Mapping the abyss off our shores.
From February through April 2026, NOAA and partners ran a hydrographic survey of federal waters off American Sāmoa — covering more than 30,000 square nautical miles with ship-based multibeam sonar, autonomous underwater vehicles, and 36 successful box-core samples from the deep seabed. Every station below is a real coordinate, a real depth, and a real photograph from a place most people will never see.
Data published by NOAA Ocean Exploration. Seafloor imagery courtesy of NOAA; shipboard imagery courtesy of the U.S. Geological Survey.
What did USGS find?
In 2026 USGS scientists — lead scientist Dr. Amy Gartman, U.S. Geological Survey — completed the first comprehensive sampling expedition in the Samoa Basin in decades. The result is scientific baseline data from April 2026 box coring in American Samoa’s U.S. Exclusive Economic Zone: what is on the seafloor, what lives there, and what the nodules are made of.
- Biological
- Sediment & geochronology
- Geochemistry & pore water
- Polymetallic nodules
Nodules of good, commercially relevant quality are present in the Samoa Basin, with some patches reaching meaningful densities (up to 21 kg/m²). This supports continued scientific analysis of our EEZ and of the area identified by BOEM for potential critical-minerals leasing.
- 1
Nodule abundance
Abundance ranged from 0 to 21 kg/m² (surface nodules up to 18.5 kg/m²). Four sites had meaningful buried nodules. Densities were variable — moderate overall compared to the richest global deposits, but with clear higher-density patches.
- 2
Nodule quality
Composition is similar to nodules from the western and south Penrhyn Basin in the Cook Islands EEZ — a very large estimated resource.
- Co
- Ni
- Cu
- Mn
- REE
Notably higher cobalt content than typical Clarion-Clipperton Zone nodules, with solid grades for nickel, copper, manganese and rare earth elements — a commercially relevant quality.
- 3
Other data collected
- Sediment geochemistry and oxygen profiles: typical abyssal patterns, with metal-enriched sediments.
- Biological baseline: 262 individuals documented, dominated by crustaceans and polychaetes; sponges on some nodules.
- Samples for ongoing microbiology (including mercury-cycling genes), organic carbon, geochronology, radon flux and more.
- 4
Comparison with other deposits
Densities are generally lower than the highest quartiles in the adjacent Cook Islands or in prime CCZ areas, but the quality aligns well with deposits under active exploration interest.
Key takeaways
- Nodule abundance, morphology and distribution generally matched previous expectations.
- Scientists found surprising differences in nodule shape over very short distances — even within the same area.
- Abundant volcanic fragments (scoria) coated with ferromanganese were found in the southern Samoa Basin.
- American Samoa nodule densities were substantially lower than those measured in the Cook Islands — up to 3× lower.
Why it mattersThe first step toward informed decisions is understanding what is actually on the seafloor.
Implications for American Samoa
- Findings show real potential in nodule quality and localized higher densities within our EEZ.
- They strengthen the scientific foundation for a responsible deep-sea minerals approach.
- They directly inform BOEM’s Area Identification process — approximately 33 million acres identified in late 2025 in the Samoa Basin.
- They support keeping the region active for further federal scientific work, while prioritizing environmental stewardship, community benefits and local capacity building.
Recommended next steps
- 01Continue close coordination with USGS, NOAA and BOEM on follow-up sampling, resource modelling and environmental baseline studies.
- 02Incorporate findings into Steering Committee discussions and public outreach.
- 03Keep parallel planning on infrastructure readiness — port upgrades, potential future transshipment needs — prudent and on the table.
- 04Request and review the full upcoming publications and data as they become available.
Source: USGS Samoa Basin Expedition Report, 2026 (preliminary cruise report, 15 June 2026). The full USGS preprint PDF and key maps are available for review; final data and publications are forthcoming.
Learn first. Decide later.
How they’re looking
Two layers of imaging. Ship-based multibeam sonar paints a wide picture of the seafloor’s shape. Autonomous underwater vehicles fly closer to the bottom for higher-resolution mapping and imagery. Box cores — a 0.75 m × 0.75 m (≈ 2.46 ft square) sediment grab — bring back the actual material so it can be analysed onshore.
