An Unexpected (Academic) Journey

By Lucy Clarke (@DrLucyClarke)

As mentioned in my previous posts I am a fluvial geomorphologist. I am interested in the processes that operate on the Earth’s surface and especially those that occur in fluvial (or ‘watery’) environments, although at the moment I have moved into exploring frozen water, looking at glacial change in Antarctica (which I will blog more about in the coming year). So how did I come to be doing this?

Always happy to be on a river!

I can honestly say that working in academia wasn’t my childhood dream – I wanted to be a vet, but as I have an allergy to virtually all animal hair that was never a realistic occupation! The main reason for my lack of ambition in academia was because I didn’t realise it was even an option, I came from a family where no one had ever been to university so I didn’t know anything about how it worked or that people like me could make a career of it. But my parents were determined that myself and my sister would break this trend and get a degree and so through school it became my aim to go to university. Loving the outdoors and exploring different places, geography had always appealed to me, so I managed to win a position studying for a BSc degree in Geography at the University of Durham and going there changed everything for me. I absolutely loved doing my undergraduate degree and that is when my passion for physical geography really took hold, and it opened my eyes to all the possible options for my future that I had never considered before.

On finishing my degree I wanted to see some more of the world and so I won a place on a research Masters at the University of Otago in New Zealand and moved Down Under. My research specialised in sediment transport in rivers and used aerial photography and field techniques to explore spatial and temporal trends. This experience was amazing as I got to learn different geographical and surveying techniques, plus, writing a 40,000 word thesis gave me a good insight into the research process and all of this in one of the most impressive and beautiful places I’ve ever visited and which I was fortunate to explore thoroughly in the couple of years I lived there.

Once I had completed my thesis I took a circuitous route back to the UK, visiting new found friends in Australia and Canada for a few months before coming back to reality. On my first day back I checked the job websites and found an advertisement for a PhD at the University of Exeter using image analysis of experimental alluvial fans (see my blog post from 28 August 2013) supported by fieldwork in New Zealand – it sounded perfect for me and within a week of my return I had been down to the South West for an interview and was offered the PhD. And so I spent the next 4.5 years in Exeter; I got my PhD and during this time I took every opportunity to attend conferences, assist on field trips (in the UK and abroad), undertake teaching and generally make the most of my time as a postgraduate. I then worked in the department on a teaching and a research fellowship and realised that a career in academia was what I wanted to do.

Me and my PhD physical model - many hours were spent in the lab

Since then I have been on the early career researcher cycle, an increasingly common experience for ‘young’ academics trying to carve out a career. Some people are lucky enough to stay in the same institution or just move once before getting a permanent position but my path has followed a different route. I took a teaching lectureship at the University of Dundee, before moving back to my native Yorkshire for a postdoctoral position at the University of Hull for a couple of years and now I am based in Cambridge at the British Antarctic Survey – at least for the next 15 months. Although moving around so much can cause a certain amount of instability in my life, it has been a fantastic opportunity to gain experience of different institutions and I have made friends and colleagues in each place and through this developed research ideas that I am excited to progress in the future.

Come rain or shine it's great to get out in the field

So, my journey into academia may have been unexpected but I couldn’t be happier to be where I am now and wouldn’t be doing anything else! I have no regrets over my career (other than the usual academic regret of not having written enough papers, but I’m working on this!) and have had some amazing experiences that I wouldn’t change. I am still hopeful for the elusive permanent position and working hard to make it happen as soon as I can, but who knows where that will be. I have no idea where I will end up next, but I am excited to find out and I’ll keep you posted on my progress through the blog…

Researcher Profile - Chris Skinner

Ok, here at GEESology we have decided to tell you all a bit about ourselves and to do this in the form of a ‘Researcher Profile’. For some reason I have drawn the short straw, to put it cynically, and have to go first. The flip side of the coin is that in going first I can set the benchmark for everyone else and have a fairly free hand in doing so. I guess it is really a chance for us all to share a little bit about ourselves and what is behind our research, in particular what motivates us and why we do it. Each of us will provide one of these posts to you over the coming weeks and months, so without any further ado, here’s me –

Who am I

I am Chris Skinner, currently working as a Research Assistant as part of the Dynamic Humber project at the University of Hull. My role is develop the CAESAR-Lisflood model for operation on the Humber Estuary with the aim of providing forecasts of changes in the estuary for the coming century.

Me before my remote sensing days

What I do and Why do I do it

Last year I completed my PhD research that looked into the effects of uncertainty in satellite rainfall estimates on hydrological models. These estimates are vital in Africa, where there is a real lack of raingauges and radar that we use in the UK to predict rainfall, but as they cannot directly record rainfall they are often a little bit wrong. This in turn affects the models that are used to forecast droughts and floods. This chance of being wrong is termed by scientists as ‘uncertainty’ and this has a major impact on the people who have to make decisions.

