1887

Abstract

Summary

Rotation measurements have found applications in various fields of geophysics ranging from near-surface archaeological mapping to large scale upper mantle tomographic inversion. In the absence of a cost-effective sensor sensitive over the typical seismic frequency bandwidth, rotation measurement can be approximated by finite-differencing the response of the vertical particle velocity over a short distance. Accurate estimates of the horizontal gradient of the vertical wavefield can be obtained when perturbations associated with the measurement are minimised. These perturbations can be sensor related, for example geophone sensitivity and natural frequency, and/or deployment related such as tilt and coupling errors. We developed a “sensitivity” chart ranking these perturbations according to impact. We recommend the use of geophones with low variance in sensitivity, deployed as vertical as possible (less than 5 degrees tilt error) at highly accurate position (error in the order of centimetres). Moreover, the distance between the two receivers should be about 1/8 of the minimum wavelength in order to reduce the error due to finite-differencing.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201702076
2017-09-03
2022-06-29
Loading full text...

Full text loading...

References

  1. Allouche, N., Ras, P., and Ozbek, A.
    , [2015] Aliased groundroll reconstruction using gradients. 77th EAGE Conference and Exhibition, Extended Abstracts.
    [Google Scholar]
  2. Edme, P., Muyzert, E., and Kragh, E.
    , [2014] Efficient land seismic acquisition sampling using rotational data. 76th EAGE Conference and Exhibition, Extended Abstracts.
    [Google Scholar]
  3. Langston, C. A.
    [2007]. Wave gradiometry in two dimensions. Bulletin of the Seismological Society of America, 97(2), 401–416.
    [Google Scholar]
  4. Krohn, C.E.
    , [1984] Geophone ground coupling. Geophysics, 49, 722–731.
    [Google Scholar]
  5. Pierson, R., Laughlin, D., and BruneR.
    , [2016] Advances in rotational seismic measurements. 86th Annual meeting SEG Expanded Abstracts, 2263–2267.
    [Google Scholar]
  6. Poppeliers, C., and Evans, E. V.
    , [2015] The effects of measurements uncertainties in seismic wave gradiometry. Bulletin of the Seismological Society of America, 105, 3143–3155.
    [Google Scholar]
  7. Woelz, S., Rabbel, W., and Mueller, C.
    , [2009] Shear waves in near surface 3D media—SH—wavefield separation, refraction time migration and tomography. Journal of Applied Geophysics, 68, 104–116.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201702076
Loading
/content/papers/10.3997/2214-4609.201702076
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error