There really is no place like this in the world. A place where the water shines a deep, mesmerizing blue to the point where you get lost in the oscillation of the waves. A place where buildings as white as snow, with roof tops a glimmering light blue fill the eye as far as it can see. Where the sheer cliffs that change color what looks like every few feet stretching down to the beginnings of the sea. This is not just a place of beauty, but a place of destruction. A place where without warning, an unworldly power can be unleashed from the depths. The violent history is that of one’s nightmares. This is not a place of fiction, this is Santorini.
The island of Nea Kameni, that rests in the center of Santorini, is the next place of extreme hazard for the volcanic area. Nea Kameni is a volcanic dome that has formed over many years from the build up of lava flows. Given that the dome lies a few kilometers above the magma chamber, the island is subject to fumaroles and hot springs. This creates a large tourist attraction which helps drive the economy here on Santorini. Everyday, large amounts of people from around the world take tours of Nea Kameni. This is what makes Nea Kameni so dangerous in that even in times of major volcanic activity the island continued to have excited, unsuspecting tourists that were standing on a ticking time bomb.
Beginning in January of 2011, Nea Kameni started to become more and more active. It began with an increase in seismic activity. This means that the number of earthquakes that occurred daily was on the rise. Sometimes, the number of earthquakes even reached up to 50 times a day with the highest magnitude being 3.5.
When taking a look at a map that shows the depths of the earthquake focuses, the largest concentration is between 2 to 5 km. This is troubling because the magma chamber that is under Nea Kameni is about 3.3 km to 6.3 km. What this map is telling us is that the earthquakes are originating from the movement of magma in the magma chamber. The map can also tell us where the magma is moving to. For instance if the magma is moving upward toward the surface, danger could be right around the corner.
Earthquakes were not the only issue that occurred during this crisis period. The ocean water surrounding Nea Kameni began to heat up. The temperature increased about 4° C. That is about a 7° F increase in ocean water temperature. This could be caused by two things, an increase in gas released from the magma chamber or an increase in gas released from the hydrothermal reservoir just above the magma chamber.
The rise in sea temperature was accompanied with a large increase in fumaroles. Fumaroles are the gases that are released from Nea Kameni. The gases are magmatic in that they originated from the magma chamber. This known because the gases released on the surface matched the composition of the gases in the magma chamber. About 12 tons of fumaroles were released a day, and the that number jumped to 36 tons of fumaroles a day. The gases being released from this island increased by a factor of 3. The fumaroles were composed of CO2, carbon dioxide, which is found in abundance in the magma chamber. This is a cause for concern because an increase in gases like this means that magma is releasing more and more gases due to decompression.
The final problem that happened during this crisis period is ground inflation. Ground inflation is where the ground beneath Nea Kameni begins to inflate like a balloon. During the crisis period the caldera floor was inflating at a rate of 20 mm per year. This is caused by two things. The first case is the magma in the magma chamber is moving closer and closer to the surface which is pushing the overlying rocks upward. The other way this happens is the hydrothermal reservoir is inflating from gases being trapped in it. During hydrothermal inflation, the gases will eventually release which deflates the ground back to its original placement. The concerning thing about Nea Kameni is that the caldera floor only subsided slightly. This means that the inflation did have a magmatic factor to it.
Two types of danger were in place during this time of inflation. The first is that there is a magmatic event in which a sub-plinian eruption occurs. The second case, and the one that was more likely to occur, is a hydrovolcanic eruption. This happens when gases and water gets trapped under the overlying rocks. Once enough pressure is built up the gases and water creates an explosion. This same phenomenon occurred in Japan in September 2014. Mt. Ontake had a hydrovolcanic eruption that killed almost 50 hikers. The reason the hikers were not aware of the danger is that there is no warning. Hydrovolcanic eruptions can happen at any moment of any day. This is also what made Nea Kameni extremely hazardous.
Between January of 2011 and May of 2012, all of this activity was happening on Nea Kameni. The hazards and dangers, including the earthquakes, fumarole increase, and ground inflation, made being on and even near the island deadly. Even with this information known by the government, tours of the island did not stop or even slow. In fact, if the island was to shut down many businesses would more than likely close given that they depend on tourists to visit. Thankfully the volcano went quiet and has been ever since. It is hazards like this, the ones for the most part you can not even see, that make volcanos a deadly place.
(1) Papazachos CB, Panagiotopoulos D, Newman AV, Stiros S, Vougioukalakis G, Fytikas M, Laopoulos T, Albanakis K, Vamvakaris D, Karagianni E, Feng L, Psimoulis P, Moschas F (2012) Quantifying the current unrest of the Santorini volcano: evidence from a multi parametric dataset, involving seismological, geodetic, geochemical and other geophysical data. Geophys Res Abs, vol 14, EGU2012-14405, EGU General Assembly, 22-27 April 2012, Vienna, Austria.