upthrust
/ˈʌpθrʌst/ (bre, ipa) · /ˈʌpθrʌst/ (ame, ipa) · /ˈəp-ˌthrəst/ (ame, mw)
upthrust — noun
1. the upward force that a fluid — a liquid or a gas — exerts on any object placed
the upward force that a fluid — a liquid or a gas — exerts on any object placed inside it, making the object feel lighter and, if the force is great enough, causing it to float.
The upthrust of the water kept the wooden raft floating on the lake.
upthrust of + [liquid] for physical force
Quan's class measured the upthrust on a rubber duck in a tank of water.
A steel ship floats because the upthrust from the sea equals the ship's weight.
The scuba divers felt the strong upthrust of the seawater pushing them upward.
Archimedes discovered the principle of upthrust while taking a bath.
- buoyancy
more common in everyday physics; upthrust is the technical term for the force itself
- buoyant force
the full phrase used in textbooks; upthrust is the shorter synonym
文法句型
the upthrust of + noun (liquid/gas)
upthrust + verb
用法筆記
In physics classrooms this force is also called buoyancy or buoyant force. The simplest demonstration is a block of wood pushed down into water — when released, the upthrust shoots it back to the surface.
常見錯誤
2. the process by which sections of the Earth's crust are pushed upward by forces d
the process by which sections of the Earth's crust are pushed upward by forces deep inside the planet, often creating mountains, plateaus, or cliffs.
The Himalayan mountain range was formed by the upthrust of the Indian tectonic plate.
upthrust of + [tectonic plate] for geological context
Geologists study the upthrust of rock layers to understand ancient earthquakes.
A powerful upthrust of the seabed created a new island near the coast of Japan.
Road builders had to cut through a ridge of upthrust limestone on the mountain pass.
- uplift
broader term in geology; upthrust emphasises forceful, sudden vertical movement
- mountain building
a more general phrase; upthrust is one specific mechanism within it
- subsidence
the sinking or downward movement of land, opposite to upthrust
- erosion
wearing away of land that counteracts the effects of upthrust over time
文法句型
the upthrust of + noun (rock/land/crust)
upthrust + verb
用法筆記
Frequently paired with plate tectonics vocabulary: fault line, collision zone, subduction. Geological upthrust happens over millions of years, but earthquake uplift can occur in seconds.
常見錯誤
upthrust — verb
- upthrustpresent simple I / you / we / they
- upthrusts3rd person singular
- upthrusting-ing form
- upthrustedpast simple
1. to push or force something suddenly upward from below, often as a result of natu
to push or force something suddenly upward from below, often as a result of natural pressure or an explosion.
The earthquake upthrusted a section of the railway track by nearly two metres.
upthrust + object + measure phrase
Frozen ground upthrusted the fence posts during the harsh winter.
The explosion upthrusted debris high into the air above the deserted warehouse.
Ravindra watched the glacier upthrust huge boulders as it crawled across the valley floor.
- push up
the everyday alternative; upthrust sounds formal and literary
- thrust upward
more common verb phrase; upthrust is a compressed version
文法句型
upthrust + noun phrase
用法筆記
Extremely rare in everyday English. In almost all situations native speakers use push up, force up, or thrust upward instead. You are most likely to encounter this sense in geology or engineering writing.
2. to rise or surge powerfully upward, especially when driven by heat, pressure, or
to rise or surge powerfully upward, especially when driven by heat, pressure, or an explosive force.
A column of steam upthrust from the broken pipe in the factory basement.
upthrust from + [place] for source of force
Hot lava upthrusts from the volcano before cooling into dark rock.
The seabed upthrusts slowly as the tectonic plates push against each other.
Superheated gas upthrust through narrow cracks in the desert floor.
文法句型
upthrust + adverb/preposition
upthrust from + noun
用法筆記
The subject is usually a natural force or substance (lava, steam, gas, magma). Never used with a human subject performing an intentional action.