“There are known knowns; there are things we know we know.

We also know there are known unknowns; that is to say we know there are some things we do not know.

But there are also unknown unknowns – there are things we do not know we don't know.” 

Donald Rumsfeld perfectly, although unwittingly, describing the nature of uncertainty. 

Uncertainty leads to a lack of confidence and can mean that important decisions that influence millions of people can be delayed, sometimes at the cost of people’s lives. A recent example of this was the Horn of Africa drought in 2011, which was forecast several months before any aid began to be mobilised. My research interests are in looking at ways to either reduce the uncertainty, measure it better or just communicate better to people who have to make the difficult choices – I blogged about this on my (largely defunct) personal blog over two years ago in Why do we bother?

How do I do it

How I do this is by using a lot of statistics and numerical computer models that are far too complex (and not all that interesting enough) to be talked about in detail here, but the main method I use to show uncertainty is by using ensembles of forecasts – a set of possible futures, each equally likely yet different, within the bounds of what we don’t know. From this you can produce what is known as a probabilistic forecast. It’s the difference between Michael Fish telling you there is absolutely no chance of being hit by a hurricane, and him telling you there’s a 30% chance – subtle difference but results in different (and probably better) decisions.

How did I get here

Short answer, I walked. That’s very important, as my job before I started my PhD was as a Sustainable Transport Policy Assistant at a local authority in the Midlands, and a large part of my job was encouraging people to walk and cycle more. It was fun job on the frontline, getting to organise events such as bike rides, but I did not like the look of the career ladder ahead of me. I wanted to stretch my mind so in 2009 I decided to quit my job and focus on a career in Academia.

Sustainable Transport - It can be dangerous!

At this point I hadn’t chosen a discipline, I just wanted to do something that looked like it might help people and make a difference. In the end I got the perfect PhD back at Hull, which is where I got my undergraduate degree and close to where I grew up and my family live. I’m pleased to still be a part of such an excellent department but I know one day the Academic career will draw me away to pastures new.

Wow, 500 words isn’t a lot – I never got to tell you about the time I spent in the nappy factory, the garlic bread factory, painting student houses, data entering, on Job Seekers, as a Geotechnical Laboratory Technician or in the Planning Department...

What drives change on alluvial fans?

By Lucy Clarke (@DrLucyClarke)

So first of all you are probably wondering what an alluvial fan is? An alluvial fan is a landform that is created when a small river feeds into a larger one or when a large river flows into a lake or sea, they form in characteristic fan shapes – hence the name. Changes on an alluvial fan system are driven by the amount of available sediment and water, and two main types of alluvial fan can be distinguished based on whether a fan is formed primarily by sediment movement (‘debris fan’) or by the action of water (‘fluvial fan’). It is the latter, fluvial fans, that I am interested in – these tend to have a shallower slope and lower grain size than their debris counterparts.

Debris fans in Canada – formed by the movement of rock and sediment due to gravity, 

these characteristically have steep slopes and large sediment on them

Fluvial fan in New Zealand – formed primarily by water flow these 

have shallower slopes and lower grain size than debris fans.

So, you may be asking why am I interested in these landforms at all? First of all, alluvial fans have a global distribution and are often prime locations for settlements and road networks. In many temperate and humid environments these fans are dynamic systems that are prone to rapid change and due to their steeper slopes (compared to the surrounding area) they are prone to flooding, so understanding how they respond to changing conditions is important in their management. A recent example of this can be seen in the floods that hit Alberta, Canada in June 2013 – one of the worst affected areas was the town of Canmore located on the Couger Creek alluvial fan, shown in the photos below. Alluvial fans are also important on a longer timescale. Fans trap sediment and therefore preserve a record of environmental change. Changes in the climatic conditions can be reflected in the amount of sediment produced; the amount of rainfall can influence erosion rates, whilst also affecting the density of vegetation growing in an area (denser vegetation traps sediment and the roots stabilise soils lowering the sediment delivery to the fan). So periods of growth and decline on the fan can help us to know what the environment was like at different stages through its formation.

Cougar Creek, Canmore, Canada: (a) Photograph I took of Cougar Creek in June 2007 showing the low flow conditions, (b) flooding in the same area in June 2013 (image courtesy of the Calgary Herald) and (c) the damage caused by the floods – the house shown is the same that is circled in Photo (a) (image courtesy of the Calgary Herald).

