stress_paths function

Theoretical Plate Tectonic Stress Paths

Construct $SHmax$ lines that are following small circles, great circles, or loxodromes of an Euler pole for the relative plate motion.

eulerpole_paths(x, type = c("sc", "gc", "ld"), n = 10, angle = 45, 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).

Returns

sf object

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.

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))

Author(s)

Tobias Stephan