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We present an analysis of the 15 February 2011 X-class solar flare,previously reported to produce the first sunquake in solar cycle 24 (Kosovichev2011). Using acoustic holography, we confirm the first, and report a second,weaker, seismic source associated with this flare. We find that the two sourcesare located at either end of a sigmoid which indicates the presence of a fluxrope. Contrary to the majority of previously reported sunquakes, the acousticemission precedes the peak of major hard X-ray (HXR) sources by severalminutes. Furthermore, the strongest hard X-ray footpoints derived from RHESSIdata are found to be located away from the seismic sources in the flareribbons. We account for these discrepancies within the context of aphenomenological model of a flux rope eruption and accompanying two-ribbonflare. We propose that the sunquakes are triggered at the footpoints of theerupting flux rope at the start of the flare impulsive phase and eruptiononset, while the main hard X-ray sources appear later at the footpoints of theflare loops formed under the rising flux rope. Possible implications of thisscenario for the theoretical interpretation of the forces driving sunquakes arediscussed.

February 15, 2011: sun-quakes produced by flux rope eruption