noun
tephra; volcanic ejecta
Technical term in volcanology for solid material ejected into the air during an eruption, including ash, lapilli, and bombs.
この地層には、約1万年前のテフラが含まれている。
This stratum contains tephra from about 10,000 years ago.
テフラの分布から、噴火の規模が推定できる。
The scale of the eruption can be estimated from the distribution of tephra.