Abiotic conditions from the local environment of Arctic kelp populations on the west coast of Svalbard, Norway

We assessed how Arctic kelp populations react to their local in situ environment in August 2022. Therefore, we sampled Saccharina latissima sporophytes from eight populations at several latitudes on the west coast of Svalbard, Norway, and correlated these results to the abiotic conditions they experienced. Data was smoothed by the mean for every meter interval. We measured the spectrally resolved underwater light climate from 400-700 nm with a RAMSES-ACC-UV/VIS radiometer (TriOS Optical Sensor, Oldenburg, Germany) from the surface until the bottom was reached (max. 10 m). The photosynthetically active irradiance (PAR) was calculated by integrating the irradiance. The light attenuation coefficient (Kd) was calculated between the surface and 3 m water depth. The spectrum peak (nm) on 3 m water depth was defined as the wavelength with the maximum irradiance transmission through the water column

Selected field photos from the Mendenhall Glacier in 2021

We gathered field observations of debris-rich ice layers from an alpine glacier margin to help inform models of glacial sediment transport across landscapes. We identified representative exposures of basal ice facies from the 500 meter-long grounded terminus at Mendenhall Glacier, Juneau, AK, in August 2021. At each exposure, we captured field photos to qualitatively document the selected exposures, the entrained debris layers, and the proximal till deposits. Photos and field notes were used to construct descriptions of the relationship between entrained sediment facies at the margin

Results of analysis of sediment core LV76-21 from Detroit Seamount

The sediment core LV76-21 was recovered from northwest of the Detroit Seamount (51°34’N, 167°15.7’E; water depth 2,769 m) using a gravity corer on the R/V “Akademik M.A. Lavrentyev” during joint Russian–Chinese expeditions in 2016. The core sediments were predominantly gray–olive gray terrigenous silty clay–clayey silt with rare sand. The sediment was coarser in the intervals of 144–167 and 434–456 cm. The upper 17 cm of the sediment was represented by an oxidized brown–gray-brown ooze. In the intervals 0–38 cm, 76–167 cm, 356–364 cm, 407–434 cm, 456–475 cm, and 519–546 cm, the sediments were represented by grayish-olive–olive weakly diatomaceous oozes. The sediments in the intervals of 0–144 cm and 519–546 cm were enriched with foraminifera shells, and sediments were weakly enriched with foraminifera at the intervals of 407–434 cm, 456–482 cm, and 546–557 cm. The lithological description shows three visible ash layers at depths of 364–366 cm, 397–404 cm, and 467–468.5 cm, with thin ash lenses at a depth of 477–479 cm

Oxygen isotope ratios of planktonic and benthic foraminifera collected from marine sediment core KR05-15_PC01 and KR05-15_PL01

A precise age model of marine sediment core is crucial for environmental studies of the past such as paleoceanography, paleoclimatology, and paleo-hazard studies. Here we report a dataset of oxygen isotope ratios of foraminifera collected from marine sediment cores recovered from the West Caroline Basin in the western equatorial pacific using a piston coring system of R/V Kairei in 2005 (KR05-15 PC01/PL01, 0.10°S 139.58°E, 3,226 m below sea level). The core depth 4.91–6.25 meters of 12.46-meter-long piston core (PC01), which corresponds to termination 2 (ca. 140–120 kyr ago), and a whole 0.53-m-long pilot core (PL01) were used for the measurement of oxygen isotopes of both planktonic (Globigerinoides ruber, Trilobus sacculifer) and benthic (Uvigerina spp.) foraminifera shells. The already published other datasets of oxygen isotopes of both planktonic and benthic foraminifera shells that were collected from the same sediment core (KR05-15 PC01) are also compiled

