Abstract. The Scotian Shelf lies at the confluence of warm Gulf Stream (GS) waters and the cold Labrador Current (LC), making it highly sensitive to large- and small-scale climate variability. Modern observations show rapid regional warming accelerated by episodic GS-derived intrusions, yet Holocene paleoceanographic reconstructions from this margin are sparse and often conflicting with respect to the frequency and extent of intrusion events. Here, we present high-resolution Mg/Ca-derived sea-surface temperature (SST) and planktonic δ¹⁸O records from St. Anns Basin on the north-eastern Scotian Shelf that provide new insights into the hydrographic surface-ocean variability of the past 8.5 ka calibrated Before Present (cal BP). While the SST record does not capture the 8.2 ka event, this event is evident in the δ¹⁸O and Ca/Sr records, indicating that its freshwater signal reached the Scotian Shelf. Reconstructed SSTs are generally cold from ~8.5 to ~6.2 cal ka BP, followed by a gradual increase in mean SSTs punctuated by multiple short-lived warm and saline events beginning around 6 cal ka BP, at 6.0–5.8, 5.5–5.4, 5.1–4.9, 3.2–3.1, 2.5–2.2 and 1.05–0.8 cal ka BP, which we interpret as intrusions of GS-sourced slope waters. We attribute these events to basin-scale reorganizations of the GS-LC system, consistent with the minimum/maximum modal state framework of Pickart et al. (1999). Minimum modal state circulation, characterized by a strong onshore LC and an intensified Deep Western Boundary Current (DWBC), which is dominated by Denmark Strait Overflow water, creates a sharp front which restricts intrusions of warm water onto the Scotian Shelf. Maximum modal state conditions feature a weakened LC and increased Labrador Sea Water (LSW) contribution to the DWBC, and reduce cross-slope temperature and salinity gradients that permit GS-derived waters to penetrate the shelf. Overall, our results indicate that warm-water intrusions occurred regularly throughout the past 6.5 ka BP with magnitudes of 6.7 °C and 1.5 psu comparable to those observed today.

Submarine landslide reconstructions are essential for understanding failure mechanisms and assessing geohazards. A key factor in this context is the initial failure volume, which strongly influences the tsunami generation potential of landslides. Accurate volume estimates require knowledge of the pre-failure morphology; however, this surface is typically not available and often approximated through extrapolation of the surrounding seafloor. We propose a hybrid reconstruction approach that combines conventional interpolation techniques with a neural network designed to refine them. Instead of replacing classical methods, the neural network builds upon their outputs as initial estimates and iteratively improves them by learning spatial and geomorphological patterns from the surrounding bathymetry. The model is trained in a self-supervised manner using masked bathymetric patches, enabling it to infer realistic pre-failure morphologies and enhance the accuracy of traditional reconstruction workflows.The method was evaluated using bathymetric datasets from different regions and resolutions, including randomly sampled EMODnet patches, a regional EMODnet subset offshore Crete (Greece), and two high-resolution multibeam datasets collected around Crete. Moreover, we analyzed how the reconstruction error changes with the distance from each masked grid cell to the nearest unmasked region. This revealed a consistent pattern that can be used to create a look-up table for estimating reconstruction uncertainty based on the spatial arrangement of missing data.Our findings demonstrate that neural networks provide a powerful improvement for reconstructing missing bathymetric data, reducing reconstruction deviation by up to 5 percentage points compared to the standard method. The approach is particularly valuable for large-scale reconstructions where conventional techniques face limitations.

