Crustal seismic anisotropy, paleostress field, seismic stresses and displacements in the Eastern Alps.

This dataset comprises spreadsheets with fault plane solutions, seismic anisotropy, paleostress data, seismic displacements in the Eastern Alps and is attached to the manuscript "Stress patterns and crustal anisotropy in the Eastern Alps: insights from seismological and geological observations" by F. Villani, A. Antonioli, M. Pastori, P. Baccheschi and M.G. Ciaccio under review on Tectonics. The used relevant papers are cited in the companion paper. The pickings and waveforms used for the splitting analysis and focal mechanisms computations are available at ISIDe (ISIDe working group, 2016 v. 1.0, doi: 10.13127/ISIDe) and EIDA (European Integrated Data Archive http://eida.rm.ingv.it/).

S1.xlsx

Selection of fault plane solutions from literature (reference work in the field “author”) and our new determinations. The following abbreviations are used: Saraò_etal2021, PondrelliSalimbeni2006, Viganò_etal2008, Reiter_etal2018, Petersen_etal2021, TDMT_Ingv (solutions after http://terremoti.ingv.it/tdmt), this work (original solutions in this study).

Other fields: date (format yyyy-mm-dd), hour (UTC), lat (latitude in decimal degrees, hereinafter dd), lon (longitude in dd), depth (in km), magnitude, type (magnitude type), strike1 (strike of plane 1 in degrees, hereinafter °), dip1 (dip of plane 1 in °), rake1 (rake of plane 1 in °), strike2 (strike of plane 2 in °), dip2 (dip of plane 2 in °), rake2 (rake of plane 2 in °), P_pl (plunge of P-axis in °), P_az (trend of P-axis in °), B_pl (plunge of B-axis in °), B_az (trend of B-axis in °), T_pl (plunge of T-axis in °), T_az (trend of T-axis in °), SHmax (orientation of most-compressive horizontal stress in °), Shmin (orientation of least-compressive horizontal stress in °), regime_ index (stress regime index R’), regime_code (faulting type; NF, normal faulting; NS, normal-strike slip faulting; SS, strike-slip faulting; TF, thrust faulting; TS thrust-strike slip faulting; UF, undefined faulting).

S2.xlsx

Results of shear wave splitting analysis. The fields are:

origin_time: origin time of the earthquake yyyy-mm-ddThh:mm:ss.ss followed by the code of the seismic station;

lon_event: earthquake longitude dd;

lat_event: earthquake latitude dd;

depth: earthquake depth in km;

station: station name;

lon_station: station longitude;

lat_station: station latitude;

elevation: station elevation in m a.s.l.;

φ: azimuth of fast direction, in ° clockwise from North;

err_φ: uncertainty in fast direction, in °;

null_orientation: azimuth of null direction, in ° clockwise from North;

err_null: uncertainty in null direction, in °;

δt: delay time in sec;

err_δt: error in delay time in sec;

CC: cross-correlation coefficient; weight (adimensional);

hypo_distance: hypocentral distance in km;

S/N_ratio: signal to noise ratio;

normalized_δt: delay time normalized by the ray path;

ic: incidence angle, in °;

back_azimuth: back azimuth in °;

julian_day: Julian day;

resampled_δt: resampled delay time, in sec;

lat_PP: latitude of piercing point;

lon_PP: longitude of piercing point.

S3.xlsx

Compilation of paleostress tensors selected from published papers plus some original paleostress determinations (this work). Each record describes a single paleostress tensor, with the following information:

ID: identifier used in this work;

No_station: station number in the reference work;

Paper_ref: abbreviated reference of the published paper (our original data are labelled as “This study”);

Source_work: the original paper from which data are taken: this field does not correspond to Paper_ref when the reference paper is a compilation of several datasets from other papers;

Station: the name of the station in the reference paper;

Stat_code: the code of the station in the reference paper;

lon_dd: longitude dd;

lat_dd: latitude dd;

Formation/Tectonic unit: the geological formation or main tectonic unit;

Lithology: the prevailing lithology;

Age_of_stratigraphic_unit: the inferred age of the studied rockmass;

N[all]: the number of fault slip data used for paleostress calculation;