Stable oxygen isotope record of Uvigerina auberiana of sediment core LV76-21

Sediments for the δ18O of planktic and benthic foraminifera analysis from core LV76-21 were sampled from 1 cm-thick slices with step of 2–5 cm along the core length. Foraminifera shells were picked from the sediment fractions of 150-250 µm in the samples where they were available. The δ18O of planktic and benthic foraminifera were measured at Tongji University (China) and at the Far Eastern Geological Institute (Russia). Isotope measurements from Tongji University were provided using a Finnigan‐MAT 252 mass spectrometer. The results were validated against a Chinese national carbonate standard (GBW04405) and NBS‐19. The standard deviation is 0.07‰ for δ18O. The isotope measurements from the Far Eastern Geological Institute were analyzed using a Finnigan-MAT 253 mass spectrometer with modification of Velivetskaya et al. (2009) without preliminary roasting. The standard deviation for the δ18O values is ± 0.05‰. All the values are reported on the Pee Dee Belemnite (PDB) scale

Boron and carbon isotope, and B/Ca data for a Siderastrea siderea coral core CIM_C_2-2-1/CIM_C_2-2-2 from the Gulf of Mexico

Massive scleractinian corals provide unique opportunities to reconstruct past climatic and chemical changes in the ocean, where there is no additional information. Regular pH measurements and carbonate chemistry observations of the ocean are still sparse but are essential to monitor the health of our oceans. Boron isotopes and B/Ca measured from coral skeletal material can be used to reconstruct the pH and the carbonate chemistry of their environment. The results from boron isotope measurements show an acidifying Gulf of Mexico over 160 years (1845-2005) and declining δ13C. A coral core was drilled in 2005 from a living Siderastrea siderea coral close to Havana, Cuba. The coral core was cut, slabbed and X-rayed at the Leibniz Center for Tropical Marine Research, Bremen. Yearly samples were drilled over two polyps with a Proxxon drill and 1 mm diamond-coated drill bit. Boron Isotopes were measured from the yearly samples for every 3rd year (if there was enough coral skeletal material) at the MARUM facilities in Bremen with a Thermo Fisher Neptune MC-ICP-MS. δ13C was measured on monthly samples on the Thermo Fisher Finnigan MAT 251 and Finnigan Mat 253plus isotope ratio mass spectrometer also at MARUM. Trace elements-Calcium ratios where measured at ZMT on a Plasma Quant MS Elite Inductively Coupled Plasma - Mass Spectrometer with monthly samples. The age model for the dataset was interpolated using the Arand software Ager and Timer (Howell et al., 2006). Outliers were identified with the detection method provided by Chen and Liu (1993)

2D multichannel seismic reflection raw data (GI Gun) of RV Petr Kottsov in 1998 to the Agulhas Plateau, seismic reflection profile AWI-98017

Seismic reflection data collected on the Agulhas Plateau during with RV Petr Kottsov in 1998. 2 GI-guns were used a seismic source, the data were recorded with a 2400 m (active length) long analog streamer. The data are demultiplexed and unprocessed. No gain, filter or mute have been applied. The data are in SEGY format. See cruise report or ReadMe file for more information on acquisition parameters

Time series of autonomous phase-sensitive radar (ApRES) measurements and determined basal melt rates at location EIS8 on Ekström Ice Shelf, Antarctica from January 2023 to November 2023

The dataset consists of raw data and derived melt rates from autonomous phase-sensitive radar (ApRES) measurements. The ApRES was operated with two broadband frame antennas at the Ekström Ice Shelf since April 2020 with one measurement every hour. These Lagrangian measurements allow the estimation of basal melt rates based on estimated vertical displacements of englacial and basal reflections. The ApRES is an autonomous operating frequency-modulated continuous wave (FMCW) radar that transmits a tone sweep - called chirp - ranging from 200 to 400 MHz over a period of one second. In order to improve the signal-to-noise ratio, 20 chirps were transmitted within a single measurement. These measurements were repeated every hour. A raw data file contains up to 4 measurements. Background of the pRES-system is published by Nicholls et al. (2015). The processing of the data is described in Zeising et al. (2025). The estimated basal melt rates are based on the analysis of firn densification, strain thinning, and the change in ice thickness from the determination of vertical displacements. The basal melt rates are averaged over 7 days (moving window). To represent the variability of the melt rate on sub-weekly timescales, we also calculated the 7 day standard deviation of the basal melt rates based on a 1 day moving window. The uncertainty of the basal melt rate is based on the uncertainty of the strain estimation and the determination of the ice thickness change. Data are exported in 4 hour intervals. A positive melt rate represents melting. Details on the processing are given in Zeising et al. (2025)