PoR_shmax {tectonicr}R Documentation

Direction of Maximum Horizontal Stress in PoR reference system

Description

Models the direction of maximum horizontal stress σHmax\sigma_{Hmax} in the Euler pole (Pole of Rotation) coordinate reference system. When type of plate boundary is given, it also gives the deviation from the theoretically predicted azimuth of σHmax\sigma_{Hmax}, the deviation, and the normalized χ2\chi^2 statistics.

Usage

PoR_shmax(df, PoR, type = c("none", "in", "out", "right", "left"))

Arguments

df

data.frame containing the coordinates of the point(s) (lat, lon), the direction of σHmax\sigma_{Hmax} azi and its standard deviation unc (optional)

PoR

"data.frame" or object of class "euler.pole" containing the geographical coordinates of the Euler pole

type

Character. Type of plate boundary (optional). Can be "out", "in", "right", or "left" for outward, inward, right-lateral, or left-lateral moving plate boundaries, respectively. If "none" (the default), only the PoR-equivalent azimuth is returned.

Details

The azimuth of σHmax\sigma_{Hmax} in the pole of rotation reference system is approximate 0 (or 180), 45, 90, 135 degrees if the stress is sourced by an outward, sinistral, inward, or dextral moving plate boundary, respectively. directions of σHmax\sigma_{Hmax} with respect to the four plate boundary types.

Value

Either a numeric vector of the azimuths in the transformed coordinate system (in degrees), or a "data.frame" with

azi.PoR

the transformed azimuths (in degrees),

prd

the predicted azimuths (in degrees),

dev

the deviation between the transformed and the predicted azimuth (in degrees),

nchisq

the Norm χ2\chi^2 test statistic, and

cdist

the angular distance between the transformed and the predicted azimuth.

References

Stephan, T., Enkelmann, E., and Kroner, U. "Analyzing the horizontal orientation of the crustal stress adjacent to plate boundaries". Sci Rep 13. 15590 (2023). doi:10.1038/s41598-023-42433-2.

See Also

model_shmax() to compute the theoretical direction of σHmax\sigma_{Hmax} in the geographical reference system. deviation_shmax() to compute the deviation of the modeled direction from the observed direction of σHmax\sigma_{Hmax}. norm_chisq() to calculate the normalized χ2\chi^2 statistics. circular_distance() to calculate the angular distance.

Examples

data("nuvel1")
# North America relative to Pacific plate:
PoR <- subset(nuvel1, nuvel1$plate.rot == "na")

data("san_andreas")
res <- PoR_shmax(san_andreas, PoR, type = "right")
head(res)

[Package tectonicr version 0.3.2 Index]