Isotropic Events Observed with a Borehole Array in the Chelungpu Fault Zone, Taiwan
Cracking Up
Hydraulic fracturing by fluids at high pressure results in damage or breakage along cracks in deep rocks, a process that in some cases causes earthquakes. This process can occur naturally when the hydrologic setting is just right, or can be induced by human activity when fluids are pumped at high pressure into deep aquifers. By studying the fault along which the 1999 magnitude 7.6 Chi-Chi earthquake occurred in Taiwan, where there are currently low tectonic stresses following the large earthquake, Ma et al. (p. 459) observed an unusual type of earthquake-like event that they attribute to natural hydraulic fracturing.
Abstract
Shear failure is the dominant mode of earthquake-causing rock failure along faults. High fluid pressure can also potentially induce rock failure by opening cavities and cracks, but an active example of this process has not been directly observed in a fault zone. Using borehole array data collected along the low-stress Chelungpu fault zone, Taiwan, we observed several small seismic events (I-type events) in a fluid-rich permeable zone directly below the impermeable slip zone of the 1999 moment magnitude 7.6 Chi-Chi earthquake. Modeling of the events suggests an isotropic, nonshear source mechanism likely associated with natural hydraulic fractures. These seismic events may be associated with the formation of veins and other fluid features often observed in rocks surrounding fault zones and may be similar to artificially induced hydraulic fracturing.
Get full access to this article
View all available purchase options and get full access to this article.
Already a subscriber or AAAS Member?Log In
Supplementary Material
Summary
Materials and Methods
Figs. S1 to S7
Table S1
Resources
File (ma.sm.pdf)
References and Notes
1
Sibson R. H., Implications of fault-valve behaviour for rupture nucleation and recurrence. Tectonophysics 211, 283 (1992).
2
Montgomery C. T., Smith M. B., J. Pet. Technol. 62, 26 (2010).
3
R. J. Davies et al., Hydraulic fractures: How far can they go? Mar. Pet. Geol. 10.1016/j.marpetgeo.2012.04.001 (2012).
4
Ma K.-F., et al., Slip zone and energetics of a large earthquake from the Taiwan Chelungpu-fault Drilling Project. Nature 444, 473 (2006).
5
Chen Y.-G., et al., Surface rupture of 1999 Chi-Chi earthquake yields insights on active tectonics of Central Taiwan. Bull. Seismol. Soc. Am. 91, 977 (2001).
6
Wu H.-Y., et al., Stress orientations of Taiwan Chelungpu-Fault Drilling Project (TCDP) hole-A as observed from geophysical logs. Geophys. Res. Lett. 34, L01303 (2007).
7
Ma K.-F., et al., Evidence for fault lubrication during the 1999 Chi-Chi, Taiwan, earthquake (Mw7.6). Geophys. Res. Lett. 30, 1244 (2003).
8
Hsu Y.-J., Segall P., Yu S.-B., Kuo L.-C., Williams C. A., Temporal and spatial variations of post-seismic deformation following the 1999 Chi-Chi, Taiwan earthquake. Geophys. J. Int. 169, 367 (2007).
9
Y.-Y. Lin, K.-F. Ma, V. Oye, Observation and scaling of microearthquakes from the Taiwan Chelungpu-fault borehole seismometers. Geophys. J. Int. 190, 665 (2012).
10
Materials and methods are available as supplementary materials on Science Online.
11
Lin A. T., et al., Terr. Atmos. Oceani. Sci. 18, 22 (2007).
12
Yeh E.-C., et al., Core description and characteristics of fault zones from hole-A of the Taiwan Chelungpu-Fault Drilling Project. Terr. Atmos. Ocean. Sci. 18, 327 (2007).
13
Wang J.-H., Hung J.-H., Dong J. J., Seismic velocities, density, porosity, and permeability measured at a deep hole penetrating the Chelungpu fault in central Taiwan. J. Asian Earth Sci. 36, 135 (2009).
14
Wang J.-H., Summary of physical properties measured at several boreholes penetrating through the Chelungpu Fault in Central Taiwan. Terr. Atoms. Ocean. Sci. 21, 655 (2010).
15
Oye V., Roth M., Automated seismic event location for hydrocarbon reservoirs. Comput. Geosci. 29, 851 (2003).
16
Carena S., Suppe J., Kao H., Active detachment of Taiwan illuminated by small earthquakes and its control of first-order topography. Geology 30, 935 (2002).