When the data lands
Ship-based bathymetry is posted in near real-time on the NOAA Hydrographic Survey Projects portal. Quality-controlled bathymetry will enter NOAA’s public archives after project completion. AUV data follows within 90–120 days. Results from onshore sample analysis will be made publicly available.
Box-core stations, station by station.
Each card pairs the seafloor photograph taken at the bottom with the sediment that came back to the deck. Coordinates are the actual lat/lon recorded by the vessel; depths are measured to the metre.
- Station BX38Apr 28, 01:06 UTC
Seafloor 
On deck - Latitude
- 13.17091°S
- Longitude
- 167.86094°W
- Depth
- −5,193 m (3.23 mi)
- Station BX37Apr 28, 08:47 UTC
Seafloor 
On deck - Latitude
- 14.02754°S
- Longitude
- 166.73176°W
- Depth
- −5,539 m (3.44 mi)
- Station BX36Apr 27, 19:47 UTC
Seafloor 
On deck - Latitude
- 14.45901°S
- Longitude
- 166.36376°W
- Depth
- −5,420 m (3.37 mi)
- Station BX35Apr 27, 13:33 UTC
Seafloor 
On deck - Latitude
- 14.20799°S
- Longitude
- 166.17642°W
- Depth
- −5,482 m (3.41 mi)
- Station BX34Apr 27, 05:36 UTC
Seafloor 
On deck - Latitude
- 14.08375°S
- Longitude
- 165.99011°W
- Depth
- −5,432 m (3.41 mi)
- Station BX33Apr 26, 21:18 UTC
Seafloor 
On deck - Latitude
- 14.19802°S
- Longitude
- 165.80447°W
- Depth
- −5,432 m (3.38 mi)
- Station BX32Apr 26, 13:13 UTC
Seafloor 
On deck - Latitude
- 14.36846°S
- Longitude
- 165.61983°W
- Depth
- −5,504 m (3.42 mi)
- Station BX31Apr 26, 01:23 UTC
Seafloor 
On deck - Latitude
- 15.10518°S
- Longitude
- 165.62162°W
- Depth
- −5,619 m (3.49 mi)
- Station BX30Apr 25, 14:57 UTC
Seafloor 
On deck - Latitude
- 15.45017°S
- Longitude
- 165.62234°W
- Depth
- −5,619 m (3.49 mi)
- Station BX29Apr 25, 05:40 UTC
Seafloor 
On deck - Latitude
- 15.46440°S
- Longitude
- 165.99623°W
- Depth
- −5,513 m (3.43 mi)
- Station BX28Apr 24, 20:37 UTC
Seafloor 
On deck - Latitude
- 15.64847°S
- Longitude
- 165.80995°W
- Depth
- −5,544 m (3.44 mi)
- Station BX27Apr 24, 12:14 UTC
Seafloor 
On deck - Latitude
- 15.80130°S
- Longitude
- 165.62353°W
- Depth
- −5,588 m (3.47 mi)
- Station BX26Apr 24, 01:50 UTC
Seafloor 
On deck - Latitude
- 16.10663°S
- Longitude
- 165.62431°W
- Depth
- −5,731 m (3.56 mi)
- Station BX25Apr 23, 17:14 UTC
Seafloor 
On deck - Latitude
- 16.01150°S
- Longitude
- 165.81141°W
- Depth
- −5,650 m (3.51 mi)
- Station BX24Apr 23, 08:20 UTC
Seafloor 
On deck - Latitude
- 16.18131°S
- Longitude
- 166.00024°W
- Depth
- −5,431 m (3.37 mi)
- Station BX23Apr 22, 23:13 UTC
Seafloor 
On deck - Latitude
- 15.82934°S
- Longitude
- 165.99801°W
- Depth
- −5,635 m (3.50 mi)
- Station BX22Apr 22, 12:07 UTC
Seafloor 
On deck - Latitude
- 16.00534°S
- Longitude
