HUMANS AS GEOMORPHIC AGENTS: ANTHROPOGENIC SINKHOLES AS A TYPE OF PSEUDOKARST (Invited Presentation)

News media frequently report the occurrence of sinkholes in urban areas, sometimes large enough to swallow cars and humans. These features are usually the result of the failure of old utility lines, and are strictly speaking not karst features since they do not originate by dissolution of soluble bedrock. They should however be considered a type of pseudokarst, similar to lava tube caves, since they are a (usually) circular depression in the earth’s surface, very often associated with subterranean drainage, and are often a significant geohazard. When such anthropogenic collapses occur the repair work falls to engineers or field technicians, but geoscientists are often contacted by local authorities to provide context and consultation about remediation strategies. With the rapid expansion of the built environment and human infrastructure in the past two centuries, there will inevitably be an increase in the occurrence of such phenomena, which may be regarded as yet another manifestation of the onset of the Anthropocene Epoch.