Sascha Flögel

GEOMAR Helmholtz Centre for Ocean Research Kiel · Division of Paleo-Oceanography

Black shale sediments from the Barremian to Aptian South Atlantic document intense and widespread burial of marine organic carbon during the initial stages of seafloor spreading between Africa and South America. The enhanced sequestration of atmospheric CO2 makes these young ocean basins potential drivers of the Early Cretaceous carbon cycle and cl...

Plain Language Summary Tectonic events and solar insolation are the two important factors impacting variations of the climate system in the geological past. Regional climate responses to variations in the radiation from the sun over 10⁴–10⁵ years were often magnified or dampened by tectonic events. Cretaceous sedimentary records in East Asia sugges...

The stable (δ¹⁸O and δ¹³C) and clumped (Δ47) isotope compositions of coral carbonate are valuable archives for paleoclimate reconstructions. However, the Δ47-temperature relationships of warm and cold-water corals deviate from that of inorganic carbonate precipitated at equilibrium. Dual clumped isotope thermometry of carbonates (i.e., simultaneous...

While the distribution patterns of cold-water corals, such as Paragorgia arborea, have received increasing attention in recent studies, little is known about their in situ activity patterns. In this paper, we examine polyp activity in P. arborea using machine learning techniques to analyze high-resolution time series data and photographs obtained f...

The Norway lobster, Nephrops norvegicus, supports a key European fishery. Stock assessments for this species are mostly based on trawling and UnderWater TeleVision (UWTV) surveys. However, N. norvegicus are Frontiers in Marine Science burrowing organisms and these survey methods are unable to sample or observe individuals in their burrows. To accou...

Similar to their tropical counterparts, cold-water corals (CWCs) are able to build large three-dimensional reef structures. These unique ecosystems are at risk due to ongoing climate change. In particular, ocean warming, ocean acidification and changes in the hydrological cycle may jeopardize the existence of CWCs. In order to predict how CWCs and...

Marine and space ocean research largely focus on satellite-and buoy-based monitoring. However, recent advances in robotic design, autonomy and sensor integration are creating solutions for the exploration of deep-sea pelagic and benthic environments that are transferable to the vast extraterrestrial oceans of the icy moons Enceladus and Europa. Tho...

Call for contributions to "Advanced Sensors and Robotic Platform Technologies for the Exploration of marine Ecosystems and Far Beyond" (contents available at: https://www.mdpi.com/topics/ASRPTEMMEFB)

Recent advances in robotic design, autonomy and sensor integration create solutions for the exploration of deep-sea environments, transferable to the oceans of icy moons. Marine platforms do not yet have the mission autonomy capacity of their space counterparts (e.g., the state of the art Mars Perseverance rover mission), although different levels...

PLOME proposes a spatially adaptive, non-invasive, modular platform of independent and wirelessly connected benthic stations and AUVs to intelligently observe, monitor and map marine ecosystems, during long-lasting periods with real-time supervision. The proposal brings together elements that can be effectively developed with current technology, to...

The Weissert Event ~133 million years ago marked a profound global cooling that punctuated the Early Cretaceous greenhouse. We present modelling, high-resolution bulk organic carbon isotopes and chronostratigraphically calibrated sea surface temperature (SSTs) based on an organic paleothermometer (the TEX86 proxy), which capture the Weissert Event...

Ocean warming and acidification pose serious threats to cold-water corals (CWCs) and the surrounding habitat. Yet, little is known about the role of natural short-term and seasonal en- vironmental variability, which could be pivotal to determine the resilience of CWCs in a changing environment. Here, we provide continuous observational data of the...

Acesta excavata (Fabricius, 1779) is a slow growing bivalve from the Limidae family and is often found associated with cold-water coral reefs along the European continental margin. Here we present the compositional variability of frequently used proxy elemental ratios (Mg/Ca, Sr/Ca, Na/Ca) measured by laser-ablation mass spectrometry (LA-ICP-MS) an...

Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processes acting o...

