scholarly journals Numerical modelling of the upper-mantle anisotropy beneath a migrating strike-slip plate boundary: the San Andreas Fault system

2012 ◽  
Vol 191 (2) ◽  
pp. 436-458 ◽  
Author(s):  
Mickaël Bonnin ◽  
Andréa Tommasi ◽  
Riad Hassani ◽  
Sébastien Chevrot ◽  
James Wookey ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Upper Mantle ◽  
San Andreas Fault ◽  
Plate Boundary ◽  
Strike Slip ◽  
Fault System ◽  
Upper Mantle Anisotropy ◽  
San Andreas ◽  
San Andreas Fault System ◽  
Mantle Anisotropy

The San Andreas Fault Zone Drilling Project: Scientific Objectives and Technological Challenges

1995 ◽  
Vol 117 (4) ◽  
pp. 263-270 ◽  
Author(s):  
S. H. Hickman ◽  
L. W. Younker ◽  
M. D. Zoback ◽  
G. A. Cooper
Keyword(s):  
Fault Zone ◽  
San Andreas Fault ◽  
Fractured Rock ◽  
Fluid Pressure ◽  
Plate Boundary ◽  
Fault System ◽  
Earthquake Activity ◽  
Scientific Drilling ◽  
San Andreas ◽  
San Andreas Fault System

We are leading a new international initiative to conduct scientific drilling within the San Andreas fault zone at depths of up to 10 km. This project is motivated by the need to understand the physical and chemical processes operating within the fault zone and to answer fundamental questions about earthquake generation along major plate-boundary faults. Through a comprehensive program of coring, fluid sampling, downhole measurements, laboratory experimentation, and long-term monitoring, we hope to obtain critical information on the structure, composition, mechanical behavior and physical state of the San Andreas fault system at depths comparable to the nucleation zones of great earthquakes. The drilling, sampling and observational requirements needed to ensure the success of this project are stringent. These include: 1) drilling stable vertical holes to depths of about 9 km in fractured rock at temperatures of up to 300°C; 2) continuous coring and completion of inclined holes branched off these vertical boreholes to intersect the fault at depths of 3, 6, and 9 km; 3) conducting sophisticated borehole geophysical measurements and fluid/rock sampling at high temperatures and pressures; and 4) instrumenting some or all of these inclined core holes for continuous monitoring of earthquake activity, fluid pressure, deformation and other parameters for periods of up to several decades. For all of these tasks, because of the overpressured clay-rich formations anticipated within the fault zone at depth, we expect to encounter difficult drilling, coring and hole-completion conditions in the region of greatest scientific interest.

Sign in / Sign up

Export Citation Format

Share Document