Risk is a term that is often misunderstood and confused with "hazard". A hazard is a potentially dangerous event, such as a lava flow, a falling volcanic bomb or a pyroclastic flow.
The risk is the likelyhood of a person or a property to be injured/killed/damaged etc. by a hazard. So, volcanic risk clearly depends on:
1) the timescale in question (e.g. the duration of the visit of a crater)
2) the location of the person/property
3) the current state of the volcano
The quantitative value of the volcanic risk is roughly a product of the time spent in a given area and the combined likelyhood of hazards during that time in that particular area, and is reduced by possible factors such as degree of experience, preparedness, and availability of suitable protection or escape possibilities.
It is therefore clear that the volcanic risk in each case can only be estimated. In particular, factor 3), the current state of a volcano, is extremely variable with time.
Risk zones: because of the variability of volcanic risk, it has no meaning to define fixed risk zones around volcanoes (e.g. "from 300 to 1000m from the crater") unless one relates such risk zones to a particular period in time where the bahaviour of the volcano is assumed constant. A qualitative description of different risk zones can be found here.
The content above reflects our personal opinion on this subject only. We cannot assume any responsability about the your decisions and actions if they are based in any way on the contents of these pages. In particular, we strongly recommend never to enter any of the high and extreme risk zones.
Many people associate "volcanoes" with "danger". Yes, volcanoes CAN be dangerous, but it has little meaning to say that volcanoes are dangerous, equivalent to saying, for instance, "cars are dangerous".
It should be seen in a more detailed context. The actual dangers involved when visiting a volcano depend on many factors, the most important of which are:
1) the present or expected or probable activity of the volcano at the time of your visit,
2) your location (mainly the distance to that activity) and the time spent there,
3) your preparedness to react in a proper way to potential hazards.
Factor 1) varies a lot from volcano to volcano and with time, factor 2) depends largely on your personal decision when visiting a volcano, and factor 3) varies from person to person.
In order to minimize the volcanic risks involved in visiting active volcanoes, you should be able to evaluate these factors. If in doubt, you should seek the advise of local experts and travel with a knowledgeable and responsible guide.
