Rusticle Formation on the RMS Titanic and the Potential Influence of Oceanography

Rusticle Formation

• Rusticles on the Titanic are massive, braided structures reaching lengths of up to 3–4 metres.
• These formations are primarily attributed to iron oxidising bacteria, which draw iron from the ship’s structure.

Comparative Analysis

• In the Gulf of Mexico, rusticles are smaller and less dense despite similar exposure times, suggesting that local environmental conditions significantly influence rusticle growth.

Environmental Factors

• The presence of dissolved and particulate iron (Fe) in the surrounding water is critical. The North Atlantic, where the Titanic rests, receives high inputs of iron from various sources, including:
  • Aeolian dust transported by wind currents.
  • Sediments carried by turbidity currents.
  • Iron-rich meltwater from the Greenland Ice Sheet.
  • Hydrothermal vents along the Arctic Mid-Ocean Ridge.
  • Oceanic currents, such as the Western Boundary Undercurrent and the Gulf Stream, transport iron to the Titanic’s site.

Bacterial Contributions

• Bacteria such as Halomonas titanicae play a role in rusticle formation. However, there is debate over whether the bacteria actively extract iron from the ship or merely exploit pre-existing environmental iron.

Corrosion Rates

• Studies estimate that the Titanic is losing approximately 0.13–0.20 tons of material daily due to rusticle formation, with a projected lifespan of 280–420 years for the wreck.

Climate Change Impact

• Global warming is increasing the flow of iron-rich meltwater from the Greenland Ice Sheet, potentially accelerating rusticle growth.
• Changes in ocean currents due to climate change could also alter iron transport and deposition.

Alternative Explanations

The article challenges the idea that bacteria alone are responsible for rusticle formation, suggesting abiotic mechanisms like iron deposition driven by oceanic currents and environmental conditions may play a significant role.

Conclusion

Rusticle formation on the Titanic is influenced by a combination of biological, chemical, and environmental factors. The large availability of iron in the surrounding area, facilitated by ocean currents and other natural processes, likely contributes significantly to the growth of these formations. Understanding these mechanisms is vital for predicting the deterioration of the Titanic and other shipwrecks under similar conditions.