Japan’s Deep‑Sea Rare Earth Mining: Strategy and Outlook

Name: Japan's Rare Earths Island
Uploaded: 2026-05-28T23:00:10+00:00
Duration: 19 min 52 s
Channel: Asianometry
Description: Summary and key takeaways on Japan's Rare Earths Island: Summary & Key Takeaways, covering Historical Context Japan intensified its search for alternative

Asianometry

May 28, 2026

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19 min video

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YouTube video ID: kaz71LziZLA

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Japan intensified its search for alternative rare‑earth supplies after China halted exports in 2010. Professor Yasuhiro Kato of the University of Tokyo led an analysis of 2,000 sediment core samples, uncovering extensive deposits in the Eastern South Pacific and Central North Pacific. The discovery linked deep‑sea sediments to a potential new source of the elements critical for modern technology.

Minamitorishima Island

Minamitorishima sits 1,211 miles east of Tokyo and marks Japan’s easternmost territory. The island changed hands several times: early guano harvesters, a World‑War‑II episode, and a U.S. occupation that ended with the 1968 return to Japan. Its location grants Japan a 200‑nautical‑mile exclusive economic zone (EEZ), allowing the nation to exploit seabed resources without adhering to International Seabed Authority (ISA) regulations.

Geological Mechanism

Rare‑earth elements accumulate in deep‑sea mud through a natural “sponge and magnet” process. Fish bones and teeth, rich in calcium phosphate, attract trace rare‑earth ions from seawater. Over geological time, these ions concentrate in the sediment, reaching 2,000–7,000 ppm in the mud surrounding Minamitorishima at a depth of 6,000 m.

Extraction Technologies

Early attempts—drag buckets, continuous line buckets, and shuttlecraft—proved inefficient, prompting the shift to pulp lifting, also called a pipeline lift. An underwater machine mixes ore and mud with seawater, forming a slurry that travels through a pipe to the surface. There, gravity separation and dewatering isolate the rare‑earth concentrate. The closed‑mining system contains sediment plumes at the seafloor, reducing noise, light, and plume dispersion.

Economic and Environmental Challenges

A 2021 financial model projected a 15‑year project internal rate of return of 3.7 % and a net present value loss of $525 million. Since then, non‑magnet rare‑earth prices have fallen 30–80 %, further eroding profitability. Environmental concerns include destruction of deep‑sea habitats and long‑term suffocation of benthic flora due to silt deposition.

Future Outlook

In 2026, a successful test extracted 70 tons of slurry per day, demonstrating the feasibility of the pulp‑lifting approach. Plans for 2027 target 350 tons of daily slurry extraction and aim to scale operations while refining the closed‑system design. If the technology proves cost‑competitive, it could open pathways to other deep‑sea mineral resources, though ecological impacts will remain a central debate.

Takeaways

Japan turned to deep‑sea mining after China’s 2010 rare‑earth export ban, targeting sediments near Minamitorishima.
The island’s location within a 200‑nautical‑mile EEZ lets Japan avoid International Seabed Authority regulations.
Pulp‑lifting, a closed‑system pipeline slurry method, is the only viable extraction technology, converting mud into seawater slurry for surface processing.
Economic analyses project a 3.7 % internal rate of return and a $525 million loss over 15 years, with falling REE prices worsening viability.
Successful 2026 test extraction and planned 2027 scaling aim to demonstrate feasibility, but environmental risks from seafloor disturbance remain a major concern.

Frequently Asked Questions

Why does Minamitorishima’s EEZ allow Japan to bypass ISA regulations?

Because the island lies within Japan’s 200‑nautical‑mile exclusive economic zone, Japan holds sovereign rights over the seabed resources, allowing mining to be governed by national law instead of the UN‑mandated International Seabed Authority.

How does the pulp‑lifting method reduce environmental impact compared to earlier techniques?

The pulp‑lifting system creates a sealed slurry that is pumped to the surface, and its closed‑mining design contains sediment plumes on the seafloor, eliminating the noise, light, and widespread disturbance caused by drag buckets or continuous line buckets.

