EGU22-11076, updated on 28 Mar 2022
https://doi.org/10.5194/egusphere-egu22-11076
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Preliminary results of the two seismic sequences in the Vienna Basin in March and April 2021 

María del Puy Papí Isaba1,2, Wolfgang Lenhardt1, Rita Meurers1, Maria Theresia Apoloner1, Helmut Hausmann1, Maurizio Mattesini2, and Elisa Buforn2
María del Puy Papí Isaba et al.
  • 1Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria
  • 2Universidad Complutense de Madrid, Madrid, Spain

We present a preliminary analysis of two seismic sequences between March and April 2021, near Neunkirchen and Gloggnitz, about 50 km from Vienna, Austria, and around 15 km apart from each other. Despite the moderate magnitudes, the recent earthquakes in the epicentral region, in the southern part of the Vienna Basin, were felt in the epicentral region and up to a distance of 300 km away. 

The Neunkirchen sequence started on March 11th, 2021. According to the Austrian Seismological Service at ZAMG, the last recorded earthquake occurred on May 12th, 2021. Over 245 earthquakes, with local magnitudes ranging from 0.5 to 4.6, were recorded until mid of May 2021. Out of the 245 earthquakes, 21 were felt by the population (1.8 ≤ ML ≤ 4.6), and two of them (ML4.6 and ML4.4) caused minor damage in the epicentral region. According to the Austrian Seismological Service, the depths of this sequence ranged from 7 to 12 km. 

The Gloggnitz sequence started on April 1st, 2021, and continued until May 8th, 2021. The epicenters of 65 detected earthquakes were located. Four earthquakes were felt, from which two (ML3.6 on April 20th and ML3.8 on April 23rd) caused slight damage. The local magnitudes of this seismic sequence ranged from -0.3 to 3.8; depths varied between 4 and 7 km. 

The relocation of the earthquakes of both sequences was carried out using the NonLinLoc by Lomax et al. (2019). We obtained the ellipse error for all relocated earthquakes. The focal mechanisms of the largest earthquakes were calculated using Seismic Moment-Tensor-Inversion. For the remaining events, a joint fault-plane solution was investigated. Furthermore, we compiled and analyzed the macro-seismic questionnaires of all felt earthquakes in the series and produced intensity maps (EMS-98). We compared the intensity attenuation as a function of distance with the newly available data and derived an Intensity Prediction Equation (IPE) for the region.

How to cite: Papí Isaba, M. P., Lenhardt, W., Meurers, R., Apoloner, M. T., Hausmann, H., Mattesini, M., and Buforn, E.: Preliminary results of the two seismic sequences in the Vienna Basin in March and April 2021 , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11076, https://doi.org/10.5194/egusphere-egu22-11076, 2022.

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