The School of Geography, Politics and Sociology

Staff Profile

Dr Stuart Dunning

Senior Lecturer in Physical Geography

Background

Interests

Keywords: Landslides; magnitude-frequency; paraglacial; geomorphology

I am a quantitative physical geographer researching hillslope processes and their magnitude-frequency, often in cryospheric systems undergoing rapid change. I have a speciality in large rock-avalanches, with a focus on their dispersion through glacial and fluvial reworking which serves to reduce our knowledge of their erosive work, and, to underestimate their hazard.

I also develop and deploy low-cost monitoring systems to both warn of increased landslide threats, or, to detect in near real-time landslides occurring 

To find out more about current projects please click on the Research tab above.













Research

Current Projects

1. Landslides in the U.K.

Over the past 5 years I have obtained funds to undertake high resolution monitoring of landslides that threaten the U.K. road and rail network (NERC Urgency; NERC Constructing a Digital Environment; Scottish Roads Research Board; Research England 'Pitch-In')

NERC CDE: Landslide Mitigation Informatics (LIMIT): Effective decision-making for complex landslide geohazards.

Landslides or the threat of landslides can cause significant economic disruption and pose a risk to life. Relatively small events can affect wide areas, particularly where the primary road network is sparse and there is limited scope for rerouting and diversion. Rainfall triggers the majority of landslides in the U.K. and national level 24-hr forecasts exist (for emergency response agencies), but there is uncertainty surrounding what combination(s) of duration and intensity trigger slope failures on a site specific level and why similar events do not always lead to the same event/no-event outcome. These knowledge gaps are critical where decisions must actively be made to warn users of (or close) linear infrastructure such as roads and rail in order to saves lives and costs. This lack of specificity, combined with the high costs of traditionally instrumenting known 'at risk' locations, hinders effective decision-making for key authorities and their partners. As a result many essential components of the environment are not monitored in advance, or on a wide-scale / high-resolution (spatial and temporal) basis. LIMIT will make use of and develop the next generation of low-cost and low-power integrated network (and networks of networks) sensors combined with edge processing and multi-threshold trigger based streaming of key data in near real-time to allow decisions underpinned by advanced theories of failure mechanics. The result is low cost, wide coverage provision of data that analyses the state of the environment and forecasts future behaviour at higher spatial and temporal resolutions than previously possible, integrated into a seamless 'data chain' from site to decision-makers. Data and key derivations based on fundamental process science are automatically ingested/shared into a newly constructed digital environment via an intelligent hierarchical platform. The outputs are fit for national data sets and modelling; policy makers deciding on sensor networks for monitoring evolving risk due to long-term environmental changes; operational decision-makers tasked with real-time management of acute threats to life; right though to data provision and two-way engagement with the individuals at risk. Innovative low-cost, in situ near real-time data streaming/processing sensors resiliently linked to an integrated portal with automated reporting offers a viable and transformative solution to end-user challenges. The LIMIT feasibility study will generate new field validated intelligent monitoring informatics, underpinned by advanced theories of failure mechanics, to provide critical data on the increasing likelihood and then the occurrence of slope failures in real-time.

NERC URGENCY: Storm Desmond produced intense and prolonged rainfall which resulted in extensive flooding in the U.K. A number of landslides were also triggered, many of which damaged infrastructure and the transport network in particular. Our proposal is to collect transient post-event data to allow follow-on funding proposals to answer the outstanding science questions, which are relevant for multiple sites beyond the RABT, and to document the transience of key evidence to inform how 'urgently' we do need respond to future large events to adequately quantify them.

SRRB 1: Building on existing infrastructure and knowledge at the A83 Rest and Be Thankful we wish to implement a novel multi-level modular monitoring system to detect landslide activity prior to, during and after landslide events. The aim is to produce a business case for appropriate monitoring to enable cost-effective management of hazardous slopes in Scotland. 

2. Landslides onto and into glaciers (Funded PhD Student William Smith)

Slope processes play a significant role in sediment delivery to ice; a role of increasing importance as landscapes transition between glacierised and ice-free configurations. Landslide magnitude-frequency (m-f) which dictates the erosion of land exposed above ice surfaces (landslides, not glaciers, reduce peak height above ice) and the resultant sediment flux through the glacier-route-way is poorly quantified, particularly when the debris is entrained and transported en- and sub-glacially and  re-emerges (altered or unaltered) in the ablation zones. Crucially, we have been unable to elucidate climate change-driven perturbations in m-f due to the sparsity and incompleteness of existing datasets and the absence of a thorough analysis of the suite of relevant environmental drivers. Estimates of the flux from landslides onto ice range from just a few percent to 60% of total glacial sediment flux.