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In 2010, the People's Republic of China
banned exports of rare earths to Japan
due to a territorial dispute.
After that, the Japanese government
began developing alternate sources of
rare earths, signing deals with
Australia and Brazil.
The most intriguing potential source,
however, lies beneath the deep-sea
sediments surrounding a tiny Japanese
island in the middle of the Pacific
Ocean.
In February 2026,
the Japanese government reported the
first successful test extraction of this
deep-sea mud thousands of meters
underneath the surface.
In today's video, a brief look at
Japan's rare earths island.
I have covered the rare earths in prior
videos. I have before described them as
like technology vitamins. We don't need
a lot of them, but nothing works without
them. Despite the name, they're not that
rare. It's the processing capability and
capacity that's rare. Yada, yada, yada.
After the 2010 rare earths crisis, the
Japanese government began searching for
alternate sources.
A research group led by Professor
Yasuhiro Kato of the University of Tokyo
went through 2,000 sediment core samples
from 78 sites in the Pacific Ocean. They
called it the International Deep Sea
Drilling Project.
In June 2011, the Japanese government
announced that there existed substantial
rare earths reserves in both the Eastern
South Pacific and Central North Pacific
Ocean regions.
And at one such rare earths sediment
deposit laid within the exclusive
economic zone of a remote island called
Minamitorishima Island.
Minamitorishima is Japan's most eastern
lying territory. The island is the only
one east of the Japan Trench. It sits
about 1,211
miles from Tokyo and 630 miles from the
closest Japanese island.
It is a coral atoll island less than a
square mile large and 9 m above the
water. The island is covered in trees
and grass and not much lives there
except for a species of gecko and
seabirds.
The history of how Japan came into
possession of this random island in the
middle of nowhere is pretty fascinating.
A lot of it had to do with bird poop.
The spot has apparently been sighted by
various ships throughout time, perhaps
going as far back as the 1600s.
But it was only first visited in 1864
by an American ship called the Morning
Star. They stayed for a short period
naming it Marcus Island. In the 1880s,
various Japanese and American ships
landed on the island and attempted to
claim it for themselves. Mostly so they
can receive the right to harvest the
island's guano. At the time, people
still heavily relied on bird guano as a
critical agricultural fertilizer. Made
quite a few island countries rich back
in the day.
In 1889, the American Captain Andrew
Ambrose Rosehill sailed to Marcus
Island. He raised an American flag on
the island's only coconut tree, left a
sign, and then sailed back to apply for
guano rights. The US Department of State
did not acknowledge this request and
Rosehill does nothing more.
In 1896, a Japanese drifted onto the
island via some storm or whatever and
claimed it for Japan. He declared that
he had brought 20 or so Japanese
settlers to the island and named it
Minami Torishima. The Japanese
government acknowledged his claim and
posted it.
Captain Rosehill heard about this and
raised money from Hawaiian plantation
lords to harvest the area's bird poop.
He commissions a ship to stop by the
island and take samples, but that ship's
crew found themselves blocked by the
Japanese now living on the island. So,
in July 1902, he sails for the island on
a schooner intending to enforce his
claim.
The Japanese hear about this and send a
letter outlining their own position.
They also send a warship. 12 days after
Rosehill set sail, ostensibly to enforce
their claim with arms.
The Americans hear about this and send
their own warship. The idea being to
protect the captain and enforce any
legitimate claims. Thus, we have a
captain and two warships from opposite
sides of the Pacific racing towards a
pile of bird poop in the ocean.
The Japanese reach the island first and
prevent Rosehill from landing on the
island. And in the end, the US
government declined to back Rosehill's
claim. Why? Mostly pragmatism.
Public perception on this kerfuffle was
muted. If anything, most seemed to feel
that Rosehill's claim was fairly weak
compared to Japan's. Rosehill put up a
flag, left, and did nothing for years
after. The Japanese landed actual
settlers onto the island.
And nobody felt it was worth
antagonizing the Japanese, who the
Americans wanted to curry favor with, by
