ALBERT

Description: Culturing experiments exposed the scleractinian corals Porites lobata and Porites lichen to a mixture of dissolved chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), cadmium (Cd), tin (Sn), mercury (Hg) and lead (Pb) in a wide concentration range for a period of more than a year. The aim was to examine whether the incorporation of heavy metals into the aragonitic skeleton of the corals is a direct function of their concentration in seawater. Therefore, the trace-element-to-calcium ratio (TE/Ca) in the coral aragonite precipitated during culturing was measured by Laser ablation ICP-MS in 2020. The measurement showed that all metals used here were measureable in the coral skeleton and only minor, non-systematic intra- and interspecies differences in the trace metal concentrations was found. A positive correlation between the TE/Ca values and the coral skeleton was found for Cr, Mn, Ni, Zn, Ag, Cd and Pb. Cu, Sn and Hg did not show any clear trend. This dataset shows time resolved trace element-to-calcium values of coral colonies A to D cultured in the metal system along the measured Laser ablation ICP-MS scanning lines (Line XY stands for different Laser ablation lines measured at different positions at one respective coral colony) and values derived from the composite lines. Measurements were carried out from the top of the coral to the bottom and the distance starting from the top is indicated as “Elapse Time”. The energy density of the laser was set to 10 J/cm3, the laser spot size was 120 µm diameter and the stage moved 50 µm/s. Prior to every scan, a preablation pass with a spot size of 160 µm diameter was carried out to clean the cut surface of the coral skeleton. Culturing experiments were configured with two identically experimental aquaria. Four different coral colonies and two different species were used (Porites lobate Coral A-C, Porites lichen Coral D). All colonies were divided into subcolonies and growth control was performed with Alizarin Red S prior and during the experiment. One subcolony was placed in each experimental tank. The control aquarium remained unmodified while the trace metal concentration in the metal aquarium was elevated stepwise (Phase 1-4, Phase 1 = lowest metal concentration). The trace metal concentration in both tanks was monitored during the culturing period. After the experiment and more than 15 months later, specimens were cut again and the trace metal concentration in the coral skeleton was determined. It should be noted that coral D died 2.5 weeks after the exposure to the highest metal concentration in phase 4. TE/Ca values are processes as followed: (1) Time resolves raw intensities (in counts per seconds) for all isotopes measured were processed with the software Iolite (Version 4). The determination of element/Ca ratios was performed after the method of Rosenthal et al. (1999). High values of 25Mg, 27Al or 55Mn at the beginning of an ablation profile were related to contamination on the surface of the coral or remains of organic matter and these parts of the profiles were excluded from further data processing. (2) The NIST SRM 612 glass (Jochum et al., 2011) was used for monitoring and correction of the instrument drift. (3) The detection limit was defined by 3.3*SD of the gas blank in counts per seconds for every element in the raw data. Only values above this limit were used for further analyses and no data below the LOQ (limit of quantification = 10*SD) were interpreted. After processing the data with Iolite, an outlier detection of the TE/Ca ratios of the samples was performed. If trace metal values from deviated more than ±2SD from the average of the samples from the corresponding culturing phase, values were defined as outliers and discarded. (4) A composite line was calculated individually for all colonies consisting of the laser ablation measurements along the main growth axis of the coral (coral A line 1-3, coral B line 1-3, coral C line 2 + 3, coral D line 1). Laser ablation measurements along lines that were deviating from the main growth axis of the coral were not taken into account. Calculations were performed with QAnalyseries (Kotov and Paelike, 2018).

