GHEAD v1.0 contains 1097 3-component accelerometric waveforms generated by 401 earthquakes occurred in the broader Aegean area with magnitude equal and greater than 4.0 for the time period 1973-2010. For the period 1973-1999 data have been recorded by the National Accelerometric Network, operated by the Institute of Engineering Seismology & Earthquake Engineering (ITSAK) Research Unit of the Earthquake Planning & Protection Organization (OASP-ITSAK) and the Geodynamic Institute of the National Observatory of Athens. For the period 2000 to 2010 only data of ITSAK are included.

All the waveforms are uniformly processed following the general steps:

  • Visual screening to identify records with “non‐standard errors” that should be screened out (not used) or given special treatment during subsequent processing.
  • Windowing of records to identify the time intervals within which the accelerograms occur.
  • Mean removal and low‐cut filtering to reduce noise effects.

For the processing procedure programs in the TSPP suite of time‐series processing routines (Boore, 2012) were used.

The GHEAD portal allows users to query earthquake, station information and ground motion parameters, as well as to select and download processed and unprocessed accelerometric waveforms and response spectra. The metadata relative to seismic events and recording stations are revised on a yearly basis according to authoritative national and international sources.

GHEAD is particularly targeted for:

  • seismologists and strong-motion data analysts
  • geotechnical and earthquake engineers
  • national agencies involved in seismic risk mitigation
  • students and professionals, if adequately trained

GHEAD v1.0 has been designed, implemented and filled under the co-ordination of OASP-ITSAK, thanks to the following contribution:

  • “GHEAD - National Accelerometric Network Information System”, (MIS 452095) which is implemented under the Action “Digital Convergence”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSFR 2007-2013) and co-financed by Greece and the European Union (European Regional Development Fund).
  • “HELPOS - Hellenic Plate Observing System” (MIS 5002697) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund).
  • Theodoulidis N., I. Kalogeras, C.B. Papazachos, V. Karastathis, B.N. Margaris, Ch. Papaioannou, Skarlatoudis A.A., (2004). HEAD v1.0: A unified Hellenic Accellerogram Database, Seism. Res. Let., 75, 36‐45.
  • Boore D.M. (2012). TSPP ‐ A Collection of FORTAN Programs for Processing and Manipulating Time Series, U.S. Geological Survey Open File Reportt 2008‐1111, V4.3, 09 Oct.. 2012, 47pp.
  • Margaris, B., I. Kalogeras, Ch. Papaioannou, A. Savvaidis, and N. Theodoulidis (2014). Evaluation of the national strong motion network in Greece : deployment, data-processing and site-characterization, Bull. Eqk. Eng. 12, 237-254.
  • Margaris B., Scordilis M., P. Stewart J-P., Boore D., Theodulidis N., Kalogeras I., Melis N., Skarlatoudis A., Klimis N., Seyhan E. (2019). Hellenic Strong‐Motion Database with Uniformly Assigned Source and Site Metadata for period of 1972‐2015, Seism. Res. Let. (under review).

This site provides access to recordings of the ITSAK Strong Motion Network, containing strong-motion records and associated earthquake, station and waveform parameters. The user can interactively search the fully relational database and download the selected strong-motion records and associated parameters.

Τhe earthquake, station and waveform parameters are obtained from the best up to date available data. Even if all the parameters have been checked by analysts, no warranty, implicit or explicit is attached to the data. Every risk due to the improper use of data or the use of inaccurate information is assumed by the user.

In no event shall ITSAK (Institute of Engineeting Seismology and Earthquake Engineering) be liable to any party for direct, indirect, special, incidental, or consequential damages, including lost profits, arising out of the use of the works.

The content of GHEAD v1.0 database is available under the Creative Commons Attribution 4.0 International (CC BY 4.0) License

According to this license, you are free to:
  • Share — copy and redistribute the material in any medium or format
  • Adapt — remix, transform, and build upon the material for any purpose, even commercially.

Under the following terms:

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

Please notice: This is a human-readable summary of (and not a substitute for) the actual license.