2009 Articles
Systematic along-axis tidal triggering of microearthquakes observed at 9°50′N East Pacific Rise
Hydrothermal fluid circulation at mid-ocean ridges facilitates the exchange of heat and chemicals between the oceans and the solid Earth, and supports chemosynthetic microbial and macro-faunal communities. The structure and evolution of newly formed oceanic crust plays a dominant role in controlling the character and longevity of hydrothermal systems; however, direct measurements of subsurface processes remain technologically challenging to obtain. Previous studies have shown that tidally-induced stresses within the subseafloor modulate both fluid flow and microearthquake origin times. In this study, we observe systematic along-axis variations between peak microearthquake activity and maximum predicted tidal extension beneath the hydrothermal vent site at 9°50′N East Pacific Rise. We interpret this systematic triggering to result from pore-pressure perturbations propagating laterally through the hydrothermal system. Based on our observations and a one-dimensional pore pressure perturbation model, we estimate bulk permeability at ∼10⁻¹³ to 10⁻¹² m² within layer 2B over a calculated diffusive lengthscale of 2.0 km.
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- grl26240.pdf application/pdf 2.17 MB Download File
Also Published In
- Title
- Geophysical Research Letters
- DOI
- https://doi.org/10.1029/2009GL039493
More About This Work
- Academic Units
- Lamont-Doherty Earth Observatory
- Marine Geology and Geophysics
- Seismology, Geology, and Tectonophysics
- Published Here
- April 28, 2014