The PrepCom of the Comprehensive Test Ban Treaty (CTBT) Organisation, based in Vienna, operates an extensive geophysical international monitoring system to detect any violations of the Nuclear Test Ban Treaty and announced the possibility of a nuclear test by the Republic of North Korea (www.ctbto.org/press-centre/press-releases/2016/ctbto-executive-secretary-lassina-zerbo-on-the-unusual-seismic-event-detected-in-the-democratic-peoples-republic-of-korea/). Explosion of the size of the January 6th event can be recognized on seismic recordings worldwide; the University of Vienna detected the event on its currently operative (30) seismic stations that are deployed within the AlpArray project. The pictures display the distribution of our seismic stations around Vienna, in Austria and Slovakia, and the recordings of the potential nuclear test. The seismograms show vertical ground motion on several stations and clearly display the arrival of a P-wave (compressional wave traveling through the Earth’s body). Seismic waves take approximately 11 minutes to propagate from North Korea to Central Europe. Scientists at the Department of Meteorology and Geophysics (IMG) are involved in CTBT research and develop techniques to detect underground cavities created by nuclear explosions during on-site inspections. Experts worldwide will now clarify, to which extent the event detected on January 6th corresponds to claim that have been made, e.g. whether it was indeed the explosion of a nuclear fusion device. More information about the IMG-Department can be found in Department of Meteorology and Geophysics, and about the AlpArray experiment in http://www.alparray.ethz.ch/home/www.alparray.ethz.ch/home/ .