N[D]: the number of fault slip data compatible with the paleostress tensor;

Stress_regime/Tectonic_event: the overall stress regime and/or associated tectonic event;

Method_applied: the applied inversion method (PBT, PBT-axes; RD: right dihedron; DI, direct inversion; NDA, numerical dynamic analysis; rot. opt., rotational optimization);

σ1_trend: trend of principal stress axis σ1 in °;

σ1_plunge: plunge of σ1 in °;

σ2_trend: trend of principal stress axis σ2 in °;

σ2_plunge: plunge of σ2 in °;

σ3_trend: trend of principal stress axis σ3 in °;

σ3_plunge: plunge of σ3 in °;

SHmax_Trend_Lund: the orientation of SHmax corrected according to Lund & Townend (2007);

R: the stress ratio R=[(s2-s3)/(s1-s3)];

notes: comments, when available.

When paleostress results are not available in numeric format, we: 1) digitized the stereonets using the Stereonet© v.11 software (Allmendiger et al., 2012); 2) inverted digitized data with the RD method. When the published data do not have coordinates, paleostress sites coordinates were obtained by georeferencing the figures with ArcMap software by ESRI.

S4.xlsx

Results of stress analysis from fault plane solutions within the seismotectonic domains defined in the companion paper. The S_Hmax direction is calculated according to Lund & Townend (2007). φ_b is the Bishop’s ratio from the BRTM method, and is equal to R = (σ2-σ3)/(σ1-σ3). The general stress regime is defined as output from the PBT and RD methods (faulting codes as in S1.xlsx).

S5.xlsx

Cumulative seismic displacement in the study area at different depth intervals (in km). The coordinates are in meters (WGS84 datum, zone 32N). The east-west, north-south and vertical displacement components (in meters) are Ux_m, Uy_m and Uz_m, respectively. Z- axis positive upward.

S6.xlsx

Coordinates and breakout orientation and intervals from the boreholes that we included in the S_Hmax maps.

Id: borehole ID;

Lat: latitude dd;

Lon: longitude dd;

Shmin: orientation of Shmin in ° clockwise from North;

SHmax: orientation of SHmax in ° clockwise from North;

Q: quality of breakout;

Reference: reference paper;

Sd: standard deviation (1σ) of S_Hmax orientation;

BO_top: breakout top in m b.s.l.);

BO_bottom: breakout bottom in m b.s.l.;

Year: year of borehole drilling;

Depth: depth of well in meters;

Well_name: name of well.

S7.xlsx

Circular statistics (Von Mises distribution) of anisotropic parameters (φ and null direction), faults and orientation of S_Hmax (from earthquakes) within each seismotectonic domain in ° (positive, clockwise from North). The fields are:

domain: name of seismotectonic domain;

N_φ: number of φ measurements;

φ _max: directional bin of maximum frequency of φ direction;

φ _av: mean trend of φ;

φ_1σ: 1σ of φ trend;

N_null: number of null measurements;

null_max: directional bin of maximum frequency of null direction;

null_av: mean trend of null direction;

null_1σ: 1σ of null direction;

N_faults: number of faults;

Faults_strike_max: directional bin of maximum frequency of fault direction;

Faults_strike_av: average fault trend;

Faults_strike_1σ: 1σ of fault direction;

N_SHmax: number of S_Hmax measurements;

SHmax_max: directional bin of maximum frequency of S_Hmax orientation;

SHmax_av: average orientation of S_Hmax;

SHmax_1σ: 1σ of S_Hmax orientation.

SHmax_interp.xlsx

Interpolated current S_Hmax orientations (from earthquakes and borehole breakouts) on regular 0.1° grid. The fieds are: Lat (latitude dd), Lon (longitude dd), SHmax_azimuth (orientation of S_Hmax in °); 90%_confidence (90% confidence interval of S_Hmax orientation in °).

paleoSHmax_interp.xlsx

Interpolated paleo-S_Hmax orientations on regular 0.1° grid. The fieds are: Lat (latitude dd), Lon (longitude dd), SHmax_azimuth (orientation of paleo-S_Hmax in °); 90%_confidence (90% confidence interval of paleo-SHmax orientation in °).