Explosive processes in the permafrost zone as a new type of geocryological hazard

Abstract

The natural and human-induced explosive processes in the permafrost area were studied. A new approach is proposed to the theory of formation of gas emission funnels. It is based on the mechanism of migration of gas fluids from the gas hydrates dissociation zone to the overlying permafrost. The dissociation zone is formed in the areas of local heating due to the heat input from above. The preparation stages of the explosive process that formed the Yamal crater are shown. The preparation phases of natural explosive processes have been identified and characterized. Different scenarios are considered for the preparation of natural explosive processes in the cryolithozone. The main conclusions of the conducted research are the following: the explosions of hydrolaccoliths and the formation of gas emission funnels belong to one group of processes, i.e., physical explosions of natural origin; preparation of explosive processes in the permafrost goes through several stages; the migration of gas fluids plays an important role in the preparation of natural explosions in the permafrost. With the ongoing economic development of the Arctic, thermal effects on permafrost increase, and so does the hazard of explosive processes for engineering structures. However, this group of processes is not taken into account when choosing design solutions and predicting the interaction of an engineering structure with permafrost soils; moreover, these processes are even not included in the group of hazardous geological processes.

Gas‐emission craters of the Yamal and Gydan peninsulas: A proposed mechanism for lake genesis and development of permafrost landscapes

“…Gas blowouts have been also observed to the south of the study area (Yuribey river, Southern Yamal) from depths less than 60 m . Therefore, we conclude that microbial methane formed due to decomposition of gas hydrates was the most likely source of gas in GEC‐1 …”

Evidence of Gas Emissions from Permafrost in the Russian Arctic

“…It was located on the left bank of the Mongoche River, 10-15 km far from the mouth, in the southwestern coast of the Yenisey Gulf near the Deryabino gas field, 110 km far from Nosok Village. Fragments of permafrost and ice dispersed by the event reached sizes of 3 × 5 m. Like the case of the Seyakha crater, the explosion triggered gas ignition [25]. Judging by historic images, the crater formed in the place of a pingo 20-25 m in diameter.…”

“…More than 10 gas-emission craters encircled with ridge-like parapets of ejected ground resulting from explosive events (cryovolcanism) have been found so far in the Yamal, Gydan, and Taymyr Peninsulas in northern Siberia (Table 1) [19,22,[24][25][26]. Cryovolcanism of this kind became first known to the international scientific community in 2014, when a 70 m deep crater (Yamal Crater) [22,[44][45][46][47][48][49] was discovered 30 km south of the Bovanenkovo field, 5 km away from the Bovanenkovo-Ukhta gas pipeline.…”

“…These craters have not been visited and documented yet, for different reasons, and some even remain not located, such as Osokin's crater discovered on 26.07.2013 in the Yamal Peninsula. The crater was named after the person who provided its photograph taken from a helicopter [25]. Note that some gas-emission craters in permafrost were observed only in helicopter surveys or detected in satellite images.…”

“…Active gas emission from the Arctic permafrost was observed during gas surveys of the near-surface atmosphere [8,11], the active layer, and water bodies [10,[12][13][14][15][16][17][18][19]. Crater features on the surface record explosive emission of deep methane [20][21][22][23][24][25][26].…”