Comparison of Gas Emission Crater Geomorphodynamics on Yamal and Gydan Peninsulas (Russia), Based on Repeat Very-High-Resolution Stereopairs

Abstract

Gas Emission Craters (GEC) represent a new phenomenon in permafrost regions discovered in the north of West Siberia. In this study we use very-high-resolution Worldview satellite stereopairs and Resurs-P images to reveal and measure the geomorphic features that preceded and followed GEC formation on the Yamal and Gydan peninsulas. Analysis of DEMs allowed us to: (1) distinguish different terrain positions of the GEC, at the foot of a gentle slope (Yamal), and on an upper edge of a terrace slope; (2) notice that the formation of both Yamal and Gydan GECs were preceded by mound development; (3) measure a funnel-shaped upper part and a cylindrical lower part for each crater; (4) and measure the expansion and plan form modification of GECs. Although the general characteristics of both craters are similar, there are differences when comparing both key sites in detail. The height of the mound and diameter of the resulting GEC in Yamal exceeds that in Gydan; GEC-1 was surrounded by a well-developed parapet, while AntGEC did not show any considerable accumulative body. Thus, using very-high-resolution remote sensing data allowed us to discriminate geomorphic features and relief positions characteristic for GEC formation. GECs are a potential threat to commercial facilities in permafrost and indigenous settlements, especially because at present there is no statistically significant number of study objects to identify the local environmental conditions in which the formation of new GEC is possible.

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

“…Kizyakov et al showed that before the GEC‐1 appeared, a 5–6 m high and 45–58 m wide mound existed at that location. Similarly, a 2 m high and 20 m wide mound preceded the emergence of AntGEC on the Gydan peninsula . Similar mounds were previously described in the submarine environment as pingo‐like features (PLFs): in the Beaufort Sea, and Barents–Kara Sea shelves 5–9 m in height and 70–1000 m in diameter, and on the Pechora Sea shelf showing base diameters from 20 to 1000 m and heights of 5–25 m. The drilling of one of these PLFs in the Pechora Sea led to the blowout of a large amount of gas from a depth of 49.5 m and failure of the drilling equipment .…”

“…In 2014, the initial depth of GEC‐1 was more than 50 m and the depth of AntGEC was 15–19 m . After the appearance of GECs in October 2013, filling of the craters with rain water, melted snow, thawed ice and sediment from the retreating crater walls initiated the formation of new lakes. As a result of GEC‐1 lake expansion, the parapet of GEC‐1 was barely visible in 2016, due to the processes of collapse and inundation.…”

“…In the case of AntGEC, which formed on the edge of a terrace, the newly formed hollow quickly filled with sediments (maximum depth of AntGEC lake in 2016 was only 3.6 m, Figure f), while the lower south‐facing slope of AntGEC limited further accumulation of water. Therefore, AntGEC lake contained only 1643 m 3 of water in 2016.…”

“…For the first time in the terrestrial permafrost environment, gas emission craters (GECs) have been observed on the Yamal and Gydan peninsulas in summer and autumn 2014 (Figure ). The Yamal GEC (69.9711 N, 68.3703°E), 42 km from Bovanenkovo gas field, was named GEC‐1 and the Gydan GEC near Antipayuta settlement (69.7946 N, 75.035° E) was named AntGEC . Initially, these two permafrost‐related features were deep and relatively narrow cylinder‐shaped depressions with subvertical frozen walls and a funnel‐shaped top .…”

“…The Yamal GEC (69.9711 N, 68.3703°E), 42 km from Bovanenkovo gas field, was named GEC-1 9 and the Gydan GEC near Antipayuta settlement (69.7946 N, 75.035°E) was named AntGEC. 8 Initially, these two permafrost-related features were deep and relatively narrow cylinder-shaped depressions with subvertical frozen walls and a funnel-shaped top. 9 The first field expeditions to GEC-1 in 2014 described the surrounding landscape of the area, provided morphometric descriptions of GEC-1 and proposed an origin of this landform as resulting from the emission of methane from permafrost.…”