Development of a Distributed Temperature and Strain Sensing (DTSS) Fiber Optic Network within the University of Patras Campus
We are pleased to announce that TRANSFΟRM² project, coordinated by the Department of Geology of the University of Patras, has initiated the development of a Distributed Temperature and Strain Sensing (DTSS) fiber optic network within the University of Patras campus. This infrastructure will serve as a high-resolution geophysical monitoring tool, enabling continuous measurement of mechanical strain and temperature variations along the cable length, with the ultimate goal of detecting subtle ground deformations associated with seismic activity and slow-onset geohazards. To assess and test the methodology the network will be deployed across the Rio-Patra fault exposed rupture crossing the University of Patras campus.
IPGP and INERIS from France are collaborating, providing know-how and a BOTDR interrogator.
Figure 1: The DTSS, 3D and Single mode fibers network that are being deployed inside the UPAT campus. White dashed line depicts the Rio-Patras fault surface rupture mapped by the Engineering Geology (EnGeo) laboratory of the department of Geology.Figure 2: The Single mode fibers network that are being deployed inside the UPAT campus. White dashed line as in previous figure. With colored circles the line of sight velocity from SENTINEL-1 ground motion is depicted.Figure 3: The Single mode fibers network that are being deployed inside the UPAT campus. White dashed line as in previous figure. With colored circles the line of sight velocity from TERRASAR-X ground motion is depicted.
Distributed Temperature and Strain Sensing (DTSS) Network
A DTSS network uses fiber optic cables to measure mechanical strain and temperature changes continuously along their entire length. In geological monitoring, DTSS serves as a high-resolution, long-range tool for detecting subtle ground movements that precede or characterize earthquake activity. DTSS provides a critical mechanism for the quantification of slow-onset geohazards and interseismic strain accumulation. The technology is uniquely capable of detecting minute ground displacements, such as fault creep and tectonic loading, which typically occur at frequencies below the detection threshold of conventional acoustic sensors. By embedding DTSS enabled fibers across active fault traces or within deep boreholes, we can map the precise spatial distribution of mechanical stress along the fault plane, identifying locked segments and potential rupture zones. This continuous monitoring capability offers a high-resolution longitudinal record of subsurface deformation, significantly enhancing the predictive accuracy of geodynamic models and contributing to the technical framework of seismic risk mitigation.
3D Network
A 3D fiber optic sensing network represents an integrated monitoring architecture that transforms passive infrastructure into a continuous, volumetric sensing array.
In the field of seismic fault monitoring, 3D networks provide a critical advantage by capturing the full vector of ground displacement. While linear sensing is restricted to axial strain, a 3D topology enables the simultaneous detection of vertical uplift, lateral slip, and longitudinal extension, offering a complete kinematic profile of fault zone activity. This high-density spatial sampling allows for the precise localization of micro-seismic events and the mapping of interseismic strain accumulation, effectively turning the subsurface into a transparent, measurable volume that reveals the complex mechanics of tectonic deformation.
A 3D network refers to a multi-axial configuration of fiber optic sensors designed to capture ground deformation and seismic waves in all three spatial dimensions.
Distributed Acoustic Sensors (DAS)
DAS is a cutting-edge technology that transforms standard fiber optic cables into a continuous string of “virtual microphones.” By sending laser pulses through the fiber and analyzing the reflected light, the system can detect and locate acoustic vibrations with extreme precision over vast distances. This technology is particularly effective for monitoring seismic faults, as it can detect micro-seismic activity and subtle movements along fault lines in real-time. This high-resolution data allows for better characterization of subsurface structures and provides critical insights into tectonic stability, significantly improving early warning systems and geological research.
Rio-Patras fault
The fault sits at the western termination of the Corinth Rift, right where it transitions into the Gulf of Patras graben. This area hosts several active faults located beneath the city of Patras and surroundings, a region of major socioeconomic importance for Greece.
The Rio-Patras fault separates two blocks with distinct deformation behavior, sitting at the critical junction where Corinth Rift extension transitions into the oblique kinematics of the western Hellenic arc. Microseismicity studies consistently show a seismic gap along much of the fault despite clear geomorphic and InSAR evidence of active displacement, suggesting significant aseismic slip accommodates part of the strain budget. The original interpretation attributed this to faults soling into a shallow decollement with velocity-strengthening rheology, though recent relocations challenge the decollement geometry and instead point to depth-dependent partitioning between normal and strike-slip mechanisms. Multi-temporal InSAR confirms measurable differential motion across the fault blocks, but cannot yet resolve whether the shallow fault plane is creeping freely or partially locked and accumulating a slip deficit. Constraining the coupling ratio on the Rio-Patras fault, through denser GNSS transects and InSAR time-series modeling, is essential for realistic seismic hazard assessment of the Patras urban area. In the area nine modern GNSS stations will be deployed until May 2026.
The Rio-Antirrio bridge sits right on this transition zone, and the city of Patras (Greece’s third-largest) straddles the fault’s hangingwall. Any fault characterization feeds directly into site-specific seismic hazard for both.
Current Progress
Equipment & Procurement: The DTSS and 3D fiber optic cables supplied by Fibrain and NerveSensors are being received and initially inspected.
