Monday, September 3, 2012

Sulphur mining on a volcano

The most eye-catching colour on White Island is yellow, as you can see from the photos below (as I mentioned in a previous post on White Island, the rocks are too corrosive to set scale cards or lens caps on, so none of the photos have scale). It forms crusts around the fumaroles and on the edges of the streams of water. This is the effect of sublimation - the sulphur transitions directly from gas to solid. Inside the fumaroles on White Island there appears to be some liquid sulphur, but I suspect this is caused by re-melting of the sublimate. 

Before I go any further, I want to address the spelling of of sulphur. I am Canadian, and I try to use the Canadian/British spellings of most words (note the 'u' in colour above). The 'American' spelling of the 16th element is sulfur, and this has been adopted by IUPAC. It is the spelling I probably should be using, but I grew up with sulphur, not sulfur, and I just prefer the look of it. There's an interesting post about f vs ph here.

Sulphur is mined for several reasons. It is used in fertilizers, fungicidal plant sprays and the manufacture of sulphuric acid (to name just a few). 

Mining of sulphur began on White Island in 1885. In 1914, part of the crater wall of the volcano collapsed causing a landslide and debris avalanche that killed 12 mine workers. The mining camp on the southern edge of the crater was destroyed and mining operations ceased.

In 1923 mining resumed, but this time the miner's camp was built outside the crater. When the water was calm the miners took a boot to the mine. In bad weather, they hiked up over the rim of the crater and down to the camp. Remnants of the camp and their path can be seen when you circumnavigate the island. The campsite is now occupied by gannets. In the 1930s mining on White Island was permanently shut down because it was not economical. In total, approximately 11200 tonnes of sulphur were extracted from White Island.

Moon, V., Bradshaw, J., and de Lange, W., 2009, Geomorphic development of White Island Volcano based on slope stability modelling: Engineering Geology, v. 104, no. 1-2, p. 16–30, doi: 10.1016/j.enggeo.2008.08.003.

Pough, Frederick H., 1988, Rocks and Minerals, Peterson Field Guides, 4th Edition

Emiliani, Cesare, 1995, Planet Earth: Cosmology, Geology, and the Evolution of Life and Environment, Cambridge University Press

The approximate location of the 1914 landslide (orange) and resulting debris flow (blue) that wiped out the  mine and mining camp (gear/purple and white circle). The location of the new mining camp (now a gannet colony) is marked with a red tent.

Sulphur on the ground around a mud pot
Sulphur on the banks of a tiny stream
Sulphur on the banks of a tiny stream


Close-up of sulphur crystals on the ground. 

Several fumaroles

Sulphur on the crater floor
Sulphur in the crater walls

Solid sulphur

Remnants of the 1914 mining operations
Rusted remnants of the 1914 mine

Remnants of the 1914 mining operations

Window to the crater

Beach view from the original mine