two large fault systems trending NNE-SSW with left-lateral movements and NW-SE with right-lateral normal components. The structural analysis of the geomorphological elements on the seafloor also allows us to establish a series of morphological elements generated by the activity of some anticline and syncline fold sets. It is basically a series of ridges heading N050-060ºE. These folds deform the shallow sedimentary units and have been active at least during the Quaternary, as evidenced by the thickness pattern of seismic units affected by the folding and the deformation of an erosive surface associated with a contouritic terrace. This pattern of structures is interpreted to be generated by the overlying deformation on a thrust fault, verging towards the north, which assumes part of the compressive deformation caused by the indentation of the Alborán Ridge block.

The dense and deep water flow that leaves the Mediterranean Sea to the Atlantic flows through the upper and middle slope of the Gulf of Cádiz as a powerful bottom stream that model sand interacts with bathymetry. The detailed analysis of underwater images,obtained with a photogrammetric sled in the central area of the upper and middle slope of the Gulf of Cádiz, together with multibeam bathymetry and oceanographic and sediment types data, has allowed conducting a detailed study of the seafloor microtopography and the predominant oceanographic dynamics in the study area. Different fine-scale spatial bedforms were identified, such as ripples, dunes, burrows, mounds, obstacle marks, rock bottoms, and low-roughness bottoms using underwater images. Besides, a geostatistical study of the different video transects studied was carried out and allowed us to differentiate three types of bottoms depending on the processes that affect their microtopography.