Description: The occurrence of previously geochemically identified tephra allowed refinement of the age-depth model by comparison with previously established volcanic eruption history (Roeser et al., 2012). Tephra layers were polished on thin sections and the glass shards were geochemically characterized using a JEOL JXA-8230 Electron Probe X-ray Micro Analyzer (EMPA; ISTerre Laboratory, University Grenoble Alpes) equipped with 5 wavelength dispersive spectrometers (WDS) and one energy dispersive spectrometer (EDS) detector. The measurements used the following conditions: 15 kV voltage, 2 nA beam current, and 5 to 7 µm beam size. For standardization, MPI-DING glasses (StHs6/80-G, GOR132-G) (http://georem.mpch-mainz.gwdg.de; Jochum et al., 2000), natural minerals, and synthetic oxides were used. Two glasses, Atho-G (http://georem.mpch-mainz.gwdg.de; Jochum et al., 2000) and KE-12 (Metrich & Rutherford, 1992), were analyzed together with the samples to verify analytical accuracy and to exclude the loss of alkalis. Analyses of glass shards yielding a total oxide sum less than 96% or suggesting mineral impurities were not included in this study. Analytical data were normalized to 100% total oxide values to enable comparison.

Description: The occurrence of previously geochemically identified tephra allowed refinement of the age-depth model by comparison with previously established volcanic eruption history (Roeser et al., 2012). Tephra layers were polished on thin sections and the glass shards were geochemically characterized using a JEOL JXA-8230 Electron Probe X-ray Micro Analyzer (EMPA; ISTerre Laboratory, University Grenoble Alpes) equipped with 5 wavelength dispersive spectrometers (WDS) and one energy dispersive spectrometer (EDS) detector. The measurements used the following conditions: 15 kV voltage, 2 nA beam current, and 5 to 7 µm beam size. For standardization, MPI-DING glasses (StHs6/80-G, GOR132-G) (http://georem.mpch-mainz.gwdg.de; Jochum et al., 2000), natural minerals, and synthetic oxides were used. Two glasses, Atho-G (http://georem.mpch-mainz.gwdg.de; Jochum et al., 2000) and KE-12 (Metrich & Rutherford, 1992), were analyzed together with the samples to verify analytical accuracy and to exclude the loss of alkalis. Analyses of glass shards yielding a total oxide sum less than 96% or suggesting mineral impurities were not included in this study. Analytical data were normalized to 100% total oxide values to enable comparison.

Description: This dataset provides the data for the four glass standards used for monitoring of the precision and accuracy of electron probe microanalyses (EPMA) during analytical runs of cryptotephra glass-shards in the International Continental Scientific Drilling Program (ICDP) sediment core 5017-1 (see first dataset). For each EPMA run, all four glass standards were measured. The major-element composition of the glass standards was measured using a JEOL JXA-8230 electron microprobe at GFZ Potsdam, Germany (15 kV, 5-10 nA, 5-10 µm beam size). Instrumental calibration used natural mineral standards. Glass standards were Lipari obsidian (Hunt & Hill 1996, doi:10.1016/1040-6182(95)00088-7; Kuehn et al. 2011, doi:10.1016/j.quaint.2011.08.022) and MPI-Ding glasses ATHO-G, StHs-6-80-G and GOR-132-G (Jochum et al. 2006, doi:10.1029/2005GC001060).

Description: Marine Isotope Stage 5e (MIS 5e; the Last Interglacial, 125 ka) represents a process analog for a warmer world. Analysis of sea-level proxies formed in this period helps in constraining both regional and global drivers of sea-level change. In Southeast Asia, several studies have reported elevation and age information on MIS 5e sea-level proxies, such as fossil coral reef terraces or tidal notches, but a standardized database of such data was hitherto missing. In this paper, we produced such a sea-level database using the framework of the World Atlas of Last Interglacial Shorelines (WALIS; https://warmcoasts.eu/world-atlas.html). Overall, we screened and reviewed 14 studies on Last Interglacial sea-level indicators in Southeast Asia, from which we report 43 proxies (42 coral reef terraces and 1 tidal notch) that were correlated to 134 dated samples. Five data points date to MIS 5a (80 ka), six data points are MIS 5c (100 ka), and the rest are dated to MIS 5e. The database compiled in this study is available at https://doi.org/10.5281/zenodo.5040784 (Maxwell et al., 2021).