Imaging technologies are being deployed on cabled observatory networks worldwide. They allow for the monitoring of the biological activity of deep-sea organisms on temporal scales that were never attained before. In this paper, we customized Convolutional Neural Network image processing to track behavioral activities in an iconic conservation deep-...

The Permian/Triassic boundary approximately 251.9 million years ago marked the most severe environmental crisis identified in the geological record, which dictated the onwards course for the evolution of life. Magmatism from Siberian Traps is thought to have played an important role, but the causational trigger and its feedbacks are yet to be fully...

The Cretaceous Period (145-66 Ma) provides an opportunity to obtain insights into the adaptation of the climate system to increased atmospheric greenhouse gas concentrations. The organic paleothermometer TEX86 is one of the few proxies available for reconstructing quantitative estimates of upper ocean temperatures of this time period. Here we show...

This paper presents the technological developments and the policy contexts for the project "Autonomous Robotic Sea-Floor Infrastructure for Bentho-Pelagic Monitoring" (ARIM). The development is based on the national experience with robotic component technologies that are combined and merged into a new product for autonomous and integrated ecologica...

Abstract. Extensive black shale deposits formed in the Early Cretaceous South Atlantic, supporting the notion that this emerging ocean basin was a globally important site of organic carbon burial. The magnitude of organic carbon burial in marine basins is known to be controlled by various tectonic, oceanographic, hydrological, and climatic processe...

Cold-water coral (CWC) communities form complex benthic ecosystems in a distinct part of the water column. The exact processes supporting CWC reef growth and changes with time are still partly unsolved. Besides local hydrographic conditions, noticeable interactions of tidal flow with topography have been reported for CWC sites. Recent studies have...

Organic carbon burial is an important driver of carbon cycle and climate dynamics on geological and shorter time scales. Ocean basins emerging during the Early Cretaceous break-up of Gondwana were primary sites of organic carbon burial, implying that their tectonic and oceanographic evolution may have affected trends and perturbations in global cli...

Thriving benthic communities were observed in the oxygen minimum zones along the southwestern African margin. On the Namibian margin, fossil cold-water coral mounds were overgrown by sponges and bryozoans, while the Angolan margin was characterized by cold-water coral mounds covered by a living coral reef. To explore why benthic communities differ...

I mound a coralli profondi, costruiti da sclerattinari di acque fredde come Lophelia pertusa e Madrepora oculata, sono diffusi lungo tutta la piattaforma della Scandinavia e nei fiordi, aree completamente ricoperte dai ghiacci durante l’ultimo massimo glaciale tra 22 e 18 ka BP. Il ritiro dei ghiacci ha rapidamente liberato la maggior parte della p...

Periodic changes in sediment composition are usually ascribed to insolation forcing controlled by Earth’s orbital parameters. During the Cretaceous Thermal Maximum at 97–91 Myr ago (Ma), a 37–50-kyr-long cycle that is generally believed to reflect obliquity forcing dominates the sediment record. Here, we use a numerical ocean model to show that a c...

Fossil cold-water coral mounds overgrown by sponges and bryozoans were observed in anoxic conditions on the Namibian margin, while mounds colonized by thriving cold-water coral reefs were found in hypoxic conditions on the Angolan margin. These low oxygen conditions do not meet known environmental ranges favoring cold-water corals and hence are exp...

The nature of the warm climates of the Cretaceous has been enigmatic since the first numerical climate models were run in the late 1970’s. Quantitative simulations of the paleoclimate have consistently failed to agree with information from plant and animal fossils and climate sensitive sediments. The ‘cold continental interior paradox’ (first descr...

The cold-water coral (CWC) Dendrophyllia cornigera is widely distributed in areas of both high and low productivity, suggesting a significant trophic plasticity of this coral depending on the food available in the environment. In this study, lipid biomarkers and their isotopic signature were compared in colonies of D. cornigera and sediment from th...

We performed a comparative test study applying conventional Conductivity-Temperature-Depth (CTD) casts and a self designed mini lander system, which was deployed on the Pagès Escarpment on the Cantabrian Margin at 762 mbsl water depth for continuous bottom water measurements. Our lander data demonstrate that the mechanical movement of CTD gear dist...

