THERMAL REGIME OF CRYOLITHOZONE AT YTYMDZHA DEPRESSION, ALDAN SHIELD
R.G. Sysolyatin, M.N. Zheleznyak
Melnikov Permafrost Institute SB RAS, Merzlotnaya str. 36, Yakutsk, 677010, Russia
Keywords: ground temperature, geothermal gradient, permafrost thickness, Ytymdzha depression
Abstract
The results of geocryological studies in the Ytymdzha depression of the Aldan Shield have been presented. From 1999 to 2001, several exploration wells were drilled in the central part of the depression, which made it possible for the first time to obtain the information on the geotemperature field, the thermophysical properties of rocks and the thickness of the permafrost stratum. The long-term series of monitoring of the temperature regime of the active layer obtained for the bogged floodplain terrace, the upland terrace, and the slope of the southern exposure have been adduced. The temperature of rocks at a depth of 1 m varies from 4.8 to -11.7 °С, with average annual temperature ranging from -1.0 to -4.9 °С. The work has resulted in the sublongitudinal permafrost-geothermal section along the central part of the Ytymdzha depression, within which the thickness of permafrost varies from 106 to 251 m.
|
