Complex Rupture Process of the 19 March 2013, Rudna Mine (Poland) Induced Seismic Event and Collapse in the Light of Local and Regional Moment Tensor Inversion

Abstract

On 19 March 2013, a strong, shallow, induced seismic event struck a mining panel in the room-and-pillar Rudna copper mine in southeastern Poland. The event caused important damage at the mining tunnel and trapped 19 miners, who were safely rescued a few hours later. Although mining-induced seismicity is frequent at this mine, the 19 March event was unusual because of its larger magnitude, its occurrence far from the mining stopes, and because it was accompanied by a strong hazardous rockburst. The mining inspections following the event verified the occurrence of a rockfall with tunnel floor uplift but also recognized the presence of a faulting structure at the hypocentral location. The availability of three monitoring networks (including local and regional data, short-period and broadband seismometers, and surface and in-mine installation) presented an optimal setup to determine rupture parameters and to compare the performance and results from different installations. We performed waveform and spectral-based analysis to infer source properties, with a particular interest to the determination of the rupture processes, using different moment tensor (MT) inversion techniques. Our results are surprisingly different, ranging from a dominant thrust mechanism, resolved at closest distances, to a collapse-type rupture, resolved at regional distances. We demonstrate that a complex rupture model is needed to explain all observations and to justify these discrepancies. The final scenario indicates that the rupture nucleated as a weaker thrust mechanism along a pre-existing weakened surface and then continued in a more energetic collapse event. The local LUMINEOS surface network has the potential to resolve both subevents but not using a standard MT decomposition. Here, we propose a new MT decomposition and an alternative MT fitting procedure that can be used to analyze the MT of collapse sources.Online Material: Tables of regional stations and source parameters, and figure of displacement seismograms.

Moment Tensor Inversion for Nuclear Explosions: What Can We Learn from the 6 January and 9 September 2016 Nuclear Tests, North Korea?

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“…The full MT decomposition into isotropic and deviatoric components is unique, but the decomposition of the deviatoric term is not (the standard one is by CLVD and DC with a common axis; see Jost and Hermann, 1989;Minson and Dreger, 2008). Recent interpretations of collapse events in mining (Rudzinski et al, 2016) and volcanic (Heimann et al, 2015) environments illustrate potential interpretation pitfalls due to the standard MT decomposition.…”

Full Moment Tensor Inversion as a Practical Tool in Case of Discrimination of Tectonic and Anthropogenic Seismicity in Poland

“…2). Moreover, the 1D velocity model in case of regional epicentral distances in Poland seems to be very general approximation (Rudziński et al 2016) and due to the complex geology of Poland it may be the source of the errors. It is proved that TornquistTeisseyre zone influence the S-wave splitting (Wiejacz 2001).…”

“…These mines produce annually several hundreds of seismic events with local magnitude in the range 0.4-4.5 (Lasocki 2005). The largest events in this area were M L = 4.5 from March 24th 1977 (Gibowicz et al 1979) and M L = 4.3 from June 20th 1987 (Gibowicz et al 1989) both located within ''Lubin'' mine, and M L = 4.2 from March 19th 2013 located in ''Rudna'' mine (Lizurek et al 2015;Rudziński et al 2016). Moment tensor solutions for most of the significant events are available (e.g.…”

Assessment of Quantitative Aftershock Productivity Potential in Mining-Induced Seismicity

“…Following Rudziński et al (2016), we assumed that the M w 4.2 main shock consisted of two subevents. The moment tensor (MT) of the first subevent was determined based on in-mine network using FOCI software (Lizurek et al 2015;Kwiatek 2013), whereas the MT of the second subevent was based on the regional network, using the Kiwi tool inversion platform (Heimann 2011;Cesca et al 2013) and the local velocity model of Poland, GM2003 (Grad et al 2003).…”