Sonardyne International has provided a major refurbishment of a network of deep water acoustic sensors which for the past decade have provided coastal communities around India with early detection of tsunami waves.
Deployed at key locations in the Bay of Bengal and Arabian Sea, the Sonardyne bottom pressure recorders (BPRs) detect the characteristic changes in water pressure caused by an earthquake in the deep ocean. If a tsunami wave is detected, an alert message is transmitted up to a satellite buoy on the surface, from where it is relayed to the tsunami warning centre onshore for comparison with recent seismic activity. If validated, a wide scale alarm is raised to alert vulnerable communities, the company explained.
The detection system is owned and operated by India’s National Institute of Ocean Technology (NIOT) based in Chennai, and was conceived following the deadly Boxing Day tsunami of 2004.
Each BPR is a customized version of Sonardyne’s Compatt transponder – a subsea instrument that has a wide range of autonomous monitoring and measuring applications within offshore energy, survey and ocean science.
In reaching the 10 year anniversary, the decision was made by NIOT to recover the BPRs one at a time and return them to Sonardyne’s main service centre in the UK for refurbishment and re-certification.
The work included replacing acoustic transducers, calibrating pressure sensors, replacing consumables and updating PCB firmware to the latest specification. All BPRs have now been returned to the field, the company noted.