How the Ocean Floor Got Filled with Riches

TL;DR

Hydrothermal vents and underwater deposits on the ocean floor contain immense amounts of valuable metals like copper, gold, and cobalt. Although these treasures are in demand, mining them is currently not being done due to uncertainty about the environmental impact.

Transcript

Thanks to Brilliant for supporting this episode of SciShow. Go to Brilliant.org/SciShow to check out their Knowledge and Uncertainty course. {♫Intro♫} Underneath kilometers of seawater, the ocean floor is full of riches. There’s gold, iron, and lots of other rare, precious metals. And no, it doesn’t have anything to do with pirates. All this treasu... Read More

Key Insights

• 🤣 The ocean floor is rich in valuable metals like gold, copper, cobalt, and manganese.
• ℹ️ Hydrothermal vents and underwater deposits formed millions of years ago are the sources of these treasures.
• ❓ Mining these underwater treasures is currently not undertaken due to concerns about the environmental impact.
• ✋ Manganese nodules contain more manganese than anywhere on land and are in demand for manufacturing high-tech electronics.
• 🤑 The slow accumulation of underwater deposits, cobalt-rich crusts, and manganese nodules highlights the immense time scales involved in their formation.
• 🤣 Protecting the ocean floor and its treasures is crucial due to their significance and the need for further scientific understanding.
• 🏑 Brilliant offers a course on Knowledge and Uncertainty, which can help individuals better understand and minimize uncertainty in various fields of study.

Questions & Answers

Q: How do hydrothermal vents form on the ocean floor?

Hydrothermal vents form along mid-ocean ridges where tectonic plates split apart, allowing seawater to seep into cracks in the ocean crust and get heated by magma. The heated seawater bursts out through vents, leaching metals from the surrounding crust.

Q: What are cobalt-rich crusts, and how do they form?

Cobalt-rich crusts form on exposed ridges, plateaus, and underwater mountains. Iron and manganese oxides in seawater latch onto rocks, forming a sponge-like network that traps other metals. Over time, this crust can grow up to 25 centimeters thick.

Q: How do manganese nodules grow on the ocean floor?

Manganese nodules start as debris, like shark teeth or pebbles, that serve as nuclei. Manganese and iron oxides attach to the debris, forming concentric rings over millions of years. Special bacteria that live on the nodules may speed up the process by depositing manganese oxide.

Q: Why aren't deep-sea treasures being mined currently?

Mining deep-sea treasures is not being done due to the uncertainty surrounding the environmental impact. The long-term effects on seafloor ecosystems and the larger ocean environment are not fully understood.

Summary & Key Takeaways

• Hydrothermal vents at the bottom of the ocean accumulate metals like copper, gold, and silver, forming chimney-like structures known as massive sulfide deposits.

• Underwater deposits grow on exposed ridges, plateaus, and extinct volcano remnants, accumulating metals like cobalt, iron, and manganese, as well as rare earth metals.

• Manganese nodules, potato-shaped clumps made of minerals, grow over millions of years on the ocean floor and contain significant amounts of manganese and other metals.