ALBERT

Description: Ice-flow velocity fields produced from optical feature tracking of Landsat data, using ImGRAFT toolbox. Data are provided in point NetCDF format along with a corresponding JPEG, a data timeline and example data structure are also provided. See attached documentation for detailed description of the data and corresponding terms of use.

Description: The transition from the last pelagic larval stage to the first benthic juvenile stage in the complex life cycle of marine invertebrates, such as the American lobster, Homarus americanus, a species of high economic importance, represents a delicate phase in these species development. Under future elevated pCO2 conditions, ocean acidification and other elevated pCO2 events can negatively affect crustaceans. This said their effects on the benthic settlement phase are virtually unknown. This study aimed to identify the cumulative effects of stage IV post-larval exposure to elevated pCO2 levels on the life history and physiology of stage V juvenile lobsters. Post-larval lobsters were exposed to a gradient of current and future pCO2 scenarios that were chosen based on current global ocean conditions (400 μatm) to predicted pCO2 values between now and the end of the century (600, 800, 1000 μatm, IPCC 2014), ecologically relevant coastal pCO2 fluctuations (1200 μatm), and levels potentially achieved from industrial accidents involving carbon capture storage leakages (2000 and 3000 μatm). Daily seawater pH readings were recorded by a pH regulation system (IKS, AquaStar, Karlsbad, Germany) in each tank, and seawater pCO2 was regulated according to these readings. Weekly seawater chemistry contains in situ measurements of the total alkalinity and salinity of seawater samples from one random tank from each pCO2 treatment. Total alkalinity was measured using an open cell potentiometric titration with a full curve Gran end-point determination (Dickson et al., 2007). Carbonate chemistry was then calculated from a combination of the daily pH readings, and the weekly average salinity and total alkalinity of all treatment tanks. The survival, intermoult period, feeding rates, oxygen consumption rates, carapace element composition, and energy metabolism enzyme function of the stage V juvenile lobsters were investigated. Results suggested an increase in mortality, slower development, variable feeding rates, a slight increase in carapace magnesium content, and an increase in aerobic capacity relative to anaerobic capacity with increasing pCO2. Our study points to potential reduction in juvenile recruitment success as seawater pCO2 increases, thus foreshadowing important socio- economic repercussions for the lobster fisheries and industry.

Description: The hydrography of the Indian‐Atlantic Ocean gateway has been connected to high‐latitude climate dynamics by oceanic and atmospheric teleconnections on orbital and suborbital timescales. A wealth of sedimentary records aiming at reconstructing the late Pleistocene paleoceanography around the southern African continent has been devoted to understanding these linkages. Most of the records are, however, clustered close to the southern South African tip, with comparatively less attention devoted to areas under the direct influence of frontal zones of the Southern Ocean/South Atlantic. Here we present data of the composition and concentration of the diatom assemblage together with bulk biogenic content and the alkenone‐based sea surface temperature (SST) variations for the past 350 kyr in the marine sediment core MD02‐2588 (approximately 41°S, 26°E) recovered from the southern Agulhas Plateau. Variations in biosiliceous productivity show a varying degree of coupling with Southern Hemisphere paleoclimate records following a glacial‐interglacial cyclicity. Ecologically well‐constrained groups of diatoms record the glacial‐interglacial changes in water masses dynamics, nutrient availability, and stratification of the upper ocean. The good match between the glacial maxima of total diatoms concentration, Chaetoceros spores abundance, and opal content with the maximum seasonal cover of Antarctic ice and the atmospheric dust records points to a dominant Southern Hemisphere forcing of diatom production. Suborbital variability of SST suggests rapid latitudinal migrations of the Subtropical Front and associated water masses over the southern Agulhas Plateau, following millennial contractions and expansions of the subtropical gyres. Warmings of the upper ocean over site MD02‐2588 during terminations IV to I occurred earlier than that in the Antarctic Vostok, which is indicative of a Northern Hemisphere lead. Our multiparameter reconstruction highlights how high‐latitude atmospheric and hydrographic processes modulated orbital highs and lows in primary production and SST as triggered by northward transport of Si, eolian dust input, and latitudinal migrations of frontal zones.

