Interpolate the trajectory of past shoreline displacement to a target location within the spatial coverage on the Skagerrak coast of south-eastern Norway. This based on the distance of the location to the shoreline isobases of the geologically derived displacement curves and is done using inverse distance weighting.

  isobases = NA,
  power = 2,
  cal_reso = 10,
  verbose = FALSE



A spatial target location to where the new displacement curve is interpolated.


4 spatial lines representing the shoreline isobases of the existing displacement curves. Multiple sets of 4 isobases with different isobase directions can be provided (see create_isobases()). Defaults to isobases with a direction of 327.


A numerical value indicating the inverse distance power for IDW. Defaults to 2.


A numerical value specifying the resolution to use on the calendar scale. Defaults to 10.


Logical value indicating whether progress should be printed to console. Defaults to FALSE.


Returns a list holding an interpolated displacement curve for each isobase direction. Each displacement curve is represented by a data frame with the columns bce where negative values indicate years BCE and positive CE, lowerelev, representing the lower limit for the elevation of the shoreline for each year. upperelev, the upper limit for elevation of the shoreline for each year, and direction which indicates the direction of the isobases used when interpolating the curve.


# Create example point using the required coordinate system
# WGS84 / zone UTM32N (EPSG: 32632)
target_point <- sf::st_sfc(sf::st_point(c(579570, 6582982)), crs = 32632)

# Interpolate shoreline displacement curve to the target point location,
# setting the resolution on the calendar scale to 2000 years for speed.
target_curve <- interpolate_curve(target_point, cal_reso = 2000)