evicting them so that someone else can
mine the guano there and get rich.
Moreover, the US had their own far more
strategic islands that they sought to
hold. Midway, Guam, and the Wake
Islands. Disrespecting Japan's claim
opened the door to the possibility of
the same thing happening to them.
So, the juice just wasn't worth the
squeeze. Rosehill thus returned having
lost some amount of money and
petitioning the Japanese for
compensation. I don't think he got it.
After that, Japan set up a guano and
bird feather harvesting facility.
At its peak, 50 people lived on this
island, which is kind of amazing. But
after 19 of them died due to dysentery,
resources and population declined, and
by 1935,
the island became uninhabited again.
During World War II, the Japanese navy
fortified the island. They likely
anticipated a possible land invasion at
some point. But while the allies bombed
it several times, killing about 191
soldiers in the process, they never
attempted such a landing.
After the war, the Americans repatriated
the soldiers and took over the renamed
Marcus Island.
There, they built a small navigation
weather station and airstrip, occupying
it for the next few decades. The
soldiers and staff there seemed to have
a good time exploring the Japanese
fortifications, fishing the rich waters,
and dodging mako sharks. Actually, the
latter doesn't sound so much a good
time.
Finally, in 1968, the United States
returned the island to Japan, along with
Iwo Jima and the Bonin Islands. This was
a major diplomatic step towards the
eventual return of Okinawa a few years
later.
The US Coast Guard did retain a powerful
radio transmitter there, the Marcus
Island Loran C transmitter. It's a
pre-GPS
boats can use its signals to triangulate
their location on the earth.
That was transferred to the Japan Coast
Guard in 1993.
In 2009, Japan turned off the
transmitting station due to the
widespread use of GPS and designated the
area a bird sanctuary. I am sure the
birds appreciated that.
Soon afterwards, the island seemed
destined to fade into obscurity. The
only people living there were a small
detachment of rotating staff from the
Self-Defense Force and the weather
agency. Then, the rare earth survey came
calling.
So, how did the mud surrounding this
island come to have so much rare earth?
As we all know, and people keep
repeating, the rare earth elements are
not actually that rare. They're just
hard to separate. So, when looking for
deposits, we're looking for geological
situations where those elements have
been collected and accumulated.
For example, deposits in the southern
China region exist because of a unique
set of circumstances. Rocks enriched
with rare earths get weathered down by
rain, releasing trace elements. Those
elements then leach into the clays,
which systematically absorb them.
In the case of the island mud, this is
what we think happened. And it has to do
with fish bones. When fish die, their
bodies sink to the ocean floor. I know,
breaking news alert. Their teeth and
bones contain calcium phosphate. So,
when that falls to the bottom and
decays, we start getting large amounts
of calcium phosphate in the mud.
This calcium phosphate is basically the
sponge and magnet for certain rare
earths, binding to elements floating
around in the sea in trace amounts.
Thus, over geological time scales, we
get significant accumulations of rare
earths. These layers are relatively
shallow, about 10 m below the floor, and
in certain locations they can get quite
rich.
There are two types of rare earths,
light and heavy. The light rare earths
have lower atomic numbers and range from
lanthanum to samarium. Cerium and
neodymium, the stuff they use for
magnets, are light rare earths.
And then you got the denser heavy rare
earths, which go from europium to
lutetium. This is where the People's
Republic of China's rare earth strengths
really lie. The lighter elements can be
found in other locations, though again,
refining capacity is not so common. But
with regards to the heavy elements, the
southern Chinese deposits have few
serious competitors.
So, Minami Torishima's rare earth
sediments are not only rich in rare
earth, anywhere from 2,000 to 5,000 and
even 7,000 parts per million,
but also the rare earth that these
sediments have are the ones that are
really hard to get.
When the sediment deposits first hit the
mainstream media in April 2018, it was
basically declared that these deposits
were, quote unquote, semi-infinite,
which is an oxymoron.
Anyway, what is meant by that is that
