The Minoan eruption was a very powerful volcanic eruption that caused a lot of damage to the Aegean island of Thera (also known as Santorini) around 1600 BC. It destroyed the Minoan settlement at Akrotiri and harmed communities and farmland on nearby islands and the coast of Crete, due to later earthquakes and tsunamis. With a Volcanic Explosivity Index (VEI) of 7, the eruption released about 28 to 41 kilometers of dense-rock equivalent (DRE), making it one of the largest volcanic events in human history. Because volcanic material from the Minoan eruption is found in many archaeological sites in the Eastern Mediterranean, knowing its exact date is very important. Scientists have debated this date for many years without reaching a clear answer.
Although there are no clear ancient records of the eruption, some believe the volcanic plume and lightning might have been described in the Egyptian Tempest Stele. However, recent studies have questioned this idea based on carbon dating of artifacts from the early 18th Dynasty. Chinese records from the Shang dynasty mention unusual yellow skies and frost during summer, which might have been caused by a volcanic winter, similar to 1816, a year with no summer after the 1815 eruption of Mount Tambora.
Eruption
Geological evidence shows that the Thera volcano erupted many times over hundreds of thousands of years before the Minoan eruption. In a repeating process, the volcano would erupt violently, then collapse into a roughly circular seawater-filled caldera, with many small islands forming the circle. The caldera would slowly refill with magma, creating a new volcano, which erupted and then collapsed in an ongoing cycle.
Just before the Minoan eruption, the caldera walls formed a nearly continuous ring of islands, with the only entrance between Thera and the small island of Aspronisi. This powerful eruption occurred on a small island north of the existing island of Nea Kameni, located in the center of the caldera at that time. The northern part of the caldera was filled with volcanic ash and lava, then collapsed again.
Estimating the size of the eruption, especially the underwater pyroclastic flows, has been difficult because most of the erupted material was deposited in the sea. These challenges make it hard to determine the exact volume of the Minoan eruption, with estimates ranging between 13–86 km (3.1–20.6 mi) DRE.
According to recent analysis of marine sediments and seismic data collected during ocean research from 2015 to 2019, the volume of material expelled during the eruption is estimated to be between 28–41 km (6.7–9.8 mi) DRE.
The study found that the initial Plinian eruption was the largest phase, releasing 14–21 km (3.4–5.0 mi) of magma and accounting for half of all erupted materials. This was followed by 3–4 km (0.72–0.96 mi) DRE of co-ignimbrite fall, 5–9 km (1.2–2.2 mi) DRE of pyroclastic flows, and 5–7 km (1.2–1.7 mi) DRE of intra-caldera deposits.
This eruption is similar in size to the 1815 eruption of Mount Tambora, the 1257 Samalas eruption, Lake Taupo’s Hatepe eruption around AD 230, and the 946 eruption of Paektu Mountain, which are among the largest eruptions in the last 2,000 years.
On Santorini, a 60-meter (200-foot) thick layer of white tephra covers the soil, clearly showing the ground level before the eruption. This layer has three distinct bands that mark the different phases of the eruption. Studies have identified four major eruption phases and one minor tephra fall before the main event. The thinness of the first ash layer and the lack of erosion from winter rains before the next layer formed suggest the volcano gave the local population several months of warning. Since no human remains have been found at the Akrotiri site, this early volcanic activity likely caused the island’s population to leave. It is also believed that several months before the eruption, Santorini experienced one or more earthquakes that damaged local settlements.
The first major phase (BO 1 /Minoan A) of the eruption involved intense magmatic activity, depositing up to 7 meters (23 feet) of pumice and ash, with some rock fragments, southeast and east. Archaeological evidence shows that man-made structures were buried with limited damage. The second (BO 2 /Minoan B) and third (BO 3 /Minoan C) phases involved pyroclastic surges, lava fountains, and possible tsunamis. Structures not buried during Minoan A were completely destroyed. The third phase also began the collapse of the caldera. The fourth and final major phase (BO 4 /Minoan D) included varied activity, such as rock-rich base surge deposits, lava flows, lahar floods, and co-ignimbrite ash-fall deposits. This phase completed the caldera collapse, which likely caused massive tsunamis.
Geomorphology
Although the exact process of fracturing is not yet understood, statistical analysis based on altitude suggests that the caldera formed shortly before the eruption. At that time, the island was smaller, and the southern and eastern coastlines had moved inland. During the eruption, the land was covered by layers of pumice. In some areas, the coastline disappeared under thick deposits of tuff. In other areas, the coastline extended farther toward the sea. After the eruption, the shape and features of the island changed as a result of a strong period of erosion, during which pumice was gradually removed from higher areas and carried to lower ones.
