Volcanoes, their eruption and risk management

Volcanoes are the most dramatic of geological processes that show that we live on a dynamic planet. Volcanism has characterised the Earth since its formation and ultimately has contributed to formation of the Earth’s crust, the oceans and the atmosphere. Life on Earth depends on the recycling of materials between the Earth’s interior and surface environments and may have been provided environments where the ingredients of life could develop. Volcanoes show that the interior of the Earth is very hot and temperatures exceeding 1000oC are typically found at depths of only 100 kilometres in most places. Although the Earth’s interior is mostly solid the rocks are very close to melting so volcanoes can form easily in different tectonic situations. Most volcanoes are formed at plate boundaries where tectonic plates are formed or collide with one another. But can also form by upwelling of very hot rocks in the Earth’s interior below the tectonic plates. Volcanoes refresh the Earth’s surface and often form landscapes of great beauty and attractive places to live. However, volcanic eruptions can also cause great destruction and loss of life. The largest volcanic eruptions even affect global climate, so that, for example, the 1815 eruption of the Tambora volcano in Indonesia caused summer frosts and snow in the northern hemisphere, resulting in inflated food prices and hardship. When volcanoes erupt scientists need to monitor the activity, make forecasts and assess the risks to nearby populations in order to protect life and livelihoods. I will discuss some examples of volcano risk management during volcanic emergencies, including the eruption of the Soufrière Hills Volcano from 1995 to 2010 on the island of Montserrat in the Eastern Caribbean. I will also discuss the largest volcanic eruptions on Earth and their potential for planet-wide impacts.