Media Advisory - CTBTO Hydroacoustic Data to Aid in Search for Missing Sub San Juan

23 November 2017

For French version click here.
For Spanish version click here.

On 15 November 2017 two CTBTO hydroacoustic stations detected an unusual signal in the vicinity of the last known position of missing Argentine submarine ARA San Juan.

Hydroacoustic stations HA10 (Ascension Island) and HA04 (Crozet) detected a signal from an underwater impulsive event that occurred at 13:51 GMT on 15 November. The location of the event is as follows: Event Latitude: -46.12 deg; Event Longitude: -59.69 deg which is in the vicinity of the last known location of the ARA San Juan.

Details and data are being made available to the Argentinian Authorities to support the search operations that are underway.

The hydroacoustic stations are part of the CTBTO’s International Monitoring System (IMS) which monitors the globe continuously for signs of nuclear explosions. Low frequency underwater sound, which can be produced by a nuclear test, propagates very efficiently through water. Consequently these underwater sounds can be detected at great distances, even thousands of kilometres, from their source. This is why the IMS requires only eleven hydroacoustic stations to effectively monitor the world’s oceans. HA04 at Crozet Island (France) was certified in June 2017 as the final of these eleven stations.

This film on HA04 was produced earlier this year. For more see:

Elisabeth Wächter            
Chief, Public Information
T: +43 1 26030 6375                
M: +43 699 1459 6375

The CTBT bans all nuclear explosions, thus hampering both the initial development of nuclear weapons as well as significant enhancements. The Treaty also helps prevent harmful radioactive releases from nuclear testing.

The CTBT has so far been signed by 183 States and ratified by 166 (map). However its demanding entry-into-force provision requires 44 particular “nuclear technology holder” States to ratify the Treaty for it to enter into force. Eight of them have yet to ratify: China, the Democratic People's Republic of Korea (DPRK), Egypt, India, Iran, Israel, Pakistan, and the United States (China, Egypt, Iran, Israel, and the United States have already signed the Treaty).

A verification regime to monitor the globe for nuclear explosions is nearing completion with around 90 percent of the 337 planned International Monitoring System (IMS) facilities already in operation. The system has proved its capability to detect even small nuclear tests during the announced DPRK nuclear tests in 2006, 2009, 2013, 2016 and 2017.

The data from the IMS facilities are also used by the wider scientific community to study a range of unrelated issues, from climate change to marine mammal migration, and contribute to disaster risk reduction, such as tsunami early warning systems and monitoring volcanic activity.
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