The full equirectangular viewBox (-90..+90 lat) leaves a tall empty
ocean band at the bottom of the hero on wide viewports. Antarctica's
coastline only reaches ~lat -75 around its perimeter, so the bottom
~5° of the viewBox is always empty. Trim to -85..+85 so 'slice' fills
the hero with land texture instead of empty space. No distortion —
preserveAspectRatio still scales uniformly.
Chad Curtis
d2ec2a0f91