Antarctic Ice-Sheet discharge over the last glacial cycle (AIS-DIS)

随着近几十年来气候变暖，南极冰盖（AIS）目前正在加速融化。这与社会息息相关，因为全球海平面可能在不久的将来大幅上升。许多科学学科试图更好地了解AIS的现状，以便为未来提供更持续的预测。在AIS- dis项目中，我们希望更好地了解过去关键时期AIS的动态，以便可以校准模型并改进未来预测。我们希望将研究重点放在末次冰期旋回上，特别是1-5次冰期终止上，因为在这些气候变暖的自然时期，AIS的质量损失最大。我们的调查将集中在冰山巷的中心，这是通往低纬度地区的独特通道，大多数从南极大陆分离出来的冰山在我们的核心地点上空融化之前都会经过这里。因此，这是唯一能够随时间获得具有代表性的AIS质量损失综合信号的区域。在这里，IODP 382考察队检索了在南极洲附近获得的最长和最高分辨率的气候和冰盖档案。我们希望分别研究多芬盆地和Pirie盆地的U1537和U1538站点。我们的目标是破译AIS质量损失的时间、速度和程度。这将主要通过分析冰山漂流碎片（IBRD）来实现。冰山漂流碎片是指包裹在冰山中、在融化时释放出来并沉积在深海沉积物中的粗粒沉积颗粒。首先，我们将测试磁化率、Ca和Fe（通过xrf扫描测量）的变化是否可以与南极冰芯的粉尘代用记录相关联，从而为我们的站点建立高分辨率年龄模型，并破译粉尘-气候耦合，这对碳循环很重要。IBRD指标应通过x射线图像记录仪和粒度分析获得。为了将我们的发现应用到更广泛的古气候背景下，傅里叶变换红外光谱和颜色反射率数据（L*a*b*）也将被利用。与IODP 382科学家合作，通过灰层和相对古强度提供独立的年龄控制，并通过地球化学指纹图谱破译IBRD的潜在来源。AIS-DIS项目成果应用到冰-海-气候模型中，并作为共同成果在高水平期刊上发表。

With climate warming in recent decades, the Antarctic Ice Sheet (AIS) is currently loosing ice at an accelerated pace. This is socially relevant because global sea levels could rise substantially in the near future. A number of scientific disciplines try to better understand the current state of the AIS to provide more sustained projections for the future. In project AIS-DIS we would like to better understand the dynamics of the AIS for key periods of the past, so that models can be calibrated and future projections improved. We would like to focus our studies on the last glacial cycles and specifically on glacial terminations 1–5 because the AIS mass loss was greatest during these natural periods of climate warming. Our investigations shall concentrate on the center of Iceberg Alley, a unique gateway to lower latitudes where most icebergs breaking off the Antarctic continent, route through before they melt down above our core sites. Hence this is the only area where a representative and integrative signal of AIS mass loss can be obtained through time. Here, IODP Expedition 382 retrieved the longest and highest resolution climate and ice-sheet archive ever obtained near Antarctica. We wish to study Sites U1537 and U1538 from Dove Basin and Pirie Basin, respectively. Our goal is to decipher the timing, pace, and magnitude of AIS mass loss. This will mainly be achieved analyzing iceberg-rafted debris (IBRD) – coarse-grained sedimentary particles that are encapsulated in icebergs, released upon melting, and deposited and in the sediments of the deep ocean. First, we shall test if variations of magnetic susceptibility, Ca and Fe (measured through XRF-scanning) can be correlated to dust proxy records of Antarctic ice cores to establish high-resolution age models for our sites and to decipher dust-climate couplings, which is important for the carbon cycle. Indicators for IBRD shall be obtained from the x-ray image logger and through grain-size analysis. To put our findings into a wider paleoclimatic context, Fourier Transform Infrared Spectroscopy and color reflectance data (L*a*b*) shall also be utilized. Collaboration with IODP 382 scientists shall provide independent age control through ash layers and relative paleointensity, and potential sources of IBRD shall be deciphered through geochemical fingerprinting. Results of project AIS-DIS shall be implemented into ice-ocean-climate models and published as common efforts in highly-ranked journals.