| 释义 |
tephra Geol.|ˈtɛfrə|
[ad. Sw. tefra (S. Thórarinsson 1944, in Geografiska Annaler XXVI. 114), f. Gr. τέϕρα ash.]
Dust and rock fragments that have been ejected into the air by a volcanic eruption. Freq. attrib.
1944Geografiska Annaler XXVI. 210 The author suggests (volcanic) ash or (better) tephra as a collective term for all clastic ejectamenta. 1970Nature 25 July 335/1 The maximum thickness of the tephra layer was 7 cm at 15 km from the volcano. 1972Nat. Geographic CXLI. 718/2 Commercial interests are removing this layer—known as tephra—since it makes a highly cohesive and waterproof mortar, serves as an insulating material, and constitutes an important component of cement. 1973Nature 9 Feb. 372/2 Because of its close vicinity to the eruption the town was threatened by tephra fall. 1979Sci. Amer. Dec. 134/2 The cloud of tephra and gas rises high above the volcano, and particles in it are carried downwind, producing a rain of tephra that forms a deposit called a tephra mantle. |