The surveillance programme is designed to identify the early onset of a volcano crisis, but not necessarily to provide real-time information, say, to visitors on the island. More than 10,000 people visit White Island every year. The number of tourists has grown steadily over the past 10 years. A number of launch operators, mostly based in Whakatane, run charter trips to the island. Volcanic hazards at White Island Volcanic hazards in and around the main crater vary considerably with the level of activity.
Hazards exist even during quiet periods.
As well as the risk of isolated eruptions during quiet periods, there is also the small possibility of a crater wall collapse. A collapse and resultant avalanche could be triggered by a shallow earthquake or through increased instability after heavy rain. Given the history of the last 25 years at the island, the most likely hazard-producing event is the resumption of enhanced activity. Hazards during enhanced activity include ashfall, steam eruptions and occasional explosions throwing ballistic blocks as far as the sea. Explosive eruptions pose a risk to visitors on the island, boats anchored in the bays, and to aircraft passing close to the island.