Collaborative Research: SHALDRIL - A Demonstration Drilling Cruise to the James Ross Basin

该奖项由极地方案办公室南极地质和地球物理方案提供，为一个示范项目提供资金，以证明基于浅海的地质钻探的可行性，同时收集有用的岩芯来评估南极冰盖的早期历史。三十多年来，美国科学家和他们的国际同事在探索南极边缘的浅陆架和海洋时，一直感到沮丧，因为他们无法穿透在这些地形的浅海底深度(上层10米以内)遇到的过度压实的冰川直径。这尤其令人沮丧，因为先进的高分辨率地震反射技术在许多地区清楚地显示出新近纪甚至古近纪的较老层序的存在，就在这个薄薄的直径岩层下面。在开发出恢复这些序列的手段之前，南极冰盖的详细历史将仍然是一个难以实现的目标，而这是在全球范围内了解新生代古气候和未来气候变化的基本前提。在一名专业工程师的帮助下，经过四年的研究和评估(并在两个研讨会的过程中)，SHALDRIL委员会，一个感兴趣的美国科学家团体，已经确定了至少两个被认为适合在现有的美国南极研究计划破冰船上使用的钻石取心系统。该项目的目标是在RV/IB纳撒尼尔·B·帕尔默号上应用钻石取心技术，以测试和论证船载钻石取心和井下测井的可行性。对于这次“示范巡航”，将尝试沿着南极半岛西摩岛附近大陆架上的高分辨率地震反射剖面进行取心，西摩岛本身就是一个具有高度科学价值的地区。在这里，明确的地质剖面估计从始新世到第四纪，有效地跨越了南极/全球气候演变中的“温室-冰屋”过渡。关于这一转变的完整记录还没有在南极边缘的任何地方获得。在岩心恢复之后，该项目将使新岩心的古气候记录与最近结束的快速冰基罗伯茨角项目在罗斯海东部较高纬度记录的冰缘详细波动相关联。如果成功，这种移动和灵活的钻探系统将提供给更广泛的科学界，用于进一步研究古环境条件和其他科学领域，这些领域目前受到美国南极计划在探索海岸线/快速冰缘和大陆斜坡之间的南极大陆架的技术能力方面存在的差距的阻碍。SHALDRIL将能够在目前存在于近岸(基于快速冰基的罗伯茨角项目成功的地方)和上坡(海洋钻探计划的JOIDES分辨率船变得最有效的地方)之间的“无人区”有效运作。这一技术突破不仅将使过去三十年的重大悬而未决的科学问题得到解决，而且还将对美国和SCAR(ICSU南极研究科学委员会)目前的许多南极或钻探相关倡议产生积极影响，如WAIS、ANTIME、ANDRILL、ANTEC、IMAGE、PAGE、GLOCHANT(包括PICE)、FORESS、ODP和STRATAFORM。

This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a demonstration project to prove the viability of shallow ship-based geological drilling while simultaneously collecting useful cores for assessing the early history of the Antarctic ice sheets. For over three decades, U.S. scientists and their international colleagues exploring the shallow shelves and seas along the margins of Antarctic have been consistently frustrated by their inability to penetrate through the over-compacted glacial diamictons encountered at shallow sub bottom depths (within the upper 10 m) over these terrains. This is particularly frustrating because advanced high resolution seismic reflection techniques clearly show in many areas the presence of older successions of Neogene and even Paleogene sequences lying just beneath this thin veneer of diamictons. Until the means are developed to recover these sequences, a detailed history of the Antarctic ice sheets, which is an essential prerequisite to understanding Cenozoic paleoclimate and future climate change on a global scale, will remain an elusive and unobtainable goal. After four years of study and evaluation with the aid of a professional engineer (and over the course of two workshops), the SHALDRIL Committee, an interested group of U.S. scientists, has identified at least two diamond-coring systems deemed suitable for use on existing ice-breaking U.S. Antarctic Research Program vessels. The goal of this project is to employ diamond-coring technology on the RV/IB Nathaniel B. Palmer in order to test out and demonstrate the feasibility of both ship-based diamond coring and down-hole logging. For this "demonstration cruise" coring will be attempted along a high-resolution seismic reflection profile on the continental shelf adjacent to Seymour Island, Antarctic Peninsula, an area of high scientific interest in its own right. Here the well-defined geologic section is estimated to range from Eocene to Quaternary in age, effectively spanning the "Greenhouse-Icehouse" transition in the evolution of Antarctic/global climate. A complete record of this transition has yet to be obtained anywhere along the Antarctic margin. Following core recovery, this project will result in correlation of the paleoclimate records from the new cores with detailed fluctuations of the ice margin recorded at higher latitudes in the eastern Ross Sea by the recently concluded, fast-ice-based Cape Roberts Project. If successful, this mobile and flexible drilling system will then be available to the broader scientific community for further research in paleoenvironmental conditions and other areas of science that are currently hindered by the present gap that exists in the US Antarctic Program's technical capability to explore the Antarctic shelves between the shore-line/fast-ice margin and the continental slope. SHALDRIL will be able to operate effectively in the "no man's land" that presently exists between the near shore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where the Ocean Drilling Program's vessel JOIDES Resolution becomes most efficient). This technological breakthrough will not only allow major outstanding scientific problems of the last three decades to be addressed, but will also favorably impact many current U.S. and SCAR (ICSU Scientific Committee on Antarctic Research) Antarctic or drilling-related initiatives, such as WAIS, ANTIME, ANDRILL, ANTEC, IMAGES, PAGES, GLOCHANT (including PICE), MARGINS, ODP, and STRATAFORM.