Geochemical fingerprinting of high latitude dust – potential environmental impacts of natural and mining related dust in Greenland in a changing climate.

Dispersion and deposition of mineral dust from natural or anthropogenic sources can have both positive and negative effects on the environment depending on the geochemical and mineralogical composition of the dust. In Greenland, proglacial river systems draining the Greenland Ice Sheet occupy extensive areas of dust prone deposits, which are commonly mobilized and transported by winds of both katabatic and cyclonic origin and subsequently deposited as high latitude dust. The geochemical fingerprint of natural dust emitted along the latitudinal transect reflects the mineralogical and elemental composition of the bedrock underlying the Ice Sheet in the different geological provinces of Greenland. As dust emissions respond to changes in climate-sensitive drivers such as soil moisture, winds speed and precipitation, marked variations in natural dust emissions are present along the climatic gradient in Greenland, ranging from high latitude arctic deserts in North Greenland to low latitude shrub tundra in the South.

With a changing climate, interest has increased to access and exploit the rich mineral resources located in the Arctic. In Greenland, development of large-scale mines range from rare earth element mines in the sub-arctic South to zinc-lead mines in the high-arctic North. While the mining sector provides society with essential raw materials for a wide range of industrial processes as well as forming the basis for the transition into a global green economy, it also has significant environmental pitfalls, which should be avoided or mitigated. Mobilization, transport, and deposition of mineral dust from mine sites is often significant in regions susceptible to wind erosion because of the dry climate and lack of vegetation. Once dispersed into the environment, this mineral dust may impair important ecosystem functions due to its potential content of heavy metals and other trace elements, as well as cause concerns for public health.

To support the sustainable development of environmentally safe mining in sensitive Arctic land areas and reduce airborne environmental pollution, an improved understanding of processes leading to the dispersion of mineral dust in a changing Arctic is needed. This involves improved methods for monitoring dust emissions and dust deposition in a cold environment as well as analytical tools and methods to source trace and differentiate between natural and mining related dust. Accurate identification of individual dust sources subsequently makes it possible to mitigate emissions and target the regulation of mining activities towards these sources.

In the following, we present a new high latitude dust sampling location in Kangerlussuaq, West Greenland, where dust is collected using a wide array of passive and active dust samplers, including a continuously operated high volume dust sampler, which will offer filter samples of large air volumes (13.000 m³) at a weekly sampling frequency over multiple years. In addition, we would like to present data from a study (1) in which we developed a fast and cost-effective surface screening methodology that is easily applicable for dust source characterization in remote Arctic areas such as Greenland, where dry conditions and high winds create a high natural dust generation potential.

(1) Søndergaard, J. & Jørgensen, C.J. (2021) DOI: 10.1007/s11270-021-05095-2