Eyes Below the Surface: Mapping Johnston Atoll

Aiming to maximize the science being done at sea, Falkor will embark on its first transruise or “Research on Transit” this December, as she sails from Guam to Honolulu, Hawaii. Dr. John Smith and his team will join Falkor crew as they stop in the Pacific Remote Islands Marine National Monument 1,830 nautical miles (3,390 kilometers) southwest of Honolulu. In this remote protected area lies Johnston Atoll, the closest landmass to Hawaii, some 717 nautical miles (1,328 km) from Honolulu.

A Stepping Stone

In 2014, the Johnston Atoll Unit was expanded from 50 to 200 nautical miles, and while there have been several cruises dedicated to mapping parts of Johnston Atoll, a vast amount is unmapped, unexplored, and unknown. A large number of seamounts, ridges and other features at Johnston are saturated with unique organisms such as high-density deep-sea coral and sponge communities, as well a high concentration of deep-sea minerals. Many researchers consider Johnston Atoll a key marker in biological boundaries – a mapping waypoint for many species. It marks the southernmost range for species common in Hawaii, and is considered a stepping stone for many central and south Pacific marine species expanding their populations to the Northwestern Hawaiian Islands (also known as the Papahanaumokuakea Marine National Monument). This remote area is ripe for mapping to better inform future ROV cruises to collect data and expand knowledge for scientific research and new discoveries.

Remote Mapping

The team plans to map over 7000 km² over four days along a portion of the unmapped Johnston Seamount group, where at least three unexplored seamounts will be investigated. Scientists will perform multibeam mapping as well as sub-bottom and magnetics surveys. Falkor’s multibeam systems will be used, as well as a Compressed High Intensity Radar Pulse sub-bottom profiler (CHIRP). CHIRP uses sound frequency within the radar ‘ping’ as it moves over a range, instead of a single frequency, bringing better resolution compared to fixed-frequency sonars. Falkor will also tow a magnetometer to collect magnetics surveys along the sub-seafloor.

With data from these sensors and tools onboard, the team will be using Falkor’s supercomputing resources to combine this newly-discovered information with existing data and maps. The results will be provided to the research community and public. The NOAA Ship Okeanos Explorer has two expeditions planned for 2017, and these opportunities can be maximized with the maps and information gathered during our research cruise prior, with data sharing resulting in more productive dives.