Humans as major geological and geomorphological agents in the Anthropocene: the significance of artificial ground in Great Britain

Abstract

Since the first prehistoric people started to dig for stone to make implements, rather than pick up loose material, humans have modified the landscape through excavation of rock and soil, generation of waste and creation of artificial ground. In Great Britain over the past 200 years, people have excavated, moved and built up the equivalent of at least six times the volume of Ben Nevis. It is estimated that the worldwide deliberate annual shift of sediment by human activity is 57 000 Mt (million tonnes) and exceeds that of transport by rivers to the oceans (22 000 Mt) almost by a factor of three. Humans sculpt and transform the landscape through the physical modification of the shape and properties of the ground. As such, humans are geological and geomorphological agents and the dominant factor in landscape evolution through settlement and widespread industrialization and urbanization. The most significant impact of this has been since the onset of the Industrial Revolution in the eighteenth century, coincident with increased release of greenhouse gases to the atmosphere. The anthropogenic sedimentological record, therefore, provides a marker on which to characterize the Anthropocene.

The Anthropocene: a new epoch of geological time?

“…The stratigraphic signal left by humans is continued by Price et al [23], who discuss the gemorphological impact of humans on Earth. They note that in the past 200 years, humans in the UK alone have excavated and built up more than four times the volume of Ben Nevis, Britain's highest mountain.…”

When did the Anthropocene begin? A mid-twentieth century boundary level is stratigraphically optimal

“…However, the anthropogenic acceleration of processes of erosion and sedimentation has led to the physical record of the Anthropocene being substantial (e.g. Price et al, 2011;Hooke et al, 2012;Ford et al, 2014), and large parts of this record are also distinctive, given the geological novelty of many human-driven processes. While the geometrical and temporal complexity of Anthropocene deposits clearly present some unusual challenges, an Anthropocene chronostratigraphical unit may be recognized and this is significant to the choice of a boundary for this unit.…”

Human bioturbation, and the subterranean landscape of the Anthropocene

“…Its nature and scale on land has been documented (e.g. Hooke, 2000, Hooke et al, 2013Wilkinson, 2005;Price et al, 2011;Ford et al, 2014) and it extends into the marine realm via deep-sea trawling (e.g. Puig et al 2012) and other submarine constructions.…”

“…It has no analogue in the Earth's 4.6 billion year history, and possesses some sharply distinctive features: for instance, the structures produced reflect a wide variety of human behaviour effected through Page 7 of 23 A c c e p t e d M a n u s c r i p t 7 tools or more typically mechanized excavation, rather than through bodily activity. Hence, the term 'anthroturbation' (Price et al, 2011; see also Schaetzl and Anderson 2005 for use in soil terminology) is fully justified, and we use this in subsequent description below.…”