Description: The latest expedition to the DISCOL experimental area (DEA, www.discol.de) was conducted in 2015 during cruise SO242 with the German RV SONNE. The entire disturbance area was extensively mapped with the ship-mounted Multibeam Echosound (MBES) System. An AUV has been deployed several times in different modes for the acquisition of high resolution MBES, Side Scan Sonar (SSS) and optical data. Even with state-of-the-art positioning technology the remaining navigation uncertainties in the deep sea and the use of a variety of acoustical and optical sensors at different resolutions require detailed post-processing in terms of absolute geographic positioning to improve the overall accuracy of the data. The ship-based bathymetric map of the survey area was used as absolute geographic reference and the AUV-acquired high resolution-data sets available here were geo-referenced and aligned to each other (see the respective assigned PANGEA-links for the different data sets and Gausepohl et al., in review, for details) resulting in the most accurate geo-referenced dataset of the DEA to date. The plough tracks from the disturbance experiment in the DEA in 1989 are visible in all of the acquired high resolution data sets, which enabled digitizing, geo-referencing and age-sequencing of the disturbance tracks (Gausepohl et al., in review). This dataset includes the gridded MBES data from the Kongsberg EM122 mounted in RV SONNE (https://doi.pangaea.de/10.1594/PANGAEA.905579) and the geo-referenced AUV ABYSS-acquired MBES (https://doi.pangaea.de/10.1594/PANGAEA.905580) and SSS (https://doi.pangaea.de/10.1594/PANGAEA.905617) datasets. Furthermore it includes two georeferenced photo mosaics generated from two AUV photo transects (https://doi.pangaea.de/10.1594/PANGAEA.905581). The identified, digitized and georeferenced plough marks are available as GIS-readable shape files here. We further provide the Matrix that was used for the age succession evaluation of the plough marks (Gausepohl et al., in review) in .xlsx and .csv format.

Description: Weathered tephra is prevalent across volcanic islands like the North Island of New Zealand and iscomposed of volcanic airfall materials that have been subjected to various soil processes. Understanding their undrained response to cyclic loading is essential for geotechnical engineering applicationsin these regions because of frequently occurring local earthquakes. The authors describe for the first time the cyclic undrained behaviour of a weathered, clay-rich and highly sensitive tephra through triaxial tests. The weathered tephra experiences brittle failure and exhibits higher friction than sedimentary clays. Cyclic contour diagrams, covering the whole compressional and extensional range of stress conditions, are used to compare the cyclic shear strength of Pahoia tephra with those derived for sedimentary clays. It is found that weathered tephra: (a) is more resistant to small cyclic loading; (b) fails within a smaller range of cyclic shear stresses; and (c) exhibits a cyclic shear strength that peaks at zero average shear stress, in contrast to sedimentary clays where cyclic shear strength peaks at small compressive average stress.

Description: To investigate the history of vertical movements in Mauritania, 22 samples were collected from the Precambrian crystalline basement, which sporadically outcrops 100 to 500 km east of the shoreline of the Atlantic margin. The large majority of the samples were taken from granitic intrusions exposed in the Reguibat Shield in the north and along the N-S trending Mauritanides belt.

