||TL 374, deep drilling, freeze-thaw cycle, heating, ice, melt water, refreezing, temperature profile, thermal probe
||Drilling into ice represents essentially a different problem than geologic boring. From an engineering standpoint, the main problems involve the vicious deformation of the ice and the refreezing of melted water, from which drilling rods or cables become jammed unless preventative measures are undertaken. In the deep ice drillings, one is interested primarily in the temperature profile. The author developed a thermal deep-drilling probe with which the deepest ice layer on earth (over 4000 com) can be pierced. Within the scope of the IGGE, two such probes were put into operation for drilling at the Jarl-Joset Expeditionary Station in summer, 1968. Apart from the heating element difficulty with the premature ending of the run, the operation proceeded according to plan and the measurement yield was copious.