A 325 m long continuous succession of uppermost Albian to lower Turonian pelagic (outer shelf) deposits was recovered from a new drill site in the central part of the Tarfaya Basin (southern Morocco). Natural gamma ray wireline logging, carbonate and organic carbon content, bulk carbonate and organic carbon stable isotopes and X-ray fluorescence (X...

We investigated the onset and development of Cretaceous Oceanic Anoxic Event 2 (OAE2) in a newly drilled core (SN°4) from the Tarfaya Basin (southern Morocco), where this interval is unusually expanded. High-resolution (cm-scale equivalent to centennial) analysis of bulk organic and carbonate stable isotopes and of carbonate and organic carbon cont...

High-latitude cold-water coral (CWC) reefs are particularly susceptible due to enhanced CO2 uptake in these regions. Using precisely dated (U/Th) CWCs (Lophelia pertusa) retrieved during research cruise POS 391 (Lopphavet 70.6°N, Oslofjord 59°N) we applied boron isotopes (δ11B), Ba/Ca, Li/Mg and U/Ca ratios to reconstruct the environmental boundary...

Carbonate buildups and mounds are impressive biogenic structures throughout Earth history. In the recent NE Atlantic, cold-water coral (CWC) reefs form giant carbonate mounds of up to 300 m of elevation. The expansion of these coral carbonate mounds is paced by climatic changes during the past 2.7 Myr. Environmental control on their development is...

The Cretaceous period (~145–65 m.y. ago) was characterized by intervals of enhanced organic carbon burial associated with increased primary production under greenhouse conditions. The global consequences of these perturbations, oceanic anoxic events (OAEs), lasted up to 1 m.y., but short-term nutrient and climatic controls on widespread anoxia are...

ABSTRACT: The community respiration of 2 tidally dominated cold-water coral (CWC) sites was estimated using the non-invasive eddy correlation (EC) technique. The first site, Mingulay Reef Complex, was a rock ridge located in the Sea of Hebrides off Scotland at a depth of 128 m and the second site, Stjernsund, was a channel-like sound in Northern No...

This study reports a new cold-water coral (CWC) province covering ~410 km2 off western Morocco (ca. 31°N) ~40 nautical miles north of the Agadir Canyon system between 678 and 863 m water depth, here named the Eugen Seibold coral mounds. Individual mounds are up to 12 m high with slope angles varying between 3° and 12°. Hydroacoustic data revealed m...

Cold-water coral ecosystems present common carbonate factories along the Atlantic continental margins, where they can form large reef structures. There is increasing knowledge on their ecology, molecular genetics, environmental controls and threats available. However, information on their carbonate production and accumulation is still very limited,...

Present day oceans are well ventilated, with the exception of mid-depth oxygen minimum zones (OMZs) under high surface water productivity, regions of sluggish circulation, and restricted marginal basins. In the Mesozoic, however, entire oceanic basins transiently became dysoxic or anoxic. The Cretaceous ocean anoxic events (OAEs) were characterised...

Present day oceans are well ventilated, with the exception of mid-depth oxygen minimum zones (OMZs) under high surface water productivity, regions of sluggish circulation, and restricted marginal basins. In the Mesozoic, however, entire oceanic basins transiently became dysoxic or anoxic. The Cretaceous ocean anoxic events (OAEs) were characterised...

This paper presents the current activities of the ROBEX alliance. ROBEX is developing innovative technologies and procedures for the exploration within extreme environments and also systems operating in the deep sea, on the moon or other celestial bodies. This paper gives a brief overview on the project’s aims and the core development activities, a...

In late 2012, the German Helmholtz Alliance ”Robotic Exploration in Extreme Environments – ROBEX ” was initiated. It joins forces among deep sea and space (especially lunar exploration) scientists and engineers in order to work together toward solutions of outstanding technical problems of robotic exploration in harsh environments being common to b...

We present the first full water column Nd isotope (εNdεNd) and concentration data for Caribbean seawater, as well as for stations close to the Orinoco River mouth and in the Florida Straits. The surface inflow into the southeastern Caribbean via the Guyana Current is characterized by an εNdεNd signature of −10.9, which is a consequence of the mixin...