The South Aegean Volcanic Arc (Greece) is among the most active volcanic systems in Europe and poses an ideal natural laboratory to study the interplay of volcanism and tectonics as drivers of explosive eruptions, earthquakes, submarine landslides and tsunamis. This study focuses on a structurally independent sub-basin in the eastern Christiana Basin, located between the Christiana and Santorini island groups and southeast of the regionally significant Christiana Fault. Although the Christiana-Santorini-Kolumbo volcanic field has been extensively investigated, this basin has not yet been specifically targeted in a comprehensive study.During the MULTI-MAREX research cruise 2 (MSM135), nearly 640 km of hydroacoustic and 2D multi-channel seismic reflection data were acquired across the eastern Christiana Basin. The MSM135 seismic grid provides increased profile density and signal penetration and establishes a connection with the IODP 398 sites U1591 and U1598. Using the prominent Archaeos Tuff (765 ka) as a marker unit, we updated and harmonised the regional seismostratigraphic model. We refine the estimated volume of the Archaeos Tuff, and map deposits of the Poseidon eruption, providing an initial minimum bulk-volume estimate of 9 km³.We discovered a syncline, measuring around 8 km in diameter, beneath the almost flat seafloor. The Archaeos Tuff drapes a pre-existing central cone in a W-shaped geometry and reaches a maximum thickness of almost 200 m near the central cone. The syncline accommodates an additional 500 m of post-Archaeos deposits, primarily the Thera Pyroclastic Formation. The infill transitions quickly from an undulating W-shape to a horizontal stratification, indicating short-lived sag-style subsidence. To the northwest, the syncline is bounded by a major fault system, dubbed Thera Fault System, that strikes parallel to the Christiana Fault exhibiting vertical offsets of up to 160 m. Like the Christiana Fault, the Thera Fault System is likely a continuation of the normal faults northeast of Santorini.The seismostratigraphic model constrains the timing of eruptive and tectonic events, assembled in a comprehensive timeline. We date the activity of at least 10 previously little-considered volcanic cones near the margin of the basin to the Late Pleistocene, based on their relative position between known stratigraphic units. Our findings imply a slow, continuous down-faulting at the Christiana Fault, likely related to the rift extension in the region, whereas the Thera Fault System faulted in two stages of shorter duration. The timing of the subsidence coincides approximately with the first explosive eruption cycle on Santorini.

The Scotian Shelf is affected by the confluence of cold polar and warm Gulf Stream-influenced waters, making it particularly sensitive to record past ocean and climate variability. Despite this paleoenvironmental significance, major gaps in our understanding of Holocene ocean and climate dynamics persist, particularly in terms of sea ice and marine productivity. Here, we use a combination of biomarkers, specifically the sea-ice proxy IP25, together with biomarkers for productivity (i.e., brassicasterol, dinosterol, total organic carbon) and terrigenous input (campesterol) in a sediment core from the northeastern Scotian Shelf to resolve Holocene changes in sea ice and marine productivity. During the Early Holocene, our results show increased spring sea-ice algae and reduced marine productivity, which we posit to be linked to a strongly reduced regional sea level together with increased inflow of meltwater favoring the formation of an expanded seasonal sea-ice cover on the Scotian Shelf. After 6 cal ka BP, the Scotian Shelf became predominantly free of sea ice due to a decreased influence of meltwater and a rise in local sea level. After 2.5 cal ka BP and coinciding with the Late Holocene Neoglacial cooling, the Scotian Shelf might have been affected by episodic sea-ice readvances, consistent with other regional on-and offshore paleoclimate studies. In summary, our records suggest a strong link between sea-ice extent, marine productivity, and Holocene variations in regional sea level, and ocean and atmosphere conditions, i.e., the strength of Gulf of St. Lawrence outflow and Labrador Current, and prevailing North Atlantic Oscillation anomalies.

ABSTRACT The Laurentide Ice Sheet covered vast areas of North America during the Wisconsinan, including the Labrador Shelf, off the coast of eastern Canada. The shelf is characterized by glacial cross‐shelf troughs, which have been considered as predominantly eroded by the last ice advance. Nevertheless, these cross‐shelf troughs contain substantial sedimentary infill that has not yet been thoroughly explored and elucidated. Therefore, we hypothesize that older, potentially non‐glacial, sediments are preserved within these cross‐shelf troughs on the Labrador Shelf. In this study, we investigate the stratigraphic infill of three major trough systems on the Labrador Shelf using 2D seismic reflection data to refine the erosional and depositional processes that produce the geomorphology and stratigraphy of the shelf. The results of the study present an updated Quaternary stratigraphy of the Labrador Shelf, comprising eight seismic units. For the first time, we interpret glaciomarine and open marine deposits between glacial till layers. Additionally, we identified sets of elongated depressions, at three different depth intervals. Some of them are classified as subglacial meltwater channels and some others as ice stream troughs. Finally, we propose a stratigraphic evolution model consisting of 10 phases and spanning two glacial–interglacial cycles. The results support our hypothesis and suggest that the deeper sediment layers on the shelf contain evidence of older glacial–interglacial cycles. They also lend support to the hypothesis of a multiphase origin over multiple glacial cycles for the cross‐shelf troughs. Consequently, new opportunities are provided for the reconstruction of ice‐sheet dynamics and associated oceanographic conditions on the Labrador Shelf, as the sedimentary succession provides an archive to reconstruct dynamics of ice sheets during at least two Quaternary glacial–interglacial cycles.

