Miaoergou Glaciers in the Kalik Mountains, western China: Report of a reconnaissance for future ice core drilling and biological study

Introduction Nozomu TAKEUCHI , Masayoshi NAKAWO , Hideaki NARITA and Jiankang HAN Miaoergou Glaciers in the Kalik Mountains, western China: Report of a reconnaissance for future ice core drilling and biological study Bulletin of Glaciological Research ( ) Japanese Society of Snow and Ice Department of Earth Sciences, Graduate School of Science, Chiba University, , Yayoicho, Inage-ku, Chiba-city, Chiba, , Japan National Institutes for the Humanities, Kamiyacho Central Place, , Toranomon, Minato-ku, Tokyo , Japan Institute of Low Temperature Science, Hokkaido University, Kita, Nishi, Kita-ku, Sapporo, , Japan Research Institute of Environment and Resources, Hunan Normal University, Changsha , Hunan, China (Received July , ; Revised manuscript accepted September , ) Glaciological field studies on Miaoergou Glaciers in the Kalik Mountains, western China were carried out in and to investigate the possibility of future ice core drilling and biological observation. Two glaciers, which have dome-shaped accumulation areas at an elevation of approximately m a.s. l. , were investigated. Radio-eco soundings showed that the ice thickness at the top of the two glaciers was . and . m, respectively. Snow-pit observations revealed that superimposed ice appeared at cm below the surfaces at the top of both glaciers, indicating that significant melting had occurred during summer. Analyses of a -m-depth ice core drilled on one of the glaciers showed that it consisted mostly of continuously refrozen ice and that the O varied from . to . with a mean of . In the ice core were three visible dust layers, one of which contained various microbes including cyanobacteria. Whereas the O record had proved rather unsatisfactory as an air temperature proxy due to melt water runo , a reconstruction of dust deposition and biological activity on the glacier might be possible using an ice-core study. world ( Kohshima, ). Such communities usually consist of snow algae, bacteria, micro animals, and insects. These are specialized species that have Several ice cores have been drilled on glaciers in adapted to live on snow and ice environments. Comhigh Asian mountains since the late s. These munity structure and biomass vary among glaciers in cores have revealed environmental conditions dating di erent geographical locations. For example, snow back hundreds to thousands of years in this region algal communities di er on glaciers from northern and have significantly contributed to our understandAsia (Altai), middle (Tibet), and southern Asia (Himaing of the climate system in that region ( Thompson layas; Takeuchi ). The characteristics of ). These cores have also revealed geoorganic matter derived from such biological activities graphical variations in the climate history of the also vary on di erent Asian glaciers (Takeuchi, Asian high plateau. For example, there have been b). The biogenic material is usually composed of a antisynchroneities in stable isotopes between the eastdark sediment called cryoconite ( Takeuchi ern and western Tibetan Plateau (Lin ), as a). These geographical variations in biological well as in accumulations between the eastern and communities and biogenic materials may be due to western Himalayas (Kaspari ) for the last di erences in the physical and/or chemical conditions thousand years. In order to understand the spatial on glaciers, but they need to be better understood for variations in former environments and climates in the future studies of glacial eco-systems and the usefulAsian high plateau, more ice cores need to be recovness of biogenic materials for ice core analysis. ered from new locations. The Kalik Mountains are located at the eastern Geographical variations can also be made apparboundary of the Tien Shan Mountains of western ent by studying microbial communities living on China at elevations up to approximately m a.s. l. those glaciers. Recent studies have revealed diverse There are more than small glaciers in this mounbiological communities on many glaciers across the tain range, some of which appear promising sites for e.g. e.g. et al., et al., e.g. et al., et al., et al., + + , ,