Hawaii leads effort to build global network of undersea 'smart cables'

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Inspecting an Xtera repeater on the High capacity, Undersea Guernsey Optical-fiber (HUGO) submarine network off the coast of Brest, France.

When it comes to disaster preparedness, every second counts.

Earthquakes, and the devastating tsunami they generate, can happen at any moment. And early warning systems are critical to saving lives.

Today, the state of the art is embodied by a global network of DART buoys, which can relay the presence of a deep ocean tsunami to shore in minutes.

But a project at the University of Hawaii aims to provide critical information almost instantly via 'smart cables.' And it just got a $7 million, five-year grant to advance from plans and prototypes toward a real-world deployment.

State of the DART

The latest-generation Easy To Deploy (ETD) DART buoy was introduced 10 years ago.

The Deep-ocean Assessment and Reporting of Tsunamis (DART) buoy was first developed in 1995, and the National Oceanic and Atmospheric Administration deployed the first six along the northern Pacific coast in 2001.

Today, there are 70 DART buoys positioned around the world, most of them in the seismically active Pacific Rim. They are a critical, front-line resource in protecting life and property along the world's densely populated coastlines.

They are effective, but expensive, and have to withstand very unfriendly environments.

For example, New Zealand last year committed to deploying 15 DART buoys at a cost of 47 million New Zealand dollars, or US$32 million. The five-year project also requires another US$500,000 in annual maintenance costs.

Meanwhile, the global system has struggled with reliability issues.

"Only about 70 percent are working at any one time," explains Bruce Howe, a Research Professor at the University of Hawaii School of Ocean and Earth Science and Technology (SOEST). "Those buoys are beat to s--t all the time and they just fail."

Between rough surf and storms, heat and cold, and the isolation of the open ocean, even the most rugged technology is pushed to its limits.

"No one's really succeeded in coming up with designs that can survive those kinds of conditions," he says.

And in other places, the threat is more basic.

"In more benign waters, say equatorial waters, you've got illegal fishing and vandalism," Howe says. "Elsewhere, the buoys just disappear in a few weeks, so it's not productive to even put them out."

Finally, getting data from DART buoys takes time.

"They're sort of slow in the sense that it takes 15 minutes to get a reading from the sea floor, up to the buoy, and then to a satellite, and then all the way to the warning center," Howe says. "So that's not ideal."

Fortunately, there are conduits that can transmit data across thousands of miles almost instantly, and they happen to also be located on the ocean floor, where deep sea earthquake and tsunami sensors need to be.

Smart seafloor cables

Part of the global submarine telecommunication network as of early 2021, comprising over a million kilometers of cable. Source: ECO/UN.

Howe is the principal investigator of the Science Monitoring And Reliable Telecommunications (SMART) Subsea Cables initiative, which just received more than $7 million from the Gordon and Betty Moore Foundation.

The grand plan is to upgrade the existing and growing network of subsea telecommunications cables to a global network of smart seafloor cables to support early warning systems for tsunamis and earthquakes.

And while it was a new idea for me, Howe's been thinking about it for decades.

"I've been working on smart cables specifically for the last 10 years," Howe says. "But I started working with cables back in 1990 when I was using Navy cables to do ocean acoustics."

One of his first large research projects was at the Applied Physics Lab at the University of Washington, where scientists wanted to directly monitor the development of life in the extreme environment around an underwater volcano.

It was an installation more than 20 years in the making, and one Howe worked on for a decade. But he's also in charge of a undersea monitoring station here in Hawaii that I've heard about: the ALOHA Cabled Observatory.

The ALOHA Cabled Observatory provides real-time oceanographic observations via a submarine fiber optic cable that comes ashore at Makaha on Oahu.

"It uses an old first generation fiber cable on the north side of the islands and has a 5,000 meter water depth," Howe explains.

In fact, the ALOHA observatory celebrated its 10th anniversary in June, marking a historic stretch of continuous temperature, salinity, currents, and acoustic observations.

