In the late Bronze Age the Minoans did not have the technology to monitor the caldera but evidence shows they left before the Minoan eruption of 1613 BC. As a class we visited the ancient Minoan city Akrotiri which is sometimes called the Greek Pompeii. The city has been preserved by the ash fall from the Minoan eruption there is clear evidence the Minoans left before the eruption. I want to know what caused them to leave and did they know that a major eruption was going to occur? Today scientists can monitor the volcanic activity of Nea Kameni but they can’t predict when a volcano will erupt or know if they should call for an evacuation.
Along the southern part of the island including Akrotiri there is a warning layer of pumice and very fine ash called phase 0. This layer has been undisturbed throughout the island. There is no evidence of footprints or the layer being swept up which means the minoans left before the start of the eruption.
Also from what archaogists have excavated at Akrotiri they can conclude the Minoans left before the eruption. They found tables that appear to be stacked up on each other like when a restaurant closes. The Minoans probably boarded up their homes before they left. When we visited Akrotiri I got to see the ancient city and you could tell it was a ghost town. Most of the artifacts that were there were things too big to carry like pithos pots and furniture. There were also bed frames preserved by the eruption but the owners probably didn’t want to take big furniture back to Crete with them when it could be easily replaced there.
From what archaeologists know about the Minoans on Crete and all of the wealth they found there, they can assume the Santorini Minoans were as just as wealthy. A golden goat was found in one of the rooms and recently archaeologists found silk proving that the Santorini Minoans were wealthy and not outcasts. Not much other wealth has been found though. The evidence of silk means the Minoans had contact and trade with East Asia further proving they were a powerful, advanced society.
The Minoans probably took all their prized possessions and wealth with them back to Crete when they left just like I would do if I was leaving my home. When I first packed for college I had to decide which items to take with me and which to leave behind; I had to figure out what was important to me and what I didn’t mind leaving behind. The Minoans probably did the same thing but on a bigger scale because they were moving back to Crete and weren’t planning on coming back to Santorini for a while.
There was an eathquake (EQ) before the eruption which may have been the trigger for the Minoans leaving Santorini and going back to Crete. There are “clear indications of premonitory activity have been found in the excavations at Akrotiri: Broken steps, collapsed walls, houses reduced to ruins, and heaps of debris gathered by the inhabitants have been found beneath the earliest deposits of the Minoan Eruption” (2). If many homes faced serious constructional damages like the one in figure 4, the Minoans probably didn’t want to spend the time fixing them if they thought another EQ was going to happen. I would leave too if my house faced serious structural damage and I could rebuild on a different island.
Unfortunately time travel doesn’t exist, at least not yet, so there is no possible way to know for sure why and when the Minoans left Santorini but with modern monitoring systems and knowledge of volcanoes scientists can assume they left because of the warning signs the caldera exhibited.
Today the island of Santorini has many monitoring systems in place observing the volcanic activity of Nea Kameni. There are monitors for the gas emissions from the fumaroles, sea temperature, seismic activity, gps for inflation, thermal cameras, and tide gauges. These monitoring systems help scientists learn more about the volcano and can be constantly aware of the activity, something the Minoans could not do.
There are active fumaroles present on Nea Kameni. Fumaroles are openings around volcanoes that emit gasses. In Santorini these fumaroles emit sulfur dioxide and other gases. There’s a fumarole in the Georgios crater at the top of Nea Kameni emitting “hot steam and yellow and white sublimates” (1) showing that magma still resides in the magma chamber. There’s also a fumarole in the form of a hot spring (figure 5) in between Nea and Palea Kameni. It’s marked by the iron oxides which are a red-brown color. We got to swim in the hot springs on boat day and you could smell the sulfur. There was a potent egg smell that got stronger the further we swam. By monitoring these fumaroles and the gas emissions scientists can keep an eye out for any drastic changes that may occur.
