Heat discharge at the dynamic magma-water-interface in subaqueous and subglacial volcanism: Experiments and thermodynamic modelling

在水下/冰下喷发期间，观察到了热脉冲。这些喷发提供了有关时间尺度和热效应的定量信息。为了直接测量从岩浆熔体到冷却剂的热流，建造了一台短期热量计。在第一个系列中，使用了冰岛最近喷发的材料和纯净水，可以在非爆炸过程中生产颗粒，这些颗粒实际上与天然透明碎屑岩的颗粒相同。通过改变熔体的性质和实验几何形状，还可以产生平水和深海特征。实验产物的热机械能量收支的第一次近似与2004年格里姆斯夫顿喷发的数据很好地吻合。热力学模型的开发正在进行中。首次用不纯冷却剂进行的实验表明，冷却剂的热容和粘度对散热有很大影响。下一步计划进行详细的研究。地震信号记录显示了碎裂和热流的同步性：热脉冲和地震微脉冲可用于实验期间的监测。它旨在使用高分辨率压力传感器直接监测声发射。如果可以指定“声学指纹”，那么在潜水器或探测器上使用适当的传感器进行直接监测是可能的。

During subaqueous/subglacial eruptions, thermal pulses have been observed. These eruptions provide quantitative information on time scales and thermal efficacy. A short-term calorimeter was built for the direct measurement of the heat-flux from a magmatic melt to a coolant. In the first series material from recent eruptions in Iceland and purified water were used and particles could be pro-duced in a non-explosive process, that are practical identical to those from natural hyaloclastites. By variations of melt properties and experimental geometry flat water and deep sea signatures could be produced as well. First approximations of the thermo-mechanical energy budget of the experimental products are in good agreement with data of the 2004 Grimsvötn eruption. The development of a thermodynamic model is in progress. First experiments with impure coolants show, that heat capacity and viscosity of the coolant have a major impact on the heat discharge. Detailed studies are planned in the next step. The records of seismic signals show the synchronicity of fragmentation and heat-flux: thermal and seismic micro-pulses can be used for monitoring during the experiments. It is intended to use high resolution pressure sensors to monitor the acoustic emission directly. If “acoustical fingerprints” can be assigned, direct monitoring using appropriate sensors on submersibles or probes may be possible.