South32 Gemco Manganese Operations Face Cyclone Narelle Supply Risk

South32, Gemco Manganese

South32 Gemco manganese operations are facing renewed weather-related disruption risk as Cyclone Narelle approaches Groote Eylandt in Australia’s Northern Territory. The company is moving non-essential personnel offsite while monitoring the incoming system with local emergency authorities.

The precautionary move comes as Cyclone Narelle is forecast to pass Groote Eylandt on Saturday afternoon. Australia’s Bureau of Meteorology expects the cyclone to reach category three strength by that time, bringing stronger wind and rain conditions to the island.

South32 Gemco manganese operations are important to the seaborne manganese ore market because Gemco is a major source of high-grade Australian ore. Any operational disruption could affect supply flows into China, where manganese ore demand is closely tied to steel and alloy production.

Groote Eylandt Weather Risk Returns After Cyclone Megan Disruption

Groote Eylandt has already shown how severe weather can affect manganese supply. South32 paused mining operations at Gemco for four months in March 2024 because of Cyclone Megan, and manganese exports from the site only resumed in May 2025.

That history makes the latest cyclone warning more significant for the market. Even if the current action is only precautionary, buyers and traders will watch closely for any damage to mining, haulage, port infrastructure, or export schedules.

South32 plans to produce 3.2 million tonnes of manganese at Gemco in July 2025-June 2026. Maintaining that output will be important for stabilizing supply after the previous weather-related disruption.

Manganese Ore Market Watches China Demand and Australian Supply

South32 Gemco manganese operations also sit at an important point in the pricing cycle. The company raised its March-delivery Australian 43pc lumpy manganese ore cif China price by $0.10/mtu to $5.20/mtu in late January, citing expectations for stronger Chinese demand after the lunar new year holidays.

Cyclone-related uncertainty could add another layer of support if the market sees a risk to Australian export availability. Manganese ore is essential for steelmaking through ferro-manganese and silico-manganese production, so supply interruptions can quickly influence alloy raw material sentiment.

For now, the key issue is whether Cyclone Narelle causes only a short safety response or a broader operational setback. The market will focus on site access, port conditions, and South32’s ability to maintain shipment schedules after the weather system passes.

The Metalnomist Commentary

South32’s latest move shows that manganese supply risk is increasingly shaped by weather resilience as much as mine capacity. For steel-linked raw materials, reliable logistics from vulnerable export hubs can become a pricing factor overnight.