noun
gas outburst; outburst of gas
Technical term used mainly in mining, geology, and safety engineering to describe a sudden release of gas from rock or coal seams.
炭鉱でガス突出が発生し、作業員が避難した。
A gas outburst occurred in the coal mine, and the workers evacuated.
ガス爆発 is a gas explosion, which involves combustion, while ガス突出 is a sudden physical release of gas without necessarily igniting.
Compound of ガス (gas, from English) and 突出 (protrusion, outburst). The exact historical derivation is uncertain; the term is used in technical contexts.