Is air pollution causing landslides in China?

• Published in: Earth and planetary science letters Vol. 481; pp. 284 - 289
• Main Authors: Zhang, Ming, McSaveney, Mauri J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2018
• Subjects: acid rain; landslide; microorganism; mining activity; organic matrix; microorganism; organic matrix; acid rain; landslide; mining activity
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2017.10.045

Air pollution in China often exceeds “unhealthy” levels, but Chinese air is not only a threat from being breathed: the pollutants may also be causing fatal landslides. Very acid rain from severe air pollution falls widely in southwest China, where coal is a major energy source. We discuss where acid rain may provide an unsuspected link between mining and the fatal 2009 Jiweishan landslide in southwest China; it may have reduced the strength of a thin, calcareous, black sapropelic shale in Jiweishan Mountain by removing cementing carbonate minerals and sapropel matrix. Mining beneath the potential slide mass may not have directly triggered the landslide, but collapse of abandoned adits drained a perched aquifer above a regional black-shale aquiclude. Inflow of acid, oxygenated water and nutrients into the aquiclude may have accelerated the reduction of strength of the weakest rocks and consequently led to rapid sliding of a large rock mass on a layer of weathered shale left composed largely of soft, and slippery talc. •Cracks caused by mining under the potential slide rock mass ruptured the aquiclude.•Acid rain supplied nutrients to organisms decomposing organic matrix in the shale.•Acid rain reduced strength of the shale layer on which the failure surface formed.