About 300 kilometres from the coast of Vancouver Island at a location dubbed Endeavor Ridge, a one-of-a-kind tsunami early warning system will soon be draped along the sea floor.
From above, X will mark the spot more than 2,000 metres below, as four ultra-sensitive pressure devices, each at the end of a 25-kilometre fibre optic cable, feed data through the Neptune system and to the Pacific Tsunami Warning Network.
Laying sausage-thick cable at 2000 metres down is painfully slow, delicate business, but it will give scientists and emergency authorities, for the first time, the direction and speed of tsunamis in the deep ocean, in real time.
“These kind of instruments do double duty,” says Kate Moran, director of Neptune Canada, a consortium of universities led by the University of Victoria. “They help us understand the physics of the ocean and also contribute to public safety.”
The giant, $3-million tsunami “antenna” will be plugged into the Neptune system, an 800-kilometre loop of powered fibre optic cable linked by 13-tonne nodes and feeding into hundreds of underwater scientific instruments. All data is streamed live through the Internet.
The tsunami device works by using extremely sensitive pressure transducers spread in a star formation. For this trip, two of the four will be installed this month, and the remainder in September. They also plan to install the pressure devices on Neptune’s sister, Venus, a cable network in the Saanich Inlet and the mouth of the Fraser River.
Moran noted that tsunamis barely cause a blip in wave height in the deep ocean, but, as well documented in disasters in Japan and the Indian Ocean, waves can reach the coast as an unstoppable wall of water.
Prototypes of the pressure device detected tsunamis near Chile in 2010 and Samoa in 2009. Moran said this device will give ocean scientists data to improve models for predicting tsunami speed, direction and intensity after an earthquake. It could also act as an early warning system for Vancouver Island.
National Oceanic and Atmospheric Administration operates a ring of buoys in the Pacific to provide tsunami early warning data. Moran hopes the tsunami antenna plugged into Neptune will help improve on that.
“We’ve tested the prototype. Now we’ll install the real McCoy,” said Moran, a tsunami expert who once served as a science advisor for the Obama administration. “We’ll collect data and continue to improve predictions of wave impacts on Vancouver Island.”
Laying the fibre optic cable involves spooling it off the 274-foot research vessel Thomas G. Thompson, and guiding it on the seafloor using a remotely operated submarine called an ROV. The ROV lays the cable and plugs it into the pressure device and a junction box on the Neptune network.
“Laying cable with the ROV is very tricky because the ship is always moving, and you’ve got to follow the ROV,” Moran said. “It takes a long time. It’s a dance between the ship and ROV in two kilometres of water.”