Tide gauges and monitors observing the sea temperature and level are helpful for scientists because they can see if there are any changes in the hydrothermal activity. This goes along with monitoring the fumaroles because there is a hydrothermal reservoir above the magma chamber. It circulates water in the rocks and feeds the fumaroles. If there are changes in sea temperatures then the hydrothermal reservoir might be changing and releasing more gasses.
Another important monitoring system in place are the seismic monitors. They monitor the magmatic seismic activity from magma movement. If magma rises in its chamber it will cause EQs. These quakes are usually small and shallow but scientist can use the monitoring systems to map out the foci and find an estimate of how big the magma chamber is seen in figure 6. Being from California I am no stranger to EQs but those are tectonic EQs. The plates are releasing pent up stress. If I felt an EQ in Santorini and found out it was magmatic I would be worried because the magma is moving in the chamber and rising.
If the sea level rises too high, sea water may get into the vent of Nea Kameni and create a violent eruption. This happened in 1924. External water got into the eruption and caused a hydrovolcanic eruption creating a giant cloud of steam. The eruption would also send ballistics and lithic fragments flying through the air and you do not want to get hit in the head with one.
Scientists also use GPS to see if there is ground inflation. Ground inflation can be caused either by magma rising and pushing against the surrounding rocks or from hydrothermal activity. If the cause is magmatic then magma is rising but if the cause is hydrothermal then gasses/water are being trapped in the magma chamber. Magmatic inflation doesn’t go down but hydrothermatic inflation does.
One last thing scientists monitor at Santorini is heat and where it is. They use thermal cameras at the Georgios crater to find out where the hottest parts are. They also can measure gas emissions this way. We worked with students from the University of Athens who were monitoring the soil temperatures. The soil temp going up Nea Kameni increased at every stop we made but not in a drastic way. We started at 26.8 degrees Celsius. When we got to the top though, the soil temperature sky rocketed to 98 degrees Celsius. That’s a 71.2 degree difference from the base of Nea Kameni to the top. The soil temperature and thermal cameras help scientist figure out where the hottest parts are on Nea Kameni.
All of these monitoring systems work together to help scientists interpret the volcanic activity of Santorini and observe any drastic changes that take place. They also have the power to call for an evacuation of the island, probably like the Minoan leaders did, if they think the volcano will erupt, but because there is no way to predict when a volcano will erupt calling for an evacuation can have major consequences.
If scientists call for an evacuation people have to leave their homes and close their businesses and if the volcano doesn’t erupt they might become angry. They would have exerted lots of energy into packing and business owners would have lost profit. Also tourism may stop which is problematic because many people and businesses on Santorini rely on tourism for their income. Tourism fuels Santorini’s economy so if people had to leave or couldn’t come to the island businesses might close or go into dept.
If an evacuation isn’t called though after “warning signs” and the volcano erupts then the scientists have to deal with the aftermath. People will get mad and even blame them because they might think that the scientists ignored the signs and put people in danger.
With all of the monitoring systems in place today and what scientists know about volcanos they can look for drastic changes. If they feel strongly about the changes in activity they might call for an evacuation but it’s still a tricky decision because scientists can’t predict when a volcano will erupt. So what did the Minoans know about volcanoes or did they even know they were living on a volcano to evacuate Santorini before the Minoan eruption?
The Minoans who lived in the Bronze Age didn’t have the technology to monitor the volcano but evidence shows they left before the eruption happened. We may never know what caused them to leave, if it was the EQ before the eruption that caused damage to their buildings or if there were other reasons. Today with modern technology scientists can monitor the volcanic activity of Nea Kameni and interpret any major changes of the volcano. If there are many drastic changes they have the choice to call for an evacuation, but it is not an easy choice to make. There were no scientists telling the Minoans to leave Santorini but they still left. The answer to the question why, frustratingly will probably be never answered.
1. Friedrich, Walter L. Santorini: volcano, natural history, mythology. Aarhus: Aarhus U Press, 2009. Print.
2. Friedrich, Walter F. “Warning Before the Eruption .” The minoan eruption of santorini around 1613 B.c. and its consequences (2013): 39. Web. 20 June 2017.