BY PROFESSOR FIONA TWEEDA dramatic display of photographs depicting the Icelandic landscape and its physical processes, captured by our own Professor of Physical Geography and specialist in glacial geomorphology and natural hazards.

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Iceland is an extraordinary country. For eleven centuries, Icelanders have lived with a range of persistent natural processes; earthquakes, volcanic eruptions, glacier floods, debris flows, glacier fluctuations, avalanches and storms have shaped the country and affected the lives and livelihoods of those within it. Volcanoes, geysers, ice caps, valley glaciers, waterfalls, canyons and mountains characterise the landscape, attracting tourists and scientific attention.

Iceland’s spectacular and scenic nature bears witness to the strong influence of its geology and the environmental conditions to which the island has been exposed.

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Iceland is one of the most active volcanic environments in the world. There are forces that help to power Iceland’s volcanic and geothermal activity, in addition to the rifting and spreading of the Mid-Atlantic Ridge.

A ‘hot spot’ exists beneath Iceland, similar to those fuelling volcanic activity in Hawaii and Yellowstone National Park.

The combination of the hot spot overlying a powerful mantle plume on the divergent plate boundary has pro-duced this volcanically dynamic island in the Mid-Atlantic.

Lava fragments litter the Icelandic landscape in a myriad of colours, from grey and brown to iridescent blues and greens, oranges and reds.

Magma contains approximately 9% water, which fre-quently emerges at the ground surface as steam, in spouting geysers or in bubbling volcanic mud pools. Icelanders have harnessed geothermal energy to heat homes and businesses and geothermal power plants are a common sight amidst the lava fields.

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Iceland has hundreds of volcanic outlets contained within 30 main volcanic systems. Volcanic activity in Iceland produced approximately one third of the global lava output during the last millennium and it is estimated that there have been over 250 eruptions in the last 1,100 years. The 2010 eruption of Eyjafjallajökull and the Grímsvötn eruption of 2011 raised the profile of Icelandic volcanoes and emphasised the trans-boundary nature of some of their impacts. Heavy ash fall in the area surrounding Eyjafjallajökull caused problems for agriculture, travel and livestock farming. A very fine-grained ash was generated, which when combined with a stable high pressure system over Europe and north-westerly winds from Iceland, resulted in the ash plume drifting southwards from Iceland. This caused the largest closure of European airspace since World War II with disruption to travel and the supply of goods. This image captures the explosive activity of Eyjafjallajökull during Spring 2010.

As global temperatures rise, glaciers are retreating into deeply eroded basins, which they carved out during their advances down-valley.

Lakes form in these basins and calving icebergs drift in the meltwater - on a sunny day, a scenic delight, but a testimony to the power of ice in the landscape whatever the weather.

Iceland provides a fascinating setting in which to examine volcanoes interacting with ice.

Rapid cooling of erupting magma causes it to become fragmented into tephra on contact with ice and water, generating hydromagmatic or phreatic activity and large quantities of ash, which can be lofted and deposited. Eyjafjallajökull eruption 2010 (Matthew Roberts)

The juxtaposition of ice and volcanic activity has also produced some of the largest glacier outburst floods or ‘jökulhlaups’ in historical times, the floodwaters creating huge outwash plains and deep canyons.

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For the last 20 years, I have been working on glacier outburst floods, or ‘jökulhlaups’, in collaboration with UK and overseas researchers.

This work has been funded by Earthwatch International and the Natural Environmental Research Council (NERC) and has necessitated extensive field work in Iceland. Research has involved mapping and measuring flood channels, characterising impacts on the glacier and surrounding area, the examination of sedimentary deposits and landforms, monitoring glaciers, lakes, and rivers, and recording changes in levels of activity and the evolution of particular sites. Earthwatch expeditions entailed working with volunteers who helped us to collect field data. These expeditions involved educational objectives such as co-learning, cultural enrichment, knowledge exchange and widening participation in science.

We have made significant advances in understanding the characteristics of glacier outburst floods and the complexities inherent in modelling such events. Our research has helped to develop knowledge of flood impacts, enabling us to advise civil defence and engineering authorities and influence land-use planning, prediction and management policies.

What might the future hold? Research work suggests that the eruptions of the last fifteen years or so could mark the start of a more active volcanic phase, during which the intensity of eruptions will increase as well as their frequency.

Recent events have taught us that explosive eruptions in Iceland, coupled with appropriate meteorological conditions, could cause further disruption to air transport in Europe and in the mid-Atlantic. By understanding processes and impacts, we are better equipped to predict and prepare.

PROFESSOR FIONA TWEED

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Credit: Jean Qinqwen loo

Credit: Alan Lindsell

Contact:Professor Fiona TweedGeography, School of SciencesFaculty of Computing, Eng and SciencesE-mail f.s.tweed@staffs.ac.uk