S01d Seismological Observation and Interpretation: Macroseismology and Historical Earthquakes

IASPEI (Seismology, Geophysics)



27-Jun-2015, 15:00 - 16:30


 
Abstract content:

Conclusions reached from environmental effects of historical earthquakes occurred in the Pannonian Basin

Macroseismic observations and contemporary records are the only primary information to reconstruct hypocenter data and shaking intensity in case of historical earthquakes. Previously attention has been paid mainly to the analysis of effects on humans and manmade structures. During this research we have focused on the environmental effects, especially on soil liquefaction caused by stronger historical earthquakes.
Most part of Hungary are low-lying plains covered by young Holocene fluvial sediments with high ground water level. Consequently, the area is susceptible to development of liquefaction. Despite the moderate seismicity, several liquefaction cases have been documented during larger (M5.4-6.3) historical earthquakes, for example in Komárom (1763, 1783, 1822), Mór (1810), Érmellék (1829, 1834), Kecskemét (1911) and Dunaharaszti (1956). Most of the earthquakes listed occurred before the start of instrumental recordings.
We have studied spatial extension of surface manifestations of liquefaction on the basis of contemporary observations, as well as local subsoil conditions and ground water level. We have modelled horizontal ground accelerations possibly caused by these historical earthquakes using ShakeMap program.
In case of Komárom earthquake in 1763, epicentral intensity has been estimated on ESI 2007 scale and compared with other intensity estimates. Distribution of settlements where liquefaction was observed supports the assumption that the epicenter of the earthquake was probably located NW from Komárom as proposed earlier on the basis of the damage distribution.
We could identify some places where liquefaction occurred during the 1956 Dunaharaszti earthquake. On the basis of SPT and CPT measurements we have estimated the maximum surface acceleration.

 
Author(s):
E. Gyori1, P. Mónus1, Z. Bán2, L. Tóth1.
1MTA CSFK Geodetic and Geophysical Institute, Seismological Observatory, Budapest, Hungary.
2Budapest University of Technology and Economics, Department of Geotechnics, Budapest, Hungary.

 

Keywords:
historical earthquakes     liquefaction     ENI 2007 scale     acceleration