Volcanoes, fumaroles and gases
An independent practical guide to Volcanoes, fumaroles and gases: context, access, seasonal conditions, safety and the primary sources to check before travel.
Volcanoes, fumaroles and gases. The information below combines stable island facts with practical decisions for travel, fieldwork and everyday use.
- Emergency number
- 112
- Main hazards
- bears, sea, fog and geothermal ground
- Signal
- not guaranteed outside settlements
- Core rule
- an early turn-back is better than a late rescue
| Question | Practical answer |
|---|---|
| Bear | do not run; leave an exit |
| Sea | account for tide |
| Earthquake | move uphill |
| Steam | stay on the boardwalk |
Immediate rule
Kunashir's volcanoes and fumarole fields are still active, releasing steam and gas continuously in some areas even with no eruption underway. Treat visible steam, a sulphur smell or bare, discoloured ground as signs of ongoing activity, not just scenery.
Stay on marked paths and viewing points near any crater, fumarole or vent, and never approach closer than official markers or a ranger allows, regardless of how calm the area looks.
If you notice a sudden increase in gas smell, rumbling, or ash in the air, leave the area immediately by the way you came rather than trying to continue past it.
How the hazard develops
Fumarole and gas activity can shift over weeks or seasons as underground channels change, so an area that was harmless on a previous visit is not guaranteed to still be safe.
Volcanic gases such as sulphur dioxide and hydrogen sulphide can pool in hollows, craters or still pockets near a vent, reaching dangerous concentrations with little warning change in smell.
A visible ash plume, a new or unusually strong smell of sulphur, or ground that suddenly feels warm underfoot are all reasons to leave the area and report what you saw to rangers.
Prevention
Check current advisories for the specific volcano or fumarole field before visiting — access to some areas can be restricted or closed if monitored activity changes.
Turning back is a normal route outcome. Falling visibility, rising water, fresh bear signs or lost time require action before the situation becomes an emergency.
Wear sturdy, closed footwear rather than sandals on volcanic terrain. Loose ash, scoria and mineral crust are sharp and can conceal unstable or hot ground beneath a normal-looking surface.
Action in the field
If you develop a headache, dizziness or breathing difficulty near a fumarole or vent, move away from the area immediately and get to fresh air upwind of the source.
Wind direction can change quickly on this terrain, so if a gas plume shifts toward you, don't wait it out. Move crosswind or back the way you came rather than trying to walk through it.
Do not leave the boardwalk around steam, thin crust or hot water.
When to turn back
Turn back if a marked boardwalk or path is damaged, if steam or gas is noticeably heavier than usual, or if rangers or signage indicate the area is temporarily closed.
If you smell gas strongly enough to notice it before you can see its source, that is already reason enough to change direction rather than continue toward the smell to investigate.
Children and anyone with respiratory conditions are more vulnerable to volcanic gas exposure, so consider giving fumarole fields extra distance or skipping them entirely if in doubt.
Safety checklist
Check current access rules and advisories for the specific site, stick to marked paths, and never approach a crater, fumarole or vent beyond the official boundary.
Watch steam, sulphur smell, ground temperature and wind direction together — any one of them changing is a prompt to reassess, not just proceed carefully.
Keep the essentials in mind: stay on the path, respect closures, watch the wind, and treat any strong gas smell as your cue to leave, not to look closer.
- Never approach or run from a bear; calmly increase distance.
- After strong coastal shaking, move promptly to higher ground.
- Check the tide before entering shoreline sections with no escape.
- Do not leave the boardwalk around steam, thin crust or hot water.
Frequently asked questions
Can this information be used for planning?
Yes — this background on volcanoes, fumaroles and gases stays fairly stable and can anchor your planning, but transport, prices, permits, forecasts and approach conditions should still be confirmed through the linked sources before departure.
Is a local guide necessary?
Local guidance is especially valuable on remote, protected and coastal routes where signal is weak, tides matter or trail conditions change quickly.
What most often disrupts a plan?
Fog, strong wind, swell, rain and transport delay. Time margin is therefore more important than completing every planned stop.
What if sources conflict?
Follow the current instruction from the responsible authority, carrier, ranger or emergency service. The emergency number is 112.