Characterization of a complex near-surface structure using well logging and passive seismic measurements

Author:

Benjumea Beatriz,Macau Albert,Gabàs Anna,Figueras Sara

Abstract

Abstract. We combine geophysical well logging and passive seismic measurements to characterize the near-surface geology of an area located in Hontomin, Burgos (Spain). This area has some near-surface challenges for a geophysical study. The irregular topography is characterized by limestone outcrops and unconsolidated sediments areas. Additionally, the near-surface geology includes an upper layer of pure limestones overlying marly limestones and marls (Upper Cretaceous). These materials lie on top of Low Cretaceous siliciclastic sediments (sandstones, clays, gravels). In any case, a layer with reduced velocity is expected. The geophysical data sets used in this study include sonic and gamma-ray logs at two boreholes and passive seismic measurements: three arrays and 224 seismic stations for applying the horizontal-to-vertical amplitude spectra ratio method (H/V). Well-logging data define two significant changes in the P-wave-velocity log within the Upper Cretaceous layer and one more at the Upper to Lower Cretaceous contact. This technique has also been used for refining the geological interpretation. The passive seismic measurements provide a map of sediment thickness with a maximum of around 40 m and shear-wave velocity profiles from the array technique. A comparison between seismic velocity coming from well logging and array measurements defines the resolution limits of the passive seismic techniques and helps it to be interpreted. This study shows how these low-cost techniques can provide useful information about near-surface complexity that could be used for designing a geophysical field survey or for seismic processing steps such as statics or imaging.

Publisher

Copernicus GmbH

Subject

Paleontology,Stratigraphy,Earth-Surface Processes,Geochemistry and Petrology,Geology,Geophysics,Soil Science

Reference40 articles.

1. Aki, K.: Space and time spectra of stationary stochastic waves, with special reference to microtremors, B. Earthq. Res. I. Tokyo, 35, 415–456, 1957.

2. Alcalde, J., Marzán, I., Saura, E., Martí, D., Ayarza, P., Juhlin, C., and Carbonell, R.: 3D geological characterization of the Hontomín CO2 storage site, Spain: Multidisciplinary approach from seismic, well-log and regional data, Tectonophysics, 627, 6–25, 2014.

3. Backus, G. E.: Long-wave elastic anisotropy produced by horizontal layering, J. Geophys. Res., 67, 4427–4440, 1962.

4. Bard, P. Y.: Microtremor measurements: a tool for site effect estimation?, in: The effects of surface geology on seismic motion-recent progress and new horizon on ESG study, edited by: Irikura, K., Kudo, K., Okada, H., and Sasatani, T., Balkema, Rotterdam, 3, 1251–1279, 1999.

5. Bard, P. Y. and SESAME-Team: Guidelines for the implementation of the H ∕ V spectral ratio technique on ambient vibrations-measurements, processing and interpretations, SESAME European research project EVG1-CT-2000-00026, deliverable D23.12, available at: http://sesame-fp5.obs.ujf-grenoble.fr, 2004.

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