Cross-hole tracer experiment reveals rapid fluid flow and low effective porosity in the upper oceanic crust
| Autor: | C. G. Wheat, Rachel M. Haymon, Andrew T. Fisher, N. M. Neira, J. F. Clark, Keir Becker |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Geochemistry & Geophysics
010504 meteorology & atmospheric sciences Aquifer 010502 geochemistry & geophysics tracer injection experiment 01 natural sciences Hydrothermal circulation borehole observatory Geochemistry and Petrology Oceanic crust TRACER Earth and Planetary Sciences (miscellaneous) Fluid dynamics Petrology 0105 earth and related environmental sciences geography geography.geographical_feature_category hydrothermal circulation Crust Juan de Fuca Ridge flank Geophysics Effective porosity Seafloor spreading Space and Planetary Science Physical Sciences Earth Sciences Geology ocean crustal properties abyssal hills |
| Zdroj: | Neira, NM; Clark, JF; Fisher, AT; Wheat, CG; Haymon, RM; & Becker, K. (2016). Cross-hole tracer experiment reveals rapid fluid flow and low effective porosity in the upper oceanic crust. EARTH AND PLANETARY SCIENCE LETTERS, 450, 355-365. doi: 10.1016/j.epsl.2016.06.048. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/24j0m61t EARTH AND PLANETARY SCIENCE LETTERS, vol 450 |
| DOI: | 10.1016/j.epsl.2016.06.048. |
| Popis: | Numerous field, laboratory, and modeling studies have explored the flows of fluid, heat, and solutes during seafloor hydrothermal circulation, but it has been challenging to determine transport rates and flow directions within natural systems. Here we present results from the first cross-hole tracer experiment in the upper oceanic crust, using four subseafloor borehole observatories equipped with autonomous samplers to track the transport of a dissolved tracer (sulfur hexafluoride, SF6) injected into a ridge-flank hydrothermal system. During the first three years after tracer injection, SF6 was transported both north and south through the basaltic aquifer. The observed tracer transport rate of ∼2–3 m/day is orders of magnitude greater than bulk rates of flow inferred from thermal and chemical observations and calculated with coupled fluid-heat flow simulations. Taken together, these results suggest that the effective porosity of the upper volcanic crust through which much tracer was transported is |
| Databáze: | OpenAIRE |
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