Magnetospheric and Ionospheric Effects Accompanying the Strongest Technogenic Catastrophe

The results of observations of quasi-periodic variations of horizontal components of the geomagnetic field, the Doppler frequency shift of the radio waves reflected from the ionosphere, and observations of anomalous traces in ionograms during a catastrophe at the largest European ammunition depot on March 23, 2017, are presented. It is shown that the catastrophe was accompanied by oscillations of the geomagnetic field level (with periods from 5–6 to 13–14 min and an amplitude of 2–3 nT) and the ionospheric electron density (with periods from 14–16 to 50–60 min and a relative amplitude of ～1–10%). A mechanism for the transfer of disturbances from the catastrophe site to the ionosphere altitudes is proposed. A key role in this mechanism is played by the acoustic gravity waves generated by widespread explosions and large-scale fire events.