Earth & SkyGreek → English
Isobath
/ˈaɪsə(ʊ)bɑːθ/noun
A line on a chart connecting points of equal depth below a water surface.
The Greek roots
ἴσος
ísos
equal, same
βάθος
báthos
depth
Literally: “equal depth”
The story of the word
Charts drew depth as scattered soundings for centuries before anyone joined the dots; the isobath turns a table of numbers into a shape you can steer by. Its dry-land twin is the contour line, and both belong to the iso- family that also gave isobar and isotherm. Greek βάθος also gave English bathos, the sudden drop from the sublime to the trivial, named by Alexander Pope in 1728.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
bathymetrybathyspherebathosisobarisotherm
In a sentence
Trawlers work the ground between the hundred and two hundred metre isobaths.
The isobaths crowd together where the shelf breaks.