Biography

I am a geomorphologist using a combination of remote sensing, fieldwork, geospatial analysis and numerical modeling to investigate landscape evolution, sediment transfer and natural hazards, predominantly in mountainous regions.

My passion for geomorphology really started during a BSc and MSc in Physical Geography at Durham University. I won a Landscape Research Group prize for my BSc dissertation on paraglacial slope adjustment on the foreland of a retreating Icelandic glacier and went on to do an MSc by research with Dave Evans. My MSc culminated in a new glacial landsystem model for the debris-charged glacier system. In 2009 I moved to Switzerland to do my PhD with Peter Molnar at ETH Zurich, Switzerland within the European Research Council project TopoEurope. My research on a mountain basin sediment cascade provided new insights into landslide magnitude-frequency scaling and into the increase in landslide and debris flow hazard in the context of regional climate change. It culminated in a novel numerical model of mountain sediment transfer, SedCas, which is now being applied around the world to model sediment cascades and future debris flow hazard. During a NASA-funded postdoc at the University of Oregon with Josh Roering (2013 – 2015) I investigated slow moving landslides (earthflows) in northern California. I found a profound landslide control on channel and landscape evolution over tectonic timescales. I also showed the depth-sensitive earthflow response to the recent historic drought. In a second postdoc at the US Forest Service and Colorado State University (2015 – 2016), I investigated the response of catchments in the Colorado Front Range to an extreme flood event in 2013. I contributed to a sediment, carbon, wood budget for one of the flood-impacted catchments and demonstrated the significant role of landslides in amplifying channel erosion and flood risk.

In my current position as Lecturer in Physical Geography and Natural Hazards at UEA, I am continuing to pursue my research interests in Switzerland and the USA as well as explore new research avenues.

All Publications

Rathburn, S., Bennett, G., Wohl, E., Briles, C., McElroy, B., Sutfin, N.

(2017)

The fate of sediment, wood and organic carbon eroded during an extreme flood, Colorado Front Range, USA,

in Geology

45

(6)

pp. 499-502

Full Text UEA Repository

(Article)

(Published)


Bennett, G., Roering, J., Mackey, B., Handwerger, A., Schmidt, D., Guillod, B.

(2016)

Historic drought puts the breaks on earthflows in Northern California,

in Geophysical Research Letters

43

(11)

pp. 5725–5731

Full Text UEA Repository

(Article)

(Published)


Bennett, G. L., Miller, S. R., Roering, J. J., Schmidt, D. A.

(2016)

Landslides, threshold slopes and the survival of relict terrain in the wake of the Mendocino Triple Junction,

in Geology

44

(5)

pp. 363-366

Full Text UEA Repository

(Article)

(Published)


Roering, J. J., Mackey, B. H., Handwerger, A. L., Booth, A. M., Schmidt, D. A., Bennett, G. L., Cerovski-Darriau, C.

(2015)

Beyond the angle of repose: A review and synthesis of landslide processes in response to rapid uplift, Eel River, Northern California,

in Geomorphology

236

pp. 109–131

Full Text UEA Repository

(Article)

(Published)


Bennett, G., Molnar, P., McArdell, B., Burlando, P.

(2014)

A probabilistic sediment cascade model of sediment transfer in the Illgraben,

in Water Resources Research

50

(2)

pp. 1225–1244

Full Text UEA Repository

(Article)

(Published)


Bennett, G., Molnar, P., McArdell, B., Schlunegger, F., Burlando, P.

(2013)

Patterns and controls of sediment production, transfer and yield in the Illgraben,

in Geomorphology

188

pp. 68–82

Full Text UEA Repository

(Article)

(Published)


Bennett, G. L., Evans, D. J. A.

(2012)

Glacier retreat and landform production on an overdeepened glacier foreland: the debris-charged glacial landsystem at Kvíárjökull, Iceland,

in Earth Surface Processes and Landforms

37

(15)

pp. 1584–1602

Full Text UEA Repository

(Article)

(Published)


Bennett, G., Molnar, P., Eisenbeiss, H., McArdell, B.

(2012)

Erosional power in the Swiss Alps: characterization of slope failure in the Illgraben,

in Earth Surface Processes and Landforms

37

(15)

pp. 1627–1640

Full Text UEA Repository

(Article)

(Published)


Bennett, G., Evans, D., Carbonneau, P., Twigg, D.

