A brick-like pattern spotted deep under the Pacific near Hawaii during a 2022 dive was not man-made. Scientists say it was cracked volcanic hyaloclastite, shaped by cooling and heating over time.
Key Takeaways
- A “yellow brick road” pattern was filmed in 2022 north of the Hawaiian Islands during a deep-ocean survey.
- The site sits on the Nootka seamount within Papahānaumokuākea Marine National Monument.
- Scientists said the feature is hyaloclastite, a volcanic rock formed when lava shatters in seawater.
- The brick-like 90-degree cracks likely formed through repeated heating and cooling during eruptions.
- The discovery underlines how little of the deep seafloor has been explored and explained.
Where the formation was spotted
Scientists found the unusual “yellow brick road” formation deep beneath the Pacific Ocean during a 2022 expedition north of the Hawaiian Islands. The observation was made while surveying the Liliʻuokalani Ridge inside Papahānaumokuākea Marine National Monument (PMNM), a huge protected ocean area.
The team operated from the exploration vessel Nautilus and used a remotely operated vehicle (ROV) to explore more than 3,000 meters below the surface. At that depth, there is no sunlight and the pressure is extreme, so researchers rely on camera feeds and artificial lights to see the terrain.
The formation was seen on the summit of the Nootka seamount. Researchers noted that the surface looked like a hardened “lakebed” and appeared unusually bare, which made the pattern stand out clearly on video.
Why it looked like a road on camera
During the live observation, researchers reacted with surprise and compared the feature to a “road to Atlantis” and a “yellow brick road.” The nickname came from how the rock fractured into straight lines and block-like shapes that resemble bricks.
These visual illusions are common in geology. Humans naturally connect repeated shapes and clean edges with construction. Nature, however, can create sharp patterns through cracking, cooling, and breakage in brittle materials.
Deep-sea video also amplifies the effect. ROV lights are strong and directional, so small ridges throw hard shadows. That lighting can make fractures look deeper and more regular than they are, especially when the camera angle is low and the surface is relatively smooth.
The scientific explanation: hyaloclastite and 90-degree cracking
Scientists later explained the formation is not man-made. It is a fractured flow of hyaloclastite, a volcanic rock that forms during high-energy eruptions when hot lava meets seawater and breaks into fragments. Those fragments settle and can later harden into rock.
Researchers described the surface as a “baked crust” that could be peeled away. That idea fits rapid cooling: a hardened outer layer forms first, then stresses build underneath. Over time, the crust can crack as the material expands and contracts.
The brick-like shapes came from cracks that meet at near 90-degree angles. The team said repeated heating and cooling during multiple eruptions likely created this pattern. When rock repeatedly heats up and cools down, it contracts and expands. That stress opens fractures, and new cracks can intersect older ones, producing blocky segments.
The “yellow” look is not evidence of anything artificial. Underwater color depends on lighting, camera settings, mineral staining, and surface weathering. In deep environments, chemistry and thin biological films can also change how rock surfaces appear on video.
Why the discovery matters and what it tells us
The find is a reminder that much of Earth’s ocean floor is still poorly explored. PMNM is one of the world’s largest protected marine areas, yet only a small fraction of its seafloor has been directly surveyed in detail.
Discoveries like this matter because they help scientists understand how underwater mountains form and how volcanic activity shapes the seabed. Studying hyaloclastite and fracture patterns can offer clues about eruption intensity, cooling history, and the conditions that existed when the seamount was active.
The public reaction is useful too. A strange-looking feature draws attention, then science explains it in a grounded way. That cycle helps people see why deep-ocean exploration is important and why surprising images are not automatically “mysteries” once geology is considered.
