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Line scan images of IODP Hole 386-M0083D
No full textCollection of line scan images from the above given hole of International Ocean Discovery Program (IODP) Expedition 386 (Japan Trench Paleoseismology). The offshore phase of this expedition took place between 2021-04-13 and 2021-06-01 onboard Japanese R/V Kaimei from and to Yokosuka, Japan. Images were obtained during the onshore phase of the expedition, which took place between 2022-02-14 – 2022-03-15 onboard D/V Chikyu. After longitudinal splitting high-resolution (100 pixels/cm) images of each core sections archive half was captured using the Tri-Sensor Core Logger (TSCL; NS Design). The camera provides a 16-bit red-green-blue color (48-bit) TIFF file, which were converted to JPG files for publication purposes. The RGB data derived from each image for each section are published under titles "Color data (RGB) of IODP Hole 386-M0083D".
For further methodological information see methods chapter in Strasser, M. et al., 2023 https://doi.org/10.14379/iodp.proc.386.102.202
Total alkalinity during laboratory incubation experiments on enhanced benthic weathering in organic rich Baltic Sea sediments
No full textEnhanced mineral dissolution in the benthic environment is currently discussed as a potential technique for ocean alkalinity enhancement (OAE) to reduce atmospheric carbon dioxide (CO2) levels. This study explores how biogeochemical processes affect the dissolution of alkaline minerals in surface sediments during laboratory incubation experiments (January - May 2022). These involved introducing dunite and calcite to organic-rich sediments from the Baltic Sea under controlled conditions in an oxic environment. The sediment cores were incubated with Baltic Sea bottom water. Eight sediment cores were placed in a rack in an upright position. The bottom water was carefully removed via suction and replaced with a known volume (1.5 l – 2.0 l) of filtered (0.2 µm) Baltic Sea bottom water in order to remove pelagic auto- and heterotrophs and suspended particles. The volume of water added depended on the height of sediment in each core which varied slightly due to the recovery method. After this procedure, a gaseous headspace of ca. 10 cm was left in each core. Furthermore, the cores were equipped with adjustable stirring heads that contained ports for inserting optodes to continuously record pH and oxygen (O2) concentrations in the overlying water. In order to prevent anoxic conditions developing, ambient air was bubbled into the water column. The water column in each core was slowly and continuously flushed with a constant throughflow of 40 µl min-1 from a single reservoir of bottom water. The residence time of the water inside the cores was thus about 4 to 5 weeks. Bottom water samples were taken from the outflow of each core over a time period of several hours. Thus, samples represent the average outflow over the respective time period. Sampling intervals increased from daily during the first two weeks to every three to four days and weekly towards the end of the experiment. All samples were filtered through a 0.2 µm cellulose membrane filter and refrigerated in 25 ml ZinsserTM scintillation vials. Samples for total alkalinity (TA) were analyzed directly after sampling by titration of 1 ml of bottom/pore water with 0.02N HCl. Titration was ended when a stable purple color appeared. During titration, the sample was degassed by continuous bubbling with nitrogen to remove any generated CO2 and H2S. The acid was standardized using an IAPSO seawater standard
Geochemical, pollen and bulk density record of MIS11-1 from Lake Petén Itzá (Site PI-6) Guatemala
No full textWe present data on bulk density, inorganic geochemistry (Ti, Ca, Al, Mn, and Fe), and pollen (Quercus, Moraceae, Pinus, tropicality index) from Lake Petén Itzá. In 2006, Lake Petén Itzá was drilled by the International Continental Scientific Drilling Program (ICDP), obtaining seven lacustrine sediment records: PI-01, PI-02, PI-03, PI-04, PI-06, PI-07, and PI-09. Here, we present data from Site PI-6 (17.00027°N, -89.78478°W), located in the northern part of the lake. At the Continental Scientific Drilling Facility at the University of Minnesota, bulk density was analyzed using a GEOTEK multi-sensor core logger with gamma-ray attenuation, with measurements taken every 0.5 cm. Inorganic geochemistry data were obtained using X-ray fluorescence (XRF) with a Cox Analytical Itrax Core Scanner. PI-6 sediments were measured with a Mo-tube at 30 kV, 20 mA, 30-second exposure, at 0.5-cm resolution. XRF data are presented in counts per second (cps). Subsequently, data were transformed to centered log-ratio (CLR). CLR values were obtained by dividing each element's concentration by the geometric mean of the elements measured at the same depth, then taking the natural logarithm of the ratio. CLR results have no units. Pollen data include a dataset of 39 samples from Site PI-6, previously published by Correa-Metrio et al. (2012). For each sample, pollen abundances were converted into percentages of the pollen sum. A "tropicality index" was calculated as ln(Moraceae% + 1) / ln(Quercus% + Pinus% + 1). Depth data correspond to the "Core composite depth below lake floor (CCLF)" or "Master composite depth (MCD)", which accounts for core recovery gaps and depth inconsistencies, while age data are based on the age-depth models presented by Martínez-Abarca et al. (2024)
Frozen fraction of INP samples from Antarctica, Neumayer Station III, measured with the Leipzig Ice Nucleating Array
No full textIce nucleating particles (INPs) are important atmospheric particles influencing the formation of ice in clouds. Their sources and atmospheric concentrations currently are subject of plenty of research.
