Tracing continental weathering and water mass mixing in the Atlantic sector of the Southern Ocean with neodymium and hafnium isotopes

本研究的主题是对南大洋大西洋部分水柱中溶解形式和颗粒形式的钕（Nd）和铪（Hf）同位素的分布进行详细调查。Nd同位素已被证明是海洋中现在和过去水团的强有力的地球化学示踪剂。结合Hf同位素对大陆风化机制进行了表征。然而，到目前为止，几乎没有关于南大洋水柱的数据，这严重限制了这种示踪剂组合在当今研究和过去重建中的可靠应用。我们在RV北极星远征antxxiv /3期间，沿着零子午线和更远的威德尔海和德雷克海峡，从相同的地点收集了大量的水样和悬浮颗粒分数。我们将首次确定溶解和颗粒形式的Nd和Hf的同位素组成，以表征南大洋不同水团及其来源的同位素组成，并获得南极风化过程对南大洋地球化学性质影响的新见解。这些数据将作为在古海洋学中更可靠地应用这些同位素作为示踪剂的基础。

The subject of this study is a detailed investigation of the distribution of neodymium (Nd) and hafnium (Hf) isotopes in dissolved and particulate form in the water column of the Atlantic sector of the Southern Ocean. Nd isotopes have been shown to be a powerful geochemical tracer for present and past water masses in the ocean. The combination with Hf isotopes was applied for the characterization of continental weathering regimes. So far there are, however, nearly no data for the water column of the Southern Ocean, which severely restricts the reliable application of this combination of tracers for present day studies and reconstructions of the past. We collected large volume water samples and the suspended particulate fraction from the same locations during RV Polarstern Expedition ANT XXIV/3 along the Zero meridian and further across the Weddell Sea and the Drake Passage. We will determine the isotope composition of Nd and for the first time Hf in dissolved and particulate form to characterize the isotope composition of the different Southern Ocean water masses and their sources and to gain new insight into the influence of Antarctic weathering processes on the geochemical properties of the Southern Ocean. These data will serve as a basis for more reliable application of these isotopes as tracers in paleo-oceanography.