Russia Completes Last IMS Station

January/February 2024

Russia has completed construction of its 32nd and final seismic station designed to detect nuclear tests banned under the Comprehensive Test Ban Treaty (CTBT), and the facility is now in operation.

The station, located at Yuzhno-Sakhalinsk, more than 6,000 kilometers east of Moscow in the Oblast Republic, is part of a unique global monitoring network operated by the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) called the International Monitoring System (IMS). The system was established to verify compliance with the CTBT.

“The 32 stations in the Russian Federation’s now complete IMS segment are crucial components of the global network that helps maintain peace and security by making sure that no nuclear test goes undetected,” CTBTO Executive Secretary Robert Floyd said in a Dec. 14 statement on the organization’s website.

When completed, the IMS will consist of 321 monitoring stations and 16 laboratories hosted by 89 countries around the globe, according to the CTBTO website. About 90 percent of these 337 facilities are already operational, providing a steady flow of real-time data.

Construction of the station at Yuzhno-Sakhalinsk commenced in May 2021, but experienced several delays due to harsh winter conditions, deforestation, and unexpected discoveries of endangered plants. The station was finished in August 2023 and now transmits seismic data to the data center at the CTBTO headquarters in Vienna.

In November 2023, Russia rescinded its ratification of the CTBT. Nevertheless, it remained a signatory to the treaty and expressed its intention to continue adhering to the nuclear testing moratorium and operating IMS stations on its territory. (See ACT, November 2023.)—SHIZUKA KURAMITSU