Earth Sandwich / City antipodes / Jacksonville

Antipode finder · United States

The antipode of
Jacksonville.

Draw a straight line from Jacksonville (30.33° N, 81.66° W) through the centre of the Earth and it comes out at 30.33° S, 98.34° E, in the Indian Ocean, 1,494 km from the nearest dry land, off the coast of Australia. The other slice of an Earth sandwich would sink.

Two globes: one centred on Jacksonville, one centred on its antipode at 30.33° S, 98.34° E
Above JacksonvilleAbove the antipode
Jacksonville
30.33° N, 81.66° W · about 40 m above sea level · 1,009,833 people
Antipode
30.33° S, 98.34° E
What is there
The Indian Ocean; the sea floor there lies about 2,440 m below the surface
Nearest dry land
1,494 km from the antipode, on the coast of Australia
Nearest town
Kalbarri, Australia · 1,564 km from the antipode
Nearest big city
Perth · 1,675 km from the antipode
Sandwich verdict
SOGGY the other slice lands in open water
Nearest exact spot
2,079 km away, 34 km from Lamar, United States ⇄ 1,410 km from Port-aux-Français, French Southern Territories

Can you make an Earth sandwich from Jacksonville?

No, not from Jacksonville itself. The other slice would land in the Indian Ocean, 1,494 km from the nearest dry land (Australia), where the sea floor lies about 2,440 m below the surface. Boats do not count (Sandwich Law § 1.3).

The nearest place from which an exact Earth sandwich is possible is 2,079 km from Jacksonville, 34 km from Lamar, United States. Its other slice would go down 1,410 km from Port-aux-Français, French Southern Territories.

How this was worked out: the antipode flips the latitude and moves the longitude by 180°. Land or sea comes from the OpenStreetMap coastline the map uses; the sandwich verdict and elevations come from the verifier's 0.2° grid (Natural Earth land, ETOPO 2022 relief); water names from Natural Earth; towns and populations from GeoNames. The city's position is GeoNames' point for it; a big city's suburbs spread tens of kilometres around that point, and the figures move with them. Generated 2026-09-29.