We hypothesise that landslides in the Arctic and Antarctic deliver significant quantities of sediment including bioavailable iron (BioFe), silica, and nitrogen to the Oceans. 

Spot the rock avalanche deposit

3.  Finding tsunami causing landslide deposits in the lakes of New Zealand (NERC IAPETUS Student Ryan Dick)

Relief in mountainous landscapes is a balance between the forces of tectonics, climate, and surface processes. Landslides are an effective means of limiting the growth of mountains to maintain some form of equilibrium, with seismic shaking in particular able to trigger widespread failure and downslope mobilisation of material. It is common that during earthquakes a number of very large, highly mobile landslides, termed rock avalanches, can be expected to be triggered from steep mountainsides with sufficient relief. If rock avalanche run out paths reach settlements or infrastructure, destruction is almost total and with death tolls historically measured in thousands. However, in many of the landscapes where these events happen, the rates of geomorphic processes are high enough to erode and remove most evidence of past events. As a result, the relative frequency of these catastrophic events remains poorly understood, and so the risks posed remains poorly understood.
Advantageously, in previously glaciated terrain deep fiords and inland lakes are common, and interestingly, provide a unique geomorphic setting that can capture the record of past large landslides through underwater preservation of the landslide deposits. If these landslide deposit post-date initial lake formation / relative sea level rise, they may also have triggered tsunami, which themselves pose further risks to a wider area.

4. A new approach to West Antarctic Ice Sheet evolution using blue-ice moraines on nunataks.

Did the West Antarctic Ice Sheet (WAIS) survive the last interglacial? We propose to use nunataks as dipsticks of ice-sheet elevation change to help answer this question. There are currently two conflicting hypotheses:  

Hypothesis 1: A dynamic WAIS. The hypothesis is that the WAIS disappeared under last-interglacial conditions ~125,000 years ago when climatic and oceanic conditions were slightly warmer than those of the present day.

Hypothesis 2: A stable WAIS. The WAIS may have varied in elevation but that it persisted as a coherent ice sheet during the last interglacial.  

The co-existence of two opposing hypotheses implies that we have much to learn about the principal controls on ice-sheet stability. This uncertainty undermines confidence in our ability to predict the future of the WAIS and its effect on global sea-level change. Important research on the WAIS relies on satellite observations which monitor changes in velocity and elevation over recent decades, while predictions of future changes rely on ice-sheet models. Both approaches would be enhanced if we knew what happened to the WAIS during the last glacial cycle. The longer term perspective tells of the trajectory of change upon which decadal changes are superimposed. Further, a history of elevation changes during a glacial cycle provides data with which to constrain and improve ice-sheet models.  

This project is testing the two hypotheses using moraines that form on nunataks in blue-ice areas. Blue-ice areas result from strong downslope winds which are often funnelled in the vicinity of nunataks and ablate the ice surface. In response the ice flows into such ablation areas, sometimes bringing basal debris to the surface which is then deposited at the ice margin. Relict moraines occur on certain nunatak slopes above the present ice surfaces and are over 400,000 years old, suggesting that there is the potential to obtain a long record of ice elevation change.  

This project brings together glaciologists, geomorphologists and geophysicists to work in the Heritage Range, a group of nunataks which protrude through the central WAIS dome. We will test predictions of the two competing hypotheses firstly by examining the processes of blue-ice moraine formation today using field survey and radar, and secondly by establishing the form and sediment characteristics of the moraines and their age. The latter will employ exposure-age dating, a technique that measures the time a rock has been at the surface and exposed to cosmic rays. By using more than one isotope we can establish times when a rock surface may have been buried by ice and thus there is the potential to reconstruct a rich history of ice elevation changes. In this way we will assess if the WAIS remained intact, or disappeared during the last interglacial. Our hope is that the approach could be extended to other nunataks in Antarctica and provide widely dispersed evidence of elevation changes in predicting the future response of the WAIS to a changing climate.

NERC Standard Grant (February 2012 – July 2015). Sugden, D., Woodward, J., Dunning, S., Fogwill, C. £557,733.00 (Northumbria £148,480.34) NE/I025840/1

Publications