A review of international cases of fault reactivation during mining subsidence and fluid abstraction

Fault reactivation, during coal mining subsidence, has been documented in the coalfields of Great Britain for at least the past 150 years. This often results in the generation of a scarp, fissure, graben or compression hump on the ground surface. These features subsequently may severely damage houses, other structures, transport networks, utilities and land. An aim of this paper is to demonstrate that mining-induced fault reactivation does not exist only in Britain but has also been observed or recorded in many other parts of the world as a result of the mining of coal, metalliferous ore-bodies and the abstraction of fluids. Examples are provided from Europe, USA, Australia, Canada, South America, Caribbean, Africa, Asia and Russia. Fault reactivation as a result of the mining of coal is the most commonly recorded and this probably reflects the long, complex mining history that has taken place in the more densely populated and urbanized parts of Europe, where there has been a greater potential for fault reactivation to cause damage to the built environment. Less reported are the examples of fault reactivation caused by the mining of metalliferous ore-bodies in more remote and sparsely populated parts of the world. Here, reactivated faults tend to be of little consequence to people and structures, therefore there has not been the need for reactivated faults to be investigated. Fault reactivation caused by groundwater, brine, oil and gas abstraction (in the USA) generates some of the largest scarps, which are recorded to be up to some 16 km long and 1 m high. Where these occur in seismically active tectonic zones it may be difficult to distinguish faults generated by fluid abstraction and those generated by earthquake activity. This paper also aims to provide some clarity to the understanding of fault reactivation, by drawing attention to and summarizing the principal effects of mining-induced fault reactivation.