The upper part of permafrost zone is undergone the largest thermal changes related to the seasonal temperature changes. Within this level rocks and particularly their upper part is undegone the additionary thermal load during the industrial development of north area. This thermal load results in the break of natural temperature regime. The temperature can both rise and dicreas. This fenomenon is accompanied by the break of physical- technical rock characteristics. The ignorence of geological- ecological effects of man's activity in permafrost zone can result in looses, equal in scales with such catstrophes as , for examples, earthquakes.

We distinguish several groups of objects of local geophysical monitoring by the character of the influence to the upper part of permafrost zone. The first group consists of the objects evolving considerable quantity of heat: thermal power stations, hydro elctric power stations, reservoirs, tale storage pound of mining enteprisis, and quarries. Another group consists of seasonal and artificial talics developing at the placer deposits. On the conrary, it is necessary to preserve permafrost during the undergraound mine workings. In the case of absence of permafrost, it is created by promorozka ( the natural freezing of the ground in the course of sinking a pit in a water-bearing horizons). During the working of pillars that are in the flooded shafts, it is necessary to reveal the zones of unfrozen water. Underground fires in coaly basins of permafrost zone are also the objects of study. The next group consists of airfields, fields, meadows, and roads. Both existence of permafrost and its degradation should be taken into account at the planning stage of these objects. The separate group consists of building constrations, underground and terrestrial communications. Ecological investigations are necessary on dumps and buirals of toxic and radioactive waste products. Sections of collapses and landslides provocated by earthquakes and atmospheric conditions belong to the objects of local monitoring. Geophysical monitoring of such local objects as restoration of permafrost near the well areas after the drilling works is also of practical interest.

In local monitoring of permafrost zone electric and seismic methods play the main role because the transformation of rocks from the melted state to frozen one, and vise versa, is accompanied by multiple change of their seismic-electric features. Geophysical methods of local monitoring in permafrost zone have the real advantages ( drive, ecological cleanness, cheapness) in comparison with drilling works and mine workings.

Dr. Boris M. Sedov
North-East Interdisciplinary Research Institute RAS
16 Portovaya st.
685000 Magadan, Russia
(413-22)3-10-24 off.
(413-22)2-73-43 home
root@neisri.magadan.su (To: Dr.Sedov)