Minamitorishima Island, Japan
roughly translates to “Southern Bird Island”
Minamitorishima, also known as Minami Torishima or Marcus Island, is a remote, uninhabited raised coral atoll in the Pacific Ocean.ย It is part of the Ogasawara Islands chain, which belongs to Japan.ย This small (less than 1 square mile) low lying island (less than 400 ft above sea level) was once mined heavily for guano, serves as a strategic location for airspace and maritime surveillance and is now the site of major sub sea floor rare-earth metal mining research and possibilities.ย Rare-earth metals are crucial in the making of high-tech products such as electric vehicles and batteries, and most of the world has relied on China for almost all of its needs.ย After China restricted exports of strategic rare-earth oxides (REO’s) in 2009 Japan began to explore its sea floor for deposits.ย ย Among the rare metals found around Minamitorishima Island are cobalt and nickel โ both essential for lithium-ion batteries.
Minamitorishima is considered Japanโs easternmost territory and plays a role in Japan’s control over its exclusive economic zone (EEZ) in the Pacific Ocean.ย The island is off limits to civilians except for Japan Meteorological Agency staff, although reporters, documentary makers, and scientific researchers can sometimes get an entry permit. No commercial boat tours or flights visit the island, and civilians are currently not allowed access to Minamitorishima for tours or sightseeing, due to its use by the JSDF as an observation station.
The Research operation investigating the existence, location, and concentration of rare-earth metals has been focusing their efforts to collect samples from the sub-sea floor from around Minamitorishima island because this atoll makes a great base of operations.ย In 2013 a deep sea research vessel obtained seven deep sea mud core samples some 5000m below the sea level that revealed extremely concentrated REO in a mud layer 2-4m beneath the seabed around the island.ย
An effort began in 2018 to create detailed maps of rare-earth elements distribution.ย ย Researchers have found 16 million tons of REO mineralized sediments within the studied area which some say is equivalent to 75-100 years worth of rare-earth materials underneath Japanese waters โ enough to supply to the world on a “semi-infinite basis,” according to a study published in Nature Publishing Group’s Scientific Reports.ย That supply term depends on the demand of course and it remains to be seen what and how human demands for products that utilize these REO’s will change in time…especially if there are more suppliers than China.
The mapping and sampling process requires a wide range of specialists and organizations, cutting edge technology and equipment, and time.ย There are marine geologists using new high resolution acoustic profiling technology that creates a narrow acoustic beam that transmits information about the soft seafloor 6000m to 11,000m deep.ย The beam is then able to penetrate 200m into the sub-seafloor allowing researchers for the first time to gather sub-seafloor data.ย Concurrently, researchers have taken hundreds of deep sea core samples which is very slow and difficult work as well.ย One sample taken 5000m deep can take an entire day.ย Samples are sent to laboratories in Tokyo for analysis.ย Together they are building an understanding of the geologic history of the area like never before and hope that they will be able to discover where the soft sediment with the material from the ocean vents has settled.
In addition to the islands particular geology, Minamitorishima is known to have a unique ecosystem, and though ‘uninhabited’ by humans, it provides a habitat for various bird species, hence the name, “Southern bird Island”. Its isolation and distance from the mainland has allowed it to remain relatively undisturbed by human activity, which is important for preserving its natural environment.ย The island is also a significant site for marine life, with surrounding waters providing a rich habitat for marine species. With this in mind, while the researchers have made many findings about the geology of the surrounding seafloor, their efforts are colossal and not without impact.ย The drivers believe that results could be worth the effort.ย In the long term and in the short term one cannot forget to ask, What are the risks?ย Will the risks be outweighed by the rewards?ย What are the impacts of this work on the surrounding environment, the local, pelagic, and migratory animals.ย Could the repeated core sampling affect the plate tectonics?ย Could the acoustic beams disrupt other ocean acoustics?ย Have they already?ย What could be affected that is not being considered or seen at this time?
As all these questions begin to bubble up it is clear is that Minamitorishimaโs isolation, strategic role, and environmental uniqueness make it an intriguing part of Japanโs territorial holdings in the Pacific.ย Japan is being strategic and hopefully considering so much more than the potential political and economic value of the extracted minerals for the human species.
By Maurisa Descheemaeker on SVย WHIRLWIND
Sources:ย https://www.nature.com/articles/d42473-020-00525-x
https://www.japantimes.co.jp/news/2024/06/22/japan/science-health/tokyo-island-rare-metals-find/
https://www.t-borderislands.metro.tokyo.lg.jp/en/minamitorishima/