Giuseppe Marra, the lead scientist at the National Physical Laboratory, shares more about new technologies that detected earthquakes in the Pacific Ocean.
Using a new detection method that converts submarine fiber optic cables into sensors for earthquakes, researchers were able to successfully detect earthquakes in the Pacific Ocean.
Scientists at New Zealand’s National Institute of Physics (NPL) and the Institute of Metrics (MSL) have performed ultra-sensitive optical measurements, converting the branches of the next submarine cables on the Southern Cross that connects New Zealand to Australia into an array of sensors for earthquakes and currents. Tested in the Tasman Sea, this technique uses optical fibers in cables as sensing elements to collect environmental data from the seabed where there are no other permanent sensors.
The team first began measurements in October 2024 and will continue until December 2025. Since they started, the team has already recorded over 50 earthquakes in the Pacific Ocean. This high detection rate dramatically accelerates the research and refinement of previously tested technologies in the Atlantic, where seismic resistance is inactive.
Currently, the seabed is not primarily monitored. This new measurement technology promises to uncover a wealth of data from existing subsea infrastructure.
To learn about research collaboration and what it means for a broader knowledge of geoscience, the Innovation Platform spoke to Giuseppe Marla, the lead scientist at NPL.
Could you explain more about research collaboration and what it is trying to achieve?
This new UK-NZ collaboration aims to test submarine cable-based sensing technology in one of the planet’s most seismically active regions, the Southwest Pacific Ocean. This work is based on pioneering tests on the Atlantic submarine cable between the UK and Canada.
Here we first demonstrated innovative long-range sensing technology that can monitor thousands of kilometers of ocean signals. The Atlantic Ocean is one of the best places to study ocean currents. However, the frequency of earthquakes in the Pacific Ocean is significantly higher, and therefore the ability to collect large amounts of geophysical data in a relatively short time frame can accelerate research. The Tasman Sea, where the cables under test are located, is also a statistically good place to test early tsunami warning techniques.
Can you explain how the technique worked and how it was developed?
This technique allows existing submarine communication cables to be used as an array of environmental sensors. This is achieved by performing ultrafast optical measurements of the light velocity of optical fibers in submarine cables.
External environmentally induced cable perturbations, such as earthquakes and ocean currents, can change the time it takes for light to propagate through the cable. However, these are very small possibilities and can be detected by ultra-advanced measurements that labs like NPL can make.
The innovative method was developed at NPL and derived from research into techniques for comparing distant optical atomic clocks via optical fiber links. Comparing watches, environmental noise is an undesirable interference that can damage the ultra-stable signal from the watch, and is cancelled with some clever techniques. However, the unnecessary noise of optical clock comparisons contains information that is very useful to geophysicists. It’s a beautiful example of someone else’s noise becoming a signal to someone else.
What do you expect and expect from the outcome?
Analyses of data collected on the Tasman Sea cable, connecting New Zealand to Australia, have recently begun and are being carried out by the GNS (New Zealand Geophysics Institute). We hope for important results that will help us understand how these methods can be integrated with existing methods (such as land earthquake stations) and future early warning systems.
The data from the UK-Canadian Cable is fundamental to understanding the earthquake and ocean capabilities of the technology, and we are currently working with oceanologists to understand how these data can help us better understand ocean circulation and global warming.
Currently, the seabed is barely monitored. Why is it important to change this?
The lack of permanent sensors on the seabed limits our understanding of the Earth’s structure and dynamic behavior. A lack of data is extremely important as 70% of the earth is covered in water. For example, there are ways to detect surface currents from satellites and other surface sensors, but subsea currents are essentially not monitored. This technology allows us to have a much better understanding of ocean currents that regulate the world’s climate.
What are the possibilities of ocean surveillance technology in terms of broader impact?
This technology is a game changer for research into geosciences such as seismology and oceanography. But in the not too distant future, offshore earthquakes and tsunamis could pave the way for a much better warning system for the coastal population. This is one of the main aspects GNS researchers are considering when analyzing data on the South Crossing Cable between New Zealand and Australia. This technology can save future lives in the event of natural disasters and can have a significant positive impact on the coastal population.
What’s next for research collaboration?
Collaboration between both the Atlantic and Pacific Oceans laid the foundation for a new era of Earth surveillance. These pioneering tests show that it is indeed possible to expand land-to-sea monitoring capabilities using existing communications infrastructure. Through these collaborations, we hope to continue to push the limits of what these technologies can do, provide new tools to better understand planets and, importantly, new possible solutions for positive social impacts from protecting coastal populations to advances in climate change research.
This article will also be featured in the 22nd edition of Quarterly Publication.
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