Scientists Uncover the Secrets of the Pacific Ocean's Vast Abyssal Plain

An international team of world-leading scientists have undertaken their third exploration expedition into one of the most far-flung parts of the Pacific Ocean in their quest to understand more about this remote environment. In total, 84 days have been spent in exploration.

The team is partnered with UK Seabed Resources which is sponsored by the UK Government to explore two of 18 contract areas granted by the International Seabed Authority in the Clarion Clipperton Zone, or CCZ. The remaining 16 CCZ exploration contracts are held by commercial and government entities sponsored by nations throughout the world, including China, Japan, Korea, Belgium, Germany and France.

The CCZ is a vast, 4.5 million square kilometre abyssal plain in a remote part of the Pacific Ocean, south east of Hawaii, containing a seafloor rich in polymetallic nodules.

The CCZ is a vast, 4.5 million square kilometre abyssal plain in a remote part of the Pacific Ocean, south east of Hawaii, containing a seafloor rich in polymetallic nodules.

The goal of the expeditions is to learn more about the potential for harvesting these mineral-rich nodules.

UK Seabed Resources is helping to build a picture of the unique geology of the CCZ and the lives of the various species of rare and undiscovered fauna that live there.  

What are polymetallic nodules?


Dr Adrian Glover, Natural History Museum, holds one of the polymetallic nodules recovered on the expedition

These tennis ball-sized nodules are found approximately four kilometres beneath the ocean’s surface, lying on the sea floor.

Chris Williams, Managing Director of UK Seabed Resources, said: “The world’s economy will need a huge amount more metal to break its dependence on fossil fuels. Nickel, Copper, Cobalt and Manganese – the ‘battery metals’ - are all essential for renewable technologies.  There just aren’t enough mining projects planned to meet the forecast demand.  We would like to see recycling play a much bigger role, but under any reasonable scenario there will still be a growing gap to fill.

“Nodules contain more critical Nickel and Cobalt than all the rest of the world’s reserves combined. But more than that, because they avoid a host of environmental and social issues associated with mining on land, we see them as among the lowest cost, lowest impact sources of critical metals for the foreseeable future.  We will not have collapsed tailings dams, destruction of cultural sites, clearing of rainforest, child artisanal miners, to name a few recent ones.” 

The Expedition


The Pacific Constructor leaving Panama earlier this year

Earlier this year, UK Seabed Resources, and another licence holder, Ocean Minerals Singapore, set out from Panama City with scientific and engineering teams on board including staff from the Natural History Museum and the National Oceanography Centre in the UK. The ship was adapted to incorporate six laboratories and two equipment stores especially for this expedition.

Along with collecting samples for research, the expedition also deployed autonomous underwater vehicles to map the uncharted territory of this sea floor using ultra high-resolution sonar.

Collecting Samples – the Box Core


Successful recovery from 4000m depths of 0.75m x 0.75m boxcore with polymetallic nodule samples

A special device called a box core was used to collect samples of mud, nodules and fauna from the sea floor. The process was not an easy one, given the depths the team are working at.

Dr Adrian Glover, Deep Sea researcher at the Natural History Museum, said: “The box core is a very clever device that brings up this virtually undisturbed cube of mud from the sea floor four thousand metres below us onto the deck. And then we can actually look at the surface of the sea floor as if we were there.”

Gravity keeps the water and sediment in place as it is winched on deck. 

Very few creatures can live at 4,000 metres depth - but scientists are finding new species of tiny creatures including molluscs, snails, clams, worms, shrimps and sea cucumbers. 


The expedition science team in a sheltered working area inspecting and sorting polymetallic nodule samples for processing

Samples are carefully cleaned and taken to the temperature-controlled labs on board for cataloguing and storage. They will be further studied by partner research institutions at their labs on land.

Two previous cruises by UK Seabed Resources, in 2013 and 2015, generated over 57,000 images of the seafloor and collected in excess of 27,000 samples.

So far there have been 84 days of exploration with world-leading scientists that have involved:

  • Surveying more than 66,000 sq kms of abyssal terrain (at a depth of 4km below the ocean surface)
  • Mapping, in high resolution, using submersible AUVs (autonomous underwater vehicles), in excess of 235 sq kms of seabed

To date over 70 peer-reviewed academic papers and conference presentations have been produced on the basis of data gathered during these two cruises. This evidence joins an ever-increasing body of research into the Clarion Clipperton Zone collected by other research institutions and exploration licence holders. 

What happens with this research? 


The biology team identifying, documenting and preserving samples in one of the on-board labs

When exploration work is complete, the research findings will inform a full economic feasibility and environmental impact assessments into the possibility of harvesting some of the mineral-rich polymetallic nodules from the top of the sea floor.  The environmental impact assessment will be publicly consulted on and ultimately assessed by the International Seabed Authority before any commercial activities can begin. Whatever happens next, the International Seabed Authority has already set aside nearly 1.5 million square kilometres of the CCZ as areas, where seabed harvesting will not be allowed. 


This map sets out the location of the two UK licence areas in the CCZ. It also shows Areas of Particular Interest (APEIs), an International Seabed Authority designation for areas that they intend to make Marine Protected Areas

As well as data from recent and future expeditions, UK Seabed Resources’ assessment will build on thousands of ship and lab-hours put in by the parent company of UK Seabed Resources, Lockheed Martin, during the 1970s and 80s, when a much larger area of seafloor was surveyed by the Lockheed Ocean Minerals Company, OMCO. That programme culminated in a successful pre-prototype test in 1979 using a 100-ton Pilot Test Collector.  

The Pilot Test collector that trialled seabed harvesting in the CCZ in the 1970s

What happens next?

In the next phase of its exploration programme, in 2022, UK Seabed Resources will work with the Natural Environment Research Council and a team of UK research institutions to return to the site of the 1979 test to look at how the area has recovered over the intervening 42 years. 

A new environmental impact test is also planned for 2023 to monitor how a prototype nodule collector vehicle disturbs the deep-sea environment. This test would mark the completion of data gathering by UK Seabed Resources’ exploration programme, allowing a final assessment to be produced.

Chris Williams said: “UK Seabed Resources’ economic and environmental impact assessment will be a key part of a licence application to collect nodules at commercial scale.  It will be published, consulted on, and will ultimately inform a decision by the UK Government on whether to support a UK Seabed Resources application, and at the International Seabed Authority on whether or not to award a licence.

“The environmental and social impacts of mining for these minerals, the use of battery technology dependent on these minerals to reduce carbon dioxide emissions, the disturbance of the marine environment, the important role of recycling to reduce demand and the sharing of benefits with humankind as a whole and developing nations in particular - all these factors will have a part to play in the future decision-making process on seabed harvesting.”