Virtual Volcano Vacation #60 WINNER! – Nisyros

nisyros island

Island of Nisyros – Original image found at

This week I really thought I was giving you all the slip by choosing a volcano that is a bit off the trodden path. Little did I know just how many paths Jesper has investigated, because he found me before I could even send my 2nd postcard clue. Note to self: — Hiding from Jesper in a volcano in the Mediterranean is like hiding from my dog inside the dog-biscuit box. I have indeed been in the Greek Isles serenading Nisyros with my pastiche of a classic cowboy song.

Nisyros is actually a volcanic island in the Aegean Sea. It is part of the Aegean (or Hellenic) Arc, which results from the northward movement and subduction of the African Plate beneath the southwestward-moving Aegean Plate.

nisyros hellenic arc

The Aegean/Hellenic Arc – By Mikenorton – Own work, CC BY-SA 3.0, – Original image found at Wikimedia

The whole circular island of Nisyros is around 8 km wide, and its centrepiece is a 3 km wide caldera. Within the caldera there are numerous active fumaroles and some historically-active craters. The western and northwestern parts of the caldera are filled by five large lava domes. A sixth dome lies outside the caldera rim on the southwest of the island. Volcanism also manifests itself in various locations along the coast as hot springs.

nisyros caldera 2

Stephanos crater within Nisyros volcano – Original image found at

Nisyros’ historical eruptions have been phreatic and usually VEI 2. The most recent occurred in 1888, an explosive event involving steam and mud. Since then, the volcano has confined its activities to fumarolic sputtering, but one might say it is “up to something” of late.

The magma chamber below Nisyros is thought to be 3-4 km deep, but is rising.  Also during 1995-98 there was a huge increase in seismic activity in and around Nisyros as well as 14 cm of ground uplift detected on the island. Then, in 2001 a ground fracture, the result of stress-release, opened up in the Lakki Plain in the east part of the caldera. In 2003 the caldera was declared off-limits due to an increase in hydrothermal temperatures from 210 C to 315 C. The volcano is now closely monitored by the EU-sponsored Geowarn project.

nisyros lakki fracture

The 600 m long rupture formed in the Lakki Plain in 2001 and 2002 superimposed on an IKONOS- 2 ortho-image – Caption and image originally found at

According to Greek mythology, the island of Nisyros was formed during the Gigantomachy, the war between the Giants and the Olympians. Legend says that when the giant Polybotes was being chased by Poseidon, the sea-god pulled off a piece of the island Kos to the north and threw it on top of the giant, crushing him. That piece of Kos became Nisyros.

nisyros polybotes poseidon

By English: Painter of the Paris Gigantomachy (eponymous vase), circle of the Brygos Painter – User:Bibi Saint-Pol, own work, 2007-05-25, Public Domain, – Original image found at Wikimedia

Thank you, Jesper, for finding me so soon even though you are not fond of farty fumaroles. Check back here this coming Monday evening for a new adventure at a new volcano.


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