Unit:
ΠΜΣ με ειδίκευση στη Γεωφυσική - ΣεισμολογίαLibrary of the School of Science
Author:
Σταυριανάκη Κατερίνα
Supervisors info:
Dr V. Kouskouna Associate professor NKUA, Dr T. Rossetto Reader UCL, Dr M. Stavropoulou Assistant professor NKUA
Original Title:
Intensity EMS-98 and vulnerability evaluation for early 20th century Greek historical earthquakes
Translated title:
Προσδιορισμός της μακροσεισμικής έντασης EMS-98 και της τρωτότητας σε ιστορικούς σεισμούς στις αρχές του 20ου αιώνα στην Ελλάδα.
Summary:
The aim of this study is to analyze damaging historical – instrumental
earthquakes of the early 20th century in Greece using contemporary
methodologies. Firstly the macroseismic intensity in the EMS-98 scale using
both macroseismic and computational methods was evaluated. Main part of the
intensity evaluation was the vulnerability assessment. Such procedure can
provide information considering the evolution of buildings with historical and
cultural interest through the time. In order to assign a vulnerability class,
contemporary photographic material and descriptions of the buildings provided
by the local newspapers and seismological compilations gathered and processed.
Since a variety of data sources was used to evaluate the intensity, the results
were distinguished into different categories with the use of a quality factor.
The quality factor provides to the reader direct information about
uncertainties in terms of reliability, veracity and locality. The significance
of the quality factor was analyzed and it was found that parameters such as the
plethora of the macroseismic data and the effects of the aftershock sequence
can cause differences on its value. The results of the evaluation were used as
an indicator of quality and did not alter the intensity evaluation.
Isoseismal maps of the earthquakes using all the available data and isoseismal
maps containing the data with the best quality factor were drawn and compared
to pre- existing maps of the same earthquake. Similarities and differences are
discussed extensively.
A second evaluation of the EMS-98 intensity was also performed. This procedure
involves the calculation of the peak ground acceleration (PGA) from ground
motion prediction equations and then the correlation of acceleration with the
intensity using a different equation. In order to calculate PGA different
parameters such as the moment magnitude, the epicentral distances and the soil
classification were determined.
More specifically the moment magnitude was taken from the macoseismic catalogue
(Makropoulos et al 2012).
The epicentral distances were calculated with respect to the geoid.
A soil classification was performed according to NEHRP, for each location by
using geological and geotechnical maps of the study area as well as information
concerning the shear velocity (Vs30 ) and Standard Penetration Test (SPT)
values. The standard penetration test (SPT) is an in-situ dynamic penetration
test designed to provide information on the geotechnical engineering properties
of soil. The number NSPT was used in empirical equations correlating this
number with the shear velocity. For every location a soil classification
integer was assigned ranging from 0 to 3, where 0 indicates rocks and 3
indicates soft soils. The importance of the local geology it is shown in our
results were differences of observed and calculated intensity can be attributed
in the soil conditions.
Finally the conclusions derived from the above mentioned methodologies are
presented.
Keywords:
Intensity EMS-98, Vulnerability evaluation, Historical earthquakes, Peak ground acceleration, Site classification
Number of index pages:
5-9
File:
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document.pdf
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