Description: The Younger Dryas was the final cold phase during the last deglaciation; it started with an abrupt cooling in the Northern Hemisphere within just a few years. However, the regional patterns of Younger Dryas cooling in the North Atlantic realm were complex and mechanistically not fully understood. We present sub-annually resolved fatty acid data from Meerfelder Maar covering the Allerød-Younger Dryas transition to revel forcing mechanisms behind the time-transgressive Younger Dryas cooling across the North Atlantic realm. Data were generated using Mass Spectrometry Imaging (MSI) on 65 cm long section from the MFM09-A5-UR core. MSI was performed using a 7T solarix XR Fourier transform-ion cyclotron resonance-mass spectrometer (FT-ICR-MS) coupled to a matrix-assisted laser desorption/ionization (MALDI) source equipped with a Smartbeam II laser (Bruker Daltonik, Bremen, Germany). We used average chain length (ACL) of long-chain fatty acids (C24, C26, C28) and three terrestrial aquatic ratios (TARs; TAR based on C26 and C16 (TAR=C26/(C26+C16)), TAR based on C24 and C16 (TARC24/(C24+C16)) and TAR based on C28, C26, C24, C16 and C14 (TAR(C24+C26+C28)/(C24+C26+C28+C14+C16)) fatty acids). Moreover, we present ACL based on gas chromatography data and stable carbon isotopes data from individual fatty acids (δ13C of C16, C24, C26, C28 and bishomohopanoic acid (δ13CBA)) from the same section in a lower resolution as supporting data.

Description: We examine the paleoceanographic record over the last ∼400 kyr derived from major, trace, and rare earth elements in bulk sediment from two sites in the East China Sea drilled during Integrated Ocean Drilling Program Expedition 346. We use multivariate statistical partitioning techniques (Q‐mode factor analysis, multiple linear regression) to identify and quantify five crustal source components (Upper Continental Crust (UCC), Luochuan Loess, Xiashu Loess, Southern Japanese Islands, Kyushu Volcanics), and model their mass accumulation rates (MARs). UCC (35–79% of terrigenous contribution) and Luochuan Loess (16–55% contribution) are the most abundant end‐members through time, while Xiashu Loess, Southern Japanese Islands, and Kyushu Volcanics (1–22% contribution) are the lowest in abundance when present. Cycles in UCC and Luochuan Loess MARs may indicate continental and loess‐like material transported by major rivers into the Okinawa Trough. Increases in sea level and grain size proxy (e.g., SiO2/Al2O3) are coincident with increased flux of Southern Japanese Islands, indicating localized sediment supply from Japan. Increases in total terrigenous MAR precede minimum relative sea levels by several thousand years and may indicate remobilization of continental shelf material. Changes in the relative contribution of these end‐members are decoupled from total MAR, indicating compositional changes in the sediment are distinct from accumulation rate changes but may be linked to variations in sea level, riverine and eolian fluxes, and shelf‐bypass processes over glacial‐interglacials, complicating accurate monsoon reconstructions from fluvial dominated sediment.

Description: Data were collected using GNSS survey methods, with a differential GPS operating in Real Time Kinematic (RTK) mode. Data from prior to 2013 were typically collected with a Magellan ProMark 3 traditional RKT-DGPS system (i.e. local base station and rover), with the base station sited on survey control markers installed in 1996, with survey control coordinates referenced to NAD83(CORS91). Starting in 2013 survey data were typically collected with an AshTech ProMark 200 RTK-DGPS system connected to the Washington State Reference Network. Survey data collected between January and November 2013 are referenced to NAD83(CORS96), and after November 2013 to NAD83(2011). Vertical data for surveys in 2012 and 2013 are referenced to NAVD88, presumably using Geoid96 (the survey control documentation does not specific a geoid). For all subsequent surveys the vertical data are referenced to NAVD88(Geoid09). No conversion were applied to these data to account for variations in horizontal or vertical coordinate system adjustments through time, but an error analysis suggests a standard deviation for the elevation data of between 0.03 and 0.05 m across the entire sampling period (2011-2018). All survey data were collected with the GNSS system mounted on a 2.05 m rover pole, held level as a transect line was traced in a cross-shore orientation on the beach. The associated text files include the horizontal (HRMS) and vertical (VRMS) root-mean-square errors estimated by the GNSS system, as well as the RTK-DGPS status reported by the GNSS system at the time each point was collected. Times are referenced to local Pacific time (either PST or PDT).

Description: The dataset includes net and gross primary production, respiration and epiphyte load on the brown algae Fucus vesiculosus under a temperature gradient (5-25 ºC). Under the same temperature gradient, we present physiological responses of Idotea balthica, i.e. respiration, feces production, growth and carbon consumption.