The MULTI-MAREX research mission, initiated by the German Marine Research Alliance (DAM), is establishing two living labs in Greece to study extreme marine geological events and related hazards. To address the challenges of communicating research outcomes and risk assessments, we have developed a workflow for creating virtual reconstructions of real study sites that transform complex geohazard scenarios into photorealistic immersive experiences. These virtual scenarios enhance situational awareness and facilitate meaningful and fact based engagement with experts, policymakers, and the public.Using a game engine as a real-time 3D rendering platform enables the integration of physics-based numerical simulations with real-world spatial data thus providing an immersive frontend to classical numerical models. Our focus is on developing workflows that support a semi-automated, asset-enhanced, immersive visualisation of geospatial data within this framework. These virtual environments synthesise numerical physical models with remote sensing data, including terrestrial and marine digital outcrop models derived from drone and submersible imagery, as well as hydroacoustic bathymetry. Digitally placed assets, such as high-resolution synthetic textures, vegetation, cars, urban furniture and buildings, enhance the visual appearance and help to bridge the gap between different data resolutions. Physics-based simulations of fluids, objects, collisions, destruction, lighting and weather further transform real-world data into photorealistic, interactive environments.By integrating numerical simulations via a custom data interface, we can visualise the effects of tsunamis, volcanic eruptions, extreme weather and wildfires with high fidelity. The framework used allows for a scalable approach across platforms, ranging from smartphones and desktop systems to head-mounted displays. These platforms ensure that visualisations and gameplay can be adapted to reach different stakeholders.Stakeholders can experience scenarios from multiple perspectives, such as first-person or external observer view, and freely explore the open-world virtual environment. Interactive storylines support learning by guiding stakeholders through the environment and different scenarios. Additionally, stakeholders can engage with task-based, competitive elements of serious gaming, such as starting in an everyday situation before a realistic scenario is triggered, and then identifying the fastest route to safety. Decisions can have consequences and can be reviewed at the end of the experience to assess choices and learn from mistakes, with virtual objects providing guidance throughout.Virtual environments are powerful tools for enhancing scientific analysis and stakeholder engagement, bridging the gap between complex geohazard science and effective stakeholder understanding. This supports informed decision-making and experience-based risk management.

Groundwater acts as a critical link between onshore and offshore environments, connecting freshwater systems to saline oceans. With 40% of the world's population residing along coastlines, understanding coastal groundwater reserves is paramount. One open question involves the vital role of submarine groundwater springs in global hydrology, and how the distribution and groundwater flux can be better constrained across the coastline to better predict both groundwater discharge into the ocean and saltwater inflow into coastal aquifers. Especially urban areas pose unique challenges where water demand is high and groundwater exploration problematic since geophysical remote sensing techniques often interfere with surface and subsurface constructions (e.g. cables, pipelines etc.), making innovative approaches for groundwater exploration crucial for sustainable groundwater management.In this study, we aim to address the complex dynamics of coastal karstic groundwater systems in urban regions, where meteoric waters discharge into the ocean through coastal and submarine freshwater springs, while concurrently facing the risk of saltwater intrusions. Our investigations in the bay of Antalya (Turkey) aim to provide a comprehensive understanding of the land-ocean transition zone in the karstic groundwater systems and provide new tools for future groundwater monitoring in coastal regions.We employ advanced hydroacoustic and resistivity methods, combining onshore and offshore electrical resistivity tomography with electromagnetic measurements to bridge the gap between onshore and offshore domains. This integration of geophysical datasets enables us to (1) delineate karstic groundwater flow pathways from land to ocean, (2) identify coastal and submarine freshwater springs, and (3) assess the risk of saltwater intrusions along the coastline.The study showcases the potential of offshore geoelectric measurements as a tool for groundwater investigations in urbanized coastal regions. The proposed approach will facilitate exploration efforts for groundwater in urbanised karstic areas, but much more importantly will facilitate monitoring strategies to avoid intrusions of saltwater into freshwater aquifers. Our findings contribute valuable insights for water management strategies in Antalya, with implications for safeguarding todays and future freshwater resources.

