thermocline
THUR-muh-klyne
/ˈθɜːr.mə.klaɪn/
A steep temperature gradient in a body of water, such as an ocean or lake, marked by a layer above and below which water is at different temperatures.
Describes a sudden boundary layer where temperature drops rapidly relative to depth.
The story behind the word. Coined by limnologists and oceanographers from Greek therme (heat) and klinein (to lean or slope), describing the rapid downward sloping of temperature on a graph.
Word relationships
- thermal layer: Thermal layer is a broad term, whereas thermocline specifically denotes the layer of rapid temperature drop.
Commonly confused with
- halocline: Halocline is a sharp gradient of salinity, whereas thermocline is a sharp gradient of temperature.
- pycnocline: Pycnocline is a sharp gradient of water density, often caused by thermoclines and haloclines combined.
Word family
- thermoclinic (adjective): Relating to or possessing a thermocline.
Collocations
- permanent thermocline
- seasonal thermocline
- cross the thermocline
- sharp thermocline
Example sentences
- "Scuba divers quickly notice a sudden drop in water temperature as they pass through the thermocline." Oceanography
Memory hook
THERMO (heat) + CLINE (incline/decline): a steep decline in heat. Sharp boundary of dropping temperature.
When not to use
Do not use for general atmospheric air temperature shifts across land.
Fun facts
- Submarines use thermoclines to hide from sonar detection because acoustic waves refract off the sudden thermal boundary.
Take your vocabulary further with LangBlitz
Our English vocabulary app: FSRS spaced repetition, 5,000+ curated words across 119 topic groups, CEFR A1 to C2. Explore your mastery with the beautiful Vocabulary World feature.