Description: Despite increasing recognition of the need for more diverse and equitable representation in the sciences, it is unclear whether measurable progress has been made. Here, we examine trends in authorship in coral reef science from 1,677 articles published over the past 16 years (2003–2018) and find that while representation of authors that are women (from 18 to 33%) and from non-OECD nations (from 4 to 13%) have increased over time, progress is slow in achieving more equitable representation. For example, at the current rate, it would take over two decades for female representation to reach 50%. Given that there are more coral reef non-OECD countries, at the current rate, truly equitable representation of non-OECD countries would take even longer. OECD nations also continue to dominate authorship contributions in coral reef science (89%), in research conducted in both OECD (63%) and non-OECD nations (68%). We identify systemic issues that remain prevalent in coral reef science (i.e., parachute science, gender bias) that likely contribute to observed trends. We provide recommendations to address systemic biases in research to foster a more inclusive global science community. Adoption of these recommendations will lead to more creative, innovative, and impactful scientific approaches urgently needed for coral reefs and contribute to environmental justice efforts.

Description: Here we present the experimental design and results from a new mid-Pliocene simulation using the latest version of the UK's physical climate model, HadGEM3-GC31-LL, conducted under the auspices of CMIP6/PMIP4/PlioMIP2. Although two other palaeoclimate simulations have been recently run using this model, they both focused on more recent periods within the Quaternary, and therefore this is the first time this version of the UK model has been run this far back in time. The mid-Pliocene Warm Period, ∼3 Ma, is of particular interest because it represents a time period when the Earth was in equilibrium with CO2 concentrations roughly equivalent to those of today, providing a possible analogue for current and future climate change. The implementation of the Pliocene boundary conditions is firstly described in detail, based on the PRISM4 dataset, including CO2, ozone, orography, ice mask, lakes, vegetation fractions and vegetation functional types. These were incrementally added into the model, to change from a pre-industrial setup to a Pliocene setup. The results of the simulation are then presented, which are firstly compared with the model's pre-industrial simulation, secondly with previous versions of the same model and with available proxy data, and thirdly with all other models included in PlioMIP2. Firstly, the comparison with the pre-industrial simulation suggests that the Pliocene simulation is consistent with current understanding and existing work, showing warmer and wetter conditions, and with the greatest warming occurring over high-latitude and polar regions. The global mean surface air temperature anomaly at the end of the Pliocene simulation is 5.1 ∘C, which is the second highest of all models included in PlioMIP2 and is consistent with the fact that HadGEM3-GC31-LL has one of the highest Effective Climate Sensitivities of all CMIP6 models. Secondly, the comparison with previous generation models and with proxy data suggests a clear increase in global sea surface temperatures as the model has undergone development. Up to a certain level of warming, this results in a better agreement with available proxy data, and the “sweet spot” appears to be the previous CMIP5 generation of the model, HadGEM2-AO. The most recent simulation presented here, however, appears to show poorer agreement with the proxy data compared with HadGEM2 and may be overly sensitive to the Pliocene boundary conditions, resulting in a climate that is too warm. Thirdly, the comparison with other models from PlioMIP2 further supports this conclusion, with HadGEM3-GC31-LL being one of the warmest and wettest models in all of PlioMIP2, and if all the models are ordered according to agreement with proxy data, HadGEM3-GC31-LL ranks approximately halfway among them. A caveat to these results is the relatively short run length of the simulation, meaning the model is not in full equilibrium. Given the computational cost of the model it was not possible to run it for a longer period; a Gregory plot analysis indicates that had it been allowed to come to full equilibrium, the final global mean surface temperature could have been approximately 1.5 ∘C higher.

Description: Relative contribution of the “marginal ice zone”, “drift-ice/pack-ice” and “summer subsurface” diatom indicator groups, diatom valve and Chaetoceros resting spore concentrations (valves or spores/g), diatom valve and Chaetoceros resting spore fluxes (valves or spores/unit surface area/yr), and total diatom fluxes (valves and spores/unit surface area/yr) from the marine sediment core AMD14-204 that was retrieved from the West Greenland shelf, offshore Upernavik, and which spans the last ca. 9,000 years.