"It's plug and play, but you need a ship and a robot to go down and connect instruments and service them or bring them up, which is expensive."

Howe wanted to overcome most of the limitations he'd worked with over the years, from sensor durability and accessibility to cost.

"Those are examples of dedicated science early warning systems with no commercial telecom involved — the technologies are not commercial," he says. "The whole point of smart repeaters and smart sensing is to try and do it cheaply, relatively speaking."

The 'piggyback' approach

Undersea telecom cables position repeaters along the route to sustain data signals across long distances.

By integrating ocean temperature, pressure, and seismic sensors into commercial submarine telecommunications systems that already crisscross the ocean floor, researchers hope to transform the current telecom network into a combined telecom and ocean, climate and geophysical sensor array capable of informing early warning systems.

“This brilliant project will transform the practical cables that link communications and commerce into a world-wide scientific instrument of profound importance to every person on Earth," said Robert Kirshner of the Gordon and Betty Moore Foundation in a press release.

To do so, however, requires the cooperation and support of telecom companies and governments. And that support means the project needs to be both unobtrusive and relatively inexpensive.

"We piggyback on the telecom infrastructure and we're tapping into their power and communication systems," Howe explains. "We think we can package all these sensors and take maybe five percent of the volume and five to ten percent of the power in these undersea repeaters."

"The main requirement is that if anything in the science sensor system fails, it will not in any way negatively impact the telecom," he adds.

To achieve planetary-scale coverage, Howe says the smart cable upgrades will likely translate into about 10 percent of the overall cost of the telecom system.

"The telecom companies are coming around, they do see that one can technically do it without interfering, and they've said all along that as long as someone else pays for it, they're happy to do it."

From concept to practical reality

The cable between New Caledonia and Vanuatu is expected to be equipped with sensors allowing to measure the effects of climate change and detect seismic activity.

The objective of the latest funding is to conduct simulations of the proposed observing system based on a planned smart cable system in Vanuatu-New Caledonia.

"There's no intent to actually pay for any of the wet system, the cable itself," Howe says. "The Moore funding will pay for the scientific and early warning ecosystem that surrounds the cable.

"It's the research, setting up the warning centers to handle the data, doing the data management to make sure the data goes internationally to every single warning center, and then doing the science to understand the data as well," he says.

Instead, the French government is providing nearly $20 million for the upgrades.

Earthquake and tidal wave causing destruction of buildings in Lisbon, Portugal, 1755. Hand-colored woodcut of a 19th-century illustration. Source: North Wind Pictures Archive.

Howe notes that a different undersea cable called CAM-2, which connects Lisbon, Madeira Island, and the Azores, will be required to include scientific sensors.

"They have a cable connecting those islands and Lisbon now, but it's approaching its nominal 25-year engineering life and they're looking to replace it," he says. "The director of the regulatory agency for telecom dictated that it shall have seismic and tsunami warning capability.

"That's almost 3,000 miles and it will have about 50 of these smart repeaters," he adds.

The reason for Portugal's strong support of smart cables is likely rooted in history.

"In 1755, there was a huge earthquake tsunami that destroyed Lisbon and much of the Portuguese and North African coastlines and effectively destroyed the Portuguese Empire," Howe says. "They were an empire, along with Spain and Britain and the Netherlands at the time, but after that, they went downhill."

A safer future

“We hope this project is a demonstration for the global audience about how communities and science can benefit from SMART cables," Howe concludes. "Ideally, the incorporation of smart capability would become a routine function for the submarine cable industry [and] will generate key reductions in human and planetary risk."

With the Gordon and Betty Moore Foundation funding, the project will be headquartered at UH Mānoa as the international project office of the Joint Task Force for Scientific Monitoring And Reliable Telecommunications cables. The task force is endorsed by the United Nations Ocean Decade for Sustainable Development, and sponsored by the International Telecommunication Union, World Meteorological Organization, and the Intergovernmental Oceanographic Commission of UNESCO.

Header image courtesy Yuichiro Chino/Getty Images.