Decade Volcanoes
The Decade Volcanoes are 16 volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to populated areas. The Decade Volcanoes project encourages studies and public-awareness activities at these volcanoes, with the aim of achieving a better understanding of the volcanoes and the dangers they present, and thus being able to reduce the severity of natural disasters. The project was initiated as part of the United Nations-sponsored International Decade for Natural Disaster Reduction.
The criteria for being designated a Decade Volcano include the following:
- Representative of more than one volcanic hazard: people living near the Decade Volcanoes may experience tephra fall, pyroclastic flows, silicic lava flows, lahars, volcanic edifice instability and lava dome collapse;
- Geological activity: all Decade Volcanoes have been active in recent history and are very likely or certain to erupt again in future;
- Located in a populated area: eruptions at any of the Decade Volcanoes may threaten tens or hundreds of thousands of people, and therefore mitigating eruptions hazards at these volcanoes is crucial;
- Politically and physically accessible for study;
- Local support for the work.
Aims of the Decade Volcano program
The general approach of Decade Volcano projects has been to convene a planning workshop, identify the major strengths and weaknesses of risk mitigation at each volcano, and to plan how to address the weaknesses identified. One of the difficulties faced in mitigating hazards at volcanoes is ensuring that geoscientists and those who will enact the mitigation measures communicate adequately with each other, and the Decade Volcano program has attempted to ensure this by making sure both groups are well represented at Decade Volcano workshops.
Funding
Hopes that United Nations funding might be available for Decade Volcano projects did not come to fruition, and funding was sought instead from a variety of sources. For example, Mexican scientific and civil defence bodies funded work at Colima, principally for Mexican scientists but also for a few foreign colleagues; major bilateral French-Indonesian and German-Indonesian programmes were initiated at Merapi; and the European Union has provided funding for many of the studies carried out at European volcanoes.
One particular activity that has not been funded -- because it typically is not allowable under most national or bilateral funding -- is the exchange of scientists and civil defense leaders between the various Decade Volcano projects of developing countries, e.g., between the Philippines and Indonesia, or between Mexico, Guatemala, and Colombia, or across the Pacific and Atlantic. Often, scientists and civil defense leaders from developing countries can relate better to each other's experiences than they can to the experience of counterparts from industrialized countries. Also, civil defence leaders who have experienced volcanic crises are far more credible witnesses, in the eyes of local civil defence leaders, than either local or visiting scientists might be.
Achievements
Since it was initiated, the Decade Volcano programme has acheived a number of successes in predicting volcanic events and mitigating disasters. One of the most notable was the successful diversion of a lava flow at Mount Etna in 1992. The flow was threatening the town of Zafferana, and had overwhelmed several barriers placed perpendicular to its flow down a valley. Scientists and civil defence leaders decided to try and dam the flow higher up, and did so by dropping large concrete blocks into a skylight in a lava tube which was feeding the flow. The flow subsequently stopped short of Zafferana.
The programme has significantly increased what is known about the Decade Volcanoes, some of which were very poorly studied before being designated. The eruptive history of Galeras volcano in now much better established than previously, and at Taal Volcano the importance of water in driving its explosive eruptions has come to light.
Measures which have been taken to mitigate disasters which might be caused by future eruptions include a new law in the vicinity of Mount Rainier, requiring assessment of geological hazards before any new developments; limitations on high density housing developments in the Taal Caldera; and the development of an evacuation plan for parts of Naples which might be affected in the event of an eruption at Vesuvius.
Problems
Although studies at many volcanoes have led to a clear reduction in the risk faced by nearby settlements, eruptions at some of the Decade Volcanoes have demonstrated the difficulties faced by the programme. Eruptions at Mount Unzen which began shortly before it was designated a Decade Volcano were heavily monitored, but despite this, a large pyroclastic flow killed 43 people including three volcanologists.
Later, a Decade Volcano conference in the city of Pasto, Colombia in 1993 ended in disaster when several of the scientists present mounted an impromptu expedition to the crater of Galeras; an eruption occurred unexpectedly while they were at the summit, and resulted in the deaths of six scientists and three tourists.
More general problems faced by the programme have included civil unrest in the vicinity of several volcanoes, such as Santamaria and Nyiragongo; scarce resources leading to studies programmes competing for funding; and ensuring that false alarms are minimised so that evacuation orders are always taken seriously.
The 16 current Decade Volcanoes are:
- Avachinsky-Koryaksky, Kamchatka Peninsula, Russia
- Colima, Mexico
- Mount Etna, Italy
- Galeras, Colombia
- Mauna Loa, Hawaii, USA
- Merapi, Indonesia
- Nyiragongo, Democratic Republic of the Congo
- Mount Rainier, Washington, USA
- Sakurajima, Japan
- Santamaria/Santiaguito, Guatemala
- Santorini, Greece
- Taal Volcano, Philippines
- Teide, Canary Islands, Spain
- Ulawun, Papua New Guinea
- Mount Unzen, Japan
- Vesuvius, Italy