(2010)

Evolution of a debris-charged glacier landsystem, Kvíárjökull, Iceland,

in Journal of Maps

6

(1)

pp. 40-67

Full Text UEA Repository

(Article)

(Published)


Key Research Interests

Landslide control on river channel form and process

In previous research I found empirical evidence of a negative feedback of landslide- delivered boulders on channel incision, knickpoint retreat and ongoing landscape erosion rates and evolution in northern California. Such a feedback has since been corroborated theoretically through numerical modeling that demonstrates how blocks both armour the river bed from incision and increase form drag, thus reducing stream power available to act on the channel bed and move boulders. This has implications for extracting tectonic information from river profiles and preconditioning the response to rivers to shorter-term flood events. I continue to research the influence of landslides on channel form and process in this and other regions. 

Wood-sediment interaction in mountain rivers

I became interested in the role of wood and its modulation of fluvial sediment transport and geomorphology whilst a postdoc at the US Forest Service and Colorado State University. My main project was investigating the geomorphic impact of an extreme flood in the Colorado Front Range in 2013 but on the side I set up a project with Sandra Ryan of the USFS on the response of fluvial bedload transport to increased wood loading. In August 2016, we radio-tagged 1000 cobbles and multiple pieces of wood within St Louis Creek in the US Forest Service Fraser Experimental Forest. We found and resurveyed the positions of 90% of these in August 2017. We will continue to monitor the movement and interaction of cobbles and large wood over the next years in response to changes in wood loading and discharge. I currently have an open PhD position to continue this research. Please contact me if interested. 

Landslide and landscape response to increased climate variability, northern California

I am interested in how landslides respond to cycles of drought and rainfall, particularly in clay dominated lithologies, susceptible to wetting and drying. I recently demonstrated the dramatic slow-down of earthflows in northern California in response to extreme drought. I continue to monitor earthflows in the region using satellite imagery available through Planet Labs and in collaboration with Alexander Handwerger and Josh Roering. I also have an undergraduate student investigating the sediment discharge response to cycles of drought and extreme rainfall in the region. 

Modeling lahar hazard on Montserrat

Lahars are hazardous sediment transport agents that gradually remove volcanic sediment deposited on the flanks of volcanoes during eruptions. I am interested the how exhaustion of this sediment supply by lahars influences subsequent lahar magnitude and frequency. I supervise a PhD student, James Christie, who is applying my sediment cascade model, SedCas, to model this process on the Caribbean island of Montserrat. This project is in collaboration with Melanie Froude (University of Sheffield) and Jenni Barclay (UEA).

Landscape preconditioning of landsliding in Nepal

A number of factors precondition hillslopes to fail, sometimes with no apparent trigger. These are climatic and tectonic processes that gradually weather and weaken the bedrock and increase the supply of mobilizable regolith such as earthquakes and rainfall events. Of course many of these processes may also be triggering factors, but there is always a long history of damage incurred to a slope in the lead up to slope failure. I co-supervise a PhD student working on untangling the varied controls that precondition and trigger landslides in Nepal (road building, river incision, earthquakes). This project is in collaboration with Sarah Boulton and Martin Stokes (University of Plymouth) and Michael Whitworth (Aecom).

Coastal erosion in East Anglia

 The East Anglian coast is one of the most vulnerable coastlines to erosion in the UK due to the high retreat rate of its soft cliffs.  Much research has focussed on the role of wave energy, modulated by tides, as a key driver of coastal erosion. Comparatively little attention has been given to role of subaerial processes in coastal erosion, although these may play an important role in driving cliff retreat, both through triggering and preconditioning slope failure (i.e. through weakening cliffs and making them more susceptible to wave erosion). Future climate projections for the UK suggest the increasing probability of warmer, drier summers and wetter winters. I hypothesize that the increased climate variability is likely to have significant impact on the cliff weathering and erosion especially where clay content is high. I currently have a PhD student working on this project in collaboration with Chris Hackney and Dan Parsons at the University of Hull, funded through Dan Parson’s ERC starter grant. I also have an undergraduate student looking at the role of subaerial processes in the evolution of cliffs along the coast that are no longer exposed to wave erosion. 

Modeling glacial sediment cascades

More to come…

 

 

 

Research Group Membership

I supervise three PhD students:

James Christie (UEA) 

Joshua Jones (University of Plymouth)

Serena Teasdale (University of Hull)

Teaching Interests

I teach on ENV-6001B Geophysical hazards, ENV-5004B Applied Geophysics, ENV-5034A Geomorphology and ENV-7018A Research Topics in Earth Science.

Professional Activities

I am a co-organizer of Steepest Descent, a one day geomorphology meeting following the annual European Geosciences Union meeting in Vienna.

I am a reviewer for Geology, Earth Surface Processes and Landforms, Geomorphology, Nature Geoscience, Nature and the National Science Foundation.

Administrative Posts

I am the EnvSoc staff liaison and sit on the Staff Student Liaiason Committee and the Teaching Committee