ALBERT

Description: A biomarker approach is applied on a well-dated core from the Beaufort Sea directly off the Mackenzie River to reconstruct changes in sea ice, sea surface temperature (SST), primary productivity, and terrigenous input. High-resolution records indicate that the southern Beaufort Sea was nearly ice-free in summer during the last deglaciation and early Holocene, and a seasonal sea-ice cover developed during the mid-late Holocene, coinciding with a drop in terrigenous sediment flux and primary production. Superimposed to this climate-driven long-term change in surface-water characteristics, we document two major flood events during the deglacial to Holocene transition. Such major flood events in the Beaufort Sea region may have profound effect on global climate change, especially during times when the massive Laurentide Ice Sheet (LIS) collapsed, and huge amount of freshwater was drained into the Beaufort Sea. This freshening of the Arctic Ocean may have resulted in increased freshwater export into the North Atlantic, causing reduced North Atlantic deep-water formation. The first flood event occurring at ca. 13 kyr BP is related to the Younger Dryas (YD) flood which may have caused severe cooling. The second flood event occurred at ca. 11 kyr BP, whose existence has been hypothesized for a long time but restricted by quality records. Through studies of our sediment core and other records nearby, we hypothesize that the second flood event is more related to shelf flooding induced by strong coastal erosion. 


Description: The data-sets comes from three locations representative of three different marine ecosystems: Fjord (Chilean Patagonia), Ny-Ålesund (Arctic) and Mediterranean (Crete). It contains chemical and biological data collected in three mesocosm and four microcosm experiments conducted in the spring - summer period, in which the physico-chemical (pH, Carbon) and biological (grazing) conditions were altered to represent potential future climate change scenarios. The data-sets contains measurements in: carbonate chemistry, macro- and micro-nutrients concentrations, primary production, phytoplankton taxonomy, virus abundance, bacterial production, bacterial abundance, Zoo- and microzoo-plankton abundance, grazing rates for different taxonomic groups.

Description: Here we represent pore water, headspace gas, and TOC data from the four cores recovered from the Chukchi Sea by Jumbo Piston Corer (JPC) during the ARA06C Expedition in 2015 to investigate the origin and diagenesis of pore water and gas. The study cores were retrieved from the Chukchi Sea Shelf (ARA06C-JPC01), the Northwind Basin (ARA06C-JPC02), the East Siberia Continental Slope (ARA06C-JPC03), and the Chukchi Basin (ARA06C-JPC04). We collected pore water from Site ARA06C-JPC01, ARA06C-JPC02, ARA06C-JPC03, and ARA06C-JPC04 and performed compositional and isotopic analyses (e.g. major cation and anions, oxygen, and deuterium isotope, carbon-13 isotope of dissolved carbon, 87Sr/86Sr). The analyzed results of pore water were displayed in the PW Table. The compositional and isotopic data of headspace gas (e.g. methane concentration, and carbon-13 isotope of methane and carbon dioxide) from Site ARA06C-JPC01, ARA06C-JPC02, ARA06C-JPC03, and ARA06C-JPC04 as well as TOC content of bulk sediment from Site ARA06C-JPC01, were represented in the HS Table and TOC Table, respectively.

Description: These data have been obtained on two cores ARA04C/37 (70°38.0212'N, 139°22.0749'W; 1173 m) and JPC15 (71°06.222'N, 135°08.129'W; 690 m). The datasets contain thermal maturity proxies, specifically of Carbon Preference Index (CPI), fractional abundance of homohopane isomer C31ββR, and Tmax, and OI, HI from the Rock-Eval pyrolysis. Additionally, compound-specific radiocarbon concentrations of bulk organic carbon and long-chain n-alkanoic acids with 26 and 28 carbon atoms have been measured and expressed as F14C with a 1 sigma uncertainty, and counts of Pediastrum spp. An additional dataset contains carbon cycle model simulations using the box model BICYCLE to describe the effect of CO2 release from deglacial terrestrial organic carbon release.

Description: This dataset contains hydrographical, biogeochemical and bioptical data from four field campaigns to the Mackenzie Delta region from spring to fall in 2019. Focus of the sampling was put on surface waters to compare with satellite imagery and capture the signal of the Mackenzie River water throughout the coastal waters of the Beaufort Sea. The water samples for the biogeochemical data were taken using pumps or niskin bottles. The repeated sampling focused on the two main outflow regions of the Mackenzie River: Shallow Bay and Mackenzie Bay in the west and Kugmallit Bay in the east as well as on the river channels across the delta. Most sampling locations were revisited four times. Sampling during different seasons was extremely challenging in this region due to uncertain ice cover and broken ice fields during and after ice break-up. Additionally, very shallow water (〈5 m) mandates the use of small draught boats, which was challenging under frequently harsh weather conditions. To tackle these challenges, various sampling platforms were used such as small boats, trucks, ski-doos and hovering helicopter. The campaigns were carried out under the umbrella of the EU Horizon 2020 project Nunataryuk.

