Mykonos, Paros, Naxos, Ios, Tinos and Andros are some of the most popular Greek islands in the Aegean, yet in the Ice Age they were all comprising one island 20,000 years ago.
During the last Ice Age, Earth’s water was locked up in ice sheets and sea level in the Aegean was about 120 meters (393 ft) lower than today. The shallow seafloor between these Greek islands dried out and joined them into a single big island. Scientists named it the “Mega-Cyclades palaeo-island”.
The Cyclades, one of the most recognizable island groups in the Mediterranean, once formed a substantially larger and more continuous landmass. Mykonos, Paros, Naxos, Tinos, Syros, Andros, Ios, Delos, and numerous small islands were connected through a landmass. Geological evidence, bathymetric mapping, palaeoclimatic research and archaeological investigation confirm the landscape of the Aegean 20,000 years..
The lost Cycladic landscape shows the extraordinary power of climate to transform geography. The islands that today attract millions of visitors with their beaches, harbors and whitewashed houses and hotels are the surviving elevated portions of a much larger prehistoric landscape.
The Ice Age and the disappearance of the sea
Around 20,000 years ago, the Earth was experiencing the Last Glacial Maximum, the coldest phase of the most recent glacial period. Vast ice sheets covered extensive areas of North America and northern Europe. Greenland and Antarctica also contained substantially greater quantities of ice than they do today.
The enormous accumulation of frozen water had a direct consequence for the oceans. Water that would otherwise have circulated through the global ocean system was locked in continental glaciers. Consequently, sea levels fell dramatically.
According to the United States Geological Survey, global sea level during the Last Glacial Maximum was about 400 feet, approximately 120 meters, below its present level. This figure is essential to understanding the ancient geography of the Greek islands and mainland Greece.
The Aegean is relatively shallow in several extensive areas. When the sea retreated, large portions of the continental shelf emerged above the water. Underwater valleys became terrestrial valleys, shallow channels became plains, and the distances between islands disappeared.
In their scientific study, Geographic Changes in the Aegean Sea Since the Last Glacial Maximum, published in 2017, Stylianos M. Simaiakis and his colleagues reconstructed the geographical transformation of the Aegean using detailed bathymetric information and geophysical modelling. Their research identifies the Cyclades as a group of continental shelf islands that were joined into what the authors call the “Mega-Cyclades palaeo-island.”
This is a particularly important finding. It means that the present-day archipelago should not be understood as an unchanging collection of islands. Its geographical identity was created, in large part, by the gradual return of the sea.
The Mega-Cyclades
What did this ancient landmass actually look like? The modern Greek islands of Naxos, Paros, Mykonos, Tinos, Syros, Andros and neighboring islands were once parts of a much larger geographical unit. The sea had retreated sufficiently to expose extensive areas of seabed, connecting islands that are now separated by navigable channels.
Instead of the fragmented maritime landscape we know today, the central Aegean contained an extensive terrestrial environment. The topography would not have been entirely flat. The mountains and hills of the present islands would have formed elevated areas within a broader landscape of valleys, plains and coastal lowlands. The mountains of Naxos, for example, would have been part of the interior of this larger territory rather than an isolated island mountain range.
Paros and Antiparos, now separated by a relatively narrow stretch of water, belonged to the same broader terrestrial environment. The surrounding shallow seabed provided additional land, extending the coastal plains and changing the relationship between the elevated areas. The landscape also extended beyond the immediate boundaries of today’s Cyclades. Other parts of the Aegean experienced major geographical changes, although not every island became connected to every other island or to the Greek mainland.
The distinction is important: the scientific evidence supports the existence of a much larger, connected Cycladic landmass, not the idea that the entire Aegean became one uninterrupted continent.
When the ice began to melt
The transformation began as the global climate gradually warmed. From approximately 19,000 years ago onwards, major ice sheets began to retreat, although the process was neither uniform nor continuous. Increasing temperatures caused enormous quantities of glacial ice to melt, returning water to the oceans.
The sea began to advance into the low-lying areas of the Aegean. At first, the changes would have been gradual. Coastal plains became wetlands, freshwater environments were replaced by saltish water, and rivers and valleys gradually disappeared beneath the advancing sea. Over thousands of years, the rising water separated elevated sections of the ancient Cycladic landmass. Valleys became channels, low-lying plains became seabeds, and former hills became islands.
The transformation was not simply a matter of water covering the land. The Earth’s crust was also responding to the changing weight of ice and ocean water. This phenomenon, known as glacial isostatic adjustment, influences the relative sea level experienced in different geographical regions.
Therefore, the local history of the Aegean cannot be reconstructed simply by subtracting 120 meters (390 ft) from today’s sea level. Scientists must also consider the movement of the Earth’s crust, gravitational effects and the complex underwater topography.
Research published in Palaeogeography, Palaeoclimatology, Palaeoecology in 2017 estimated that the total area of the Aegean islands decreased by more than 70 percent during the period of post-glacial sea-level rise. The authors describe the process as a major episode of geographical fragmentation.