17
Dong J.-J., et al., Stress-dependence of the permeability and porosity of sandstone and shale from TCDP Hole-A. Int. J. Rock Mech. Mining Sci. 47, 1141 (2010).
18
Julian B. R., Foulger G. R., Bull. Seismol. Soc. Am. 86, 972 (1996).
19
McGarr A., An implosive component in the seismic moment tensor of a mining‐Induced tremor. Geophys. Res. Lett. 19, 1579 (1992).
20
Lee S. J., Chen H. W., Ma K. F., Strong ground motion simulation of the 1999 Chi-Chi, Taiwan earthquake from a realistic three-dimensional source and crustal structure. J. Geophys. Res. 112, B06307 (2007).
21
Tanikawa W., et al., Transport properties and dynamic processes in a fault zone from samples recovered from TCDP Hole B of the Taiwan Chelungpu Fault Drilling Project. Geochem. Geophys. Geosyst. 10, Q04013 (2009).
22
Doan M. L., Brodsky E. E., Kano Y., Ma K. F., In situ measurement of the hydraulic diffusivity of the active Chelungpu Fault, Taiwan. Geophys. Res. Lett. 33, L16317 (2006).
23
Tanaka H., et al., Terr. Atmos. Ocean. Sci. 13, 227 (2002).
24
C.-Y. Chen, National Taiwan University, thesis (2010).
25
Sibson R. H., Frictional mechanics of seismogenic thrust systems in the upper continental crust: Implications for fluid overpressures and redistribution. Am. Assoc. Petrol. Geol. Mem. 82, 1 (2004).
26
Chan Y. C., Okamoto K., Yui T.-F., Iizuka Y., Chu H.-T., Fossil fluid reservoir beneath a duplex fault structure within the Central Range of Taiwan: Implications for fluid leakage and lubrication during earthquake rupturing process. Terra Nova 17, 493 (2005).
27
Cappa F., Guglielmi Y., Virieux J., Stress and fluid transfer in a fault zone due to overpressures in the seismogenic crust. Geophys. Res. Lett. 34, L05301 (2007).
28
Ben-Zion Y., Ampuero J.-P., Seismic radiation from regions sustaining material damage. Geophys. J. Int. 178, 1351 (2009).
29
Bohnhoff M., Zoback M. D., Oscillation of fluid-filled cracks triggered by degassing of CO2 due to leakage along wellbores. J. Geophys. Res. 115, B11305 (2010).
30
Cappa F., Guglielmi Y., Fénart P., Merrien-Soukatchoff V., Thoraval A., Hydromechanical interactions in a fractured carbonate reservoir inferred from hydraulic and mechanical measurements. Int. J. Rock Mech. Min. Sci. 42, 287 (2005).
31
Hung J.-H., et al., Subsurface structure, physical properties, fault-zone characteristics and stress state in scientific drill holes of Taiwan Chelungpu Fault Drilling Project. Tectonophysics 466, 307 (2009).
Information & Authors
Information
Published In
Science
Volume 337 | Issue 6093
27 July 2012
27 July 2012
Copyright
Copyright © 2012, American Association for the Advancement of Science.
Submission history
Received: 19 March 2012
Accepted: 5 June 2012
Published in print: 27 July 2012
Acknowledgments
We thank C. Y. Wang for operational support for the TCDP site. This study benefited from discussions with H. Kanamori, M. Campillo, and T.-R. Alex Song. The TCDP BHS data are available to the public at the Data Center of the Taiwan Earthquake Research Center (TECDC) (http://tecws.earth.sinica.edu.tw/TCDP). This project is supported by National Science Council of Taiwan, NSC 100-2119-M-008 -031, and Ministry of Education 100G901-26 at National Central University.
Authors
Metrics & Citations
Metrics
Article Usage
Altmetrics
Citations
Export citation
Select the format you want to export the citation of this publication.
View Options
Get Access
Log in to view the full text
AAAS login provides access to Science for AAAS Members, and access to other journals in the Science family to users who have purchased individual subscriptions.
- Become a AAAS Member
- Activate your AAAS ID
- Purchase Access to Other Journals in the Science Family
- Account Help
Log in via OpenAthens.
Log in via Shibboleth.
More options
Register for free to read this article
As a service to the community, this article is available for free. Login or register for free to read this article.
Buy a single issue of Science for just $15 USD.
View options
PDF format
Download this article as a PDF file
Download PDF