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Concluding Remarks

  • A. John HainesEmail author
  • Lada L. Dimitrova
  • Laura M. Wallace
  • Charles A. Williams
Chapter
  • 370 Downloads
Part of the SpringerBriefs in Earth Sciences book series (BRIEFSEARTH)

Abstract

We reiterate the reasons for considering the force balance equations at the Earth’s surface separate from the full 3-dimensional problem, with the former involving the much simpler physics of purely-elastic behavior. This leads us to inverting for VDoHS rates, which are surface terms containing all information that can be deduced from surface observations about subsurface deformation sources. VDoHS rates have inherently high spatial resolution, and are much better than velocities or strain rates for identifying individual source signal. When source signals are small (<1 mm/year in horizontal velocity at the surface), low signal-to-noise-ratio can be counterbalanced by having very dense GPS networks (station spacing <0.5 times the source depth). We briefly discuss that our methodology can be extended to include InSAR and strainmeter data, and we conclude by outlining how the surface-based methodology and full 3-dimensional physical modelling are complementary tools. That is, the new methodology provides the most detailed surface images possible of the subsurface sources irrespective of their nature, whereas physical modeling provides understanding of what is actually happening below the surface.

Keywords

Force balance equations Earth’s surface Purely elastic behavior High spatial resolution Individual source signal InSAR and strainmeter 3-dimensional physical modelling Detailed surface images Subsurface sources 

References

  1. Hammond W, Blewitt G, Kreemer C (2011) Block modeling of crustal deformation of the northern Walker lane and basin and range from GPS velocities. J Geophys Res 116(B04402). doi: 10.1029/2010JB007817
  2. Hudnut K, Bock Y, Galetzka J et al (2002) The Southern California integrated GPS network (SCIGN). In: Fujinawa Y, Yoshida A (eds) Seismotectonics in convergent plate boundary:167-189. TERRAPUB, TokyoGoogle Scholar
  3. McCaffrey R, King R, Payne S et al (2013) Active tectonics of northwestern U.S. inferred from GPS-derived surface velocities. J Geophys Res Solid Earth 118:709–723. doi: 10.1029/2012JB009473 CrossRefGoogle Scholar
  4. Murray J, Langbein J (2006) Slip on the San Andreas fault at Parkfield, California, over two earthquake cycles and the implications for seismic hazard. Bull Seism Soc Am 96(4B):S283–S303CrossRefGoogle Scholar
  5. Norris R, Cooper A (2007) The alpine fault, New Zealand: surface geology and field relationships. In: A continental plate boundary: tectonics at South Island, New Zealand. AGU, WashingtonGoogle Scholar
  6. Smith B, Sandwell D (2003) Coulomb stress accumulation along the San Andreas fault system. J Geophys Res 108(B6):2296. doi: 10.1029/2002JB002136 CrossRefGoogle Scholar
  7. Wallace L, Beavan J, McCaffrey R et al (2007) Balancing the plate motion budget in the South Island, New Zealand using GPS, geological and seismological data. Geophys J Int 168(1):332–352. doi: 10.1111/j.1365-246X.2006.03183.x CrossRefGoogle Scholar

Copyright information

© The Author(s) 2015

Authors and Affiliations

  • A. John Haines
    • 1
    Email author
  • Lada L. Dimitrova
    • 2
  • Laura M. Wallace
    • 2
  • Charles A. Williams
    • 3
  1. 1.GNS ScienceDunedinNew Zealand
  2. 2.Institute for GeophysicsUniversity of TexasAustinUSA
  3. 3.GNS ScienceAvalonNew Zealand

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