NPL, UK and MSL in New Zealand successfully detected a multitude of earthquakes in the Pacific Ocean using a pioneering detection technique
News from Members - NPL, UK

credit for the photo : Shutterstock/Vismar UK

First earthquakes detected in Pacific Ocean using ultra-stable optical interferometry on undersea cables

The team are performing ultra-sensitive optical measurements, converting a branch of the Southern Cross Next seafloor cable, which connects New Zealand to Australia, into an array of sensors for earthquakes and ocean currents. The technique uses the optical fibre inside the cable as the sensing element and gathers environmental data from the seabed, where no other permanent sensors exist.  

The Pacific Ocean is a highly seismically active area and since the start of the measurements in October 2024, the team have already recorded more than 50 earthquakes, with epicentre from tens to hundreds of km from the cable. This high rate of detection will drastically accelerate the research and the refinement of the technique, which was previously tested in the less seismically active Atlantic Ocean.  

Using NPL’s technique, the team will be collecting measurements until December 2025, providing the game-changing potential to develop a worldwide monitoring network of seafloor sensors using the existing subsea infrastructure. Indeed, whilst over 70% of the Earth’s surface is covered by water, the ocean floor is largely unmonitored. This limits our understanding of the Earth structure and dynamic behaviour. The innovative sensing technique being tested in the Tasman Sea can help start filling the existing data gap and improve our understanding in a number of science areas, from seismology to oceanography and climate change.  

Tsunami experts at GNS Science (in New Zealand) will analyse the data to assess its potential also for detecting tsunamis and explore how these new technologies can be complementary to more traditional approaches. The synergy between old and new techniques could significantly improve our ability to respond to natural hazards with significant benefits to coastal communities, especially those in areas frequently affected by earthquakes and tsunamis such as in the Pacific. 

This international collaboration is enabled by the UK’s International Science Partnership Fund and supported by New Zealand’s Quantum Technologies Aotearoa programme.  

More information can be found here: 

First earthquakes detected in Pacific Ocean using ultra-stable optical interferometry on undersea cables

Fiona Jones (NPL, UK)

fiona.jones@npl.co.uk