Site Preparation: Preliminary groundwork are being commenced on the deployment site. Vegetation clearing and terrain leveling have been carried out to prepare the field for the installation of the infrastructure. Node and well positions are accurately marked, establishing the precise layout of the sensing network.
Trenching & Sand bedding Operations (13–17 April): Excavation is complete, defining the path for our monitoring infrastructure. Delivery and placement of specialized sand bedding material have been finalized. This ensures the protection of the fiber optic cables and optimal signal coupling for ground deformation sensing.
Upcoming Milestones & Forward Plan
Timeframe
Activity
Week of 20-24 April
Deployment of the fibers
Work involved in preparing the terrain, highlighting the scale of the trenching and the preparation of the bedding.
Development of a Distributed Temperature and Strain Sensing (DTSS) Fiber Optic Network within the University of Patras Campus
We are pleased to announce that TRANSFΟRM² project, coordinated by the Department of Geology of the University of Patras, has initiated the development of a Distributed Temperature and Strain Sensing (DTSS) fiber optic network within the University of Patras campus. This infrastructure will serve as a high-resolution geophysical monitoring tool, enabling continuous measurement of mechanical strain and temperature variations along the cable length, with the ultimate goal of detecting subtle ground deformations associated with seismic activity and slow-onset geohazards. To assess and test the methodology the network will be deployed across the Rio-Patra fault exposed rupture crossing the University of Patras campus.
IPGP and INERIS from France are collaborating, providing know-how and a BOTDR interrogator.
Distributed Temperature and Strain Sensing (DTSS) Network
A DTSS network uses fiber optic cables to measure mechanical strain and temperature changes continuously along their entire length. In geological monitoring, DTSS serves as a high-resolution, long-range tool for detecting subtle ground movements that precede or characterize earthquake activity. DTSS provides a critical mechanism for the quantification of slow-onset geohazards and interseismic strain accumulation. The technology is uniquely capable of detecting minute ground displacements, such as fault creep and tectonic loading, which typically occur at frequencies below the detection threshold of conventional acoustic sensors. By embedding DTSS enabled fibers across active fault traces or within deep boreholes, we can map the precise spatial distribution of mechanical stress along the fault plane, identifying locked segments and potential rupture zones. This continuous monitoring capability offers a high-resolution longitudinal record of subsurface deformation, significantly enhancing the predictive accuracy of geodynamic models and contributing to the technical framework of seismic risk mitigation.
3D Network
A 3D fiber optic sensing network represents an integrated monitoring architecture that transforms passive infrastructure into a continuous, volumetric sensing array.
In the field of seismic fault monitoring, 3D networks provide a critical advantage by capturing the full vector of ground displacement. While linear sensing is restricted to axial strain, a 3D topology enables the simultaneous detection of vertical uplift, lateral slip, and longitudinal extension, offering a complete kinematic profile of fault zone activity. This high-density spatial sampling allows for the precise localization of micro-seismic events and the mapping of interseismic strain accumulation, effectively turning the subsurface into a transparent, measurable volume that reveals the complex mechanics of tectonic deformation.
A 3D network refers to a multi-axial configuration of fiber optic sensors designed to capture ground deformation and seismic waves in all three spatial dimensions.
Distributed Acoustic Sensors (DAS)
DAS is a cutting-edge technology that transforms standard fiber optic cables into a continuous string of “virtual microphones.” By sending laser pulses through the fiber and analyzing the reflected light, the system can detect and locate acoustic vibrations with extreme precision over vast distances. This technology is particularly effective for monitoring seismic faults, as it can detect micro-seismic activity and subtle movements along fault lines in real-time. This high-resolution data allows for better characterization of subsurface structures and provides critical insights into tectonic stability, significantly improving early warning systems and geological research.
Rio-Patras fault
The fault sits at the western termination of the Corinth Rift, right where it transitions into the Gulf of Patras graben. This area hosts several active faults located beneath the city of Patras and surroundings, a region of major socioeconomic importance for Greece.
The Rio-Patras fault separates two blocks with distinct deformation behavior, sitting at the critical junction where Corinth Rift extension transitions into the oblique kinematics of the western Hellenic arc. Microseismicity studies consistently show a seismic gap along much of the fault despite clear geomorphic and InSAR evidence of active displacement, suggesting significant aseismic slip accommodates part of the strain budget. The original interpretation attributed this to faults soling into a shallow decollement with velocity-strengthening rheology, though recent relocations challenge the decollement geometry and instead point to depth-dependent partitioning between normal and strike-slip mechanisms. Multi-temporal InSAR confirms measurable differential motion across the fault blocks, but cannot yet resolve whether the shallow fault plane is creeping freely or partially locked and accumulating a slip deficit. Constraining the coupling ratio on the Rio-Patras fault, through denser GNSS transects and InSAR time-series modeling, is essential for realistic seismic hazard assessment of the Patras urban area. In the area nine modern GNSS stations will be deployed until May 2026.
The Rio-Antirrio bridge sits right on this transition zone, and the city of Patras (Greece’s third-largest) straddles the fault’s hangingwall. Any fault characterization feeds directly into site-specific seismic hazard for both.
Current Progress
Upcoming Milestones & Forward Plan
Work involved in preparing the terrain, highlighting the scale of the trenching and the preparation of the bedding.
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