Jonathan Richard Ford

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

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.

An assessment of lithostratigraphy for anthropogenic deposits

Abstract The deliberate anthropogenic movement of reworked natural and novel manufactured materials represents a novel sedimentary environment associated with mining, waste disposal, construction and urbanization. Anthropogenic deposits display distinctive engineering and environmental properties, and can be of archaeological importance. This paper shows that temporal changes in the scale and lithological character of anthropogenic deposits may be indicative of the Anthropocene. However, the stratigraphy of such deposits is not readily described by existing classification schemes, which do not differentiate separate phases or lithologically distinct deposits beyond a local scale. Lithostratigraphy is a scalable, hierarchical classification used to distinguish successive and lithologically distinct natural deposits. Many natural and anthropogenic deposits exhibit common characteristics; they typically conform to the Law (or Principle) of Superposition and exhibit lithological distinction. The lithostratigraphical classification of surficial anthropogenic deposits may be effective, although defined units may be significantly thinner and far less continuous than those defined for natural deposits. Further challenges include the designation of stratotypes, accommodating the highly diachronous nature of anthropogenic deposits and the common presence of disconformities. International lithostratigraphical guidelines would require significant modification before being effective for the classification of anthropogenic deposits. A practical alternative may be to establish an ‘anthrostratigraphical’ approach, or ‘anthrostratigraphy’.

Rapid observations to guide the design of systems for long-term monitoring of a complex landslide in the Upper Lias clays of North Yorkshire, UK

The Whitby Mudstone Formation has one of the highest landslide densities in the UK with 42 landslides per 100 km2. Landsliding at Hollin Hill in North Yorkshire, UK is complex and continuing, and includes shallow, retrogressive rotational failure on the upper slope, translation, and flow from the base of the Whitby Mudstone Formation over the scarp slope of the Staithes Sandstone Formation. Surface observations augmented by information relating to lithological, moisture and strength variation with depth allowed rapid initial interpretation of the masses affected by movement. These were provided by a single person operating portable probes providing depth logs of cone penetration resistance and soil moisture based upon dielectric property measurements in conjunction with a sampling auger. The gathered information was used to guide the design of further invasive site investigation and the configuration of permanent systems to monitor changes in dynamic moisture distribution and direct movement. At Hollin Hill, the near-surface materials in the upper 5 m interval are distinctly weathered or destructured, predominantly comprising silty clay in the Whitby Mudstone Formation, and fine silty, clayey sand and silty clay in the Staithes Sandstone Formation. Direct and secondary evidence was observed showing high moisture variation to be related to narrow intervals within the upper 5 m. Cyclic variation in moisture has played a key role in the movement and break-up of sliding materials, especially within the prograding lobes resulting from flow over the Staithes Sandstone Formation. Since these observations, permanent monitoring systems have been installed, including electrical resistivity tomography (ERT) arrays, which have successfully mapped the distribution of the Whitby Mudstone and the Staithes Sandstone, but will also be used in time lapse mode to image the near-surface moisture movement driving the landsliding processes. ERT array installations included a large area, low spatial resolution grid designed to investigate the potential coupling between the upper and lower slope hydrogeological processes and a small area, high spatial resolution grid designed to investigate the hydrogeological processes driving the earth flow.

Geological 3D modelling : scientific discovery and enhanced understanding of the subsurface, with examples from the UK

In recent years, with the improvement of computer processing power and the development of sophisticated visualisation software, the traditional static views of geological maps, cross-sections and other analogue representations have been replaced by digital, three-dimensional (3D) models. Building these 3D models involves the assembly of many previously isolated and disparate datasets into a single 3D spatial framework for visualisation and analysis. This enables the construction of the best possible geological 3D model using all available information. This paper gives examples of how geoscientific understanding has benefited from the construction of 3D models by the British Geological Survey using several examples to illustrate how structural, stratigraphical and sedimentological discovery can result from the construction of 3D models.

Urban Futures: the sustainable management of the ground beneath cities

Abstract Over half of the worlds population now live in cities. In 2011 it was estimated that the global population exceeded 7 billion. Pressures on the environment including land use are increasing. The ground beneath cities and the interaction between physical, biological and chemical processes provides natural capital on which society depends. These benefits and the ground properties and processes that support and deliver them can be considered ecosystem services. Characterizing the ground properties on which ecosystem services depend involves a qualitative assessment of positive and negative impacts of proposed urban sustainability solutions, including use of the ground. The sustainability of a proposed solution depends on how the future might unfold. Future scenario analysis allows consideration of the social, technological, economic, environmental and political changes that may determine the ability of a proposed solution to deliver its benefits now and in the future. Analysis of the positive and negative impacts of a proposed use of the ground on ecosystem function, measured against future scenarios of change, can be integrated to deliver strategies for the future management of the ground and the wider environment beneath cities.

