Formation of Gas-Emission Craters in Northern West Siberia: Shallow Controls

Evgeny Mikhailovich Chuvilin,Natalia Sergeevna Sokolova,Dinara Anvarovna Davletshina,Boris Aleksandrovich Bukhanov,Mikhail Yurievich Spasennykh

doi:10.3390/geosciences11090393

Abstract

Gas-emission craters discovered in northern West Siberia may arise under a specific combination of shallow and deep-seated permafrost conditions. A formation model for such craters is suggested based on cryological and geological data from the Yamal Peninsula, where shallow permafrost encloses thick ground ice and lenses of intra- and subpermafrost saline cold water (cryopegs). Additionally, the permafrost in the area is highly saturated with gas and stores large accumulations of hydrocarbons that release gas-water fluids rising to the surface through faulted and fractured crusts. Gas emission craters in the Arctic can form in the presence of gas-filled cavities in ground ice caused by climate warming, rich sources of gas that can migrate and accumulate under pressure in the cavities, intrapermafrost gas-water fluids that circulate more rapidly in degrading permafrost, or weak permafrost caps over gas pools.

Highlights

The effects of global warming observed worldwide in recent decades are especially evident in the Arctic, including the vast territories of northern Russia
The permafrost of northern West Siberia, where gas-emission craters were found in the Yamal and Gydan Peninsulas [13,26], is composed of silty and clayey marine sediments deposited at high rates in the Pleistocene [31,32,33,34,35]
West Siberia are due to the active economic development of the area and It should be noted that the presented scheme of models does not reflect some imto global change, especially warming which leads to thawing of shallow permafrost and portant factors causing permafrost degradation and a crater’s formation

Summary

Introduction

The effects of global warming observed worldwide in recent decades are especially evident in the Arctic, including the vast territories of northern Russia. Greenhouse gases can be released in multiple ways, as summarized and mapped in a number of recent publications [13,14]: from emission from the surfaces of the active layer and lakes to gas flow during drilling to different depths in permafrost. The first large crater to be discovered, ~40 m in diameter and 50 m deep, was located in the Yamal Peninsula (northern West Siberia) in the summer of 2014 (Figure 2, C1). It was spotted by accident from helicopter, 30 km south of the Bovanenkovo gas-condensate field, which had commenced operations shortly before (in 2012).

Crater

Permafrost Properties in the Area of Gas-Emission Craters

Possible

Findings

Conclusions