Present day oceans are generally well ventilated except mid-depth oxygen minimum zones (OMZs) under high surface water productivity regimes, regions of sluggish circulation, and restricted marginal basins. In the Mesozoic, however, entire oceanic basins transiently became dysoxic or even anoxic. In particular the Cretaceous Ocean Anoxic Events (OAE...

The increasing pCO2 in seawater is a serious threat for marine calcifiers and alters the biogeochemistry of the ocean. Therefore, the reconstruction of past-seawater properties and their impact on marine ecosystems is an important way to investigate the underlying mechanisms and to better constrain the effects of possible changes in the future ocea...

Neodymium isotopes and concentrations from 11 stations in the Caribbean, Gulf of Mexico, Florida Straits and close to the mouth of the Orinoco. CTD data (potential temperature, salinity, potential density and oxygen concentration) for the same samples are also reported. Sampling took place during February and March 2009 as part of the Meteor Cruise...

The increasing pCO2 in seawater is a serious threat for marine calcifiers and alters the biogeochemistry of the ocean. Therefore, the reconstruction of past-seawater properties and their impact on marine ecosystems is an important way to investigate the underlying mechanisms and to better constrain the effects of possible changes in the future ocea...

The increasing pCO2 in seawater is a serious threat for marine calcifiers and alters the biogeochemistry of the ocean. Therefore, the reconstruction of past-seawater properties and their impact on marine ecosystems is an important way to investigate the underlying mechanisms and to better constrain the effects of possible changes in the future ocea...

Cold-water coral communities cover a wide range of possible habitats in terms of latitude, ocean basins, and depth, with ongoing studies continually expanding occurrences in various regions of the global ocean. A range of factors determines the formation of cold-water coral reefs, such as physical, hydrochemical, and biological (e.g. food supply) f...

Most of the marine biotic crises that occurred during the hot Mesozoic era have been linked to episodes of extreme warmth1, 2. Others, however, may have occurred during cooler intervals that interrupted Cretaceous greenhouse warmth3, 4, 5. There are some indications of cooling in the late Aptian6, 7, 8 (116–114 Myr ago), but it has not been definit...

Understanding the controls that determine the spatial distribution and internal heterogeneities of black shales in the Mesozoic ocean has been a focal point of research over many decades. The consensus is that atmosphere-land-ocean interactions influenced variations in marine biogeochemistry and sediment supply, thus exerting fundamental controls o...

New drill cores from the Lower Aptian historical stratotype at Roquefort-La Bédoule (SE France) provide continuous high-resolution geochemical and isotope records which closely track the onset of OAE 1a in a subtropical intra-shelf basin (South Provençal Basin). The drilling operation recovered a total of 180 m of undisturbed sediments in three hol...

Several new discoveries suggest that the climate of the Cretaceous may have been more different from that of today than has been previously supposed. Detailed maps of climate-sensitive fossils and sediments compiled by Nicolai Chumakov and his colleagues in Russia indicate widespread aridity in the equatorial region during the Early Cretaceous. The...

The Mid-Cretaceous (~ 100 Ma) was one of the warmest climate episodes during the Phanerozoic. During the Mid-Cretaceous, Earth received about 1% less solar radiation compared to the present and the atmospheric carbon dioxide concentration was in the range of 800-2000 ppm. Proxy data suggest global mean temperatures of more than 20°C, a reduced meri...

The question whether large scale glaciations on Antarctica were possible in a late Mesozoic greenhouse climate such as the Late Cretaceous is an intriguing one. The most recent years have provided an increasing number of studies investigating the growth and decay of paleo-continental ice sheets on Antarctica possibly large enough to affect sea leve...

Cretaceous anoxic events may have been triggered by massive volcanic CO 2 degassing as large igneous provinces (LIPs) were emplaced on the seaoor. Here, we present a comprehensive modeling study to decipher the marine biogeochemical consequences of enhanced volcanic CO 2 emissions. A biogeochemical box model has been developed for transient model r...