Climatology, Volcanism, and Microbial Life in Ice with Downhole Loggers

该合同支持使用三种井下仪器的项目：光学记录仪；420纳米氨化生物光谱记录仪（miniBSL-420）；声波电视观测器(ATV) -在WAIS Divide钻井现场记录350米的井眼。此外，miniBSL-224 （224nm）和miniBSL-420将扫描NICL冰芯剖面，寻找气候突变、火山灰、微生物浓度及其相互关系。利用光学记录仪和ATV记录WAIS Divide井眼中的气泡数密度与深度的关系，我们将检测每年的层数，从中我们可以建立井眼底部的年龄与深度关系，这将在三年的资助期内可用。利用同样的仪器，我们将寻找气泡和尘埃浓度的长周期调制，以便为太阳或太阳风的长周期变化对气候的影响提供明确的证据。我们将在WAIS Divide钻孔中检测并准确确定灰层的年代。我们将把它们与我们之前在simple Dome钻孔中检测到的火山灰层进行比对，并将它们与其他在Vostok、Dome Fuji、Dome C和GISP2发现的硫酸盐和火山灰层进行比对。预期的新数据将使我们能够扩展我们最近的研究，该研究表明南极火山活动记录与气候突变的相关性为95%至99.8%的显著性水平，两极位置的火山特征在2至45千年的间隔内匹配优于3西格玛。在此资助期间获得的结果将使我们能够将准确的年龄-深度关系和火山-气候相关性扩展到未来将钻探的WAIS Divide钻孔到基岩之前的150万年。利用微型bsls通过荧光识别生物分子，我们将在WAIS分水岭记录一个350米的钻孔，并在NICL扫描选定长度的冰芯。miniBSLs可以识别的生物分子包括叶绿素和F420，前者将提供冰上需氧微生物的第一张图谱，后者将提供冰上产甲烷菌的第一张图谱。我们将与其他人合作，将WAIS Divide和NICL冰芯的结果与气候学、火山学和微生物生态学等更广泛的主题联系起来。我们将继续为本科生和研究生提供广泛的培训，吸引未被充分代表的少数民族学习科学、工程和数学，并对新闻界和大学教师进行教育。更深入地了解气候突变的原因，包括与强烈火山爆发的因果关系，可以使我们了解和减轻对气候的不利影响。

This award supports a project to use three downhole instruments - an optical logger; aminiaturized biospectral logger at 420 nm (miniBSL-420); and an Acoustic TeleViewer (ATV) - to log a 350-m borehole at the WAIS Divide drill site. In addition, miniBSL-224 (at 224 nm) and miniBSL-420 will scan ice core sections at NICL to look for abrupt climate changes, volcanic ash, microbial concentrations, and correlations among them. Using the optical logger and ATV to log bubble number densities vs depth in a WAIS Divide borehole, we will detect annual layers, from which we can establish the age vs depth relation to the bottom of the borehole that will be available during the three-year grant period. With the same instruments we will search for long-period modulation of bubble and dust concentrations in order to provide definitive evidence for or against an effect of long-period variability of the sun or solar wind on climate. We will detect and accurately date ash layers in a WAIS Divide borehole. We will match them with ash layers that we previously detected in the Siple Dome borehole, and also match them with sulfate and ash layers found by others at Vostok, Dome Fuji, Dome C, and GISP2. The expected new data will allow us to extend our recent study which showed that the Antarctic record of volcanism correlates with abrupt climate change at a 95% to 99.8% significance level and that the volcanic signatures at bipolar locations match at better than 3 sigma during the interval 2 to 45 kiloyears. The results to be obtained during this grant period will position us to extend an accurate age vs depth relation and volcano-climate correlations to earlier than 150 kiloyears ago in the future WAIS Divide borehole to be drilled to bedrock. Using the miniBSLs to identify biomolecules via their fluorescence, we will log a 350-m borehole at WAIS Divide, and we will scan selected lengths of ice core at NICL. Among the biomolecules the miniBSLs can identify will be chlorophyll, which will provide the first map of aerobic microbes in ice, and F420, which will provide the first map of methanogens in ice. We will collaborate with others in relating results from WAIS Divide and NICL ice cores to broader topics in climatology, volcanology, and microbial ecology. We will continue to give broad training to undergraduate and graduate students, to attract underrepresented minorities to science, engineering, and math, and to educate the press and college teachers. A deeper understanding of the causes of abrupt climate change, including a causal relationship with strong volcanic eruptions, can enable us to understand and mitigate adverse effects on climate.