certain sample regions are claimed to
have decades worth of supply of yttrium,
europium, terbium, and dysprosium,
valuable heavy rare earths. I've also
seen mentions of the lighter neodymium
and samarium, both used for magnets.
I note, however, that all estimates of
the size of the reserves assume that we
can extrapolate a substantial grid area
blocks of many kilometers wide with just
a few samples. The geology there is
quite mountainous. Reality seems that
the actual amount will be very up and
down.
So, that is all the happy good stuff to
be optimistic about, the stuff that the
headlines are going to blare out. Yay,
there's all these reserves down there.
Now, let us drill into the real work.
How do we get it? The main problem is
that these are not shallow seas. The mud
is only about 10 m below the sea floor,
but the sea floor sits some 6,000 m
underwater. To compare, the Titanic lies
a mere 3,800
m deep.
While we have long known that the deep
sea floor harbors economically valuable
minerals, the technology surrounding
their extraction are not well developed.
For such technologies have been
developed over the past years, three do
not work.
The first and simplest is the submarine
drag bucket. This does exactly what it
says on the label. We drag a bucket
across the seafloor, bring up the bucket
when it's full, scrape it clean, and
then drop it back down for more
dragging.
First proposed in the 1960s, technicians
found the bucket dragging behavior
difficult to control and intermittent.
You lose productivity during the time
when you lift and drop the bucket again.
So, later was proposed a continuous line
bucket system, a loop with multiple
buckets constantly bringing up deep-sea
sediment. It kind of works, but there
were substantial risks of entangling the
buckets or the buckets accidentally
spilling their contents on the way up.
The big overarching problem with both
these bucket-based methods is that they
are hilariously environmentally
destructive, scarring the entire seabed
for many kilometers. Like, this is
Disney villainy levels of stuff. Let's
Let's not do that.
In the 1970s, the French developed
another method called shuttlecraft
mining system. There is a collecting
device on the seabed that gathers
minerals or ores. The ores are collected
onto a shuttle that brings them to the
surface.
It kind of works, but it is more science
fiction. You add another whole set of
complicated deep-sea vehicles that can
break. And can these machines actually
work autonomously? How are they going to
be powered? So on.
Lastly, we are left with the last and
most feasible technology, pulp lifting
or the pipeline lift. An underwater
machine on the seafloor turns the ore
and mud into a seawater slurry, and that
slurry is then sucked up like a
milkshake through a fat pipe. By
carefully controlling the slurry solids
concentration, we can get a fluid that
pumps up easier, requiring less energy
and a thinner pipe to do so.
After the slurry is brought up to the
surface, it is separated out using
gravity and then dewatered. This is done
on Minami-Tori-shima Island itself.
The silt is then put on a transport boat
that brings it to a processing facility
where the rare earths are leached out
using hydrochloric or sulfuric acids.
Many of the technical details on this
are sparse and I presume it's being
worked out.
The environmental risks of this pulp
lifting mechanism are substantial.
First, there is immediate loss of
whatever marine life is living on the
seafloor. This includes sponges, filter
feeding animals, deep-sea fish,
shellfish, corals, and jellyfish.
Second then will be the knock-on effects
from kicking up massive amounts of silt,
suffocating any flora in the area and
preventing them from returning, perhaps
for weeks or months on end as the silt
settles.
The Japanese system employs what they
call a closed mining system on the
ground, which they say will suppress
sediment plumes. It is also said to
reduce various externalities of deep-sea
mining relating to light and noise
pollution. How much, I'm not certain.
I must admit that none of this is really
pleasant, but I do want to remind you
that rare earths mining on land isn't
exactly wonderful, either.
A key thing why Minami-Tori-shima Island
is so valuable to Japan isn't that its
sediments are particularly unique,
though they are quite nice. It is that
the deposits lie entirely within Japan's
200 nautical mile exclusive economic
zone.
This means that a deep-sea mining
project there bypasses the authority of
the United Nations mandated body
