Buried beneath meters of thick solidified volcanic material, is an ancient city named Akrotiri. Hidden for approximately 3600 years, the ruins of an ancient Minoan civilization were found on the southern region of Thera, Santorini’s largest island. Excavation began in 1967 by a professor named Spyridon Marinatos who believed that the eruption of the volcanic complex that makes up Santorini, was the reason behind the fall of Minoan civilization.
The architecture composed of stone and wood was no match for one of the most destructive volcanoes of all time, so how is it that this fragile settlement stands preserved and mostly in tact? What prevented this antique establishment from being incinerated by the wake of powerful pyroclastic flows and the bombardment of massive volcanic boulders?
There were four main eruptive phases (and one precursor phase) of the cataclysmic Minoan eruption. (For more information on these phases read Carly Sefano’s blog: A Geologic Lesson For the Little Ones) It is the first of these phases that modern archeologists, like Professor Marinatos are indebted to because it acts as a window into an extinct culture.
In the first phase, the volcano began to “clear its throat”, emitting carbon dioxide and mass amounts of ash into the atmosphere. Akrotiri was cloaked in darkness as volcanic material intruded the space between the surface of the Earth and the Sun. Magma upwelled from deep within earth’s surface and traveled through the volcano’s conduit. Small amounts of magma broke through the surface of the vent to become lava and were ejected into the air by the force of highly pressured gas and intense heat. Rapidly cooling in the air, the lava solidified into gaseous, vesicular pieces of glass-rich pumice.
A compilation of pumice and ash fell from the sky in a manner comparable to a snow fall. Giant volcanic flakes enveloped the environment, filling every crevice they could find. When snow falls, it sticks together creating an arctic mold of whatever it covers; pumice behaves the same way. It is a light rock full of holes that enables it to cool quickly, preventing it from incinerating anything it lands on.
These processes encompass the first phase of the Minoan eruption. The pumice promptly accumulated (up to seven meters in some areas) and concealed the city of Akrotiri. Every inch of the development was covered, just as the Minoans left it before they fled the ultra-plinian eruption. The pumice solidified creating molds of everything it came into contact with. Rooms, doorways, staircases, tools, and sculptures are preserved.
The volcano that is associated with the decline of an entire civilization, is the same volcano that conserved the methods by which they lived. There are many present day volcanoes that can have the same magnitude eruption as the Minoan, which begs the question: will our civilization one day be buried and frozen in time like Akrotiri?
(1) Friedrich, W.L., 2009, Santorini: Volcano, Natural History and Mythology, Denmark: Aaruh University Press,
(2) Druitt, T.H. 2014, New insights into the initiation and venting of the Bronze-Age eruption of Santorini (Greece), from component analysis. Bull Volcanology, 76:794