DOI: 10.5281/zenodo.18341310
title: Enhanced Seismicity Monitoring in the Rapid Scientific Response to the 2025 Santorini Crisis - Earthquake Catalogues

description: This dataset accompanies the article: Segou, M., Dervisi, F., Tan, X., Choudhary, R., Martínez-Garzón, P., Scotto di Uccio, F., Beroza, G., Giacomuzzi, G., Chiarabba, C., Shelley, W., Prejean, S., Pesicek, J., Wellik, J. J., Bohnhoff, M., Pyle, D., Synolakis, C., Parsons, T., Ganas, A., Ellsworth, W., Baptie, B., Festa, G., Poli, P., and Marzocchi, W., “Enhanced Seismicity Monitoring in the Rapid Scientific Response to the 2025 Santorini Crisis”

We provide three seismicity catalogues for the Santorini region covering the 2025 crisis: an initial DL catalogue generated via QuakeFlow, an enhanced DL catalogue extended by template matching, and a relocated catalogue.

 

DL catalogue (DL_catalogue_Santorini_2025.csv): This catalogue was generated with the QuakeFlow deep learning workflow, which uses PhaseNet for phase picking and GaMMA for event association.




event_index
Unique event identifier


time
Event time (UTC)


magnitude
Event magnitude


longitude
Event longitude


latitude
Event latitude


depth_km
Event depth (km)


sigma_time
Standard deviation of phase time residuals (s)


sigma_amp
Standard deviation of amplitude residuals (in log scale)


cov_time_amp
Covariance between phase time and amplitude residuals


gamma_score
Sum of the posterior probabilities of all picks associated with the event (indicates association confidence)




 

Enhanced DL catalogue (enhanced_DL_catalogue_Santorini_2025.csv): This catalogue was produced with the EQCorrscan template matching technique using the initial deep learning detections as templates to scan continuous waveforms. Locations and magnitudes are assigned to newly detected events based on their cross-correlation similarity and amplitude ratios relative to the template events.




time
Event time (UTC)


ml
Local magnitude


ml_est_type
Local magnitude estimation type (AR or GAMMA)*


latitude
Event latitude**


longitude
Event longitude**


depth_km
Event depth (km)**




* For events detected by QuakeFlow, the magnitude was taken from the DL catalogue (GAMMA). For new events detected by template matching, the magnitude was derived through amplitude ratio with the most similar template (AR).

** For new events introduced by template matching, the location attributed is that of the most similar template.

 

Relocated catalogue (relocated_catalogue_Santorini_2025.csv): This is the relocated catalogue that was created using TomoDD, incorporating a 1D velocity model inverted with VELEST.




ID
Unique event identifier


LAT
Relocated latitude (decimal degrees)


LON
Relocated longitude (decimal degrees)


DEPTH
Relocated depth (km)


X
East-west location (m) relative to cluster centroid


Y
North-south location (m) relative to cluster centroid


Z
Depth location (m) relative to cluster centroid


EX
East-west error (m)


EY
North-south error (m)


EZ
Depth error (m)


NCCP
Number of cross-correlated P-wave data


NCCS
Number of cross-correlated S-wave data


NCTP
Number of catalogue P-wave data


NCTS
Number of catalogue S-wave data


RCC
RMS residual for cross-correlated data


RCT
RMS residual for catalogue data


time
Event time (UTC)


x(km)
2D Euclidean coordinate (Easting) based on (25.50E, 36.50N)


y(km)
2D Euclidean coordinate (Northing) based on (25.50E, 36.50N)


year_noa
Year from NOA catalogue


month_noa
Month from NOA catalogue


date_noa
Date from NOA catalogue


hour_noa
Hour from NOA catalogue


min_noa
Minute from NOA catalogue


sec_noa
Second from NOA catalogue


lat_noa
Latitude from NOA catalogue


lon_noa
Longitude from NOA catalogue


depth_noa
Depth from NOA catalogue


ml_noa
Local magnitude from NOA catalogue


x(km)_noa
2D Euclidean coordinate (Easting) based on (25.50E, 36.50N) from NOA catalogue


y(km)_noa
2D Euclidean coordinate (Northing) based on (25.50E, 36.50N) from NOA catalogue


ml
Calculated local magnitude


fi
Calculated Frequency Index




Further information can be found in the user guide of HypoDD (pages 21-22): https://www.ldeo.columbia.edu/~felixw/hypoDD.html

NCCP, NCCS, NCTP and NCTS can be used for quality control. Higher values (any individual, especially NCCP and NCCS, or the sum of four ($\geq 200$)) indicate a good constraint of the location.

Event info from NOA catalogue is provided if an earthquake could be associated with one from NOA catalogue based on a $\pm 1.5s$ time criterion.