Skip to contents

Premade maps

Mikko Vihtakari (Institute of Marine Research)

22 June, 2026

Source: vignettes/premade-maps.Rmd
premade-maps.Rmd

Overview

ggOceanMaps plots maps from pre-made shapefiles. Most of the time you do not need to think about them: basemap() picks the right set automatically from the limits (or data) you give it. This article shows the maps that ship with — or are downloadable for — the package, and the projection each uses.

The available sets are listed by shapefile_list():

shapes <- shapefile_list("all")
datapath <- path.expand(getOption("ggOceanMaps.datapath"))
userpath <- path.expand(getOption("ggOceanMaps.userpath", ""))
shapes[] <- lapply(shapes, function(x) {
  if (!is.character(x)) return(x)
  x <- gsub(datapath, "<ggOceanMaps.datapath>", x, fixed = TRUE)
  if (nzchar(userpath)) {
    x <- gsub(userpath, "<ggOceanMaps.userpath>", x, fixed = TRUE)
  }
  x
})
shapes
#>                     name                                  land
#> 1    ArcticStereographic    <ggOceanMaps.datapath>/arctic_land
#> 2 AntarcticStereographic <ggOceanMaps.datapath>/antarctic_land
#> 3          DecimalDegree                               dd_land
#> 4               Svalbard  <ggOceanMaps.datapath>/svalbard_land
#> 5                 Europe    <ggOceanMaps.datapath>/europe_land
#>                                    glacier
#> 1    <ggOceanMaps.datapath>/arctic_glacier
#> 2 <ggOceanMaps.datapath>/antarctic_glacier
#> 3        <ggOceanMaps.datapath>/dd_glacier
#> 4  <ggOceanMaps.datapath>/svalbard_glacier
#> 5                                     <NA>
#>                                                                                    bathy
#> 1    dd_rbathy|<ggOceanMaps.datapath>/dd_rbathy_cont|<ggOceanMaps.datapath>/arctic_bathy
#> 2 dd_rbathy|<ggOceanMaps.datapath>/dd_rbathy_cont|<ggOceanMaps.datapath>/antarctic_bathy
#> 3        dd_rbathy|<ggOceanMaps.datapath>/dd_rbathy_cont|<ggOceanMaps.datapath>/dd_bathy
#> 4  dd_rbathy|<ggOceanMaps.datapath>/dd_rbathy_cont|<ggOceanMaps.datapath>/svalbard_bathy
#> 5        dd_rbathy|<ggOceanMaps.datapath>/dd_rbathy_cont|<ggOceanMaps.datapath>/dd_bathy
#>     crs                                      limits
#> 1  3995                                       c(30)
#> 2  3031                                      c(-35)
#> 3  4326                       c(-180, 180, -90, 90)
#> 4 32633 c(402204.7, 845943.9, 8253526.1, 8978517.5)
#> 5  3035        c(943609, 7601958, -375446, 6825119)
#>                                                                      path
#> 1 https://github.com/MikkoVihtakari/ggOceanMapsLargeData/raw/master/data/
#> 2 https://github.com/MikkoVihtakari/ggOceanMapsLargeData/raw/master/data/
#> 3 https://github.com/MikkoVihtakari/ggOceanMapsLargeData/raw/master/data/
#> 4 https://github.com/MikkoVihtakari/ggOceanMapsLargeData/raw/master/data/
#> 5 https://github.com/MikkoVihtakari/ggOceanMapsLargeData/raw/master/data/

Each row is a named shapefile set with a coordinate reference system (crs), a default extent (limits), and the names of its land / glacier / bathymetry objects. You can force a particular set with the first argument or the shapefiles argument (partial matching works, so "Arctic" resolves to "ArcticStereographic"):

basemap(shapefiles = "Svalbard", bathymetry = TRUE)

Low-resolution global data (dd_land, dd_rbathy) ship with the package. The higher-resolution regional sets live in the ggOceanMapsLargeData repository and are downloaded automatically on first use to getOption("ggOceanMaps.datapath"). Set that option to a permanent folder in your .Rprofile so the files are reused across sessions; otherwise they land in tempdir() and are re-downloaded each session.

Standard maps (selected automatically)

These three sets cover the whole globe and are chosen automatically from the latitude range of your limits: polar-stereographic projections near the poles, decimal degrees elsewhere. See the user manual for the exact selection rule.

Decimal degree

The default map uses decimal degrees (EPSG:4326) and Natural Earth 1:10m land and minor-island polygons.

basemap("DecimalDegree", bathymetry = TRUE, glaciers = TRUE)
Figure: Global basemap in decimal degrees (EPSG:4326) with land, glaciers, and binned bathymetry.
Figure: Global basemap in decimal degrees (EPSG:4326) with land, glaciers, and binned bathymetry.

Arctic Stereographic

Used automatically when the map sits in the high north (EPSG:3995). Land and glacier polygons and vector bathymetry are downloaded from ggOceanMapsLargeData on first use.

basemap("ArcticStereographic", bathymetry = TRUE, glaciers = TRUE)
Figure: Arctic stereographic basemap (EPSG:3995) with land, glaciers, and bathymetry.
Figure: Arctic stereographic basemap (EPSG:3995) with land, glaciers, and bathymetry.

Antarctic Stereographic

The southern equivalent (EPSG:3031).

basemap("AntarcticStereographic", bathymetry = TRUE, glaciers = TRUE)
Figure: Antarctic stereographic basemap (EPSG:3031) with land, glaciers, and bathymetry.
Figure: Antarctic stereographic basemap (EPSG:3031) with land, glaciers, and bathymetry.

Detailed regional maps

Higher-resolution sets for regions the package author works in. They are downloaded from ggOceanMapsLargeData when first requested. The detailed shapefiles can be large: find your limits with the standard maps first, and export to a file rather than plotting into the screen device for big extents.

Only a handful of regions have a dedicated high-resolution set. If your area of interest is not in the list above — or you need finer land or bathymetry than the standard maps provide — you can build your own land and bathymetry shapefiles and pass them to basemap() via the shapefiles argument. See the Customising shapefiles article for the full workflow.

Europe

A detailed European coastline (EPSG:3035) based on the EEA coastline. Useful for coastal maps around the European seas. Can be paired with EMODnet bathymetry for ~115 m resolution bathymetric maps (see New features in v3 for example).

basemap(shapefiles = "Europe")
Figure: Detailed European coastline (EPSG:3035) from the EEA coastline dataset.
Figure: Detailed European coastline (EPSG:3035) from the EEA coastline dataset.

The Europe land polygons are downloaded from ggOceanMapsLargeData on first use.

Svalbard

A detailed Svalbard map (EPSG:32633), originally from the PlotSvalbard package. The function asks to download the data the first time you use it.

basemap("Svalbard", glaciers = TRUE)
Figure: Detailed Svalbard map matching from the now deprecated PlotSvalbard package.
Figure: Detailed Svalbard map matching from the now deprecated PlotSvalbard package.

Zooming to Kongsfjorden. Svalbard and Europe maps can be paired with the EMODnet bathymetry:

basemap(
  limits = c(10.9, 12.65, 78.83, 79.12),
  bathy.style = "wemb",
  shapefiles = "Svalbard",
  legends = FALSE,
  glaciers = TRUE
)
Figure: High-resolution map of Kongsfjorden, Svalbard, with bathymetry and glaciers.
Figure: High-resolution map of Kongsfjorden, Svalbard, with bathymetry and glaciers.

Citing the data

The data used by the package are not the property of the Institute of Marine Research nor the package author. Please cite the data sources used in any map you generate. See the data-source list for the references.