ELF Q-burst caused by extragalactic gamma ray burst

Experimental results are presented on the electromagnetic pulse associated with the abrupt change in the Earth-ionosphere cavity caused by the intense gamma ray burst of December 27, 2004. Parameters of observed extremely low frequency pulse correspond to expectations: the source bearing points to the epicenter of the ionosphere modification, the pulsed waveform is similar to that computed, and its amplitude exceeds by a few times the level of regular Schumann resonance background. The ELF pulse onset at the Karymshino observatory (52.8° N, 158.3° E) is ~0.16 s prior to the published time of modification in the VLF records.