A joint permafrost study on the Fuji volcano (3776 m a.s.l., MAAT = −6°C), the highest mountain in Japan, has progressed (A. Ikeda, G.. Iwahana, T. Sueyoshi and R. Nishii). A 10 m-deep borehole was dug on the summit area, to monitor permafrost temperature. The ground temperature in the borehole was much lower than that in the 3-m deep boreholes dug on the same summit area in 2008. On the summit area, temporal variations in ground temperature strongly depend on the local topography and composition.

 


Drilling a 10-m deep borehole on the top of Fuji volcano.

Several overseas projects are also going on. In Alaska, a project named ‘2004 Forest Fire Impacts to Hydrological Cycles, Permafrost and Eco Systems in Central Alaska’ has progressed since 2005 in order to monitor permafrost conditions after a severe wildfire (K. Harada, K. Narita and K. Saito). In summer 2010, observations were carried out at the Kougarok site near Nome, Alaska in August, and thaw depths were measured from the ground surface. Measurements of surface roughness were also conducted to compare with the satellite data. Ground temperatures have been measured with data loggers since 2007. Vegetation surveys were also made in order to clarify the recovery after wildfire at burned sites. Continuous data of thaw depth and ground temperature could be obtained and the effect of the wildfire to permafrost condition and vegetation recovery will be clarified.

In Svalbard, a monitoring campaign has continued in order to understand the dynamics of patterned ground (including ice-wedge polygons, mudboils and hummocks) and a polar rock glacier with a variety of methods (N. Matsuoka and T. Watanabe), collaborated with UNIS (H.H. Christiansen) and University of Oslo (O. Humlum). Detailed (2D and 3D) geophysical sounding was applied to illustrate subsurface structures under the patterned ground and temporal variation in the subsurface moisture regime (T. Watanabe). The study sites were demonstrated to the EUCOPIII attendants during the half-day excursion in Adventdalen.

 


Tatsuya Watanabe presents his observations on mudboil dynamics during the EUCOPIII half-day excursion in Adventdalen.

The Japanese Permafrost Association had a two-day annual meeting in January 2011 in Sapporo. About 30 scientists and students participated and presented their newest results. The meeting involved a memorial lecture on ‘Glacial and periglacial studies over 20 years’ by Prof. Kazuomi Hirakawa, who is officially retiring from Hokkaido University in March 2011, and closed with discussion on an interdisciplinary project on Arctic permafrost.

Compiled by Norikazu Matsuoka (matsuoka@geoenv.tsukuba.ac.jp)