Surtsey is a small, uninhabited volcanic island off the southern coast of Iceland; coordinates 63°18' N, 20°36' W. Its surface area is approximately 1.4km² (0.6 mi²) and its maximum elevation is 169m. Both values are likely to fall as the island is eroded by the North Atlantic. Its name is taken from Surtur, a Norse fire deity.

What makes this tiny piece of land so remarkable is the way and time in which it was created. Iceland is one of the most active volcanic "hot spots" on the planet. Virtually its entire landmass is of volcanic origin and there is still a large number of active volcanoes. Surtsey was created by what is now termed a Surtseyan eruption--the eruption of an underwater volcano in relatively shallow waters with characteristics that, in this case, led to the formation of an island.

The Surtsey eruption is noteworthy because it happened in historic times and in an accessible location. The waters around Iceland are never quiet, as is natural for a nation which largely depends on the sea for its livelihood. Around 06:30 on the morning of 1963-11-14 a group of fishermen working about 10 n.m. south-west of the island of Heimaey noticed the beginnings of an underwater eruption, the depth of which was at only 130m. The column of ash spewing from the sea rose as high as 10km into the atmosphere and, on a clear day, could be seen as far away as Reykjavik.

The formation of Surtsey added another link to the Vestmannaeyjar chain of islands which are part of the Mid-Atlantic Ridge (the same volcanic region would produce the eruption on Heimaey in 1973). The undersea volcano had already been around a fair bit longer and the above sea level eruptions were preceded by several undersea ones accompanied by a rise on 7-9°C in the surface temperature of the ocean around it. The time elapsed between detection of the first associated seismic activity and the surface eruption was about six months.

Over the next four years and until the last eruption on 1967-06-04, the island of Surtsey grew to a bit over its current height and altogether about 3km². The fact that a lava flow commenced as early as 1964-04-04 and persisted until the end of the eruption allowed a cone to form that kept the ocean out of the crater and allowed ash and other less solid material to accumulate instead of being washed away immediately. Nonetheless a portion of Surtsey and all of the two islets that grew with it have eroded since, particularly the parts made of unconsolidated tephra.

The core of Surtsey was formed in conditions hot enough to allow much of the material to fuse into rock and thus resist erosion much better. It's reckoned that Surtsey is good for at least another hundred years and probably much longer. The fact that it stabilized into a pahoehoe flow that resulted in a volcanic shield rather than a mere agglomeration of loose pyroclastic material makes it much more durable than other islands which have formed and disappeared in historic times. Any lesser island would fall victim to the fierce marine conditions of that part of the world much sooner. Its main geographic features are the twin craters and a tongue of land jutting out to the north.

Surtsey provided science with a playground that wound make even the most stone-faced botanist and biologist jump with glee. It was created as virgin black rock miles from land and gave scientists an unequalled opportunity to study not only the geological aspects of its creation but also how plant and animal life would colonize it in the years that followed. It was declared an off-limits nature preserve by Iceland before the eruptions were over and remains a window into a natural process rarely, if ever, observed by man.

The first study subject, aside from subjects commonly examined in regard to developing volcanoes, was that of volcanic lightning over sea water since previous observations had always had more of a land element involved. Soon, howere, life became the focus of the studies. Even as early as 1965, while the island was still in the throes of its birth, the first plants and animals arrived. Initially there was only one fly, which fed on algae at the waterline, and a hardy arctic plant called the sea rocket, whose seeds can survive prolonged periods of floating on salt water. The first gulls made the parts farthest from the crater a rest stop as early as 1963-12-01, only a few weeks after the eruption when the first scientific expedition landed on the island.

In the 50-odd years since the eruption marine life has taken a liking to Surtsey, as it does to anything that's not made entirely of salt water. A dozen species of seabird can be found on the island. Plant life has also become quite diverse with thirty different established species, the seeds of some arriving by sea, others blown over from the mainland and some carried there by birds.

Surtsey is not open to visitors and a special permit is required for scientists to visit the island.

Factual sources:
NASA's Laboratory for Terrestrial Physics
University of Hawaii
Vefur.is
Vestmannaeyjar Museum
Dr. Colin Pounder, An Electromagnetic Miscellany
Last update: 2014-08-06

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