Volcanology
The eruption was a Plinian type, involving rhyodacite, and created an eruption column estimated to be 30 to 35 kilometers (19 to 22 miles) high, reaching the stratosphere. Additionally, the magma beneath the volcano came into contact with a shallow marine area, causing violent phreatomagmatic explosions.
The eruption also produced tsunamis 35 to 150 meters (115 to 492 feet) high, which severely damaged the northern coastline of Crete, 110 kilometers (68 miles) away. Coastal towns like Amnisos were affected, with building walls pushed out of place. On the island of Anafi, 27 kilometers (17 miles) east, ash layers 3 meters (10 feet) deep were found, along with pumice layers on slopes 250 meters (820 feet) above sea level.
Pumice deposits found elsewhere in the Mediterranean may have been carried by the Thera eruption. Ash layers in samples taken from seabeds and lakes in Turkey show that the heaviest ashfall occurred to the east and northeast of Santorini. The ash found on Crete was from a phase before the main eruption, weeks or months earlier, and likely had little effect on the island. Ash deposits from Santorini were once thought to be found in the Nile Delta, but this has since been corrected as an incorrect identification.
Eruption dating
The Minoan eruption is a key event used to help determine the timeline of the Bronze Age in the Eastern Mediterranean. It serves as a fixed reference point for aligning the timeline of the second millennium BC in the Aegean region, as evidence of the eruption is found across the area. However, archaeological dating methods, which rely on the styles of artifacts and comparisons with Egyptian timelines, suggest the eruption occurred about 100 years later than radiocarbon dating indicates. This difference in dates has led to debates about whether the timelines of the Aegean and Egypt are misaligned.
Archaeologists created the Late Bronze Age timelines for cultures in the Eastern Mediterranean by studying the designs of artifacts found in different layers of archaeological sites. If the types of artifacts can be correctly identified, the layer's position in a timeline can be determined. This method is called sequence dating or seriation. In Aegean timelines, the frequent exchange of objects and styles allows relative dating (based on artifact styles) to be compared with Egypt’s absolute dates, helping to determine exact dates in the Aegean.
The Minoan eruption has been clearly placed in the late or end of the Late Minoan IA (LM-IA) period on Crete and the late or end of the Late Helladic I (LH-I) period on the mainland. The debate centers on which Egyptian period occurred at the same time as LM-IA and LM-IB. Archaeological work over decades has linked the end of LM-IA to Dynasty XVI in Egypt and the start of Thutmose III. Stone vessels found in Shaft Graves from LH-I match New Kingdom styles. Pumice workshops on Santorini and a milk bowl from before the eruption also show New Kingdom pottery styles. An Egyptian inscription on the Ahmose Tempest Stele describes a disaster similar to the Minoan eruption. Together, these findings suggest the eruption occurred after Ahmose I became king. Based on Egyptian and radiocarbon dating, Ahmose I likely ruled between 1550 BC and 1570–1544 BC (IntCal04) or 1569–1548 BC (IntCal20). Archaeological evidence points to the eruption happening between about 1550 and 1480 BC.
Some researchers argue that pottery styles from the Aegean and Egypt can overlap in ways that allow for a broader range of dates. Interpretations of LM-IA and LM-IB pottery styles vary and could align with earlier dates than traditionally believed. Before the LM-IIIAI/Amenhotep III period, pottery synchronizations were less certain. Pumice found in workshops and the Ahmose Tempest Stele are seen as minimum age markers for the eruption. The timing of pottery with the Santorini milk bowl style in other regions is unclear and may predate the eruption. Information about stone vessel styles during this time is also incomplete.
Radiocarbon dating can be inaccurate due to changes in atmospheric carbon levels. To correct this, scientists use calibration curves that are updated regularly. The accuracy of these curves affects how well radiocarbon dates match real calendar dates. The most recent calibration curve, IntCal20, was finalized in 2020. Early radiocarbon studies from the 1970s showed large discrepancies and were initially dismissed. Over time, better calibration methods, improved precision, and better sample analysis narrowed the possible eruption dates. Radiocarbon dating now strongly supports an eruption date in the late 17th century BC.
In 2018, scientists found that previous calibration curves (IntCal) might have been slightly off between 1660–1540 BC. This discovery allowed radiocarbon dates to align better with archaeological evidence, including dates in the 16th century BC. This correction was confirmed by other labs and added to IntCal20. However, some studies questioned the reliability of using olive tree rings for wiggle-matching, suggesting growth patterns could cause dating errors.
In 2020, researchers found possible regional differences in calibration curves based on juniper wood from Gordion. If true, this would shift the eruption date back to the 17th century BC. Others argue these differences are already accounted for in IntCal20, which uses data from many locations worldwide.
