Vertical electric resistivity sounding of natural and anthropogenically affected cryosols of Fildes Peninsula, Western Antarctica

Abstract

Natural and anthropogenically-affected Cryosols of the Fildes Peninsula (King George Island, NWAntarcticPeninsula) from the surroundings of Russian polar station Bellingshausen were investigated by vertical electric sounding. The aim of the study was to asses the thawing depth and active layer thickness. Natural Turbic Croysols showed lesser thickness of active layer than the soils of former reclaimed wastes disposals. Average thickness of the active layer was 0.3-0.4 m in natural soil and 1.3-1.4 m in anthropogenically-affected ones. This was affected by the change in the temperature regime of soils, and related to the destruction of upper organic layer and mechanical disturbance of the active soil layer on the waste polygons. Itwasshown,thattheuseof vertical electric soundingmethodologyinthesoilsurveysisusefulfor the identificationofthe permafrostdepthwithoutdiggingofsoilpit.Thismethodallowstheidentificationofsoilheterogeneity, because the electric resistivity (ER) values are strongly affected by soil properties. ER also intensively changes on the border of differentgeochemicalregimes,i.e.ontheborderoftheactivelayerandthepermafrost. The lowest ER values were found for the upper organic horizons, the highest for permafrost table. Technogenic Superficial Formations exhibit lower resistivity values than natural soils. Therefore, disposition of WP and disturbance of the soil surface, results in permafrost degradation and an increase in the active layer thickness.