Seismic Monitoring of Novaya Zemlya: Progress, Challenges, and Prospects

The permanent seismic stations of the European Arctic maintain a detection threshold of around magnitude 2 for events on and around Novaya Zemlya. Events above mag-nitude 3 are clearly observed by multiple stations at regional and far-regional distances and, with improved travel-time models, can be located with high accuracy. The mon-itoring capability for smaller magnitude events is dominated by the small aperture seis-mic arrays ARCES and SPITS. We review the properties of Novaya Zemlya seismic signals on key stations and discuss how empirical signal processing may enhance detection and interpretation of future events in the region. We present a joint probabilistic location for 21 low-magnitude events between 1986 and 2020 in which the joint probability dis-tribution for all events simultaneously exploits both constraints on earlier events from stations no longer in operation and constraints on newer events from more recently deployed stations. Advances in signal processing, enhanced exploitation of archive data, new permanent stations, and comparative multiple event analysis will all contrib-ute both to a more robust and sensitive detection capability and higher confidence in signal interpretation.