3D geometry of superposed folds in a large-scale refolded fault surface using geostatistical methods (internal zones of the Betic Cordillera, SE Spain)

Winter driving conditions pose a real hazard to road users with increased chance of collisions during inclement weather events. As such, road authorities strive to service the hazardous roads or collision hot spots by increasing road safety, mobility, and accessibility. One measure of a hot spot would be winter collision statistics. Using the ratio of winter collisions (WC) to all collisions, roads that show a high ratio of WC should be given a high priority for further diagnosis and countermeasure selection. This study presents a unique methodological framework that is built on one of the least explored yet most powerful geostatistical techniques, namely, regression kriging (RK). Unlike other variants of kriging, RK uses auxiliary variables to gain a deeper understanding of contributing factors while also utilizing the spatial autocorrelation structure for predicting WC ratios. The applicability and validity of RK for a large-scale hot spot analysis is evaluated using the northeast quarter of the State of Iowa, spanning five winter seasons from 2013/14 to 2017/18. The findings of the case study assessed via three different statistical measures (mean squared error, root mean square error, and root mean squared standardized error) suggest that RK is very effective for modeling WC ratios, thereby further supporting its robustness and feasibility for a statewide implementation.

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The Nevado-Filabride metaophiolitic association in the Cobdar region (Betic Cordillera, SE Spain): preservation of pillow structures and development of coronitic eclogites

Geodinamica Acta ◽

10.1080/09853111.1989.11105172 ◽

1989 ◽

Vol 3 (1) ◽

pp. 17-36 ◽

Cited By ~ 19

Author(s):

Encarnacion Puga ◽

Antonio Diaz De Federico ◽

Giuseppe Maria Bargossi ◽

Lauro Morten

Keyword(s):

Betic Cordillera ◽

Se Spain

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High-frequency ground-motion variability for rough-fault ruptures

10.5194/egusphere-egu21-11998 ◽

2021 ◽

Author(s):

Jagdish Chandra Vyas ◽

Martin Galis ◽

Paul Martin Mai

Keyword(s):

Ground Motion ◽

Large Scale ◽

Earthquake Ground Motion ◽

Small Scale ◽

Dynamic Rupture ◽

Roughness Effects ◽

Ground Shaking ◽

Fault Surface ◽

Fault Roughness ◽

Ground Motion Variability

Geological observations show variations in fault-surface topography not only at large scale (segmentation) but also at small scale (roughness). These geometrical complexities strongly affect the stress distribution and frictional strength of the fault, and therefore control the earthquake rupture process and resulting ground-shaking. Previous studies examined fault-segmentation effects on ground-shaking, but our understanding of fault-roughness effects on seismic wavefield radiation and earthquake ground-motion is still limited.&#160;&#160;In this study we examine the effects of fault roughness on ground-shaking variability as a function of distance based on 3D dynamic rupture simulations. We consider linear slip-weakening friction, variations of fault-roughness parametrizations, and alternative nucleation positions (unilateral and bilateral ruptures). We use generalized finite difference method to compute synthetic waveforms (max. resolved frequency 5.75 Hz) at numerous surface sites&#160; to carry out statistical analysis.&#160;&#160;Our simulations reveal that ground-motion variability from unilateral ruptures is almost independent of&#160; distance from the fault, with comparable or higher values than estimates from ground-motion prediction equations (e.g., Boore and Atkinson, 2008; Campbell and Bozornia, 2008). However, ground-motion variability from bilateral ruptures decreases with increasing distance, in contrast to previous studies (e.g., Imtiaz et. al., 2015) who observe an increasing trend with distance. Ground-shaking variability from unilateral ruptures is higher than for bilateral ruptures, a feature due to intricate seismic radiation patterns related to fault roughness and hypocenter location. Moreover, ground-shaking variability for rougher faults is lower than for smoother faults. As fault roughness increases the difference in ground-shaking variabilities between unilateral and bilateral ruptures increases. In summary, our simulations help develop a fundamental understanding of ground-motion variability at high frequencies (~ 6 Hz) due small-scale geometrical fault-surface variations.

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Onshore and offshore compressional tectonics in the eastern Betic Cordillera (SE Spain)

Marine Geology ◽

10.1016/s0025-3227(02)00336-5 ◽

2002 ◽

Vol 186 (3-4) ◽

pp. 337-349 ◽

Cited By ~ 22

Author(s):

P Alfaro ◽

J Delgado ◽

A Estévez ◽

J.M Soria ◽

A Yébenes

Keyword(s):

Betic Cordillera ◽

Se Spain

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Throw variations and strain partitioning associated with fault-bend folding along normal faults

10.5194/se-2019-171 ◽

2019 ◽

Author(s):

Efstratios Delogkos ◽

Muhammad Mudasar Saqab ◽

John J. Walsh ◽

Vincent Roche ◽

Conrad Childs

Keyword(s):

