Collaborative Research: Volcanic Records from the Siple and Taylor Dome Ice Cores, Antarctica

摘要该奖项支持了一个项目，该项目描述了simple Dome和Taylor Dome冰芯中的火山物质。在高分辨率的双极冰芯中获得的火山气溶胶和火山灰沉积的时间序列是发展过去火山活动的连续和长期记录以及评估全球火山活动对气候和环境影响的最可靠手段。简单穹窿冰芯、西南极洲冰芯项目（WAISCORES）的初始冰芯以及最近从横越南极山脉收集的泰勒穹窿冰芯的火山记录将提供这一记录的南半球部分。这些结果将补充格陵兰岛漫长的GISP2火山记录。全新世的年分辨率应该可以在简单圆顶岩心中获得，从而获得南极洲具有此类分辨率的最长火山记录。简单圆顶地核记录的总长度被认为是8万年，而泰勒圆顶地核的记录可能超过10万年。尽管在simple Dome岩心的冰川部分和Taylor Dome岩心的大部分地区，时间分辨率要粗得多，但这些岩心的火山记录与GISP2岩心的火山记录的相关性和比较仍然是可能的。根据这些冰芯中现有的气候条件变化记录，对火山信号的时间进行评估，可提供有关全新世全球火山作用在年代际到世纪时间尺度上的气候强迫能力的关键信息。从simple Dome岩心中建立可靠的过去火山活动年表的关键是同时和连续测量SO42-，直接测量火山喷发产生的H2SO4，并在岩心的整个长度的相同亚样本中寻找tephra。冰川化学记录将通过“简单圆顶”项目的其他调查人员提供。泰勒穹窿冰芯的冰川化学记录目前是可用的。通过光学显微镜和微束（电子和离子微探针）分析确定火山玻璃的来源和确定火山玻璃的位置，将验证化学信号的来源，并有助于区分赤道和局部火山爆发。与GISP2火山记录的比较将有助于实现这一目标。这种破译火山记录的多参数方法将提高我们对火山作用对半球间和半球内气候影响的理解。这些岩心中发现的温体与海洋沉积物和陆地记录中发现的温体的对比将扩展全球火山作用的年代学，并改善冰芯、海洋和陆地代用气候记录之间的相关性。应该存在于简单穹窿地核和确实存在于泰勒穹窿地核中的可见的天帘层将为两个地核之间的可能相关性提供额外的绝对时间线，在先前收集的南极洲冰芯中，以及在南极洲西部和南极横越山脉的蓝色冰区进行的天帘研究。

9614384 Zielinski 9615167 Dunbar Abstract This award supports a project to characterize the volcanic material in the Siple Dome and Taylor Dome ice cores. The time series of volcanic aerosol and tephra deposition available in high-resolution, bi-polar ice cores is the most reliable means of developing continuous and lengthy records of past volcanic activity and assessing the climatic and environmental impact of global volcanism. The volcanic records from the Siple Dome ice core, initial ice core in the West Antarctica Ice Core Program (WAISCORES), and the Taylor Dome core, recently collected from the Transantarctic Mountains, will provide the Southern Hemisphere component of this record. These results will complement the lengthy GISP2 volcanic record from Greenland. Annual resolution should be available in the Siple Dome core for the Holocene resulting in the longest volcanic record with such resolution from Antarctica. Total length of record thought to be available from the Siple Dome core is 80,000 years whereas that for the Taylor Dome core is probably over 100,000 years. Although temporal resolution will be much coarser in the glacial portion of the Siple Dome core and in much of the Taylor Dome core, correlations and comparisons of the volcanic records from those cores with those from the GISP2 core are still possible. Evaluation of the timing of the volcanic signals in relationship to the record of changing climatic conditions available in these ice cores provides critical information on the climate forcing capabilities of global volcanism on decadal to century time scales through the Holocene. The key to developing a reliable chronology of past volcanism from the Siple Dome core is the simultaneous and continuous measurement of SO42-, a direct measure of the volcanic H2SO4 produced from the eruption, and the search for tephra in the same subsamples over the entire length of the core. The glaciochemical record will be available through other investigators in the Siple Dome project. The glaciochemical record for the Taylor Dome core is presently available. Locating tephra and identifying the source of the volcanic glass through both optical microscope and microbeam (both electron and ion microprobes) analyses will verify the source of the chemical signal and help differentiate between equatorial and local eruptions. Comparisons with the GISP2 volcanic record will assist in achieving this goal. This multiparameter approach to deciphering the volcanic record will improve on our understanding of the influence of volcanism on climate both interhemispherically and intrahemispherically. The correlation of tephra found in these cores with that found in marine sediments and in the terrestrial record will expand on the chronology of global volcanism and improve the correlation among ice core, marine, and terrestrial proxy climatic records. Visible tephra layers that should exist in the Siple Dome core and do exist in the Taylor Dome core will provide additional absolute time lines for possible correlations between the two cores, among previously collected Antarctica ice cores and with tephra studies in blue ice areas of Western Antarctica and the Transantarctic Mountains.