Rare earth elements, nutrient, oxygen isotope and strontium isotope samples in the Arctic Ocean of T/S Oshoro-maru cruise (C255) 2013

Rare earth elements (REEs) water samples, were collected from 40 stations with 500 ml X-NISKIN bottles. After sampling, the seawater was filtrated through 0.22 micro m membrane filter and acidified immediately to pH < 1.6 with ultrapure HCl (TAMAPURE AA-100, Tama Chemicals) at the Clean Room on board. Acidified samples will be pre-concentrated then analyzed for REE concentration with SF-ICP-MS (Sector Field Inductively-Coupled Plasma Mass Spectrometer, Thermo Fisher Scientific, KK) in laboratories in the University of Toyama. Oxygen and strontium isotope ratios samples, were collected with 50 ml glass bottles during the cruise. They will be analyzed for oxygen isotopes by IR-MS (Isotope Ratio Mass Spectrometry) and strontium isotopes by TIMS (Thermal Ionization Mass Spectrometry) in laboratories in the University of Toyama. Marine sediment samples were taken from multiple cores from 8 stations. Sediment samples were continuously sliced at every 0.5 cm from the top to 2.0 cm, every 1.0 cm from 2.0 cm to 10 cm and 2.0 cm deeper than 10.0 cm in thickness throughout the cores on board. Then, pore water samples were squeezed from them. The squeezing for multiple cores was carried out by pressure filtration through 0.45 micro m Millipore filter for nutrients and 0.45 micro m and 0.20 micro m Millipore filters for REEs, using a stainless steel clamp at 4 deg C in the incubator. Porewater samples are used to analyze the nutrients and REEs in the laboratories after the cruise.