Large Scale ◽

Full Range ◽

Quantitative Model ◽

Normal Faults ◽

Strain Partitioning ◽

Fault Surface ◽

Irregular Geometries ◽

Surface Irregularities ◽

Fault Bend ◽

Constant Displacement

Abstract. Normal faults have irregular geometries on a range of scales arising from different processes including refraction and segmentation. A fault with an average dip and constant displacement on a large-scale, will have irregular geometries on smaller scales, the presence of which will generate fault-related folds, with major implications for across-fault throw variations. A quantitative model has been presented which illustrates the range of deformation arising from movement on fault surface irregularities, with fault-bend folding generating geometries reminiscent of normal drag and reverse drag. The model highlights how along-fault displacements are partitioned between continuous (i.e. folding) and discontinuous (i.e. discrete displacement) strain along fault bends characterised by the full range of fault dip changes. Strain partitioning has a profound effect on measured throw values across faults, if account is not taken of the continuous strains accommodated by folding and bed rotations. We show that fault throw can be subject to errors of up to ca. 50 % for realistic fault bend geometries (up to ca. 40°), even on otherwise sub-planar faults with constant displacement. This effect will provide apparently more irregular variations in throw and bed geometries that must be accounted for in associated kinematic interpretations.

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THE ORIGIN AND DEVELOPMENT OF NEOGENE BASINS IN THE SE BETIC CORDILLERA (SE SPAIN): A CASE STUDY OF THE TABERNAS-SORBAS AND HUERCAL OVERA BASINS

Journal of Petroleum Geology ◽

10.1111/j.1747-5457.1999.tb00461.x ◽

1999 ◽

Vol 22 (1) ◽

pp. 97-114 ◽

Cited By ~ 16

Author(s):

A. M. Poisson ◽

J. L. Morel ◽

J. Andrieux ◽

M. Coulon ◽

R. Wernli ◽

...

Keyword(s):

Betic Cordillera ◽

Se Spain

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Melt Migration and Intrusion during Exhumation of the Alboran Lithosphere: the Tallante Mantle Xenolith Record (Betic Cordillera, SE Spain)

Journal of Petrology ◽

10.1093/petrology/egp061 ◽

2009 ◽

Vol 51 (1-2) ◽

pp. 295-325 ◽

Cited By ~ 28

Author(s):

E. Rampone ◽

R. L. M. Vissers ◽

M. Poggio ◽

M. Scambelluri ◽

A. Zanetti

Keyword(s):

Mantle Xenolith ◽

Betic Cordillera ◽

Se Spain ◽

Melt Migration

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Spatial analysis of the distribution of intestinal nematode infections in Uganda

Epidemiology and Infection ◽

10.1017/s0950268804003024 ◽

2004 ◽

Vol 132 (6) ◽

pp. 1065-1071 ◽

Cited By ~ 48

Author(s):

S. BROOKER ◽

N. B. KABATEREINE ◽

E. M. TUKAHEBWA ◽

F. KAZIBWE

Keyword(s):

Spatial Structure ◽

Land Surface ◽

Large Scale ◽

Spatial Epidemiology ◽

Generalized Additive Models ◽

Additive Models ◽

Spatial Dependency ◽

Geostatistical Methods ◽

Semivariogram Analysis ◽

Intestinal Nematode

The spatial epidemiology of intestinal nematodes in Uganda was investigated using generalized additive models and geostatistical methods. The prevalence of Ascaris lumbricoides and Trichuris trichiura was unevenly distributed in the country with prevalence greatest in southwest Uganda whereas hookworm was more homogeneously distributed. A. lumbricoides and T. Trichiura prevalence were nonlinearly related to satellite sensor-based estimates of land surface temperature; hookworm was nonlinearly associated with rainfall. Semivariogram analysis indicated that T. trichiura prevalence exhibited no spatial structure and that A. lumbricoides exhibited some spatial dependency at small spatial distances, once large-scale, mainly environmental, trends had been removed. In contrast, there was much more spatial structure in hookworm prevalence although the underlying factors are at present unclear. The implications of the results are discussed in relation to parasite spatial epidemiology and the prediction of infection distributions.

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The 11 May 2011 earthquake at Lorca (SE Spain) viewed in a structural-tectonic context

Solid Earth Discussions ◽

10.5194/sed-3-527-2011 ◽

2011 ◽

Vol 3 (1) ◽

pp. 527-540 ◽

Cited By ~ 4

Author(s):

R. L. M. Vissers ◽

B. M. L. Meijninger

Keyword(s):

Strike Slip ◽

Focal Mechanisms ◽

Strike Slip Fault ◽

Betic Cordillera ◽

Structural Studies ◽

Directed Motion ◽

Se Spain ◽

Lorca Earthquake ◽

Fault Belt

Abstract. The Lorca earthquake of 11 May 2011 in the Betic Cordillera of SE Spain occurred almost exactly on the Alhama de Murcia fault, a marked fault that forms part of a NE-SW trending belt of faults and thrusts. The fault belt is reminiscent of a strike-slip corridor, but recent structural studies have provided clear evidence for reverse motions on these faults. Focal mechanisms of the main earthquake but also of a foreshock are strikingly consistent with structural observations on the Alhama de Murcia fault. This strengthens the conclusion that, rather than a strike-slip fault, the fault is at present a contractional fault with an oblique reverse sense of motion, presumably in response to NW directed motion of Africa with respect to Europe.

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