The Mid-Norwegian continental margin is home to multiple submarine landslides of prodigious volume (megaslides), thought to have occurred once each glacial cycle over the last -500 kyr. Here, we present new 2D seismic reflection data that image the headwall of a previously unknown mega-slide buried beneath Quaternary sediment in the North Sea Fan. The deposits linked to this mega-slide, named the Solsikke Slide, have a volume exceeding 15,000 km3. This is five times greater than the neighboring tsunamigenic Holocene Storegga Slide's volume, and makes the Solsikke Slide one of the largest landslides yet discovered on our planet. The Solsikke Slide remobilized deposits from the previous three mega-slides within the North Sea Fan, including the Tampen Slide that is thought to have occurred ca. 120 kyr BP. Together with the overlying deposits, this constrains the timing of the Solsikke Slide to between 120 and 57 kyr BP (MIS 5-3), which indicates that mega-slides may happen more frequently than previously thought along this margin. Furthermore, we identify a network of faults that extend up from the acoustic basement to the base of the Solsikke headwall, and seismic evidence of lateral fluid migration within the underlying unit. These observations suggest seismic shaking and fluid migration, together with sediment loading, likely played an important role in pre-conditioning and/or triggering failure. Our findings thus have significant implications for understanding the hazard posed by mega-slides in the Northern Atlantic, in terms of their frequency, potential magnitude, and pre-conditioning factors.

Study Region: This study investigates the on- and offshore fresh to saline groundwater distribution as well as the submarine groundwater discharge within a coastal karstic aquifer system in Antalya (Türkiye). Study Focus: Groundwater acts as a critical link between on- and offshore environments, connecting freshwater systems to the saline oceans. With an increasing population along coastlines, understanding coastal groundwater interactions is essential. In this study we utilize on- and offshore hydrogeophysical techniques to image variations in subsurface porewater salinities. Offshore continuous resistivity profiling and hydroacoustic measurements are complemented by land based electromagnetic measurements. New hydrological insights for the region: Our findings show how groundwater discharges into the sea through coastal and submarine freshwater springs while simultaneously facing the risk of saltwater intrusions nearby. Diffuse groundwater flow dominates along the main beach area of Antalya, while channelized flow occurs primarily along the cliff coastline where submarine springs occur. The springs create distinct salinity anomalies in the water column and remove the sediment cover from the carbonate aquifer, exposing hard rock on the seafloor and creating different habitats. The multi-method geophysical approach provides a detailed picture of freshwater-saltwater interactions and highlights regions of varying groundwater discharge into the sea. Our findings contribute valuable insights for water management strategies in Antalya, with implications for safeguarding freshwater resources and mitigating the risk of saltwater intrusions.

Newly acquired high-resolution geophysical data from four glacial cross-shelf troughs of the Labrador Shelf, namely the Okak, Hopedale, Makkovik and Cartwright troughs, are presented in this study. These cross-shelf troughs were repeatedly excavated by the former Laurentide Ice Sheet (LIS) during past glaciations. We map and describe three previously unknown grounding-zone wedges (GZWs) from an area where only sparse information about the retreat of the LIS is available. Based on our geomorphological analysis, we derive the dynamics and the direction of the ice retreat. For the Okak, Makkovik, and Cartwright troughs, the newly identified GZWs indicate fast-flowing ice streams with a high sediment load. We propose that a stable ice grounding-zone paralleled the present-day coastline in the Okak and Makkovik troughs, while in the Cartwright Trough, an icemargin retreat towards the outlet of Lake Melville is more likely. We date available sediment samples of the deposits that onlap one of the GZWs to 14.5 ka cal BP and can show that the discovered GZWs must be older. This new information updates our understanding of the dynamics of the LIS, particularly at its eastern boundary, the Labrador Shelf and Sea, which is important to better reconstruct the effects of the LIS dynamics on global ocean currents and climate.

Mixed turbidite-contourite depositional systems result from interactions between down-slope turbidity currents and along-slope bottom currents, comprising excellent records of past oceanographic currents. Modern and ancient systems have been widely documented along the continental margins of the Atlantic Ocean. Yet, few examples have so far been identified on the North-west African continental margin, limiting understanding of the sedimentary and palaeoceanographic evolution in this area. This work uses two-dimensional seismic reflection profiles to report, for the first time, the presence of three giant sediment mounds beneath the headwall region of the Sahara Slide Complex. The sediment mounds are elongated and separated by two broad canyons, showing a north-west/south-east orientation that is roughly perpendicular to the continental margin. These mounds are 24 to 37 km long and 12 to 17 km wide, reaching a maximum height of ca 1000 m. Numerous slide scarps are observed within and along the flanks of the mounds, hinting at the occurrence of submarine landslides during their development. Based on their geometries, external shapes, internal seismic architecture and stratigraphic stacking patterns, it is proposed that these sediment mounds comprise down-slope elongated mounded drifts formed in a mixed turbidite-contourite system during four evolutionary stages: onset, growth, maintenance and burial. The significance of this work is that it demonstrates the gradual transition from a turbidite system to a full mixed turbidite-contourite system to be associated, in the study area, with the establishment of strong ocean currents along north-west Africa.

