Skip to Main Content

Source properties of the 29 January 2011 M (sub l) 4.5 Oroszlany (Hungary) mainshock and its aftershocks

Zoltan Weber and Balint Sule
Source properties of the 29 January 2011 M (sub l) 4.5 Oroszlany (Hungary) mainshock and its aftershocks
Bulletin of the Seismological Society of America (February 2014) 104 (1): 113-127


In the most seismically active region of Hungary, an earthquake of M (sub L) 4.5 occurred near the town of Oroszlany on 29 January 2011. The mainshock was followed by more than 200 aftershocks. This event is the first earthquake in the country above M (sub L) 4 that was recorded on a significant number of three-component digital seismic stations. According to the inversion of arrival times, the hypocenter of the mainshock was at a depth of about 5 km near Oroszlany with horizontal errors of about 1.5 km. The aftershocks were confined to a small region next to the mainshock. For the main event, we obtained an average moment magnitude of M (sub w) 4.2, P- and S-wave source radii of r (super P) =970 and r (super S) =972 m, and static stress drops of Delta sigma (super P) =6.67X10 (super 5) and Delta sigma (super S) =17.60X10 (super 5) Pa from the analysis of P- and S-wave displacement spectra, respectively. The retrieved spectral source parameters for the investigated events agree well with the results of earlier research. We have also shown that our local waveform-inversion method applied in this study is suitable to estimate the earthquake source mechanism for low-magnitude events using local waveforms exclusively. The moment tensor computed for the mainshock from local waveform data shows a strike-slip mechanism with a north-south-striking and an east-west-striking nodal plane, agreeing well with regional moment tensor solutions of other agencies. The source mechanisms of four aftershocks with M (sub L) > or =2 were also successfully estimated. Three of them had strike-slip mechanism very similar to that of the mainshock, whereas the fourth one was a thrust faulting event with some strike-slip component. The subhorizontal P axis struck about northeast-southwest for both the mainshock and all the analyzed aftershocks, coinciding with the general trend of the compressional stress field in the epicentral region.

ISSN: 0037-1106
EISSN: 1943-3573
Serial Title: Bulletin of the Seismological Society of America
Serial Volume: 104
Serial Issue: 1
Title: Source properties of the 29 January 2011 M (sub l) 4.5 Oroszlany (Hungary) mainshock and its aftershocks
Affiliation: Hungarian Academy of Sciences, Kovesligethy Rado Seismological Observatory, Geodetic and Geophysical Institute, Budapest, Hungary
Pages: 113-127
Published: 201402
Text Language: English
Publisher: Seismological Society of America, Berkeley, CA, United States
References: 37
Accession Number: 2014-018563
Categories: Seismology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 4 tables, sketch maps
N47°00'00" - N48°00'00", E18°00'00" - E19°00'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Seismological Society of America. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201412
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal