New Heat Flow Values Along the San Andreas Fault System

犹他大学的研究人员将与旧金山湾区的美国地质勘探局一起沿着圣安德烈亚斯、海沃德和卡拉维拉斯断层进行热调查。作为放置钻孔应变仪的“迷你板块边界观测站”实验的一部分，将在目前计划钻探的钻孔中收集热测量数据。该研究的现场部分包括热测井和收集钻屑和岩石样品，以确定岩石的热物理性质。岩石的热物理性质将使用现代实验室技术进行测量。这些井眼将随着时间的推移重新记录，以研究热瞬态（例如，流体流动、地表温度变化、与断层相关的热事件）。本项目的建模部分旨在解决：I)沿着这一复杂的板块边界传热的性质和热流的变化；2)地震活动性下限和上限的热条件；3)热对变形瞬态的影响，由大地测量数据和变形粘弹性模型确定。由于旧金山湾区具有相对较高的热流（~85 mW m-2）和高应变率，因此该区域是拟议工作的理想区域。这两个性质为研究地壳热状态和地震瞬态之间的关系提供了最大的机会。

EAR-00877577Harris, RobertThe investigators at University of Utah will conduct a thermal investigation with the U.S.G.S of the San Francisco Bay Area along the San Andreas, Hayward and Calaveras faults. Thermal measurements will be collected in boreholes currently scheduled for drilling as part of the 'Mini Plate Boundary Observatory' experiment for the emplacement of borehole strainmeters. The field component of the study consists of thermal logging and the collection of drill cuttings and rock samples for the determination of thermal physical rock properties. Thermal physical rock properties will be measured using modern laboratory techniques. These boreholes will be re-logged through time to investigate thermal transients (e.g., fluid flow, ground surface temperature changes, thermal events associated with faulting). The modeling component of this project is aimed at resolving: I ) the nature of heat transfer and variation of heat flow along this complex plate boundary; 2) the thermal conditions at both the lower and upper limits of seismicity; and 3) the thermal influence on deformation transients as determined from geodetic data and viscoelastic models of deformation. The field area is ideal for the proposed work because the San Francisco Bay Area has relatively high heat flow (~85 mW m-2) and high strain rates. These two properties maximize opportunities to investigate relationships between the thermal regime of the crust and aseismic transients.