Description: The database reports the results of bulk rock geochemical measurements realized on 105 ultramafic lithologies (harzburgites and dunites) samples collected from Holes CM1A (46 samples) and CM2B (59 samples) drilled in the Wadi Tayin massif in the SE of the ophiolite during Phase 2 of the ICDP OmanDP (Nov. 2017-Jan. 2018) (Kelemen et al. [2020]). The studied samples were selected following two strategies. First, a homogeneous sample was selected every 10 m downhole cores during the OmanDP Phase 2 drilling operations, onsite in Oman, in order to get a petrological and geochemical overview continuously along the cores. Second, additional samples have been selected during the daily ChikyuOman Leg 3 sampling meetings in consultation with the core description teams, to focus on more specific facies or levels. These samples are referred to as onsite samples and shipboard samples respectively. Adjacent to each onsite and shipboard sample an oriented thin section billet was taken for mineralogical and lithological characterization. Geochemical data of onsite and shipboard samples were measured both aboard the D/V Chikyu during the ChikyuOman Phase 2 Leg 3 for major element and volatile contents for part of the samples, and at Institute of Earth Science, Academia Sinica, Taiwan (IES-AS), the University of Edinburgh, Scotland (EU), Université Toulouse III - Paul Sabatier, France (TU), and Niigata University, Japan (NU) for trace element contents and additional major element and volatile contents. The purpose of the study was to obtain a high-density and high analytical quality bulk geochemical characterization along continuous cores recovered from OmanDP Holes CM1A and CM2B, from the crust to the mantle through the crust-mantle transition zone. Loss on ignition (LOI) of all onsite and shipboard samples were determined onboard the D/V Chikyu, using the OHTI (Ocean High Technology Institute, Inc., Tokyo, Japan) motion compensated balance system into a pre-weighed ceramic crucible using a spatula (that was never in contact with lithium metaborate flux). Duplicate LOI measurements were done on the onsite samples at EU, following the same steps and procedures. Major element abundances (wt.% oxides) in powdered rock samples were determined using the RIGAKU Supermini wavelength dispersive X-ray fluorescence spectrometer equipped with a 200 W Pd anode tube at 50 kV and 4 mA onboard DV Chikyu during OmanDP Phase 2 Leg 3. Major element analyses were determined to be acceptable if the sum of the anhydrous oxide concentrations totaled to between 99 and 101 wt.%. Precision and accuracy are better than 2.5 % for all oxides except for TiO2 for reference materials DTS-2B and JP-1 (better than 11%) and Na2O, P2O5 and K2O for JGb-2 (3.40, 17.60, and 7.49% respectively). Duplicates of onsite samples whole rock major element analyses were performed at EU, using the Panalytical PW2404 wavelength-dispersive sequential X-ray spectrometer. Gas chromatographic separation was undertaken on non-ignited powders to determine their volatile element contents (total carbon, CTotal and water recalculated from hydrogen) using the Thermo Finnigan™ FlashEA® 1112 elemental analyzers (EA) onboard D/V Chikyu. Whole rock trace element analyses were measured by ICP-MS using acid digestion of powder samples after ChikyuOman 2018 Leg 3. Sample powders were divided into three batches. One batch was sent to each IES-AS, TU and NU laboratory for trace element measurements. The measurements were conducted at IES-AS using an Agilent 7500s inductively coupled plasma‐mass spectrometer (ICP‐MS); at TU using a Thermo Scientific™ Element XR™ HR-ICP-MS; and at NU using Yokogawa HP4500 ICP-MS. To compare the accuracy and the precision in the three different laboratories, trace element measurements were performed on a selection of duplicate samples, and on the same reference materials (DTS-2B and JP-1a).