While IntCal20 does not rule out a 17th-century BC eruption, it now includes much of the 16th century BC as a possible timeframe, helping to reduce the long-standing date conflict. However, the exact year of the eruption remains uncertain.
A major eruption like the Minoan one would leave traces in environmental records such as ice cores and tree rings. Studies estimate the Minoan eruption released between 0.3 and 35.9 trillion grams of sulfur. The higher amounts could cause climate changes detectable in ice cores and tree rings. Tree rings provide precise yearly dating and can reveal climate details with high accuracy.
In 1987, a large sulfate spike in Greenland ice cores around 1644 ± 20 BC was linked to the Minoan eruption based on early radiocarbon data. In 1988, a major global cooling event around 1627 ± 0 BC, marked by frost rings in trees, was also linked to the eruption. However, archaeologists who believed the eruption occurred in the late 16th century BC were not convinced, as no direct connection between these events and the eruption was proven.
Since 2003, studies of volcanic ash in the 1644 ± 20 BC sulfate layer failed to match it to Santorini. Instead, the ash was linked to the Mount Aniakchak eruption, ruling out the Minoan eruption as the source. In 2019, a revised Greenland ice-core timeline was proposed, based on matching frost-ring data and sulfate spikes.
Historical impact
The eruption destroyed the settlement at Akrotiri on Santorini, which was covered by layers of pumice and ash. Evidence at the site shows that survivors returned later and tried to retrieve their belongings or bury the dead.
The eruption was felt at Minoan sites on Crete. In northeastern Crete, earthquakes damaged areas like Petras, while 9-meter-high tsunamis flooded coastal places such as Palaikastro. Ash and pumice fell across the island and were sometimes gathered and stored.
After the eruption, the Minoans recovered quickly, and the time that followed is considered the peak of Minoan culture. Many damaged sites, including Petras and Palaikastro, were rebuilt. At Palaikastro, new buildings were made using strong stone masonry. New Minoan palaces were built at Zakros and Phaistos. However, other places, such as Galatas and Kommos, declined.
The long-term effects of the eruption are still debated. Immediately after the eruption, some puzzling cultural changes occurred, such as the filling of lustral basins. In their book The Troubled Island, Driessen and MacDonald argued that the wealth of material culture after the eruption hid serious economic and political issues that eventually led to the collapse of Neopalatial society. Later evidence suggests this was not a widespread pattern across the island.
Some researchers claim that a volcanic winter from an eruption in the late 17th century BC matches Chinese records describing the fall of the semi-legendary Xia dynasty. According to the Bamboo Annals, the Xia dynasty collapsed and the Shang dynasty rose around 1618 BC. This event was described as having "yellow fog, a dim sun, three suns, frost in July, famine, and the withering of all five cereals."
Apocalyptic rainstorms, which severely damaged parts of Egypt, are described on the Tempest Stele of Ahmose I. These storms are believed to have been caused by short-term climate changes from the Theran eruption. Dates for Ahmose I’s reign are debated by Egyptologists, with proposed ranges from 1570–1546 BC to 1539–1514 BC. A radiocarbon test of his mummy suggested an average date of 1557 BC. This overlaps with later estimates of the eruption’s date. In 2025, carbon dating of materials from the early 18th Dynasty, such as mudbricks from temples of Ahmose I, produced results that did not match the date of the Thera eruption.
If the eruption occurred during Egypt’s Second Intermediate Period, the lack of Egyptian records about it might be due to the chaos in Egypt at that time.
Some argue that damage from the storms was caused by an earthquake after the Thera eruption. Others suggest the damage resulted from a war with the Hyksos, with the storm reference symbolizing the chaos the Pharaoh sought to control. Other Egyptian texts, like the Speos Artemidos stele, describe storms that are clearly symbolic, such as Hatshepsut overcoming chaos and darkness.
The eruption of Thera and its volcanic effects may have inspired the myth of the Titanomachy in Hesiod’s Theogony. The story might have included memories from western Anatolia, especially in the eastern Aegean. This version of the myth could have absorbed influences from the eastern Aegean as the story spread to mainland Greece.
Hesiod’s descriptions have been compared to volcanic activity. For example, Zeus’s thunderbolts are likened to volcanic lightning, the boiling earth and sea to magma breaking through, and intense heat and flames to phreatic explosions.
Spyridon Marinatos, who discovered the Akrotiri site, proposed that the Minoan eruption is reflected in Plato’s story of Atlantis. This idea is common in popular culture, such as in the TV show Atlantis. However, scholars do not support this view.
Geologist Barbara J. Sivertsen is trying to connect the Santorini eruption (around 1600 BC) with the Exodus of the Israelites from Egypt in the Bible.