Earthquake region around SantoriniMapping the seafloor from the Peloponnese to Crete

4 March 2025, by Kiel University

Photo: Felix Gross

Maria S. Merian is ready to set sail for the research cruise to the Aegean and Santorini.

On March 5, the research vessel Maria S. Merian will depart from the Spanish port of Málaga for a six-week expedition to the Greek Aegean Sea. Led by the Center for Earth System Research and Sustainability (CEN) at the University of Hamburg, in collaboration with Kiel University, the expedition aims to collect underwater data to better understand tectonic processes and natural hazards in this seismically active region. The route will take the team from Methana through the Aegean volcanic belt to the island of Nisyros and conclude around Crete, Greece’s southernmost island.

A key focus of the expedition will be extensive acoustic measurements and the collection of sediment samples from depths of up to 2,000 meters. Scientists hope to gain new insights into past and present tectonic movements, slope instabilities and submarine landslides. The data collected will also help reconstruct the geological history of the region and may even reveal previously undiscovered underwater volcanic structures.

The expedition will include research in the area of the Greek underwater volcano Kolumbo, which has recently experienced increased seismic activity and numerous minor to moderate earthquakes. Kolumbo, located about seven kilometers northeast of Santorini, is one of the most active submarine volcanoes in the Mediterranean. Investigating this region is crucial for assessing potential risks to nearby islands.

Exploration of the Aegean Volcanic Arc between Milos and Nisyros

The first area of investigation will focus on the Aegean Volcanic Arc, particularly the region between the islands of Milos and Nisyros. This area, which includes the Christiana-Santorini-Kolumbo Volcanic Field (CSKVF), has been extensivly studied in the past. The researchers rely on a good base of data from various institutions and previous expeditions. "We are eager to see, if new sediment shifts have occured and how recent tectonic activity is affecting the area. It is quite possible that seismic activities near Kolumbo have left traces detectable even kilometers away," explains Chief-Scientist Prof. Dr. Christian-Hübscher of the University of Hamburg, a marine Geophysicist, who has been researching the region for many years.

Investigating the continental slopes around Crete

Another important research area of the MSM135 expedition is the continental slope around Crete, the largest Greek island. Sediment movements and submarine landslides in the so-called Hellenic Arc are not yet wel documented. The region is geologically very active and is characterized by plate movements that can trigger submarine landslides. Researchers will collect data and sediment cores at key locations around Crete to gain insights into past geological events. Smaller landslides near the coast will also be examined, as they could pose risks to offshore infrastructure such as pipelines and communication cables, despite their relatively small size. " With this expedition, we aim to close critical knowledge gaps and compile a comprehensive dataset for the entire Aegean Sea. The findings will be used to develop reliable hazard scenarios, ultimately contributing to better risk assessment in the region," says Co-Chief Scientist Dr. Felix Gross from the Institute of Geosciences at Kiel University.

The research expedition is part of the joint project MULTI-MAREX "A living laboratory for improved forecasting and action options for multiple geomarine extreme events" of the research mission mareXtreme of the German Marine Research Alliance (DAM) and is the second of a total of three planned expeditions to the Greek Aegean. In addition to researchers from the Universities of Hamburg and Kiel, scientists from the GEOMAR Helmholtz Centre for Ocean Research Kiel and the University of Athens are on board.