Athens, Greece – Scientists from the National Observatory of Athens (NOA), in collaboration with New Zealand colleagues, have unveiled AFG (Active Faults Greece), the country’s first comprehensive database and seismic map identifying 892 active fault lines across Greece. This pioneering effort, utilizing high-resolution Digital Elevation Models (DEMs), reveals hundreds of previously unrecorded faults and refines the mapping of known ones, offering critical insights into Greece’s complex geological landscape.
Greece: A Perpetual Geological Machine
The research team, which includes Dr. John Begg, Dr. Vasiliki Mouslopoulou, Dr. Dave Heron, and Professor Andy Nicol, emphasized that Greece is “squeezed” between the African plate to the south and the Eurasian plate to the north. This continuous geological pressure drives significant seismic activity, making the country a “perpetual geological machine.”
“The country, wedged between two continents, is deformed by the ongoing movement of Africa toward the north and Eurasia to the south. Greece’s relief continues to evolve today, primarily through the activity of seismic faults. Many of these faults remain concealed beneath vegetation, within expanding urban areas, or in the complexity of the terrain itself,” the researchers explained.
The strategic importance of these findings is underscored by Greece’s growing reliance on tourism and its aspirations to become an energy hub in the Eastern Mediterranean. “It is essential to understand the distribution of seismic sources throughout the country. This necessitates detailed mapping of active faults, both on land and underwater,” they stated. AFG provides the scientific community with the first nationwide map of active faults based on terrain morphology, presented at a consistent scale of 1:25,000.
AFG: Documenting Greece’s Active Faults
The AFG seismic map meticulously documents 3,815 fault traces, which are grouped into 892 individual faults. Over half of these faults have been recorded for the first time. The database also includes 35 surface ruptures linked to historical earthquakes, providing a more complete picture of past seismic events.
Each fault in the AFG database is classified based on its observed activity:
- Active: The relief shows clear signs of recent deformation.
- Possibly active: The fault is visible in the landscape, but evidence of activity is less definitive.
- Uncertain: Additional observations are required to confirm the fault’s existence.
The scientific team further detailed the classification based on how distinctly faults have shaped the terrain. “Traces resembling ‘stabs’ indicate recent activity, likely within the Holocene-the last 10,000 years-while more rounded traces reflect progressively older seismic events,” they noted. In total, over two thousand fault traces in the AFG are characterized as active, with approximately 1,600 deemed possibly active.
Analysis also revealed that over half of Greece’s active faults influence river courses, sediment deposition, and the boundaries between mountains and valleys. These relationships suggest that many active faults remain hidden, often “buried” beneath newer sediments, highlighting the ongoing need for detailed seismic mapping.
Advanced Methodology and Human Expertise
The researchers emphasized that recent technological advancements, particularly in Digital Elevation Models (DEMs), have revolutionized the ability to “see” the Earth. DEMs, which are three-dimensional representations of the Earth’s surface, allow scientists to visualize terrain with unprecedented accuracy and identify structures invisible to the naked eye.
“In digital models, scientists study the landscape as if stripped of cities or vegetation, searching for systematic signs of active faults,” the team explained. Dr. Vasiliki Mouslopoulou, Principal Researcher at the Geodynamic Institute of the National Observatory of Athens, highlighted the practical implications of this work: “Understanding the distribution of active seismic sources has direct implications for the safety and resilience of infrastructure. Roads, bridges, dams, and power plants must be designed with knowledge of the faults that can move the ground. When combined with instrumental recordings of earthquakes and ground deformation, the data provided by AFG can significantly enhance seismic hazard models in Greece.”
However, Dr. John Begg, a key contributor to AFG, stressed that technology alone is insufficient. “Interpreting DEMs requires the experienced eye of a geologist-someone who can distinguish a tectonic front from an erosion surface. Digital indications must be validated by cross-referencing fault activity criteria, on-site observations, and existing studies. The strength of AFG lies in combining advanced technological tools with decades of geological expertise.”
This integrated approach is particularly effective in Greece’s complex terrain. “Careful observation, paired with the insight of an experienced observer, can separate traces left by earthquakes from those shaped by natural erosion or human activity,” the team clarified. “Derived images using special lighting (hillshades) and slope maps reveal unmistakable ‘geomorphological fingerprints’ of past earthquakes along active faults-such as inverted valleys, diverted rivers, or triangular mountain fronts.”
Public Accessibility and Future Impact
The AFG database is freely accessible to the public through an interactive map. This allows engineers, researchers, and citizens to locate active faults in their vicinity and explore their key characteristics. AFG aims not only to support national efforts in documenting seismic sources but also to serve as a model for other seismically active countries seeking to leverage digital landscapes for identifying active faults.
This comprehensive mapping effort marks a significant step forward in understanding and mitigating seismic risks in Greece, contributing to enhanced safety and more resilient infrastructure for the future.
Source: https://greekreporter.com/2025/11/29/greece-complete-seismic-map-active-faults/
