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 knolls data in that polygon(s) will be returned

name

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 data 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/Rtmpj5K8Rh/eez-2205f12f/eez.shp
#> (Last Modified: 2024-09-11 02:15:56.249906)
# 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