Welaptega has observed possible “Rusticles” at a depth of approximately 1000m in a mooring system in West Africa.
The term “Rusticle” was first coined to describe the unique corrosion formations observed on the wreck of the Titanic after 95 years at the bottom of the Atlantic (Brenda J Little, Jason S Lee, Microbiologically Influenced Corrosion).
Rusticles appear as stalactite-like features of fragile, red-brown rust, primarily Iron oxyhydroxide (FeOOH). Rusticles are thought to be caused by Iron Oxidizing Bacteria (IOB) in cooperation with Sulfate Reducing Bacteria (SRB), both of which are forms of Microbiologically Influenced Corrosion (MIC).
In some cases MIC can cause exceptionally high corrosion rates in mooring systems, while in other cases they add little to no contribution beyond expected aerobic corrosion rates. The first step towards inspecting for accelerated corrosion rates is recognizing the signs and focusing inspection on the most likely affected areas.
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