International Seabed Authority, which
controls, authorizes, and protects the
ocean seafloor bed and international
deep sea.
The sediments being inside Japan's own
lets them apply their own environmental
regulations, skipping a lot of
bureaucracy and permit work.
If Japan were to try to do this in
international waters, they may be
subject to the ISA's international
environmental codes. That's going to be
difficult considering that the body has
not yet finalized rules for mining
deep-sea mud despite several looming
deadlines.
The main issue is and always has been
economics. Are these sediments more
economically practical to produce than
land-based alternatives?
Frankly, early feasibility analyses of
the Minami Torishima Island sediments
found their extraction to be
uneconomical compared to land-based
alternatives. This remained the case
even when richer rare earth deposits of
5,000 ppm were located. Researchers have
proposed to improve the economics by
adding something else to the mix,
ferromanganese nodules. These are
metallic clumps scattered across the
seafloor laying on or under the seabed
sediment. You can harvest the metals in
these nodules for additional money.
Even so, the economic viability of such
an operation does not look good. A 2021
economic analysis using 10-year average
pricing found that a 15-year project
would have an IRR of 3.7%
and a net present value of a $525
million loss.
And that is assuming there are no
serious technical hang-ups, which
considering the pioneering nature of
this technology will probably crop up
somewhere or sometime.
In 2017, Chinese researchers using Japan
Oil, claimed
that the operation only earns money if
rare earths remain at peak 2011 prices,
which were in a bubble for literally
decades. And they're they're not wrong.
Here I want to add that a precursory
look at various rare earth prices, not a
deep analysis, just I Googled it, show
that outside of the magnet-related rare
earths, prices are down between 30 to
80% from the 10-year price averages used
for the 2021 analysis. So, price floors
may be necessary.
Considering that and all the money being
invested into the space right now,
Chinese and non-Chinese, no private
investor will undertake such a project.
I guess that is why the Japanese
government is taking the lead. Such and
strategic projects are why we do
industrial policy. The successful 2026
extraction comes after years of
engineering work and tests. The team
designed and built the aforementioned
deep-sea close mining apparatus, a
3,000-m pipe that lifts the slurry using
compressed air, and an ultrasonic
metrology system to monitor performance.
And prior to running the on-site
February 2026 test, the team did a
smaller-scale, but fully integrated test
in waters 2,400 m deep off the coast of
Japan's Ibaraki Prefecture in 2022,
successfully pumping up 70 tons of
slurry a day.
The government's long-term commitment to
this sort of wild project is actually
pretty impressive.
Despite some successes and
diversification, Japan still sources
some 60 to 80% of its rare earths from
the People's Republic of China.
$500 million
over 15 years seems like a fair price to
pay, considering especially that the
alternative would simply be not getting
the rare earths.
Japan also holds an ISA exploration
contract for international waters many
hundreds of miles off the islands of
Hawaii. The work done in
Minami-Tori-shima can be applied to
there as well. I believe China has a
contract too.
Mastering deep-sea pipeline lift-style
mining has other benefits. The seafloor
has a great deal of other metals and
minerals like gold, zinc, copper,
nickel, manganese, and cobalt. The
mining technology might be applicable to
that as well.
With the successful February 2026
extraction test behind them, Japan now
seeks to scale up the deep-sea mining
trials on site. They're scheduled to
begin a year later in February 2027,
targeting 350 tons of rare earth
sediment slurry per day.
All right, everyone, that's it for
tonight. Thanks for watching. Subscribe
to the channel, sign up for the Patreon,
and I'll see you guys next time.

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Asianometry

Jun 18, 2026

Minamitorishima Island

Geological Mechanism

Extraction Technologies

Economic and Environmental Challenges

Future Outlook

Takeaways

Frequently Asked Questions

Why does Minamitorishima’s EEZ allow Japan to bypass ISA regulations?

How does the pulp‑lifting method reduce environmental impact compared to earlier techniques?

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