Get knolls base areas

Get knolls base area data in a spatial grid or polygon

Usage

get_knolls(
  spatial_grid = NULL,
  raw = FALSE,
  name = "knolls",
  antimeridian = NULL
)

Arguments

spatial_grid

sf or terra::rast() grid, e.g. created using get_grid(). Alternatively, if raw data is required, an sf polygon can be provided, e.g. created using get_boundary(), and set raw = TRUE.

raw

logical if TRUE, spatial_grid should be an sf polygon, and the raw data in that polygon(s) will be returned

name

string; name of raster or column in sf object that is returned

antimeridian

Does spatial_grid span the antimeridian? If so, this should be set to TRUE, otherwise set to FALSE. If set to NULL (default) the function will try to check if spatial_grid spans the antimeridian and set this appropriately.

Value

For gridded data, a terra::rast() or sf object, depending on the spatial_grid format. If raw = TRUE an sf object crop and intersected with the polygon supplied.

Details

Knolls are small seamounts; seamounts with peaks 200-1000 m higher than the surrounding seafloor (Morato et al., 2008). The knolls base area data is from Yesson et al. 2011

Examples

# Get EEZ data first 
bermuda_eez <- get_boundary(name = "Bermuda")
#> Cache is fresh. Reading: /tmp/Rtmpr2qcG5/eez-2205f12f/eez.shp
#> (Last Modified: 2025-05-23 05:43:02.97636)
# Get raw knolls data for Bermuda's EEZ
knolls <- get_knolls(spatial_grid= bermuda_eez, raw = TRUE)
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
# Get gridded knolls data: first create a grid
bermuda_grid <- get_grid(boundary = bermuda_eez, crs = '+proj=laea +lon_0=-64.8108333 +lat_0=32.3571917 +datum=WGS84 +units=m +no_defs', resolution = 10000)
knolls_gridded <- get_knolls(spatial_grid = bermuda_grid)
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on