Description: Palynological and sedimentological analyses were performed on the sediment core HH16-1205-GC retrieved from the central Isfjorden, West Spitsbergen in order to retrace the climate of the last 7000 years. The record revealed an overall cooling trend with an important climate shift between 4.4 and 3.8 cal. ka BP, and millennial-scale oscillations. Over the last 7000 years, sea-surface reconstruction from dinocyst assemblages indicates a decrease in summer sea-surface temperature, from 2.5 to 1.5 °C, and primary productivity, from 750 to 650 gC m-² a-1. Predominant sediment supply from the inner part of the fjord, ice rafting, dense sea-ice cover, strongly stratified water masses, and high primary productivity is observed in the sedimentological and palynological data between 6.8 and 5.8 cal. ka BP. The interval from 4.4 to 3.8 cal. ka BP is marked by a layer of coarser material followed by a significant decrease in the grain size mode, as well as changes in geochemical properties. large-amplitude fluctuations is observed in our geochemical data after 2.0 cal. ka BP, while an increase of the dinocysts Impagidinium pallidum and Spiniferites elongatus from 2.0 to 1.2 cal. ka BP suggests enhanced Atlantic Water inflow. The sea surface conditions reconstructions and XRF ratios also reveal large-amplitude millennial fluctuations. Wavelet analysis and cross-wavelet analysis performed on multiple variables confirm a strong cyclic signal with a periodicity of 1200 to 1500 years.

Description: The XRD data has been gained from pulverized and homogenized samples of every 5 cm by KOPRI personal at KOPRI and University of Tromsoe sampling parties. XRD raw measurements were run at Crystallography, Geosciences, University of Bremen in 2018-2020. Measurement conditions: Philips X'Pert Diffractometer, Cu radiation, fixed divergence, secoundary Ni filter, 3-85 ° 2theta, 0.0016° step size, 100 sec calculated step time. XRD mineral assemblage determination were subsequently gained through the QUAX full pattern quantitative determination software (see Vogt et al. 2002 at Pangaea methods wiki). The software allows for differentiation of all minerals. Here, the Fe-oxides and hydroxides were in the focus of the research manuscript. A QXRD investigation allows for not only identification of mineral content but also for detailing authigenic vs. allochthonous minerals, transport of detrital input to the sediment core and the interpretation of the transport processes and the local environment as well as the paleoceanographic reconstruction of the region. Sediment ages are given through the below mentioned data sets. A series of fjord surface sediments were collected from various Svalbard fjord systems during expeditions of RV Helmer Hanssen from UiT The Arctic University of Norway between 2012 and 2019 (Fig. 1). Four gravity cores were retrieved along a 150 km long N‒S transect from the continental shelf off northern Svalbard to the innermost Wijdefjorden: core HH17-1085-GC (hereafter 1085; 80.27°N, 16.21°E, 322 m water depth; continental shelf), HH17-1094-GC (hereafter 1094; 79.74°N, 15.42°E, 148 m water depth; fjord mouth), HH17-1100-GC (hereafter 1100; 79.30°N, 15.78°E, 112 m water depth; central fjord), and HH17-1106-GC (hereafter 1106; 79.00°N, 16.21°E, 160 m water depth; inner fjord)

Description: Multibeam bathymetry raw data using the ship's own Kongsberg (Simrad) EM 120 multibeam echosounder was continuously recorded during RV SONNE cruise SO184/3. Data was recorded on 20 days between 2005-08-22 and 2005-09-10. This dataset contains an elongated transit survey south of the islands of Indonesia. Data covers parts of the continental shelf and continental slope. The approximate average depth of the entire dataset is around 2500m. The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. No ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus no SVP files are added to this dataset. However, data analysis of the multibeam raw data revealed that SVP has been changed during the survey. This publication is conducted within the efforts of the German Marine Research Alliance in the core area 'Data management and Digitalization' (Deutsche Allianz Meeresforschung, DAM). Data are unprocessed and therefore contains incorrect depth measurements (artifacts) without further processing. Note that refraction errors can be expected due to the lack of proper SVP. Overall, it appears that the data quality is rather good since the gridded hillshade data showed relatively few obstacles. Data can be processed e.g. with the open source software package MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, http://www.mbari.org/products/research-software/mb-system/, 2022).

Description: Multibeam bathymetry raw data using the ship's own Kongsberg EM 122 multibeam echosounder was almost continuously recorded during RV SONNE cruise SO268/3. Data was recorded on 29 days between 2019-05-31 and 2019-06-28. This dataset contains a transit survey in the North Pacific Ocean. The approximate average depth of the entire dataset is around 5300m. The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. Ancillary sound velocity profiles (SVP) files from the cruise are archived at the BSH, thus SVP files are added to this dataset. Also data analysis of the multibeam raw data revealed that SVP has been changed several times during the survey. This publication is conducted within the efforts of the German Marine Research Alliance in the core area 'Data management and Digitalization' (Deutsche Allianz Meeresforschung, DAM). Data are unprocessed and therefore contains incorrect depth measurements (artifacts) without further processing. Note that refraction errors can be expected due to the lack of proper SVP. Overall, it appears that the data quality is rather good since the gridded hillshade data showed relatively few obstacles. Data can be processed e.g. with the open source software package MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, http://www.mbari.org/products/research-software/mb-system/, 2022).