Recent earthquakes in Santorini have raised concerns about potential volcanic eruptions or tsunamis, highlighting the geological risks in the Mediterranean. Research indicates rising magma beneath the Aegean Sea, prompting fears of future seismic events. Advances in tsunami warning systems, driven by past disasters, aim to improve preparedness, but challenges remain in accurately predicting tsunami risks. Innovative sensor technologies are being developed to enhance monitoring and early detection of landslide-induced tsunamis, with projects underway to implement these solutions.
In recent weeks, the picturesque Greek island of Santorini has been rocked by a series of earthquakes, leaving both locals and vacationers feeling anxious. The looming question on everyone’s mind is whether a significant seismic event, volcanic eruption, or even a tsunami might be on the horizon.
Santorini serves as a stark reminder of the geological hazards that permeate the Mediterranean region. Similar threats can arise from other active sites, such as Mount Etna in Sicily or the northern edge of the African Plate, which has a history of producing powerful earthquakes in both Italy and Greece.
Wherever tectonic activity occurs, the potential for tsunamis becomes a critical concern. These devastating waves can result not only from earthquakes but also from volcanic eruptions or underwater landslides, complicating early detection efforts. The Mediterranean’s relatively small size, with densely populated and vulnerable coastlines, means that any tidal waves could strike land with alarming speed.
Signs of Rising Magma in the Aegean Sea
In the case of Santorini, many of the earthquakes’ epicenters are situated approximately 25 kilometers northeast of the island, deep beneath the sea. “Our data indicates that magma is likely rising from the Earth’s crust,” states Morelia Urlaub from the Geomar Research Center in Kiel, who has extensive experience studying the area. While seismic activity has lessened recently, the future remains unpredictable.
“The magma could continue its ascent and potentially reach the seabed,” Urlaub explains. Researchers are currently unable to determine whether this would occur gradually or result in a more explosive eruption. The chemical composition of the magma, which remains uncertain, plays a crucial role in this assessment. Historical evidence suggests that explosive eruptions have occurred in this region before, such as the notable Minoan eruption around 1600 BC, which generated tidal waves in the eastern Mediterranean.
“Even if the magma remains deep within the Earth, tsunamis can still be triggered,” Urlaub adds. This risk arises from strong earthquakes that could lead to underwater landslides. Estimating the height of potential waves is challenging, as various factors come into play, including the volume and velocity of material displaced, the slope’s configuration, and the seabed’s characteristics. Research into tsunamis generated by landslides is still in its infancy compared to studies on earthquake-induced tsunamis.
Advancements in Tsunami Warning Systems
When it comes to tsunamis triggered by earthquakes, there has been significant progress in research and response systems. The devastating tsunami that struck Southeast Asia in late 2004, resulting in the loss of around a quarter of a million lives, spurred a global enhancement of early warning systems. In the Mediterranean, these systems operate on a simplified model: a network of seismometers detects earthquakes, allowing for a rough estimation of which coastlines may be at risk. Timely warnings are then issued by national “Tsunami Service Providers,” who interpret the data and coordinate civil protection efforts, including potential evacuation measures.
Authorities routinely conduct training exercises to refine emergency protocols and ensure effective communication during crises. Additionally, they have established alert systems to notify residents of impending dangers via mobile notifications.
Through a UNESCO initiative, municipalities can achieve “Tsunami Ready” certification. This requires them to identify and mark danger zones along the coast, designate safe evacuation routes, and conduct public drills at least every two years. Recently, the Italian city of Minturno near Naples earned this designation, with plans for 25 municipalities across the Mediterranean to achieve similar status by the end of 2026.
Despite these advancements, challenges remain. According to Stefano Lorito from the Italian National Institute of Geophysics and Volcanology (INGV), the evaluation of earthquakes relies on a decision matrix that primarily considers location and magnitude. “It’s equally important to assess whether an earthquake causes vertical or horizontal shifts between tectonic plates,” which significantly affects tsunami potential.
To enhance prediction accuracy, INGV researchers have crafted a probabilistic model that incorporates all available measurement and simulation data, accounting for uncertainties that diminish as more information is gathered. This approach helps to reduce false alarms, as seen in February 2023 when a 7.8 magnitude quake in eastern Turkey and Syria led to a tsunami warning in Italy despite the actual plate movement being primarily horizontal.
Furthermore, expanding the sensor network is crucial for early detection, Lorito notes. This includes additional seismometers, GPS stations to monitor Earth’s surface deformations, and gauge stations and buoys to confirm or cancel tsunami warnings.
Innovative Technologies for Enhanced Monitoring
Implementing a comprehensive network of sensors in marine environments can greatly improve our understanding of landslides and the subsequent tsunamis they may generate. One promising approach involves special fiber optic cables equipped with temperature and pressure sensors, which can detect ground deformations through optical methods while lying on the seabed.
Pressure sensors can monitor tidal waves as they pass overhead. “Cables of this type have already been deployed off the coast of Japan,” remarks Andrey Babeyko, a tsunami early warning researcher at the GFZ Helmholtz Centre for Geosciences in Potsdam. “These cables provide valuable data from difficult-to-reach marine regions, enhancing our modeling capabilities.” However, the financial costs can be substantial, often reaching millions.
One potential solution is to collaborate with telecommunications companies, which already install numerous fiber optic cables on land and in marine areas. However, many companies hesitate to partner with researchers due to concerns about espionage or damage to their infrastructure from monitoring devices.
Researchers from GFZ and Geomar are working to demonstrate that these concerns are unwarranted. The Safator project (Smart Cables and Fiber-optic Sensing Amphibious Demonstrator), set to launch on March 5, aims to equip a new telecommunications cable with numerous sensors to show that they do not interfere with telecom operations. The Mediterranean is a potential deployment site, and this demonstration cable could serve as a prototype for future endeavors.
Additionally, GFZ plans to establish permanent monitoring at three observatories: one at the northern Chilean subduction zone, known for its frequent strong earthquakes, another near the seismically active North Anatolian fault zone that poses risks to Istanbul, and a third at Mount Etna, the famed Sicilian volcano.