Beryllium isotope and planktonic foraminifera d18O for sediment core MD05-2970

Reactive phase Be isotopes, 10Be and 9Be, and major elament measurements were performed on 53 samples from core MD05-2970. d18O of Globigerinoides ruber are measured from the same core for 288 samples, respectively. We constrained a new age model using planktonic foraminifera (G. ruber) δ18O data along with the existing radiocarbon ages (Nemoto et al., 2024) in BIGMACS (Lee et al., 2023). The use of planktonic rather than benthic foraminifera δ18O is consistent with previous studies in the Indian Ocean (Khan et al., 2022; Kim et al., 2018; Lathika et al., 2021; Lu et al., 2022; Qian et al., 2025; Saher et al., 2009). A Thermo ELEMENT XR™ single collector sector field high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) installed at the Atmosphere and Occean Research Institute was used to obtain [9Be] (Sproson, Aze et al., 2021). 10Be/9Be was measured using a National Electrostatic Corporation (NEC) accelerator mass spectrometer (AMS), of 5 MV terminal voltage, at the University of Tokyo (UTokyo), Micro Analysis Laboratory, Tandem accelerator (Matsuzaki et al., 2007). Absolute values were obtained using the KNB5-2 standard (10Be/9Be = 8.558 × 10−12; (Nishiizumi et al., 2007). Decay correction is performed on 10Be concentration using a 10Be half-life of 1.387 Ma. The 10Be/9Be ratios were corrected for 10Be paleo-production using the paleomagnetic reference records of the geomagnetic dipole moment (Korte et al., 2011) following von Blanckenburg et al. (2015).