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Imaggeo on Mondays: Coastal erosion

Imaggeo on Mondays: Coastal erosion

Coastlines take a battering from stormy seas, gales, windy conditions and every-day wave action. The combined effect of these processes shapes coastal landscapes across the globe.

In calm weather, constructive waves deposit materials eroded elsewhere and transported along the coast line via longshore-drift, onto beaches, thus building them up. Terrestrial material, brought to beaches by rivers and the wind, also contribute.  In stormy weather, waves become destructive, eroding material away from beaches and sea cliffs.

In some areas, the removal of material far exceeds the quantity of sediments being supplied to sandy stretches, leading to coastal erosion. It is a dynamic process, with the consequences depending largely on the geomorphology of the coast.

Striking images of receding coastlines, where households once far away from a cliff edge, tumble into the sea after a storm surge, are an all too familiar consequence of the power of coastal erosion.

In sandy beaches where dunes are common, coastal erosion can be managed by the addition of vegetation. In these settings, it is not only the force of the sea which drives erosion, but also wind, as the fine, loose sand grains are easily picked-up by the breeze, especially in blustery weather.

Grasses, such as the ones pictured in this week’s featured imaggeo image, work by slowing down wind speeds across the face of the dunes and trapping and stabilising wind-blown sands. The grasses don’t directly prevent erosion, but they do allow greater accumulation of sands over short periods of time, when compared to vegetation-free dunes.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Going deeper underground – why do we want to know how rocks behave?

Going deeper underground – why do we want to know how rocks behave?

Imagine you find yourself standing atop a wooden box in the middle of your home town, on a rainy weekend day, with the sole aim of talking to passersby about your research work. It can be a rather daunting prospect! How do you decide what the take-home message of your work is: which single nugget of information do you want members of the public to take away after having spoken to you? Even more important still, how are you going to grab their attention in the first place? After all, they’ll be going about their business and not expecting to see you there, on top of your box, least of all talk to you about your work! But if you fancy the challenge, then read on, as Stephanie Zihms, the ECS Representative of the Earth Magnetism and Rock Physics Division, describes her experience doing just that!

Now in its 6th year Soapbox Science is spreading and I was selected to take part in the 1st Edinburgh event on July 24th on The Mound. The weather was typically Scottish but it didn’t seem to bother the crowds and it definitely did not dampen the enthusiasm of the 12 speakers.

I have done a range of different outreach events but I was particularly drawn to Soapbox Science because it specifically promotes female scientists and their work. It was great to meet the other scientists and to see the range of soapbox “performances” as well as the variety of props utilised to showcase each research topic.

Photo taken at the Soapbox Science event courtesy of Sarah Caldwell (smcneem)

Photo taken at the Soapbox Science event courtesy of Sarah Caldwell (smcneem)

The scary thing for this type of event is that you don’t know who might stop, listen & ask questions since we were standing on The Mound in Edinburgh – this also means that your  material has to be accessible and engaging to a wide audience.

Here is what I did to explain my research in geomechanics: Going deeper underground – why do we want to know how rocks behave?

I opted for a big PVC banner showing different heights & depths. With help from the audience I added a picture to each line to show what it represented. I used this banner to set the scene for the type of work I do. I’m a researcher in geomechanics – I want to understand why rocks deform the way they do and what part or component of the rock controls the deformation. The rocks I work with are related to a very deep oil field that lies under 2km of ocean and 5km of rocks. It would take me ~1 hour to run this. At this depth the pressure squeezing the rocks is very high – each square meter of rock experiences the pressure of 16 African elephants per km of depth. So at 5km depths that is 80 African Elephants per square meter.

Under these high pressures the slightest change in conditions e.g. through oil production affects the rocks and changes the distribution of this pressure onto the rocks. I want to understand how different rocks respond to these changes. I do this by collecting rock samples that are easy to get to e.g. from quarries. But they have to be similar to the ones found in the oil field of interest – we call this an analogue (or think of it as a sibling).

Rock sample before it is placed into the Hoek Cell. Image Credit: Stephanie Zihms

Rock sample before it is placed into the Hoek Cell. Image Credit: Stephanie Zihms

In the lab at Heriot-Watt University I have an apparatus that lets me deform rocks under different conditions. The sample, usually a core sample (seeimage above) gets placed into a rubber sleeve before being placed into a stainless steel cell called a Hoek Cell. The space between the rubber sleeve and stainless stell cell is filled with oil that can be pressurised. That way the rock samples can be placed under different pressures that mimic the conditions at different depths. After this initial pressurisation the rock is squeezed in a press until it deforms. When the readings pass a peak value it indicates that the rock sample can’t withstand the squeeze pressure any longer and the test is stopped.

Unfortunatley we can’t see what happens to the rock during the squeezing process but we measure the sample before and after testing – we can also take a x-ray images of the entire sample. We do this with the sample before it is deformed and then again afterwards. This technique lets us see inside the rock – similar to having a x-ray in hospital to see if a bone is broken or not.

