In June and August 2017, we will be embarking on a voyage to Iceland, Faroes & Shetlands – an exploration of the beautiful landscape of Iceland, the gushing geysers, rumbling volcanoes and creeping glaciers. Guest lecturer Professor Brian Williams, Emeritus Professor of Geology at the University of Aberdeen will be accompanying the Iceland cruise in August 2017, he tells us the importance of Iceland for geologists.
Iceland, the land of “Fire, Ice and Water”, is best known for it’s dramatic and frequent volcanic activity as it sits astride the Mid – Atlantic Ridge, a fundamental feature of our planet. Iceland is situated at the junction of two gigantic tectonic plates (the N. American and Eurasian) as they slowly move apart at c. 2 cm/year. New ocean crust is being created in Iceland and has been doing so for eons of geological time. Thus, Iceland is of great importance to geologists as it provides a natural laboratory for the understanding of Earth processes.
The stunning rift – Thingvellir – of Iceland, where the Vikings had their parliamentary meetings, is where the two tectonic plates are visibly tearing apart in a riot of volcanism, producing kms of black, basaltic lava. Associated geothermal activity, e.g. at Akureyri and Geysir, generates spectacular hot lagoons and eruptive water spouts (Strokkur), and is the essential energy resource for the Icelandic population. The rifting plates have also produced river diversion and dramatic waterfalls at Gullfoss.
The Icelandic volcanism is essentially “effusive”, in that fluid, black basaltic lava wells up through fissures/rifts from an underlying magma source and spreads over the surface. Other volcanoes are “eruptive” with large volumes of lava and ash, and occur at over 10 discrete locations throughout Iceland. These can occur on the land surface (Hekla) or from the sea bed (Heimaey Island with eruptions of Eldfell 1973 & Surtsey 1963). Where the eruptive volcanoes are sub-glacial, dramatic explosions with vast ash clouds are generated. The best known, and most recent – in 2010, is Eyjafjallajokull ; also known as the “billion dollar volcano” due to the costs incurred in grounding most of W. European airlines because of the ash plumes!
Ice has also played a pivotal role in shaping the landscape of Iceland. From large glaciers carving out gigantic fjords (Westfjord area with Isafjordur and Husavik in N. Iceland) to major Ice Caps (Langjokull and Vatnajokkull – the largest ice cap in W. Europe!). These Ice Caps have marginal glaciers producing lagoons filled pale blue Ice Bergs (Jokulsarlon). Recession of the ice, assisted by sub-glacial volcanic activity, can generate huge, sudden flash floods called “jokulhlaups” which can sweep away roads and bridges (Skaftafell in 1996) and produce vast sandur plains of river-deposited black sand. This is truly Earth surface processes in action!!
Some 690 km SE of Iceland lie the Faroe Islands; these are situated on the Eurasian plate and are composed solely of black lava produced by volcanic activity some 56 million years ago – the hot spot that produced the Faroes now lies below Iceland ! These flat-topped Islands are a surface expression of a huge basalt plateau, stretching to Rockall, the thickness of which exceeds 5 km and below which there is an on-going search for oil and gas.
The Shetland Islands are part of the geographic divide that separates the N. Atlantic Ocean from the North Sea. The Islands are 280 km south of the Faroes but have a different foundation and therefore landscape pattern to both Iceland and the Faroes. Shetland scenery has flat to rolling hills with a dramatic and varied coastline due to its complex geology. The Island complex is the third largest in Scotland and has a stunning archaeological heritage with over 5000 sites dating back to the Mesolithic, some 4300 BC.
Discover the dramtic scenery on our Iceland, Faroes and Shetlands deaparting in 29th June 2017 and 8th August 2017.