Publication Date:
2017-04-04
Description:
This article has been accepted for publication in Geophysical Journal International ©: The Authors 2003. Published by Oxford University Press on behalf of The Royal Astronomical Society. All rights reserved.
Description:
In this study, we modify and extend a data analysis technique to determine the stress orientations between data clusters by adding an additional constraint governing the probability algorithm. We apply this technique to produce a map of the maximum horizontal compressive stress (S_Hmax) orientations in the greater European region (including Europe, Turkey and Mediterranean Africa). Using the World Stress Map dataset release 2008, we obtain analytical probability distributions of the directional differences as a function of the angular distance, θ. We then multiply the probability distributions that are based on pre-averaged data within θ〈3° of the interpolation point and determine the maximum likelihood estimate of the S_Hmax orientation. At a given distance, the probability of obtaining a particular discrepancy decreases exponentially with discrepancy. By exploiting this feature observed in the World Stress Map release 2008 dataset, we increase the robustness of our S_Hmax determinations. For a reliable determination of the most likely S_Hmax orientation, we require that 90% confidence limits be less than ±60° and a minimum of three clusters, which is achieved for 57% of the study area, with small uncertainties of less than ±10° for 7% of the area. When the data density exceeds 0.8×10^-3 data/km2, our method provides a means of reproducing significant local patterns in the stress field. Several mountain ranges in the Mediterranean display 90° changes in the S_Hmax orientation from their crests (which often experience normal faulting) and their foothills (which often experience thrust faulting). This pattern constrains the tectonic stresses to a magnitude similar to that of the topographic stresses.
Description:
This work was supported by the DPC-INGV 2008-2010 S1 project, the EU-FP7 project “Seismic Hazard Harmonization in Europe” (SHARE; Grant agreement no. 226967), and project MIUR-FIRB "Abruzzo" (code: RBAP10ZC8K_003).
Description:
Published
Description:
3.1. Fisica dei terremoti
Description:
3.3. Geodinamica e struttura dell'interno della Terra
Description:
4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
Description:
JCR Journal
Description:
partially_open
Keywords:
Neotectonics
;
Seismicity and tectonics
;
Fractures and faults
;
Intra-plate processes
;
Plate motions
;
Dynamics: gravity and tectonics
;
04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
;
04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress
;
05. General::05.02. Data dissemination::05.02.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