Using special computer software we can then look at different parts of the rock’s inside – I am particularly interested in the fractures that formed during the deformation and I’m working on ways to relate these observed features to the rock type, grain size and pore shape.

Why is this important? As I mentioned above I look at rocks related to an oil field – and the response of the rocks to oil production could hinder or help extraction. Oil companies are very interested in predicting the rock response to ensure it does not have a negative impact on oil production.

3D reconstruction of the rock sample using the x-ray images. Image Credit: Stephanie Zihms

3D reconstruction of the rock sample using the x-ray images. Image Credit: Stephanie Zihms

Additionally this research is also relevant to other areas: for example geothermal energy. One method of generating geothermal energy is by pumping water into a rock that is hotter than the surface to increase the water temperature. When this water then reaches the surface it can be used to generate electricity. Adding water into the rock also changes the pressure conditions. Another field is Carbon Capture & Storage – If we want to store CO2 securely and long-term into the subsurface e.g. in a disused gas field – understanding how rocks respond to changes in conditions firstly by removal of gas & secondly by filling the rocks with CO2 is important.

By Stephanie Zihms, Postdoctoral researcher and ECS Representative of the Earth Magnetism and Rock Physics Division.

This post was published under the original title:Going deeper underground – My Soapbox Science Edinburgh contribution, on Stephanie Zihms’ personal blog.

Imaggeo on Mondays: Glacier de la Pilatte

Imaggeo on Mondays: Glacier de la Pilatte

The relentless retreat of glaciers, globally, is widely studied and reported. The causes for the loss of these precious landforms are complex and the dynamics which govern them difficult to unravel. So are the consequences and impacts of reduced glacial extent atop the world’s high peaks, as Alexis Merlaud, explains in this week’s edition of Imaggeo on Mondays.

This picture was taken on 20 August 2009 at the Pilatte Hutt (44.87° N, 6.33° E,  2572 m.a.s.l.), located in the massif des Ecrins in the French Alps. It shows the Pilatte Glacier, which  was recently described as being 2.64km2 wide and 2.6 km long.

As most of the glaciers in the world, the Pilatte Glacier has been retreating over the last decades as can be seen from the two pictures in figure 1, taken respectively in 1921 and 2003, and from quantitative measurements since the 19th century. The glacier has lost 1.8 km since the end of the Little Ice Age (1850).

Figure 1: Retreat of the Pilatte Glacier over the last decades (pictures adapted from Bonet et al, 2005, time series from Reynaud and Vincent, 2000).

Figure 1: Retreat of the Pilatte Glacier over the last decades (pictures adapted from Bonet et al, 2005, time series from Reynaud and Vincent, 2000).

Two climatic variables affect glacier extents in opposite directions: the amount of winter precipitations (which accumulates snow converting to ice on the glacier) and the summer temperatures (which determines the melting altitude and thus the glacier ablation area – the zone where ice is lost from the glacier, commonly via melting).

The initial retreat of the Alpine glaciers in the 19th century can’t be explained by summer temperatures which remained stable until the 20th century. It has thus been explained by a reduction in snowfall . On the other hand, a recent study suggests that industrial black carbon could have triggered the end of the little ice age in Europe, by reducing the glaciers’albedo. But the globally observed glacier retreat from the 20th century is attributed to the increasing summer temperatures.

Figure 2: Global mean temperature series (Oerlemans, 2005, supporting online material)

Figure 2: Global mean temperature series (Oerlemans, 2005, supporting online material)

Understanding the relationship between glacier dynamics and climate enables to use glacier extents  as proxies to reconstruct global temperature time series, as was done by Oerlemans (2005). Using 169 glacier across the globe, this study provided independent evidences on the timing and magnitude of the warming, that are useful to corroborate other time series obtained through other proxies (such as tree rings) or by direct temperature measurements (see Figure. 2), all showing a temperature increase by around 0.5K across the 20th century.

Glaciers continued to retreat in the 20th century, at an accelerating rate. In the 2015 foreword of the Bulletin of the World Glacier Monitoring Service, its director Michael Zemp writes: “The record ice loss of  the 20thcentury, observed in 1998, was exceeded in 2003, 2006, 2011, 2013, and probably again in 2014 (based on the ‘reference’ glacier sample)”. Using climate models, it appears now possible to distinguish an increasing anthropogenic signature in this phenomenon.

Figure 3: Average glacier retreat worldwide from 1980 in mm of water equivalent (mm.w.e), a unit representing the average thickness of a glacier (WGMS website)

Figure 3: Average glacier retreat worldwide from 1980 in mm of water equivalent (mm.w.e), a unit representing the average thickness of a glacier (WGMS website)

One of the many problems caused by glaciers depletion is the impact on water supplies: glaciers are huge reservoirs of fresh water and their vanishings affect drinking water stock and irrigation for the neighboring population. In the Alps, the idea of replacing the glaciers by dams is already studied. This solution would probably be more difficult to implement in other parts of the world, such as in nothern Pakistan, an area covered with over 5000 glaciers, whose melting is already problematic, causing in particular severe floods.