- 166.56193°W
- Depth
- −5,594 m (3.48 mi)
- Station BX21Apr 22, 02:31 UTC
Seafloor 
On deck - Latitude
- 16.37013°S
- Longitude
- 166.56459°W
- Depth
- −5,719 m (3.55 mi)
- Station BX20Apr 21, 15:37 UTC
Seafloor 
On deck - Latitude
- 16.18131°S
- Longitude
- 166.00024°W
- Depth
- −5,431 m (3.37 mi)
- Station BX19Apr 21, 07:21 UTC
Seafloor 
On deck - Latitude
- 16.37395°S
- Longitude
- 165.81294°W
- Depth
- −5,680 m (3.53 mi)
- Station BX18Apr 21, 00:34 UTCNot collected
Seafloor 
On deck - Latitude
- 16.37395°S
- Longitude
- 165.81294°W
- Depth
- −5,680 m (3.53 mi)
- Station BX17Apr 20, 15:45 UTC
Seafloor 
On deck - Latitude
- 16.51520°S
- Longitude
- 166.00153°W
- Depth
- −5,562 m (3.46 mi)
- Station BX16Apr 20, 04:21 UTC
Seafloor 
On deck - Latitude
- 16.73255°S
- Longitude
- 166.56682°W
- Depth
- −5,580 m (3.47 mi)
- Station BX15Apr 19, 17:41 UTCNot collected
Seafloor 
On deck - Latitude
- 17.03596°S
- Longitude
- 166.97288°W
- Depth
- −5,592 m (3.47 mi)
- Station BX14Apr 19, 06:33 UTCNot collected
Seafloor 
On deck - Latitude
- 16.54338°S
- Longitude
- 166.94020°W
- Depth
- −5,580 m (3.47 mi)
- Station BX13Apr 18, 20:58 UTC
Seafloor 
On deck - Latitude
- 16.36286°S
- Longitude
- 167.31582°W
- Depth
- −5,704 m (3.54 mi)
- Station BX12Apr 18, 11:04 UTC
Seafloor 
On deck - Latitude
- 16.18838°S
- Longitude
- 166.93333°W
- Depth
- −5,691 m (3.54 mi)
- Station BX11Apr 18, 01:06 UTC
Seafloor 
On deck - Latitude
- 15.82092°S
- Longitude
- 167.12134°W
- Depth
- −5,779 m (3.59 mi)
- Station BX10Apr 17, 14:22 UTC
Seafloor 
On deck - Latitude
- 15.46210°S
- Longitude
- 166.74218°W
- Depth
- −5,497 m (3.42 mi)
- Station BX09Apr 17, 04:46 UTCNot collected
Seafloor 
On deck - Latitude
- 15.46485°S
- Longitude
- 166.37020°W
- Depth
- −5,482 m (3.41 mi)
- Station BX08Apr 16, 19:14 UTC
Seafloor 
On deck - Latitude
- 15.10228°S
- Longitude
- 166.36780°W
- Depth
- −5,544 m (3.44 mi)
- Station BX07Apr 16, 09:54 UTC
Seafloor 
On deck - Latitude
- 14.79937°S
- Longitude
- 166.36590°W
- Depth
- −5,570 m (3.46 mi)
- Station BX06Apr 16, 00:16 UTCNot collected
Seafloor 
On deck - Latitude
- 14.39356°S
- Longitude
- 166.36330°W
- Depth
- −5,594 m (3.48 mi)
- Station BX05Apr 15, 14:41 UTC
Seafloor 
On deck - Latitude
- 14.04159°S
- Longitude
- 166.36119°W
- Depth
- −5,498 m (3.42 mi)
- Station BX04Apr 15, 04:40 UTCNot collected
Seafloor 
On deck - Latitude
- 13.46947°S
- Longitude
- 166.54230°W
- Depth
- —
- Station BX03Apr 14, 19:00 UTCNot collected
Seafloor 
On deck - Latitude
- 13.46947°S
- Longitude
- 166.54230°W
- Depth
- —
- Station BX02Apr 14, 09:44 UTCNo image
Seafloor 
On deck (no sample) - Latitude
- 13.46947°S
- Longitude
- 166.54230°W
- Depth
- —
No sample collected