In 2021, La Palma's southern volcanic complex Cumbre Vieja erupted for its longest period in historic times. Although the geological record shows no evidence for a collapse of Cumbre Vieja, ground deformation studies and field observations suggest that its western flank is moving seawards, following the direction of previous collapses of the island. To better estimate the hazard of a potential flank collapse of Cumbre Vieja, it is important to identify the lateral extent and depth of the mobile sector. Here, we analyse the volcano-tectonic deformation along Cumbre Vieja's western flank, based on geomorphological analysis of combined topographic and new ship-born bathymetric data as well as the analysis of shallow seismicity records associated with the 2021 eruption. In our interpretation, the shoreline-crossing Puerto Naos Ridge results from tectonic uplift accompanying transpressional deformation along the northern boundary of Cumbre Vieja's moving flank, therefore decoupling a stable sector in the north from the mobile sector farther south. The proposed moving sector is consistent in scale with previous ground deformation studies and documented flank collapses of structurally similar volcanoes. We present a workflow for semi-automatically detecting boundaries of unstable volcanic flanks based on morphological changes captured in digital elevation data. The method correctly delineated the known boundaries of the unstable flanks of Mt. Etna and Kilauea volcanoes. The ability to constrain potential boundaries of unstable volcanic flanks should inform the planning of future geophysical and geodetic campaigns aiming to identify precursory signals of potential flank failures.

The volcanic history of Mt. Etna is mainly known from studies of subaerial deposits and stratigraphy. However, little is known about the offshore deposits, which can provide a more detailed insight into geological and sedimentological processes affecting the flanks of Mt. Etna. During RV Meteor Cruise M178, eight gravity cores were taken offshore across the continental margin east of the volcanic edifice to re-evaluate the volcanic history of pre-historic eruptions and mass wasting events in the area. In total, we investigated 87 marine tephra layers in order to build a marine tephrostratigraphic framework. Based on major element compositions of glass shards, sediment componentry, and petrographic characteristics, 27 layers were identified as primary pyroclastic flow and fall deposits, i.e., directly related to an explosive volcanic eruption. However, most of the remaining tephra layers are interpreted to represent deposits of secondary density currents and are not necessarily related to a volcanic eruption. The marine dataset is complemented by twelve onshore samples taken from major explosive eruptions. Applying geochemical fingerprinting of volcanic glass shard compositions, we correlated eleven marine tephra deposits to seven well-known Mt. Etna eruptions (FV, FF, FG, FL, FS, TV, and M1 eruptions) within the last 12 kyr, which provide valuable time markers in the marine sediment record. Furthermore, we correlated ten marine tephra layers between the marine cores (four individual eruptions) and identified another six primary layers in single cores. In total, we discovered 17 widespread volcanic events in the marine record, including four previously unknown eruptions between 10 and 7.7 ka, which indicate that Mt. Etna was more active than previously thought during this time period.

Tectono-stratigraphic analysis coupled with digital 3D surface modelling derived from high-resolution seismic profiles is performed along a narrow turbidite basin offshore E-Sicily in order to increase understanding on the processes that contributed to the shaping of the Western Ionian Basin. Seismic-reflector patterns of the identified Pliocene-Quaternary sequence point to syn-depositional deformation during the Pliocene associated with the simultaneous activity of regional faults and underlying ductile units. Long-wavelength sediment fanning results from the extensional activity of the Malta Escarpment faults. Conversely, internal reflector architecture and lateral terminations indicate localized subsidence associated with the growth of uprising structures in the easternmost part of the basin. Lateral shifting of basin depocenters is in line with withdrawal effects observed in basins floored by ductile units (salt or shale). 3D modelling of time-reference surfaces highlights sub-circular depressions associated with nearby structural culminations. This pattern is similar to salt-withdrawal minibasins commonly reported in evaporite-floored basins. Accordingly, salt migration/flow triggered by sediment loading, locally enhanced by fault activity, is proposed as the process controlling basin evolution during the Pliocene in the Western Ionian Domain. Nevertheless, the possibility of shale/mud tectonics as the ductile source of deformation cannot be discounted.

