Adv. Geosci., 36, 77–80, 2014 www.adv-geosci.net/36/77/2014/ doi:10.5194/adgeo-36-77-2014 © Author(s) 2014. CC Attribution 3.0 License. The 2013 Earthquake Series in the Southern Vienna Basin: location M.-T. Apoloner 1 , G. Bokelmann 1 , I. Bianchi 1 , E. Brückl 2 , H. Hausmann 3 , S. Mertl 4 , and R. Meurers 3 1 Department of Meteorology and Geophysics, University of Vienna, Vienna, Austria 2 Department of Geodesy and Geoinformation, Vienna University of Technology, Vienna, Austria 3 Zentralanstalt für Meteorologie und Geodynamik, Vienna, Austria 4 Mertl Research GmbH, Vienna, Austria Correspondence to: M.-T. Apoloner (maria-theresia.apoloner@univie.ac.at) Received: 13 June 2014 – Revised: 22 July 2014 – Accepted: 24 July 2014 – Published: 27 August 2014 Abstract. Eastern Austria is a region of low to moderate seis- micity, and hence the seismological network coverage is rel- atively sparse. Nevertheless accurate earthquake location is very important, as the area is one of the most densely popu- lated and most developed areas in Austria. In 2013 a series of earthquakes with magnitudes up to 4.2 was recorded in the Southern Vienna Basin. With portable broadband, semi-permanent, and permanent installed seismic sensors from different institutions it was possible to record the main- and aftershocks with an unusual multitude of close- by seismic stations. In this study we combine records from all available sta- tions up to 240 km distance in one dataset. First, we sta- bilize the location with three stations deployed in the epi- central area. The higher network density moves the location of smaller magnitude events closer to the main shocks, with respect to preliminary locations achieved by permanent and semi-permanent networks. Then we locate with NonLinLoc using consistent picks, a 3-D velocity model and apply sta- tion corrections. This second approach results in stable epi- centers, for limited and even changing station availability. This dataset can then be inspected more closely for the presence of regional phases, which then can be used for more accurate localizations and especially depth estimation. Fur- ther research will address directivity effects and the asym- metry in earthquake intensity observed throughout the area, using double differences and cross-correlations. 1 Introduction The study area is situated at the transition of the Eastern Alps to the Pannonian Basin and the Western Carpathians. The Vienna Basin is, due to the vicinity to Vienna, one of the most densely populated and developed areas in the region. Instrumentally recorded seismicity in the area is moder- ate, with a maximum registered magnitude of around 5. The Vienna Basin Fault System occasionally shows earthquakes with magnitudes larger than 4, for example in 1938 close to Ebreichsdorf one event with a magnitude of 5.0. Historical records (e.g., Gutdeutsch et al., 1987) and paleoseismicity (e.g., Hintersberger et al., 2010) indicate that even stronger earthquakes occur, more infrequently. The Austrian seismological network is built of very high quality stations. However, due to large inter-station distances the allocation of an events to a fault is not always definite. Earthquake location and depth estimation accuracy can be increased with different approaches: additional seismic sta- tions, particularly close to the epicenter, are the easiest way of improvement. As most location techniques are strongly dependent on the velocity model, the use of a regionally adapted model has a significant impact. The location tech- nique itself has a big influence as well, in particular as seis- mic data and the velocity model enter in different ways. In this article, we show an earthquake series south of Vi- enna in fall 2013, and which steps can be taken to improve and stabilize location. We deployed additional stations and collected all available data up to 240 km distance to form a comprehensive dataset. We use two different location tech- niques with two distinct velocity models. This article illustrates the change in location and tries to allocate the earthquakes to known faults. Published by Copernicus Publications on behalf of the European Geosciences Union.