Dissertation committee:
Λέκκας Ευθύμιος, Καθηγητής, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών (Επιβλέπων)
Κουκουβέλας Ιωάννης, Καθηγητής, Τμήμα Γεωλογίας, Πανεπιστήμιο Πατρών
Κασσάρας Ιωάννης, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Σκορδύλης Εμμανουήλ, Καθηγητής, Τμήμα Γεωλογίας, Αριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης
Γκανάς Αθανάσιος, Ερευνητής Α, Διευθυντής Ερευνών, Εθνικό Αστεροσκοπείο Αθηνών
Σταυροπούλου Μαρία, Καθηγήτρια, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Baptista Μaria Αna Viana , Καθηγήτρια, Ανώτατη Σχολή Μηχανικής, Πολυτεχνείο Λισαβόνας
Summary:
The impact of the earthquakes on the human communities and on the natural environment is multifold
and comes as a direct or indirect result of the earth’s shaking. The present thesis is a contribution
towards two main objectives: (1) to organize for the first time an earthquake impact database in
Greece, and (2) to investigate the spatio-temporal distribution of the earthquake impact and how it
possibly depends on various factors, such as seismicity parameters, macroseismic intensity, time of
the day, season, and others.
In this frame, the overall research performed included three distinct phases: (1) The first phase has
been devoted to the compilation of the “best” seismicity data sets for both the instrumental (1900-
2020) and the historical time periods; (2) The second phase comprised the collection and examination
of a large number of earthquake impact data sources and the organization of the Greek Earthquake
Impact Database (GEIDB) as well as the determination of appropriate Earthquake Impact Metrics
(EIMs) based on the data availability and on the international experience in this field; as a supplement
to GEIDB, the Greek Tsunami Impact Database (GTIDB) has been organized; (3) Finally, statistical
methods and GIS tools have been used to investigate, map and examine statistically possible
variations patterns of the several EIMs selected for the casualties, both fatalities and injuries, and for
the building damage.
The overall thesis is structured in nine chapters. Chapter 1 reviews the geodynamic and
seismotectonic setting of the Greek region. What follows is the analysis of seismicity catalogues
available for that region, an issue which is needed for the next chapters anyway. Based on the
descriptive and parametric catalogue by Papazachos and Papazachou (2003), which is a reference
work, we performed a first statistics about the impact data collected for earthquakes occurring from
the 6th century BC up to recently. We found that the reporting rate of destructive earthquakes
(MMIo≥VIII) remained nearly constant in the time interval from 1800 up to 2001. For this reason the
time interval 1800-2020 has been selected as the reference period for the examination of the
earthquake impact in Greece.
To investigate the dependence of the earthquake impact on seismicity parameters, e.g. earthquake
epicenters, focal depths and magnitudes, the “best” seismicity parameters should be selected.
Therefore, in Chapter 2, modern methods have been used to examine the level of completeness of the
various earthquake catalogues utilizing the statistical z-map toolbox. The results provide a clear
picture of the completeness of several Greek earthquake catalogues covering the entire reference
period 1800-2020.
In Chapter 3 a methodology has been developed to re-determine magnitudes of 52 shallow and
intermediate-depth earthquakes of M~5 and over. To this purpose, trace wave amplitudes recorded
by five Agamennone-type seismographs that operated in Greece in that period, and published in the
Bulletins of the National Observatory of Athens (NOA), have been utilized for the first time to recalculate magnitudes calibrated over surface-wave magnitudes determined at the Institute of
Geodynamics, NOA, from post-1910 records in Mainka and Wiechert seismographs. This has been
achieved thanks to that the three types of seismographs (Agamennone, Mainka and Wiechert) shared
the common feature of being instruments of intermediate natural period, i.e. ~3.5-6.0 s. 11
In Chapter 4 statistical methods have been used to compare magnitudes and focal depths inserted in
various earthquake catalogues available for the time period 1911-2010.
Chapter 5 is devoted to the organization, format, internal structure and content of the Greek
Earthquake Impact Database (GEIDB), while in Chapter 6 several Earthquake Impact Metrics
(EIMs) have been introduced. Then, in Chapter 7 statistical and GIS tools were used to examine and
map the variation in space and time of the several EIMs as well as their correlation with seismicity
parameters, i.e. earthquake origin time, epicentral location, focal depth, and magnitude, as well as
with macroseismic intensity.
In Chapter 8 we focused our interest to the impact caused by tsunamis in the Greek region. However,
the organization of tsunami impact data sets has been rather neglected so far, since only a few
preliminary results have been presented. Therefore, we organized the Greek Tsunami Impact
Database (GTIDB) which has a structure similar to that of the GEIDB and it should be considered as
a supplement to it. Although this database covers the entire period from the antiquity up to the present
time, in this thesis we are interested for the part of the GEIDB that covers the reference period 1800-
2020.To show how tsunami impact data could be useful for the tsunami risk assessment two different
approaches have been applied. The first is the extreme scenario method applied to the coastal zone of
the test-site of Heraklion city, Crete. The second approach is a probabilistic method which utilizes
incomplete data sets and is based on the maximum likelihood estimation of the hazard parameters.
This approach was applied utilizing tsunami intensity data from Heraklion, from the city of Rhodes
and from the area of Aegion in Corinth Gulf, Central Greece.
Chapter 9 is devoted to a summary of the conclusions reached at in each one of the previous chapters of the thesis as well as on some suggestions and discussion for further research.
Keywords:
earthquake catalogues, magnitude comparison, magnitude determination, casualties from earthquakes, building damage, earthquake impact database, tsunami impact database, impact mapping, tsunami risk assessment