To understand the response of an alluvial fan during its evolution we need to look at the sediment and water delivery to the fan system and how these alter the processes that are operating on the fan. The impact of fluctuating climate and tectonics in changing the relative amounts of sediment and water and how these drive change are pretty well understood, but lots of work has shown that reconstructing just these variables doesn’t give a complete picture of what is happening on the fan. As well as these ‘external’ controls, there seems to be something else going on, an internal reaction in the fan system itself that is promoting change. And it is this that I am interested in trying to look at.

It is impossible to try to isolate these variables out in the field, as there are too many complex interactions taking place on a field fan to determine what is driven by climate, tectonics or internal processes. So I used a physical model, or a miniature landform, in which I could create my own scaled alluvial fans and control the conditions that were feeding them (if you are interested in learning more about using physical models in geomorphology see my blog post from 5 July 2013). So I ran lots of experiments where I kept the sediment and water supply constant, so there were no external factors impacting the experimental fans, so any changes that I saw must have been driven by internal processes.

Experimental plot used in these experiments; experiments were carried at the Sediment
Research Facility at the University of Exeter.

The experiments I ran were not scaled to a specific fan in the field, but I was instead interested in learning more about the general trends that occurred using what is known as a similarity of processes model. The experimental fans behaved as we would expect fans in the field to, which was a good indication that we were replicating natural processes. The initial results of these experiments were published in a paper (Clarke et al., 2010) and demonstrated that independent of any change in the external conditions the shape and flow patterns on the fans changed through time. I will highlight two of the main findings. First of all I calculated the fan volume at various points through time, to show the overall size of the fan. These are shown for three example experimental runs below, Run 1 has the lowest sediment and water rates fed onto the fan with Run 3 having the highest. Fans grow rapidly in the initial stages (Stage 1) and then begins to stabilise (Stage 3), this is because the fan fills up all the available space and so starts moving sediment out of the system rather than storing it. The higher the discharge rates (increases from Run 1 to Run 3) the quicker the space is filled and so the sooner the fan stops building, therefore lowering the overall volume.

Changes in fan volume through the experiments driven by internal processes. 

The experimental fans also displayed a change in flow patterns through time. Four stages were observed: (1) at the beginning sheetflow dominated, this is when over 50% of the fan area is covered in water; (2) unstable channelised, with multiple channels covering wide areas of the fan; (3) formation of 1-2 main channels that continually move across the fan surface; and (4) a single channel forms that erodes (cuts into) the fan surface.

Changes in the flow conditions through the experiments driven by internal processes on the fan. From left to right: (1) sheetflow dominated, (2) unstable channelised, (3) formation of 1-2 main channels, and (4) single channel. 

This paper highlighted the importance of internal processes in driving change on alluvial fans. I have recently submitted a paper exploring the quantitative data from the flow patterns from these experiments and I will hopefully talk more about that in a later blog. I am now working to try to understand more about the triggers behind these processes and how to identify these features in the field.

Reference: L Clarke, T Quine and A Nicholas (2010) An experimental investigation of autogenic behaviour during fan evolution. Geomorphology, 115, p 278 – 285.

GEES flock to Leeds...

10^th International Conference on Fluvial Sedimentology

By Lucy Clarke (@DrLucyClarke)

One of the most important elements of academic work is actually telling others what you are doing and what you have found out, which is why we created this blog.  In addition we need to get our research out to the wider academic community in more conventional ways, either through the publication of articles or attendance at conferences. The latter are particularly useful as you can present complete pieces of work or work in progress that you want to discuss. Conferences are not a one way process in which you just tell others what you are doing, they allow you to sound board ideas, receive input from others in the same field and thus refine your ideas, as well have having the opportunity to find out what other researchers are up to.

I recently attended the 10^th International Conference on Fluvial Sedimentology (ICFS10), held at the University of Leeds in the UK from the 14-19^th July 2013. The conference attracts a wide range of delegates from across geography, geomorphology, geology and the petroleum industry and is interested in the processes and response of modern river systems as well as relict rivers that are preserved in the rock record. Session themes ranged from ancient fluvial systems, alluvial architecture and stratigraphy (how are river deposits preserved in the rock record), processes and challenges for resource extraction, to rivers in different environments (glacio-fluvial, fluvial-tidal and tropical and monsoonal systems), how we model river systems and flash flooding, sediment transport, and vegetation and eco-engineering on modern rivers - the last one being the session that I presented in. About 350 people attended over the 5 days, there were 140 oral presentations run over 2 parallel sessions and 127 posters summarising people’s research.  In addition, there were 5 keynote speakers; these are world leaders in their field that are invited by the conference organisers to come and present extended talks on what they see as key issues in their areas. 

Conference hall at the University of Leeds with delegates and poster displays over coffee break.    

