Volcanic gases are widely understood to be one of the more dangerous aspects of active volcanoes. Where they can certainly be hazardous to your health or even deadly, the volcanic gases also have a more positive side that never seems to get enough light. Hot springs pop up all around the world near active volcanoes, and gases emitted by volcanic vents provide useful scientific opportunities. Such opportunities should be taken, though cautiously, because these gases don’t have a bad reputation for no reason.
During our class boat tour to Nea Kameni we stopped by a warm spring to swim around and witness the effects of volcanic gases firsthand as well as the extreme presence of sulfur. Our reactions were very comical when we all jumped into the water and discovered what lukewarm, liquid, rotten eggs tasted like. I’ve always wondered what that would taste like. Why couldn’t it have tasted like liquid bacon instead? One could say we ‘sulfered’ in the name of science. Between the warm springs and the magma chamber lays a hydrothermal reservoir, or layer of groundwater. The hydrothermal reservoirs chemical composition comes from the magma chamber itself as it heats the reservoir to a boil. The water then boils its way up to the surface and creates warm springs like the one we swam in. In fact, while we were swimming we witnessed bubbles bubbling up from the sea floor. One gas in particular, H2S, is what creates the egg like smell and taste (other volcanoes emit large amounts of SO2 which will produce the same effect). The chemicals of that water can be studied to provide further insight of the magma chamber and how quickly the magma may be rising beneath the crust.
Another well-known aspect of the warm springs is the abundance of iron. The investigation by Puchelt et al (1973) shows that the warm reactive gases rising from the hydrothermal systems dissolve iron from the rocks through which they rise and deposit it on the sea floor (1). This is what gives the warm springs their classic reddish brown color. Floating in the water we found pieces of ‘algae like’ iron, some as large as my hand.
Warm springs are not the only way volcanic gasses are released, fumaroles are another significant method. Our class was lucky enough to get the chance to climb Nea Kameni and see the fumaroles first hand. I will never the moment when I saw the gasses leaking out of the rock as if the entire volcano we were standing on was one large witch’s cauldron. Once again sulfur was the dominant smell marking the presence of H2S. The sulfur crystals form a yellow crust on the rocks around the fumaroles making them easy to spot. The presence of this gas that is magmatic in origin is proof that magma still resided beneath Nea Kameni to this day.
In my opinion, volcanic gases have a bad reputation. Even though they are certainly hazardous to our respiratory systems and should not be taken lightly, we should study as much as we can. The more we know about these volcanic systems the better we can prepare for future dangers by analyzing the chemical composition and activity. Our class got to experience firsthand how these gases affect the land through both the warm springs and the fumaroles. Although the smell and taste was exceedingly…memorable, it was an enjoyable experience both recreationally and scientifically.
Friedrich W.L., 2009, Santorini: Volcano, Natural History, & Mythology, Denmark: Aarhus University Press, 312 P.