insular

island

peninsula

islet

marine

maritime

moist

ledge

oasis

tide

ebb

continent

terrestrial

outskirt

region

endemic

cosmopolitan

subterrane

subterranean

cavern

flaw

cleft

crevice

gap

zone

equator

longitude

altitude

latitude

meridian

subsidiary

antarctic

antarctica

arctic

coastland

hemisphere

contour

geography

horizon

lowland

plain

strait

channel

valley

volcano

plateau

basin

navigation

ranges

salinity

sediment

elevation

formation

geothermy

terrain

topography

tropical

tropics

temperate