Communicating environmental change and mitigation scenarios to stakeholders and decision-makers can be challenging. Immersive environments offer an innovative approach for knowledge transfer, allowing science-based scenarios to be discussed interactively. The use of such environments is particularly helpful for the analysis of large, multi-component geospatial datasets, as commonly employed in the classification of ecosystems. Virtual environments can play an important role in conveying and discussing the findings gathered from these geomorphometric datasets. However, textured meshes and point clouds are not always well suited for direct import to a virtual reality or the creation of a truly immersive environment, and often result in geometrical artifacts, which can be misinterpreted during the import to a game engine. Such technical hurdles may lead to viewers rejecting the experience altogether, failing to achieve a higher educational purpose. In this study, we apply an asset-based approach to create an immersive virtual representation of a coastal environment. The focus hereby is on the coastal vegetation and changes in species distribution, which could potentially be triggered by the impact of climate change. We present an easy-to-use blueprint for the game engine EPIC Unreal Engine 5. In contrast to traditional virtual reality environments, which use static textured mesh data derived from photogrammetry, this asset-based approach enables the use of dynamic and physical properties (e.g. vegetation moving due to wind or waves), which makes the virtual environment more immersive. This will help to stimulate understanding and discussion amongst different stakeholders, and will also help to foster inclusion in earth- and environmental science education.

Oceans cover more than 70 percent of the Earth's surface making it difficult and costly to deploy modern seismological instruments here. The rapidly expanding global network of submarine telecom cables offers tremendous possibilities for seismological monitoring using laser light. Recent pioneer studies have demonstrated earthquake detection using lasers in onland and submarine fiber optic cables. However, permanent strain at the seafloor has never before been measured directly as it happens. With this aim, we deployed a dedicated 6-km-long fiber optic strain cable, offshore Catania Sicily, in 2000 m water depth, and connected it to a 29-km long electro-optical cable for science use. We report here that deformation of the cable equivalent to a total elongation of 2.5 cm was observed over a 21-month period (from Oct. 2020 to Jul. 2022). Brillouin laser reflectometry observations over the first 10 months indicate significant strain (+25 to +40 microstrain) at two locations where the cable crosses an active strike-slip fault on the seafloor, with most of the change occurring between 19 and 21 Nov. 2020. The cause of the strain could be fault slip or seabottom currents. During the following 11 months, the strain amplitude increased to +45 to +55 microstrain, affecting a longer portion of the cable up to 500 m to either side of the first fault crossing. A sandbag experiment performed on the distal portion of the cable (3.2–6.0 km) starting Sept. 2021 demonstrates how the fiber optic cable deforms in response to an applied load and how the deformation signal partially dissipates over time due to the elastic properties of the cable. These preliminary results are highly encouraging for the use of BOTDR (Brillouin Optical Time Domain Reflectometry) laser reflectometry as a technique to detect strain at the seafloor in near real time and to monitor the structural health of submarine cables.

The ultimate demise of the Laurentide Ice Sheet (LIS) and the preceding and succeeding oceanographic changes along the western Labrador Sea offer insights critically important to improve climate predictions of expected future climate warming and further melting of the Greenland ice cap. However, while the final disappearance of the LIS during the Holocene is rather well constrained, the response of sea ice during the resulting meltwater events is not fully understood. Here, we present reconstructions of paleoceanographic changes over the past 9.3 Kyr BP on the northwestern Labrador Shelf, with a special focus on the interaction between the final meltwater event around 8.2 Kyr BP and sea ice and phytoplankton productivity (e.g., IP 25 , HBI III (Z), brassicasterol, dinosterol, biogenic opal, total organic carbon). Our records indicate low sea‐ice cover and high phytoplankton productivity on the Labrador Shelf prior to 8.9 Kyr BP, sea‐ice formation was favored by decreased surface salinities due to the meltwater events from Lake Agassiz‐Ojibway and the Hudson Bay Ice Saddle from 8.55 Kyr BP onwards. For the past ca. 7.5 Kyr BP sea ice is mainly transported to the study area by local ocean currents such as the inner Labrador and Baffin Current. Our findings provide new insights into the response of sea ice to increased meltwater discharge as well as shifts in atmospheric and oceanic circulation.