Long-term thermal effect of asphalt pavement on permafrost under an embankment

Permafrost temperatures have been monitored through six boreholes drilled up to 15 m in depth under asphalt pavement along the centerline of an embankment along the Qinghai–Tibetan Highway. Temperatures have been measured twice monthly from 1996 through 2007. Soil temperatures at 1.0 m depth under asphalt pavement in the northern areas of the Tanggula Mountains have shown a significant increasing trend, but a significantly decreasing trend in...