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On February 22, 2023, a devastating landslide occurred on the mining slope of an open-pit coal mine in Inner Mongolia, China, leading to the mining area being buried and 53 fatalities. The source area of the landslide measured approximately 500 m in both length and width, with an estimated volume of the deposited material reaching approximately 5 million cubic metres. Based on the severe impact of this incident, our study conducted preliminary research using a combination of methodologies, including particle image analysis, synthetic aperture radar interferometry, interpretation of optical remote sensing data, and post-event news reports analysis. The results indicated that the landslide lasted 23 s from initiation to cessation of movement. The historical deformation indicated that prior to the resumption of the mining activities, only localized deformation was observed at the rear edge of the landslide. However, when mining activities resumed in April 2021 and extended to the vicinity of the north slope, the deformation range and rate in the source area of the landslide rapidly increased. The investigation deduced that the soft foundation at the slope bottom and mining activities are the primary causative factors of this event. Mining activities, which stripped coal seams within the slope and surface rock masses, led to the expansion of tension cracks within the landslide body, weakening resisting forces at the leading edge and thus playing a significant role in destabilizing the landslide body. The evolution of the landslide from incubation to instability could be divided into four stages: early microcrack development, slow creep, accelerated deformation after resumption of mining, and ultimate instability. Therefore, it is of great significance to advance real-time deformation monitoring and early warning systems specifically those designed for mining slope areas by comprehensive measures. Furthermore, enhancing the high-frequency monitoring capabilities of synthetic aperture radar satellites is crucial to reducing the occurrence of these catastrophic events. [ABSTRACT FROM AUTHOR]

Central Inner Mongolia is one of the areas with intense volcanic activity in the Cenozoic. In order to better understand the origin of these volcanoes, a study of magnetotelluric sounding (MT) was carried out. This study aims to learn about the mechanism of deep volcanic areas from the electrical point of view. Broadband and long-period MT data were collected on a 500-kilometer section at central Inner Mongolia. Two-dimensional inversion was applied since the data show no obvious three-dimensional effect. Impedance tensor decomposition and phase tensor analysis show that the electric strike angle of the study area is N45°E. A 2-D resistivity model was obtained with a depth range from surface to the uppermost mantle (0–150 km). The resistivity model imaged the ascending channels and the sources of the magma beneath the Abaga and the Dalinor volcanic groups. There are low resistivity anomalies (C1 and C2) related to volcanic activities at depths of 60–100 km below the two volcanic groups. The percentage of melt in the low-resistivity areas below the Abaga volcanic group and the Dalinor volcanic group are as high as 5–10% and 3–5% respectively. This difference in terms of melt fraction explains why the volcanic activity of the Abaga volcanic group is larger than that of the Dalinor volcanic group. Two magma chambers were found in the lower crust of the Dalinor volcanic group, and no magma chamber was found beneath the Abaga group. Based on the resistivity model, it is further speculated that the formation mechanism of volcanic activity in central Inner Mongolia is that the partial molten asthenosphere in an extensive environment flowed up to the surface through structural fissures and formed a large area of basalt platform. The magmatic body imaged at the depths of 60–100 km may be the source of volcanic eruptions of the study area. • Magma channels connected to the asthenospheric mantle beneath two volcanic groups were revealed by the resistivity model. • Partial melting percentage of the mantle low-resistivity bodies C1, C2 and C3 was estimated. • The differences between the Dalinor and Abaga volcanic groups were given according to the resistivity model. [ABSTRACT FROM AUTHOR]