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Super-Eruptions Pose Global Threat "5-10 Times More Likely Than Asteroid Impact"

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The occurrence of a super-eruption would have severe environmental effects and might threaten global civilisation. This is the assessment of a Geological Society of London working group [Notes 1,2] composed of senior Earth Scientists. The effects of a super-eruption would be comparable to those predicted for the impact of a 1km-diameter asteroid with the Earth. In fact, super-eruptions are 5-10 times more likely to occur than such an impact. The assessment of the working party has been presented to the UK Government’s Natural Hazard Working Group [Note 3].

Many very large volcanoes on the Earth are capable of colossal eruptions with global consequences. Such eruptions are quite frequent on a “geological” timescale, although not one has occurred on Earth in the short time that an interdependent human civilisation has existed. However, our present civilisation depends on global trade and food production, air travel and space-borne communications, all of which could be at considerable risk if a super-eruption occurred.

There may be several super-eruptions large enough to cause a global disaster every 100,000 years. This means super-eruptions are a significant global humanitarian hazard. They occur more frequently than impacts of asteroids and comets of comparable damage potential.

Prof. Steve Sparks FRS (University of Bristol), co-lead author, said: “Several of the largest volcanic eruptions of the last few hundred years, such as Tambora (1815), Krakatoa (1883) and Pinatubo (1991) have caused major climatic anomalies in the two to three years after the eruption by creating a cloud of sulphuric acid droplets in the upper atmosphere. These droplets reflect and absorb sunlight, and absorb heat from the Earth - warming the upper atmosphere and cooling the lower atmosphere. The global climate system is disturbed, resulting in pronounced, anomalous warming and cooling of different parts of the Earth at different times.

Prof. Stephen Self (Open University) said: “Super-eruptions are up to hundreds of times larger than these, and their global effects are likely to be much more severe. An area the size of North America can be devastated, and pronounced deterioration of global climate would be expected for a few years following the eruption. They could result in the devastation of world agriculture, severe disruption of food supplies, and mass starvation. These effects could be sufficiently severe to threaten the fabric of civilisation.”

The report concludes: “Problems such as global warming, impacts by asteroids and comets, rapid use of natural resources and nuclear waste disposal require world leaders and governments to address issues with very long-term consequences for the global community. Sooner or later a super-eruption will happen on Earth and this issue also demands serious attention. While it may in future be possible to deflect asteroids or somehow avoid their impact, even science fiction cannot produce a credible mechanism for averting a super-eruption. The point is worth repeating. No strategies can be envisaged for reducing the power of major volcanic eruptions.”

The Working Group has recommended:

• Investment in research to improve our understanding of regional and global impacts of major volcanic eruptions.
• Research to determine more accurately the composition and amounts of volcanic gases and dust released in super-eruptions – these are the major factors governing widespread environmental effects.
• An expanded programme to produce a comprehensive inventory of large magnitude explosive eruptions in recent geological times, such as the initiative started under the auspices of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) [http://www-volcano.geog.cam.ac.uk/database/ on www.iavcei.org]
• Initiatives to improve public understanding of the nature of volcanic hazards with regional and global effects.
• Establishment of a multidisciplinary Task Force to consider the environmental, economic, social, and political consequences of large magnitude volcanic eruptions. As in the case of impacts by asteroids and comets, these proposed activities will be best developed by collaboration within an international context.

Notes:

1. Sparks, R S J & Self, S et al., 2005: Super-eruptions: global effects and future threats: Report of a Geological Society of London Working Group. Other authors include: Dr David Pyle (Cambridge University) Dr Clive Oppenheimer (Cambridge University) Dr Hazel Rymer (Open University) and Dr John Grattan (University of Wales, Aberystwyth) Published at: www.geolsoc.org.uk/supereruptions

2. The Geological Society of London is a learned and professional body, of some 9000 Earth scientists with a remit to investigate, interpret, discuss, inform and advise on the nature and processes of the Earth, their practical importance to humanity, and, in the interests of the public, to promote professional excellence. The Society offers advice to Parliament and Government, at individual and corporate levels. Registered Charity No. 210161.

3. The Natural Hazard Working Group (NHWG) has been established under the auspices of Sir David King, the Government’s Chief Scientific Adviser, as an ad hoc advisory group to advise the Prime Minister on the mechanisms that could and should be established for the detection and early warning of physical natural hazards. This group has been established as part of the Government’s Response to the Asian Tsunami disaster. http://www.ost.gov.uk/policy/bodies/nhwg/

Ted Nield | Quelle: alphagalileo
Weitere Informationen: www.geolsoc.org.uk/template.cfm?name=Super1

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