More - Mofette Research

莫夫岩是气体排放点，二氧化碳通过管道从地幔一样深的地方上升到地球表面，因此为深处的岩浆/火山作用提供了天然窗口。拟议中的莫夫石研究的主要目标是澄清流体性质、它们的路径和地震之间的物理联系。建议的最先进的流体监测技术允许高时间分辨率，与过去几十年使用的离散采样方法完全不同。天然气成分及其同位素特征将在不同深度的现场连续分析。在世界上独一无二的是，从几百米深到地表的一系列钻探将沿着垂直坡度追踪上升的地幔流体。这可以提供与断层阀门的开启、地壳流体与背景地幔流动的混合或断层破裂期间氢的释放有关的时间变化的起源的线索。作为试验区，HartoušOv Mofette被选为重点地点。将对一口300m深的井进行钻前、钻中和钻后的详细测量，以了解钻井活动对当地和区域流体状况可能产生的影响。定期收集用于惰性气体同位素分析的样品。这项提议与计划于2019年在国际地球科学中心“钻探埃格尔裂谷：驱动震群和深层生物圈的岩浆流体”项目框架内的流体钻孔直接相关。

Mofettes are gas emission sites where CO2 ascends through conduits from as deep as the mantle to the Earth’s surface and as such provide natural windows to magmatic/volcanic processes at depth. The primary objective of the proposed research on mofettes is to clarify the physical link between fluid properties, their pathways and earthquakes. The suggested state-of-the-art fluid monitoring techniques allow for a high temporal resolution and are completely different from the discrete sampling approach used in the last decades. Gas composition and its isotope signature will be continuously analysed in-situ at different depth levels. Unique in the world, ascending mantle fluids will be tracked along a vertical gradient in a set of drillings from a depth of a few hundred metres to the surface. This can provide hints on the origin of temporal variations related to the opening of fault-valves, admixture of crustal fluids to a background mantle-flow or the release of hydrogen during fault rupturing. As a test area the Hartoušov mofette has been chosen as a key site. Detailed measurements before, during and after drilling of a 300 m deep well will be carried out to realize possible influences of the drilling activity on the local and regional fluid regime. Periodically, samples for noble gas isotope analysis will be collected. This proposal is directly linked to the drilling of the fluid-borehole scheduled for 2019 in the frame of the ICDP project “Drilling the Eger Rift: Magmatic fluids driving the earthquake swarms and the deep biosphere”.