+ :url => "http://data.openstreetmapdata.com/land-polygons-split-3857.zip",
+ :refresh => true
+ },
+ :antarctica_icesheet_polygons => {
+ :url => "http://data.openstreetmapdata.com/antarctica-icesheet-polygons-3857.zip",
+ :refresh => true
+ },
+ :antarctica_icesheet_outlines => {
+ :url => "http://data.openstreetmapdata.com/antarctica-icesheet-outlines-3857.zip",
+ :refresh => true