President of Portugal visits IMS
station on the Azores

On 21 September 2011, the President of Portugal, Aníbal Cavaco Silva, visited International Monitoring System (IMS) Infrasound Station IS42 on Graciosa Island as part of his 5-day visit to the Autonomous Region of the Azores. His delegation included the President of the Azores government, the Mayor of Santa Cruz da Graciosa (the island's main settlement), government officials and media.
Graciosa is one of nine volcanic islands constituting the Azores archipelago. IS42 was installed in 2010 and is one of 60 infrasound stations in 35 countries worldwide. The station comprises eight data acquisition elements and one central recording facility. Since its installation in 2010, the station has had an impressive data availability of almost 100%.
Infrasound stations are capable of measuring acoustic waves with very low frequencies, inaudible to the human ear. As part of the Comprehensive Nuclear-Test-Ban Treaty's (CTBT) IMS network, they help monitor the Earth mainly for atmospheric nuclear explosions. The Azores also profit directly from the station, which has been integrated into the national volcanic earthquake surveillance network of the Azores to monitor geological hazards and general seismic activity in the region.

Nicolau Wallenstein from the Center for Volcanology and Geological Risk Assessment of the University of the Azores (right) showing President Aníbal Cavaco Silva and First Lady Maria Alves da Silva around the station.

IS42 is operated and maintained by the Center for Volcanology and Geological Hazard Assessment of the University of the Azores. Through better coverage of the North Atlantic, the station makes a vital contribution to the monitoring performance of the IMS worldwide network. The 60 infrasound stations work in synergy with 170 seismic, 11 hydroacoustic, 80 radionuclide stations and 16 radionuclide laboratories to monitor the planet around the clock for tell-tale signs of  a nuclear explosion. Around 85% of this network has been established to date.

Station IS42 is one of 337 facilities that monitor the globe for any sign of a nuclear explosion.

The verification regime of the CTBT is an extremely important element to make sure that the world can react in time to an event that may endanger international peace and security.

In addition to IS42, Portugal also hosts a radionuclide and a hydroacoustic monitoring station, both located on the islands Flores and São Miguel in the Azores. In February 2011, Portugal signed a facility agreement with the CTBTO covering the maintenance and operation of the three stations. See interview with Portugal's Secretary of State João Gomes Cravinho in CTBTO Spectrum. For more information on how infrasound technology works, read here.

IS42 on Graciosa Island was certified as meeting the CTBTO's quality standards in December 2010. Click for detailed information (PDF).