I doubt that many of my readers have heard about the Samoan Passage. I certainly hadn’t until several weeks ago when I saw the video below. You already know that I’m a science geek, so it shouldn’t surprise you that I was drawn to a story about groundbreaking oceanographic and climate research funded by the U.S. Government and carried out by a world-class team from the University of Washington in conjunction with the Scripps Institution of Oceanography.
The Samoan Passage is the largest and deepest slot in a series of ridges separating the deep basins of the North and South Pacific. It’s essentially a choke point or “nozzle” approximately 18,000 feet (5,500 m) beneath the surface of the ocean near the Samoan islands through which cold Antarctic water must flow on its way to the North Pacific. Part of Earth’s complex ocean circulation patterns, the Passage funnels more than six million tons of water every second. That’s 50 Apia Rugby Stadiums full of water passing through each second.
Approximately 70% of all water deeper than 2.5 miles (about 4 km, or 4,000 m) heading northward from the Antarctic and the South Atlantic passes through the Samoan Passage. Because of the volume and pressure, the flow accelerates greatly, as though through the nozzle of a fire hose. It becomes a raging underwater river — with a flow 36 times that the world’s largest above-ground river, the Amazon – that can produce underwater waves more than 1,000 feet (305 m) high. Those waves are what the Wave Chasers are chasing. Just extraordinary.
Led by Matthew Alford, Senior Oceanographer at the Applied Physics Laboratory and School of Oceanography at the University of Washington, the Wave Chasers are working to improve our understanding of the complex physical processes in the ocean, primarily through measurements and observations within the Samoan Passage. Over the next 39 days, the team will study this flow including its turbulence characteristics, the routes it takes, and how it changes with the tides.
The turbulence research is particularly important. According to Professor Alford, the more turbulent the flow, the more heat is exchanged with warmer water above. (As you know from high school, cooler water and air sink, and warmer water and air rise.) Heat exchange helps define deep circulation patterns in the Pacific, which in turn are important to understanding sea level rise and other climate change issues.
The Wave Chasers recently sailed into Apia Harbor on the Scripps Institution’sR/V Roger Revelle. Named for Roger Randall Dougan Revelle, one of the first scientists to study climate change and the movement of the Earth’s tectonic plates, the ship is brimming with sophisticated scientific instruments and populated with highly acclaimed oceanographers, scientists, and engineers.
As part of our program of scientific outreach and collaboration with Samoa, we have invited two Samoan scientists from the Ministry of Natural Resources and Environment to join the Revelle during its 39 days in or near Samoan waters. Tessa Tafua (Geophysics Meteorology Officer) and Muaausa Pau Ioane (Principal Mapping Officer) will roll up their sleeves, join the Wave Chasers team, and work alongside scientists from the University of Washington and Scripps. It should prove to be an interesting and productive voyage.
This is not the Wave Chasers’ first visit. They came to Samoa in 2011 to map the sea floor, take pilot measurements, and prepare for future research missions. The current trip, known as the “pathways” cruise, will now turn to the highly complex work of determining the paths that water flow takes as it winds its way through the complicated bathymetry of the Samoan Passage.
During the current port call the Wave Chasers hosted tours of the Revelle for students from the National University of Samoa, as well as members of my Young Professionals adviser group. The scientists demonstrated equipment and talked about the work they are doing in Samoan waters. I’ve heard that the tours and discussion sessions were highly interactive, enlightening, and fun. I regret that I wasn’t able to fly up to participate. I hope that the engagements stimulated interest both in science careers generally and in the fierce, important maelstrom swirling sight unseen around the Samoan islands.
The Samoan Passage project is funded by the National Science Foundation, the U.S. agency charged with stimulating, supporting, and sharing fundamental research and education in all non-medical fields of science and engineering.
As I have said before and will say again, the NSF is not just an American treasure but a resource of immense value to the world at large. I have seen the NSF’s work on Antarctica, deep below the sea, and high up in the atmosphere. Its contributions to studying life on Earth and addressing humankind’s greatest challenges are unparalleled, yet often under appreciated.
I will talk more about the Passage in a future blog post, once the researchers complete the current phase of their work.
For now, bon voyage to the Wave Chasers of the R/V Roger Revelle, including our Samoan friends. We wish the entire team well on (and beneath) the high seas, and we eagerly await their return to Apia in late August. In the meantime, you can access photos from the voyage and pinpoint the ship’s exact location here.
Manuia le Malaga.