Received: 25 Oct 2021 – Accepted for review: 16 Dec 2021 – Discussion started: 20 Dec 2021
Abstract. Perennial snow patches are considered as indicators of permafrost occurence. There are no large glaciers on the territory of Bulgaria but small patches of snow and firn have been observed in the high mountains in the end of the summer. Perennial snow patches are considered as indicators of permafrost occurrence. In this paper we present results from geophysical investigations of Snezhnika microglacier situated in the Golyam Kazan cirque, Pirin Mountain, Bulgaria. Ground penetrating radar (GPR) and 2D Electro Resistivity Tomography (ERT) were used to estimate the thickness of the perennial snow patch as well as its subsurface structure. Measurements started in 2018 and continued over the next three years in order to evaluate changes in the snow patches' size and thickness. The mean thickness of Snezhnika is about 4–6 m, reaching up to 8 m in some areas. ERT measurements of the deeper parts of the microglacier beds show high electrical resistivities reaching over 60000 Ωm at a depth of 4–10 m. An anomaly at this depth is likewise distinguishable on the GPR profiles. These anomalies are interpreted as frozen zones and are consistently observed on the ERT and GPR profiles in the next two years of the study. These results imply for the first time the existence of permafrost in Pirin mountain and respectively in Bulgaria.
The southernmost microglacier in Europe is Snezhnika in Pirin Mountain Bulgaria. We have used geophysical measurements to investigate its thickness and internal structure. While its size is well monitored since more than 20 years, the estimations of its thickness is poor. This motivated us to conduct the research. Perennial snow patches and microglaciers are considered as indicators of permafrost occurrence, although no evidence for permafrost existence in Bulgaria was published until our paper.
The southernmost microglacier in Europe is Snezhnika in Pirin Mountain Bulgaria. We have used...
