asthenosphere: meaning, definition, pronunciation and examples
LowTechnical/Scientific
Quick answer
What does “asthenosphere” mean?
The weak, ductile, partially molten layer of the Earth's upper mantle below the lithosphere.
Audio
Pronunciation
Definition
Meaning and Definition
The weak, ductile, partially molten layer of the Earth's upper mantle below the lithosphere.
In geology, the ductile, mechanically weak region of the upper mantle where tectonic plates move. More broadly, it can refer to a zone of weakness or deformation beneath a rigid layer in other planetary bodies.
Dialectal Variation
British vs American Usage
Differences
No lexical differences. Minor potential variation in hyphenation in compound adjectives (e.g., 'asthenosphere-lithosphere boundary' vs. 'asthenosphere lithosphere boundary'), following general BrE/AmE hyphenation trends.
Connotations
Identical technical connotations.
Frequency
Identical, exclusive to geological/geophysical contexts.
Grammar
How to Use “asthenosphere” in a Sentence
The asthenosphere [VERB] (e.g., flows, deforms, convects).[NOUN] of the asthenosphere[ADJECTIVE] asthenosphere (e.g., viscous, underlying)Vocabulary
Collocations
Examples
Examples of “asthenosphere” in a Sentence
verb
British English
- The material is theorised to asthenospherically weaken at those depths. (highly technical, non-standard derivative)
American English
- The model simulates how the mantle asthenospherizes below the crust. (highly technical, non-standard derivative)
adjective
British English
- The asthenospheric flow patterns are key to the model.
- They studied the asthenosphere-lithosphere interaction.
American English
- Asthenospheric viscosity is a critical parameter.
- The research focuses on the asthenosphere mantle boundary.
Usage
Meaning in Context
Business
Not used.
Academic
Exclusively used in geology, geophysics, and earth science literature and lectures.
Everyday
Virtually never used.
Technical
The primary domain. Used to discuss plate tectonics, mantle convection, isostasy, and seismic wave propagation.
Vocabulary
Synonyms of “asthenosphere”
Strong
Neutral
Weak
Vocabulary
Antonyms of “asthenosphere”
Watch out
Common Mistakes When Using “asthenosphere”
- Mispronunciation: /æsˈθen.ə.sfɪr/ (incorrectly stressing the second syllable as 'then').
- Misspelling: 'asthenospere' (dropping the 'h').
- Confusing it with the atmosphere or mesosphere.
FAQ
Frequently Asked Questions
No, it is not liquid. It is solid rock, but it is hot, weak, and ductile enough to flow very slowly over geologic time, behaving in a plastic manner.
It is generally considered to extend from about 80-100 km to 660 km below the Earth's surface, though its depth varies regionally.
The term was coined by the American geologist Joseph Barrell in 1914, derived from the Greek 'asthenes' meaning weak.
Its weak, ductile nature provides the lubricating layer on which the rigid tectonic plates (lithosphere) can move laterally via convection currents.
The weak, ductile, partially molten layer of the Earth's upper mantle below the lithosphere.
Asthenosphere is usually technical/scientific in register.
Asthenosphere: in British English it is pronounced /æsˈθiː.nəʊ.sfɪə/, and in American English it is pronounced /æsˈθɛ.nəˌsfɪr/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think: ASTHENOSPHERE = A-STHEN-O-SPHERE. 'A' (without) + 'sthenos' (Greek for strength) + 'sphere'. So, 'the sphere without strength' – the weak layer beneath the strong lithosphere.
Conceptual Metaphor
The asthenosphere is the SLIPPERY FLOOR upon which the rigid plates (lithosphere) slide.
Practice
Quiz
What is the primary characteristic of the asthenosphere?