1.
volcanic crater; volcanic vent
The opening at the top of a volcano (or on its flanks) from which lava, ash, and gases are ejected during an eruption. 噴火口 refers specifically to the active vent, while the broader bowl-shaped depression that may form around it is more often called 火口.
The researchers analyzed the composition of the gases erupting from the volcanic vent.
噴火口 is the specific term for the opening through which a volcano erupts. It is formed transparently from 噴火 ("eruption") + 口 ("opening, mouth"), with the on'yomi reading こう in this compound.
Forms
- 噴火 ("eruption") + 口 ("opening") → 噴火口
Common collocations
- 噴火口から噴出する: to be ejected from the crater
- 噴火口を覗き込む: to peer into the crater
- 活動中の噴火口: an active crater
- 新しい噴火口が開く: for a new vent to open
- 噴火口付近: the vicinity of the crater
Similar words
- 火口: crater (the broader depression at a volcano's summit; can also include extinct or dormant craters)
- 噴火: eruption (the event itself)
- 火山: volcano (the mountain as a whole)
- カルデラ: caldera (a much larger collapse-formed depression)
- 溶岩: lava
- 火砕流: pyroclastic flow
Usage
- 噴火口 emphasizes the active vent that ejects material; in news reports about ongoing volcanic activity, this is the term most often used.
- 火口 is more general and can refer to any volcanic crater regardless of activity. In casual speech, 火口 alone is often sufficient.
- The same kanji compound 噴火 also appears in 大噴火 ("major eruption") and 噴火警報 ("eruption warning").