Cloud-optimized copies of the International Bathymetric Chart of the Southern Ocean grids, with virtual multidimensional indexes (GDAL VRT, Kerchunk, Icechunk, STAC). 500 m polar stereographic grids south of 50°S: bed and ice surface elevation, with source and type identifiers. Holds Version 1.0 (doi:10.1594/PANGAEA.805734), Version 2 (doi:10.1594/PANGAEA.937574) and archived snapshots of the rolling annual releases, each under its own prefix, with georeferenced copies of the printed charts. Repackaged from the AWI and IBCSO releases, CC BY 4.0 (Version 1.0: CC BY 3.0). Not for navigation.
Cloud-optimized copies of the International Bathymetric Chart of the Southern Ocean (IBCSO) grids, with virtual multidimensional indexes over them. Each release has its own prefix. This is a repackaged copy; the authoritative releases are those of AWI and IBCSO, cited below.
IBCSO products are not for navigation or any other purpose involving safety at sea. They are provided as is, and their accuracy and completeness are not guaranteed (IBCSO release readme).
The annual release is a rolling product: each replaces the previous one at the same address. The annual prefixes here keep each release as it was published.
Version 2 and the annual releases: 19,200 x 19,200 cells at 500 m in EPSG:9354 (IBCSO Polar Stereographic), Int16, nodata -32768, one Cloud Optimized GeoTIFF per grid.
Version 1.0: 13,335 x 13,341 cells at 500 m in EPSG:3031, Float32, arrays
bed, ice_surface and sid (source identifier). Elevation nodata is
+inf, as stored in the GMT grids; sid nodata is -3.4028235e+38. The grids
carry no CRS: EPSG:3031 is stated by the file names (PS71) and by the
GeoTIFF of the ice surface in the same release, IBCSO_v1_is.tif. That
GeoTIFF has the same nodata mask as ibcso_v1_is.grd and values within
0.18 m of it, without being identical; the COGs are written from the GMT
grids.
Identifier codes and nodata differ between releases: v2 tid has no nodata
cells, the annual releases have about 122.7 million.
Layout:
The COGs are written from the GeoTIFFs of each release with values, type and
nodata unchanged, and compared with them pixel by pixel; v2 is also compared
with the netCDF of the same release, which is stored south-up. Checksums of
every source file are in provenance.json.
The annual bed and ice-surface GeoTIFFs state an origin of
(-4800018.55, 4800018.55), 18.55 m off the grid of their own RID and TID and of
v2. A regression of the difference from v2 on the v2 terrain gradient gives a
shift of at most 0.005 cells, against 0.037 for 18.55 m, so the values lie on
the v2 grid. These COGs take the v2 origin (-4800000, 4800000); the pixels are
unchanged, and the correction is recorded in the tag GEOTRANSFORM_CORRECTED
and in provenance.json.
The printed charts are PDFs with no georeferencing. Each page is rendered at 300 dpi and georeferenced from what it states: the pixel size from the printed scale, the pole from a circle fitted to the edge of the ocean disc, checked against the projected radius of the rim parallel.
All three are in EPSG:9354. Compared with the ocean of the grid of the same release at 1 km, the chart ocean aligns at zero offset (within 1 km).
Beside each chart COG: <chart>.gdalg.json, a GDAL streamed algorithm (GDAL
3.11 or later) that clips the page to the rim parallel with an alpha band;
neatline-<lat>S.geojson, the rim parallel as a polygon, for readers without
GDALG; <chart>.json, a STAC item; and <chart>.provenance.json. The charts
are display products, kept apart from the grids and their virtual forms.
v1/background/ibcso-v1-background-hq.tif is the shaded background image of
the v1.0 release (IBCSO_background_hq.zip), RGB at 541.57 m in EPSG:9354,
with its georeferencing as published; its ocean edge lies within about 1 km
of the v1.0 ice surface.
Use of these data requires citation, under CC BY 4.0:
Dorschel, B., Hehemann, L., Viquerat, S., et al. (2022). The International Bathymetric Chart of the Southern Ocean Version 2. Scientific Data, 9(1), 275. https://doi.org/10.1038/s41597-022-01366-7
For Version 2 also: Dorschel, B., et al. (2022). The International Bathymetric Chart of the Southern Ocean Version 2 (IBCSO v2). PANGAEA. https://doi.org/10.1594/PANGAEA.937574
For Version 1.0, under CC BY 3.0: Arndt, J. E., Schenke, H. W., Jakobsson, M., et al. (2013). The International Bathymetric Chart of the Southern Ocean (IBCSO) Version 1.0, a new bathymetric compilation covering circum-Antarctic waters. Geophysical Research Letters, 40, 3111-3117. https://doi.org/10.1002/grl.50413 Data: https://doi.org/10.1594/PANGAEA.805734; chart: https://doi.org/10.1594/PANGAEA.805735