bathybˈius noun

(Gr bios life) a substance on the sea bottom formerly thought to be living matter

bathygraphˈical adjective

(Gr graphein to write) of maps, representing the contours of the seabed

bathylite or bathylith noun see batholith

bathymeter /bath-imˈət-ər/ noun

(Gr metron measure) a sounding instrument

bathymetˈric or bathymetˈrical adjective

bathymˈetry noun

The science of sounding seas and lakes

bathyorographˈical adjective

(Gr oros mountain) of maps, representing the contours of land height and water depth

bathypelagic /-ajˈik/ adjective

(Gr pelagos sea) found in the depths of the sea, down to 4000m below sea level

bathˈyscaphe or bathˈyscape noun

(Gr skaphos ship) an electrically powered crewed vessel with a spherical observation cabin on its underside, used for deep-sea exploration

bathˈysphere noun

(Gr sphaira sphere) a submersible observation chamber lowered and raised from a surface vessel