In other words, the sea did not merely surround an existing collection of islands. It helped create the archipelago itself.
Was this lost Aegean landscape inhabited?
The geological story of the Mega-Cyclades palaeo-island raises the question: was that ancient landmass inhabited?
The central Aegean has an exceptionally long history of human activity. One of the most important archaeological discoveries is the prehistoric site of Stelida on Naxos. In a 2019 study published in Science Advances, archaeologists Tristan Carter, Daniel A. Contreras and their colleagues presented evidence of Middle Pleistocene activity at Stelida. Their investigation identified approximately 9,000 stone artefacts in geological layers dating from around 13,000 to 200,000 years ago.
Some of these artefacts are associated with technologies characteristic of Neanderthal populations. This discovery demonstrated that the region was explored and used by ancient human populations far earlier than many previous archaeological interpretations had suggested. The researchers also raised the possibility that periods of lower sea level facilitated terrestrial movement through parts of the Aegean.
However, it would be scientifically incorrect to claim that the discovery proves that Neanderthals inhabited every part of the Mega-Cyclades 20,000 years ago. The archaeological evidence establishes human activity in the region over a much longer period, but the precise distribution of populations during the Last Glacial Maximum remains a subject for further research.
The landscape would nevertheless have offered a different range of opportunities. Larger areas of land, freshwater sources, valleys and accessible natural resources could have supported animal and human activity.
The disappearance of this land beneath the sea may also explain why some archaeological evidence of prehistoric coastal life remains difficult to discover. Ancient settlements, campsites and resource-gathering locations could now lie beneath the modern seabed.
A maritime civilization
The rising sea gradually transformed the geographical and economic character of the Cyclades. What had once been a largely terrestrial environment became an archipelago. Communities that had previously been able to move across extensive areas of land increasingly depended on boats and maritime knowledge.
This transformation is particularly interesting when considering the later development of Cycladic civilisation. British archaeologist Colin Renfrew, in his contribution to The Oxford Handbook of the Bronze Age Aegean, observes that “the Cyclades have played a central role in the prehistory of the Aegean.”
The islands became important centers of exchange, navigation, mineral exploitation and cultural interaction. The volcanic glass known as obsidian, particularly associated with the island of Milos, became an important material for prehistoric tools. Its distribution across the Aegean demonstrates the development of communication and exchange networks.
As Renfrew explains in his archaeological discussion, obsidian from Milos was reaching Franchthi Cave in the Argolid even during the Upper Palaeolithic, before permanent settlement in the islands is established. This evidence reminds us that the relationship between the Cyclades and the surrounding world was never static. The islands were successively connected through land, coastal environments and maritime routes. The sea that separated communities could also become the means through which they exchanged knowledge, materials and ideas.
Scientific evidence beneath the modern sea
One of the most compelling aspects of this subject is that the lost landscape has not disappeared entirely from scientific investigation. Its geological history can still be reconstructed through the study of the seabed. Marine geologists examine underwater sediment deposits, ancient shorelines, submerged beaches and geological formations that were created when the sea stood at a lower level.
A particularly interesting study, published in the journal Marine Geology in 2017, examined submerged beachrock formations around Paros and Naxos. By combining underwater surveys, sediment analysis and dating techniques, the researchers reconstructed changes in the coastline.
They identified submerged beachrocks reaching approximately 6.3 meters (21 ft) below present sea level. Their research demonstrated that the coastlines of these islands had undergone significant changes during the last several thousand years. Such investigations are important because they provide physical evidence of the changing relationship between land and sea. They also help scientists distinguish between changes caused by rising water levels and those resulting from tectonic movements.
Oceanographers and geologists are increasingly able to combine modern seafloor mapping with historical sea-level records to reconstruct ancient geographical environments with greater accuracy. The work of Simaiakis and his colleagues is particularly significant because it applies detailed geophysical modelling to the entire Aegean archipelago rather than examining individual islands in isolation.
The Cycladic islands as witnesses to climate change
The history of the Mega-Cyclades also has a contemporary significance. The transformation of the central Aegean landmass to a cluster of islands demonstrates how sensitive coastal geography can be to changes in global climate. The difference between an interconnected landmass and an archipelago was produced by changes in sea level over geological time.
Today, the world is experiencing another period of rising sea levels, although the causes and timescales are different from those of the post-glacial transition. During the end of the last Ice Age, the rise was driven principally by the melting of enormous continental ice sheets as the climate warmed naturally. Today, human-induced global warming is causing glaciers and ice sheets to lose mass, while warming seawater expands.
The geological record provides an essential long-term perspective for understanding these processes. The Greek islands in the Aegean also remind us that sea-level change is not simply a matter of meters on a scientific graph. It can fundamentally alter coastlines, ecosystems, human settlements, transport routes and the relationships between communities.
See all the latest news from Greece and the world at Greekreporter.com. Contact our newsroom to report an update or send your story, photos and videos. Follow GR on Google News and subscribe here to our daily email!