My presentation at ICFS10 (photo courtesy of Leiping Ye)

The first keynote was Bill Deitrich from the University of California, Berkeley in the USA, an eminent geomorphologist and a personal academic hero of mine! Bill discussed the unknowns as he sees it in modern fluvial systems and the questions he feels that remain unanswered. I was thrilled to see that he highlighted alluvial fans as an important landform to be working on, as this is my specialism. These landforms are found on Mars! Therefore having a better understanding of the mechanisms that form these and knowing the amount of water needed to build fans on Earth can be used to approximate what’s happening on Mars.

Dave Moreton from Imperial Oil Resources in Canada launched the 2^nd day of the conference with his keynote. The petroleum industry rely on geologists to understand the way that rivers and other landforms are preserved in the rocks; cycles of erosion and deposition mean that landscapes from thousands to millions of years ago are buried in the land beneath us and it’s within these that oil deposits can be located. Focusing on the McMurray Formation in Canada he explained about how geologists have been using new technology to map these features to try and ensure that the oil deposits can be extracted with maximum efficiency and minimal costs.

River features preserved in the rock record at the McMurray Sands Formation in Canada. The left hand image shows preserved scrollbars – the migration of the river around a bend (taken from Fustic et al, 2008).

Martin Gibling from Dalhousie University in Canada took us back in time to the Paleozoic rivers formed 540 to 240 million years ago, before vegetation existed. The Paleozoic ‘greening’ of the Earth had a profound impact on the Earth’s environment and the way that rivers evolve. Vegetation and their root systems impact the stability of rivers and influence the channel form. Martin showed how the rise of vascular plants then shrubs and finally tall trees irreversibly changed the shape and form of the rivers from braided (multiple channels with lots of islands) to the development of meandering (a single sinuous river channel) systems.

Plants and fluvial systems in ancient and modern systems (taken from Gibling and Davies, 2012).

James Syvitski from the University of Colorado, Boulder in the USA creates numerical models that simulate climate, oceanic and hydrological responses both for present day situations and into the future. He discussed the new WBMsed model, which provides the flow and suspended sediment concentrations for rivers across the Earth. The take home message for me was the impact that human modification and especially dam building since the start of the twentieth century has had on the World’s rivers. The model includes the ability to remove ‘anthropogenic’ structures and see how rivers would behave in their natural state, and it showed have dramatically we have altered these systems.

The final keynote was delivered by Doug Jerolmack from the University of Pennsylvania in the USA. Doug reduced the scale of interest right down from landscapes to individual grains. He discussed the importance of understanding how single grains interact in river systems and how this in turn influences the way that sediment is transported and therefore the bedforms and character of the river itself.

Just from this taster you can see what a varied set of subjects were discussed. I think that the success of a conference can be measured on what you take away from it, so reflecting on my attendance at the ICFS10 conference what did I get from it?  I listened to lots of interesting talks in different areas of my discipline that have made me think about the wider context of what I am doing. I had the opportunity to present my current research and subsequently discuss it with the key people in my field  - which was invaluable! I have a potential new collaborator, as well as receiving a dataset to work on from a previous colleague after chatting to them over coffee break. I discovered a new link for my research and will be writing a joint paper on this next year, and on top of all that I really enjoyed my week at ICFS10 – so I would definitely say that my attendance at the conference was worthwhile!


Presentation references:
LE Clarke, SJ McLelland and T Coulthard. 2013. The impact of vegetation seeding on fan dynamics. Presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

WE Dietrich. 2013. Fans, meanders and floodplains: familiar features, still surprising unknowns. Keynote presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

MR Gibling and NS Davies. 2013. Evolving Paleozoic rivers: the co-evolution of landforms, plants and animals. Keynote presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

D Jerolmack. 2013. Granularity and noise in geomorphology. Keynote presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

D Moreton. 2013. Characterising alluvial architecture of the McMurray Formation, Alberta, Canada: challenges for bitumen recovery. Keynote presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

JPM Syvitski and S Cohen. 2013. Simulating the modern discharge of water and sediment: a global approach. Keynote presentation at the 10th International Conference on Fluvial Sedimentology: University of Leeds, 14-19 July 2013.

Blog references:

M Fustic, L Skulski, W Hanson, D Vanhooren, P Bessette, D Hinks, L Bellman and D Leckie. 2008. Geological mapping and reservoir characterization of oil sands reservoir by integrating 3D seismic, dipmeter, core descriptions and analogs in the McMurray formation, NE Alberta. AAPG Hedberg Conference, Heavy Oil and Bitumen in Forland Basins – From Processes to Products: Search and Dicovery Article 40281.

MR Gibling and NS Davies. 2012. Palaeozoic landscapes shaped by plant evolution. Nature Geoscience, 5, p 99-105.