The 1999 Athens earthquake

One of the most significant natural disasters which stroke Greece in the 20th century was the September 7, 1999, 11h56m50s UTC, Mw (moment magnitude) 5.9 Athens earthquake. It claimed the lives of 143 people, and caused the collapse of several buildings, mainly in the northwest suburbs of the Greek capital. The approximate location of the earthquake epicenter was 38:10° N, 23:56° E, roughly 20 km northwest from the center of Athens.

The vertical displacement field at the surface level caused by this tectonic event was investigated with space born Synthetic Aperture Radar Interferometry (InSAR), using ERS-2 data and leveling data along the Mornos aqueduct. InSAR processing showed significant deformation with the maximum line-of-sight subsidence being approximately 6 cm. This observation was used in earthquake modeling and fault location mapping.

Earthquakes1 web

DInSAR over Athens and earthquake modeling (a) Seismotectonic map of Athens with seismogeological elements. The Aspropyrgos (F1) and Fyli (F2) faults are indicated, (b) distribution of aftershocks recorded by the Geodynamics Institute of the National Observatory of Athens array, (c) Co-seismic interferogram spanning the period Sept. 19, 1998 to Oct. 9, 1999, and (d) modeled interferogram calculated by least square inversion of the fringes. The two modeled fault segments and their traces on the surface, as well as the mapped Aspropyrgos (F1) and Fyli (F2) faults are illustrated.

Publications:

  • Kontoes, C., Elias, P., Sykioti, O., Briole, P., Remy, D., Sachpazi, M., Veis, G., and Kotsis, I. (2000). Displacement field and fault model for the September 7, 1999 Athens Earthquake inferred from ERS2 Satellite radar interferometry. Geophysical Research Letters, 27(24), pp. 3989-3992, DOI: 10.1029/2000GL008510.
  • Kotsis, I., Kontoes, C., Paradissis, D., Karamitsos, S., Elias, P., and Papoutsis, I. (2008). A methodology to validate the insar derived displacement field of the September 7th, 1999 Athens earthquake using terrestrial surveying. Improvement of the assessed deformation field by interferometric stacking. Sensors, 8(7), pp. 4119-4134, DOI: 10.3390/s8074119.