The distribution of tephra (i.e. volcanic ejecta) from a particular volcanic eruption depends on its force and the dominant wind direction at the time. Before being deposited fine-grained tephra may travel hundreds of kilometers. It has been demonstrated that volcanic gases and particles from the eruptions produced by high-latitude volcanoes may encompass the poles faster due to the shorter pathway and higher wind speed. Thus, volcanic emissions from Mt. Hudson and Puyehue-Cordon Caulle, Chile, or Kasatochi, Alaska, were transported around the pole within 10-14 days (Barton et al., 1992; Schoeberl et al., 1993; Langmann, 2014).
Despite active volcanism, permafrost and glaciers often exist on slopes of high-elevation or high-latitude volcanoes (Kellerer‐Pirklbauer et al., 2007) in places such as Hawaii (Woodcock 1974), Iceland (Etzelmüller et al., 2007), Kamchatka (Demidov and Gilichinsky, 2009), Mexico (Palacios et al., 2007), Peru (Rabatel et al., 2013), North America (Denton and Karlén, 1977; Dyke,1990), and Antarctica (Marchant et al., 1996).
Volcanic eruptions are one of the major causes of the burial of ice and snow in volcanic areas. This has been demonstrated on volcanoes in Iceland, USA and Chile, where the combination of a permafrost-favorable climate and a thin layer of tephra (with low thermal conductivity) is sufficient to reduce the sub-tephra layer snow ablation substantially, even to zero, causing ground ice formation and permafrost aggradation (Driedger, 1981; Major and Newhall, 1989; Kirkbride and Dugmore, 2003; Kellerer‐Pirklbauer et al., 2007; Reid and Brock, 2010).
Properties of volcanic ash and pumice, as well as volcanic soils have been widely investigated due to their unique properties. Paleoscientists and tephrochronologists use volcanic ash as a tool for linking and dating geological, paleoecological, paleoclimatic, and archaeological sequences or events (Lowe, 2010; Lowe, 2011; Ponomareva et al., 2007; Marchant et al., 1996). Soil scientists are concerned with the unique physical, chemical and mineralogical properties of the soils formed on the volcanic ash (or Andisols) in respect to their high permeability, organic matter, secondary minerals, high surface area etc. (Nanzyo, 2002). In the cold environment volcanic ash is (1) an important factor in process-based studies that are investigating the influence of permafrost aggradation and degradation upon carbon and peat accumulation, and (2) as a marker in studies of rock glaciers and glacial moraines, as well as glacier fluctuations, moraine development and the chronology of glacial/glaciofluvial deposition ((Denton and Karlén, 1977; Dyke, 1990; Robinson and Moore, 2000; Bäumler, 2003; Froese et al., 2008). Glaciologists and permafrost researchers have investigated the influence of tephra on snow and ice ablation, permafrost aggradation, and the energy balance at the glacier–atmosphere interface (Pellicciotti et al., 2009; Brock et al., 2007; Kellerer‐Pirklbauer et al., 2007; Hock, 2005; Greuell and Oerlemans, 1986). Terrestrial volcanoes in permafrost areas are being studied in order to establish volcanic permafrost models for Mars (Arvidson et al., 2004; Squyres et al., 2006; Demidov and Gilichinsky, 2009).
The paper discusses the application of multidisciplinary research on volcanic material covering permafrost and glaciers in volcanic areas. In cold environments, volcanic ash is widely used in different science disciplines in process-based studies examining paleoclimate reconstruction; the influence of permafrost aggradation and degradation; influence of tephra on snow and ice ablation; glacier fluctuations, deposition and moraine development; volcanic glass weathering and new minerals formation (e.g. allophane, palagonite).
Vis fullstendig beskrivelse
