superimposed_shmax function

SHmax direction resulting from multiple plate boundaries

Calculates a $SHmax$ direction at given coordinates, sourced by multiple plate boundaries. This first-order approximation is the circular mean of the superimposed theoretical directions, weighted by the rotation rates of the underlying PoRs.

superimposed_shmax(df, PoRs, types, absolute = TRUE, PoR_weighting = NULL)

Arguments

• df: data.frame containing the coordinates of the point(s) (lat, lon), and the direction of $SHmax$ azi (in degrees)
• PoRs: multirow data.frame or "euler.pole" object that must contain lat, lon and angle
• types: character vector with length equal to number of rows in PoRs. Type of plate boundary. Must be "out", "in", "right", or "left" for outward, inward, right-lateral, or left-lateral moving plate boundaries, respectively.
• absolute: logical. Whether the resultant azimuth should be weighted using the absolute rotation at the points or the angular rotation of the PoRs.
• PoR_weighting: (optional) numeric vector with length equal to number of rows in PoRs. Extra weightings for the used PoRs.

Returns

two column vector. azi is the resultant azimuth in degrees / geographical CRS), R is the resultant length.

Examples

data(san_andreas)
data(nuvel1)
pors <- subset(nuvel1, plate.rot %in% c("eu", "na"))
res <- superimposed_shmax(san_andreas, pors, types = c("in", "right"), PoR_weighting = c(2, 1))
head(res)

See Also

model_shmax()

superimposed_shmax_PB() for considering distances to plate boundaries