Abstract:
Improved interpretations of the strength of the San
Andreas Fault near Parkfield, CA based on thermal data
require quantification of processes causing significant
scatter and uncertainty in existing heat flow data. These
effects include topographic refraction, heat advection by
topographically-driven groundwater flow, and uncertainty
in thermal conductivity. Here, we re-evaluate the heat flow
data in this area by correcting for full 3-D terrain effects. We
then investigate the potential role of groundwater flow in
redistributing fault-generated heat, using numerical models
of coupled heat and fluid flow for a wide range of
hydrologic scenarios. We find that a large degree of the
scatter in the data can be accounted for by 3-D terrain
effects, and that for plausible groundwater flow scenarios
frictional heat generated along a strong fault is unlikely to
be redistributed by topographically-driven groundwater
flow in a manner consistent with the 3-D corrected
data.
