How Was Santorini Formed? The 4 Volcanoes That Shaped It

Santorini, the stunning island of the Cyclades, owes its very existence to a series of volcanic eruptions and seismic activity spanning hundreds of thousands of years.

This dramatic geological evolution sculpted the island’s unique landscape, characterized by its towering caldera cliffs, vibrant beaches, and a breathtaking central lagoon.

Early Volcanic Activity

Approximately two million years ago, submarine volcanoes west of what is now Santorini began erupting, gradually accumulating lava and forming the island’s landmass.

Over time, successive volcanic eruptions and lava flows overlapped and expanded, creating a complex volcanic structure—the foundation of the Santorini we know today.

The Formation of the Caldera

Santorini’s striking landscape is the result of at least four major volcanic eruptions, each of which played a role in shaping its famous caldera:

1. Southern Caldera (180,000 years ago) – This was the earliest and most significant eruption, forming a massive depression in the island’s southern region.

2. Skaros Caldera (70,000 years ago) – A later eruption further reshaped the island’s terrain, creating what is now known as the Skaros caldera.

3. Akrotiri Caldera (21,000 years ago) – Another significant eruption contributed to the island’s modern geological structure.

4. The Minoan Eruption (3,600 years ago) – One of the most powerful volcanic eruptions in recorded history, it ejected vast amounts of magma and rock, causing the collapse of the island’s central region and forming Santorini’s present-day caldera.

The Minoan Eruption: A Catastrophic Event

Around 1600 BCE, the Minoan eruption dramatically altered Santorini’s landscape. This massive explosion expelled an estimated 28–41 cubic kilometers of volcanic material, burying the island under thick layers of pumice and ash.

The eruption led to the collapse of Santorini’s central landmass, giving rise to the modern caldera. Many historians believe that this event contributed to the decline of the Minoan civilization, as the resulting tsunamis and climatic changes had far-reaching consequences.

Post-Minoan Volcanic Activity

Volcanic activity didn’t stop after the Minoan eruption. It continued primarily in the Kameni islands, located within the caldera. Historical records document several eruptions, the most recent occurring in 1950.

These eruptions gradually expanded the Kameni islands and influenced the region’s geothermal features, shaping the Santorini we see today.

Would you like to witness the island’s volcanic history for yourself? Watch the video below to explore Santorini’s fascinating geological past!