Guest essay by J.I. Thacker

The Te Moeka o Tuawe (REF 1) is a southern-hemisphere glacier in New Zealand that is unusual among glaciers in that its terminus is very close to sea level in a temperate zone. Although relatively long – about 13 km – the glacier has been receding since about 2009 because of anthropogenic climate change, which scientists say is caused by fossil-fuel carbon emissions.

From Wikipedia’s description of the Fox glacier in New Zealand:

Fed by four alpine glaciers, Fox Glacier falls 2,600 m (8,500 ft) on its 13 km journey from the Southern Alps down to the coast, with it having the distinction of being one of the few glaciers to end among lush rainforest only 300 metres (980 ft) above sea level. Although retreating throughout most of the last 100 years, it was advancing between 1985 and 2009. In 2006 the average rate of advance was about a metre a week. In January 2009, the terminal face of the glacier was still advancing and had vertical or overhanging faces which were continually collapsing. Since then there has been a significant retreat, with the 2009 high level clearly visible as vegetation line on the southern slope above what is left of the lower glacier today.

Lower part of Fox Glacier with glacier mouth, February 2013. Note the clearly visible limit of vegetation on the right (southern) slope, which marks the temporary maximum height of the glacier around 2009.

That Te Moeka o Tuawe is retreating should not be surprising. Currently, nearly all glaciers have a negative mass balance and are retreating to the extent that they are contributing 30% of the current rate of sea-level rise (REF 2). The IPCC stated in 2007 that Himalayan glaciers could be gone by 2035(REF 3). “The Arctic is screaming,” said Mark Serreze, senior scientist at the US government’s snow and ice data center in Boulder, Colorado (REF 4).

Glacial retreat can have unexpected knock-on consequences like reducing the availability of drinking water for downstream communities, as well as increasing local temperatures via decreases in albedo: even old ice has twice the reflectance of bedrock exposed as it retreats.

The unique location of Te Moeka o Tuawe gave cryoengineer Dr. Eric Fox (REF 5 – no relation to the glacier) an idea.

“I thought it would be an ideal place to test a theory I had about glacial dynamics,” he tells me via Skype. “The idea is to supplement the glacier with an ice-mimic, a surrogate substance with similar spectral properties to frozen water but much higher levels of stability.”

The logistics of the glacier slowing experiment are quite difficult – that’s why the low-altitude terminus of Te Moeka o Tuawe is so important. The project involves reinforcing the glacier with 57,000 tonnes of the substitute ice, which would be impossible to transport to a high-altitude terminus.

Fox’s team decided on creating reinforcing ice by combining regular ice with a complex, but easy to manufacture, molecule called (2R,3R,4S,5S,6R)-2-[(2S,3S,4S,5R)-3,4-Dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol (REF 6) for the initial trial. The molecule is based on natural compounds, and is harmless to plants, wildlife, and to humans. In nature, the compound is present in many plant roots, fruits and nectars, and serves to store energy, primarily from photosynthesis.

3D model of (2R,3R,4S,5S,6R)-2-[(2S,3S,4S,5R)-3,4-Dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol

“It is very important that we do no harm to the environment in our attempt to slow the retreat of the glacier. That’s why the team settled on this naturally occurring compound. It was my idea to add a dash of 5-Methyl-2-(propan-2-yl)-cyclohexan-1-ol (REF 7),” Fox notes. My compound has interesting cryo-properties. And it even smells good.”

Fox calls the experimental glacier trial a “Win-win-win” scenario.

“We’ll slow the glacier’s retreat, increase albedo, and because the chemical substitute contains a high proportion of carbon, it effectively locks up Carbon that would otherwise be polluting the atmosphere.”

It is expected that after the application of this compound to the reinforcing ice, retreat of Te Moeka o Tuawe is going to be slowed and eventually the glacier will be as good as new, returning to its maximum volume observed in 2009. The scientists are calling their project “Fox’s Glacier Mint.”

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References

REF 1 Known by Western interlopers as Fox Glacier.

REF 2 Gardner et al. 2013; Science 340 (6134): 852–857.

REF 3 It was apparently a typo.

REF 4 He said it about ten years ago about something else, but it seemed somehow apropos to mention it here.

REF 5 Also, by pure coincidence, the name of the inventor of Fox’s Glacier Mints.

REF 6 (2R,3R,4S,5S,6R)-2-[(2S,3S,4S,5R)-3,4-Dihydroxy-2,5-bis(hydroxymethyl)oxolan-2-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol is known by the great unwashed as sucrose.

REF 7 5-Methyl-2-(propan-2-yl)-cyclohexan-1-ol a.k.a. Menthol.