The here provided data on INPs (Ice Nucleating Particles) were derived from particles collected onto filters at the German Antarctic Neumayer Station III in Queen Maud Land, East Antarctica continuously for two years from December 2019 until December 2021. Filters were analyzed at the TROPOS ice-lab in Germany using well established off-line techniques. Detailed information on sampling and data evaluation are given in the abovementioned publication which this data-set accompanies.
Measured frozen fractions are provided for samples, field blinds and heated samples, INP concentrations are provided for samples both with and without subtracting the background
Accumulation measurements from stake farm Neumayer Pegelfeld Süd, Ekström Ice Shelf, Antarctica, 1995
No full textThis publication series contains the accumulation measurements from stake farm Pegelfeld Süd on the Ekström Ice Shelf, Antarctica. The stake farm, located approximately 6 km to the southwest from the past and present Neumayer Station, has been in operation since December 1990. It consists of 16 aluminum poles (balise), placed in a grid of 4 x 4. Readings have been carried out in bi-weekly to monthly intervals by the overwintering staff of the air chemistry observatory (Spuso). Each data set in the series contains all measurements of each stake from one calendar year in a csv file, the average accumulation of the stake farm for each measurement and the standard deviation of the stake farm for each measurement. The data sets are accompanied by figures illustrating the development of the cumulative accumulation since the beginning of the measurements to date, a bar chart of the monthly accumulation for the year and a collection of panels (one panel per measurement) illustrating the variation of accumulation within the stake farm
Macroscopic charcoal record from the sediment core EN21437-1
No full textMacroscopic charcoal records and radiocarbon age dating information of sediment cores from eight lakes in central and eastern Yakutia. Sediment cores were obtained during fieldwork in August 2021, jointly organized by the Alfred Wegener Institute and the North-Eastern Federal University of Yakutsk. Charcoal data includes the total amount of particles per sample as well as their respective distributions in size classes (150-300 µm, 300-500 µm, > 500 µm), morphotype categories, and (for some of the records) average particle length-to-width ratios. More detailed information about the data and an approach to age-depth modelling can be found in the research paper (in preparation). Details of fieldwork in 2021 is available in the corresponding expedition report (Morgenstern et al., 2023)
Macroscopic charcoal record from the sediment core EN21419-2
No full textMacroscopic charcoal records and radiocarbon age dating information of sediment cores from eight lakes in central and eastern Yakutia. Sediment cores were obtained during fieldwork in August 2021, jointly organized by the Alfred Wegener Institute and the North-Eastern Federal University of Yakutsk. Charcoal data includes the total amount of particles per sample as well as their respective distributions in size classes (150-300 µm, 300-500 µm, > 500 µm), morphotype categories, and (for some of the records) average particle length-to-width ratios. More detailed information about the data and an approach to age-depth modelling can be found in the research paper (in preparation). Details of fieldwork in 2021 is available in the corresponding expedition report (Morgenstern et al., 2023)
Annotated and filtered molecular formulas associated with dissolved organic matter molecular composition data of exemplary water masses resolved by online LC-FT-Orbitrap-MS
No full textThe unique chromatographic behaviour of DOM was investigated on three exemplary water samples representing coastal DOM, oceanic surface DOM and oceanic refractory DOM. Weddell Sea surface (30 m depth, oceanic surface DOM) and deep water (1356 m depth, refractory DOM) was sampled with a rosette sampler on RV Polarstern during ANT XXII/2 (station PS67/006-130, latitude -67.5633, longitude -55.3448) and are described elsewhere (El Naggar et al., 2007; Koch et al., 2008). Coastal DOM is routinely extracted from southern North Sea (latitude 54.1447, longitude 7.8711) and used as an in-house laboratory standard. Mass spectra were obtained with liquid chromatography coupled to a Fourier-transform Orbitrap mass spectrometer (LC-FT-Orbitrap-MS) with negative electrospray ionisation. A Q-Exactive Plus (Thermo Fisher Scientific, Bremen, Germany) was coupled to an ultra-performance liquid chromatography system (UPLC, Vanquish, Thermo Fisher Scientific, Bremen, Germany).Reversed phase chromatography was done with a C18 column (Waters AQUITY 2 x 100 mm, 1.7 µm) column at 0.3 mL min 1 and a linear gradient: A (ultrapure water, 4 mmol L 1 ammonium formate) 2 min: 99 %, 11 min: 0 %, 14.9 min: 99 %; B (MeOH, 4 mmol L 1 ammonium formate) 2 min: 1 %, 11 min: 100 %, 14.5 min 100 %, 14.9 min 1 %. The exact mass lists and intensities of the 1.1 min binned scans were exported with the Xcalibur software package (Thermo Electron Corporation). Scans were calibrated with an in-house script. Molecular formulas were assigned with the following elemental composition: 12C≤∞1H≤∞16O≤∞14N≤232S≤1 within 0.8 ppm mass deviation, and filtered with the Ultra Mass Explorer (UME, www.awi.de/en/ume, (Leefmann et al., 2019))