TY - JOUR A1 - Serno, Sascha A1 - Winckler, Gisela A1 - Anderson, Robert F. A1 - Maier, Edith A1 - Ren, Haojia A1 - Gersonde, Rainer A1 - Haug, Gerald H. T1 - Comparing dust flux records from the Subarctic North Pacific and Greenland: Implications for atmospheric transport to Greenland and for the application of dust as a chronostratigraphic tool JF - Paleoceanography N2 - We present a new record of eolian dust flux to the western Subarctic North Pacific (SNP) covering the past 27,000years based on a core from the Detroit Seamount. Comparing the SNP dust record to the North Greenland Ice Core Project (NGRIP) ice core record shows significant differences in the amplitude of dust changes to the two regions during the last deglaciation, while the timing of abrupt changes is synchronous. If dust deposition in the SNP faithfully records its mobilization in East Asian source regions, then the difference in the relative amplitude must reflect climate-related changes in atmospheric dust transport to Greenland. Based on the synchronicity in the timing of dust changes in the SNP and Greenland, we tie abrupt deglacial transitions in the Th-230-normalized He-4 flux record to corresponding transitions in the well-dated NGRIP dust flux record to provide a new chronostratigraphic technique for marine sediments from the SNP. Results from this technique are complemented by radiocarbon dating, which allows us to independently constrain radiocarbon paleoreservoir ages. We find paleoreservoir ages of 745140years at 11,653year B.P., 680228years at 14,630year B.P., and 790498years at 23,290year B.P. Our reconstructed paleoreservoir ages are consistent with modern surface water reservoir ages in the western SNP. Good temporal synchronicity between eolian dust records from the Subantarctic Atlantic and equatorial Pacific and the ice core record from Antarctica supports the reliability of the proposed dust tuning method to be used more widely in other global ocean regions. KW - Subarctic North Pacific KW - eolian dust KW - helium-4 KW - atmospheric circulation KW - chronostratigrapy KW - paleoreservoir age Y1 - 2015 U6 - https://doi.org/10.1002/2014PA002748 SN - 0883-8305 SN - 1944-9186 VL - 30 IS - 6 SP - 583 EP - 600 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Serno, Sascha A1 - Winckler, Gisela A1 - Anderson, Robert F. A1 - Hayes, Christopher T. A1 - McGee, David A1 - Machalett, Bjoern A1 - Ren, Haojia A1 - Straub, Susanne M. A1 - Gersonde, Rainer A1 - Haug, Gerald H. T1 - Eolian dust input to the Subarctic North Pacific JF - Earth & planetary science letters N2 - Eolian dust is a significant source of iron and other nutrients that are essential for the health of marine ecosystems and potentially a controlling factor of the high nutrient-low chlorophyll status of the Subarctic North Pacific. We map the spatial distribution of dust input using three different geochemical tracers of eolian dust, He-4, Th-232 and rare earth elements, in combination with grain size distribution data, from a set of core-top sediments covering the entire Subarctic North Pacific. Using the suite of geochemical proxies to fingerprint different lithogenic components, we deconvolve eolian dust input from other lithogenic inputs such as volcanic ash, ice-rafted debris, riverine and hemipelagic input. While the open ocean sites far away from the volcanic arcs are dominantly composed of pure eolian dust, lithogenic components other than eolian dust play a more crucial role along the arcs. In sites dominated by dust, eolian dust input appears to be characterized by a nearly uniform grain size mode at similar to 4 mu m. Applying the Th-230-normalization technique, our proxies yield a consistent pattern of uniform dust fluxes of 1-2 g/m(2)/yr across the Subarctic North Pacific. Elevated eolian dust fluxes of 2-4 g/m(2)/yr characterize the westernmost region off Japan and the southern Kurile Islands south of 45 degrees N and west of 165 degrees E along the main pathway of the westerly winds. The core-top based dust flux reconstruction is consistent with recent estimates based on dissolved thorium isotope concentrations in seawater from the Subarctic North Pacific. The dust flux pattern compares well with state-of-the-art dust model predictions in the western and central Subarctic North Pacific, but we find that dust fluxes are higher than modeled fluxes by 0.5-1 g/m(2)/yr in the northwest, northeast and eastern Subarctic North Pacific. Our results provide an important benchmark for biogeochemical models and a robust approach for downcore studies testing dust-induced iron fertilization of past changes in biological productivity in the Subarctic North Pacific. KW - eolian dust KW - Subarctic North Pacific KW - INOPEX KW - helium-4 KW - Th-232 KW - REE Y1 - 2014 U6 - https://doi.org/10.1016/j.epsl.2013.11.008 SN - 0012-821X SN - 1385-013X VL - 387 SP - 252 EP - 263 PB - Elsevier CY - Amsterdam ER -