Geophysical anatomy of the Hollin Hill landslide, North Yorkshire, UK.

Geophysical methods are playing an increasingly important role in the investigation and monitoring of landslides; such methods are proving to be particularly effective for revealing the 3D structure, failures surfaces, and the hydrogeological regimes associated with rock and earth slides. In this paper we present the results of a geoelectrical reconnaissance survey of the Hollin Hill landslide, UK. This work was undertaken in advance of the installation of a permanent geophysical and geotechnical monitoring system, and was designed to assess the suitability of resistivity (resistivity mapping and 2D/3D ERT) and self-potential methods (profiling and mapping) for investigating and monitoring this site. In particular, we were concerned to assess the electrical property contrasts and the magnitude of SP response across the study area. The surveys revealed that there was a good resistivity contrast between the slipped material and sandstone bedrock, which allowed us to use resistivity mapping data and ERT models to define the geometry of the landslide. An SP signature consistent with the movement of groundwater through the landslide was observed at the site, and was used to identify seepage patterns associated with the slipped material.

The use of NEXTMap Britain for geological surveying in the Vale of York

Abstract The NEXTMap Britain digital elevation model (DEM) has opened many new opportunities that considerably help and enhance the way we undertake our geological mapping of bedrock, structure, and superficial and artificial deposits. The dataset has been successfully integrated into the digital and conventional mapping workflows of the Vale of York mapping team. A variety of visualization and analysis techniques have been applied throughout the mapping process. These techniques include an initial appraisal of NEXTMap with a comparison to existing geological mapping to define the field mapping strategy and site-specific manipulation using Tablet PCs. NEXTMap interpretation has made an important contribution to the understanding of the extensive glacial and proglacial deposits found in the Vale of York; such as sand bodies resting on lake deposits, and identifying details within morainic and alluvial complexes. For bedrock mapping, NEXTMap has been used to identify landform features that relate to the underlying geology, such as breaks in slope, the extent of escarpments, hillcrests and dip slopes, to provide an overview of the landscape and to save time in mapping out features in the field. Techniques have also been developed to automatically generate these landform features. The dataset has also been used to identify areas where landsliding has occurred, for the accurate mapping of artificial ground and as a key surface for three-dimensional (3D) geological modelling.

Why 3D? The Need for Solution Based Modeling in a National Geoscience Organization.

In recent years national geoscience organizations have increasingly utilized 3D model data as an output to the stakeholder community. Advances in both software and hardware have led to an increasing use of 3D depictions of geoscience data alongside the standard 2D data formats such as maps and GIS data. By characterizing geoscience data in 3D, knowledge transfer between geoscientists and stakeholders is improved as the mindset and thought processes are communicated more effectively in a 3D model than in a 2D flat file format. 3D models allow the user to understand the conceptual basis of the 2D data and aids the decision making process at local, regional and national scales. Some of these issues include foundation and engineering conditions, ground water vulnerability, aquifer recharge and flow, and resource extraction and storage. The British Geological Survey has established a mechanism and infrastructure through the Digital Geoscience Spatial Model Programme (DGSM) to produce these types of 3D geoscien...

Humans are the most significant global geomorphological driving force of the 21st century

The transformation of the Earth’s land surface by mineral extraction and construction is on a scale greater than natural erosive terrestrial geological processes. Mineral extraction statistics can be used as a proxy to measure the size of the total anthropogenic global sediment flux related to mineral extraction and construction. It is demonstrated that the annual direct anthropogenic contribution to the global production of sediment in 2015 was conservatively some 316 Gt (150 km3), a figure more than 24 times greater than the sediment supplied annually by the world’s major rivers to the oceans. The major long-term acceleration in anthropogenic sediment flux started just after the Second World War and anthropogenic sediment flux overtook natural fluvial sediment flux in the mid-1950s. Humans are now the major global geomorphological driving force and an important component of Earth System processes in landscape evolution. The changing magnitude of anthropogenic sediments and landforms over time are significant factors in the characterisation of the proposed new epoch of geological time – the Anthropocene.