stress_paths {tectonicr}

Theoretical Plate Tectonic Stress Paths

Description

Construct \sigma_{Hmax} lines that are following small circles, great circles, or loxodromes of an Euler pole for the relative plate motion.

Usage

eulerpole_paths(x, type = c("sc", "gc", "ld"), n = 10, angle, cw)

eulerpole_smallcircles(x, n = 10)

eulerpole_greatcircles(x, n = 10)

eulerpole_loxodromes(x, n = 10, angle = 45, cw)

Arguments

x

Either an object of class "euler.pole" or "data.frame" containing coordinates of Euler pole in lat, lon, and rotation angle (optional).

type

Character string specifying the type of curves to export. Either "sm" for small circles (default), "gc" for great circles, or "ld" for loxodromes.

n

Number of equally spaced curves; n = 10 by default (angular distance between curves: 180 / n)

angle

Direction of loxodromes; angle = 45 by default.

cw

logical. Sense of loxodromes: TRUE for clockwise loxodromes (left-lateral displaced plate boundaries). FALSE for counterclockwise loxodromes (right-lateral displaced plate boundaries).

Details

Maximum horizontal stress can be aligned to three types of curves related to relative plate motion:

Small circles

Lines that have a constant distance to the Euler pole. If x contains angle, output additionally gives absolute velocity on small circle (degree/Myr -> km/Myr).

Great circles

Paths of the shortest distance between the Euler pole and its antipodal position.

Loxodromes

Lines of constant bearing, i.e. curves cutting small circles at a constant angle.

Value

sf object

Author(s)

Tobias Stephan

Examples

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

eulerpole_smallcircles(por)
eulerpole_greatcircles(por)
eulerpole_loxodromes(x = por, angle = 45, n = 10, cw = FALSE)
eulerpole_loxodromes(x = por, angle = 30, cw = TRUE)
eulerpole_smallcircles(data.frame(lat = 30, lon = 10))