 

By Alexis Merlaud, Belgian Institute for Space Aeronomy, Brussels, Belgium

References

Bonet, R., Arnaud, F., Bodin, X., Bouche, M., Boulangeat, I., Bourdeau, P., … Thuiller, W. (2015). Indicators of climate: Ecrins National Park participates in long-term monitoring to help determine the effects of climate change. Eco.mont (Journal on Protected Mountain Areas Research), 8(1), 44–52. http://doi.org/10.1553/eco.mont-8-1s44

Ravanel, L., Dubois, L., Fabre, S., Duvillard, P.-A., & Deline, P. (2015). The destabilization of the Pilatte hut (2577 m a.s.l. – Ecrins massif, France), a paraglacial process? EGU General Assembly 2015, Held 12-17 April, 2015 in Vienna, Austria.  id.8720, 17.

Reynaud, L., Vincent, C., & Vincent, C. (2000). Relevés de fluctuations sur quelques glaciers des Alpes Françaises. La Houille Blanche, (5), 79–86. http://doi.org/10.1051/lhb/2000052

Pointer, T. H., Flanner, M. G., Kaser, G., Marzeion, B., VanCuren, R. A., & Abdalati, W. (2013). End of the Little Ice Age in the Alps forced by industrial black carbon. Proceedings of the National Academy of Sciences of the United States of America, 110(38), 15216–21. http://doi.org/10.1073/pnas.1302570110

Vincent, C., Le Meur, E., Six, D., & Funk, M. (2005). Solving the paradox of the end of the Little Ice Age in the Alps. Geophysical Research Letters, 32(9), L09706. http://doi.org/10.1029/2005GL022552

Oerlemans, J. (2005). Extracting a climate signal from 169 glacier records. Science (New York, N.Y.), 308(5722), 675–7. http://doi.org/10.1126/science.1107046

Farinotti, D., Pistocchi, A., Huss, M., al, A. A. et, Barnett T P, A. J. C. and L. D. P., Bavay M, L. M. J. T. and L. H., … Zemp M, H. W. H. M. and P. F. (2016). From dwindling ice to headwater lakes: could dams replace glaciers in the European Alps? Environmental Research Letters, 11(5), 054022. http://doi.org/10.1088/1748-9326/11/5/054022

Marzeion, B., Cogley, J. G., Richter, K., Parkes, D., Gregory, J. M., White, N. J., … Adams, W. (2014). Glaciers. Attribution of global glacier mass loss to anthropogenic and natural causes. Science (New York, N.Y.), 345(6199), 919–21. http://doi.org/10.1126/science.1254702

WGMS (2008): Global Glacier Changes: facts and figures. Zemp, M., Roer, I., Kääb, A., Hoelzle, M., Paul, F. and Haeberli, W. (eds.), UNEP, World Glacier Monitoring Service, Zurich, Switzerland: 88 pp

 

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/

GeoEd: Career pathways and expectations in the geosciences – straight lines, wiggles and all out chaos.

GeoEd: Career pathways and expectations in the geosciences – straight lines, wiggles and all out chaos.

 ‘What do you want to be when you grow up?’ From a tender age, we are regularly asked that question, with answers ranging from the downright hilarious through to those kids who’ve got it all figured out. As we grow older the question of what career we want to pursue carries more weight and the outcome of our choices is scrutinised closely.  In today’s GeoEd column, Rhian Meara (a geography and geology lecturer at Swansea University), explores the notion that as young adults adapt to a changing working environment, it is ok to be unsure, to change your mind, and that pursuing the one-time holy grail, linear career path might no longer be a realistic expectation.

My role as a lecturer in the Geography Department at Swansea University includes participating in the university admissions process which includes organising and attending open and visit days, reading application forms and meeting with potential applicants and their parents. Time and time again, I’m asked about employability, work experience opportunities and career pathways – what sort of work will I get after graduation? What are the work experience opportunities? Should I go into post-graduate studies? Will the degree give me transferable skills? What if I choose not to work in the same field as my degree? Current and prospective students are under immense pressure to know what they want to do with their lives from an early age and often feel like failures if they don’t have a “plan”.  And as tuition fees continue to rise, the idea of having a post-graduation “plan” to justify the expense of higher education is becoming more and more important.

The inspiration for this post came after a recent school visit, where most of the students were 16 years old and had no idea what they wanted to study or even if they wanted to go to university. My colleague and I discussed these issues with the students and answered their questions. We explained our backgrounds, what we had studied and how we had gotten to where we are now. My colleague and I had been to the same high school and were now both lecturers at the same university, but our paths in between have been completely different.

Many of us grew up with the “straight line plan”. That is:

Finish school → Go to university (complete PG qualification) → Get a Career → Retire.

Where a university qualification should (in theory) guarantee you a job and a career in your chosen field until retirement. This plan or route is characteristic of our parents’ generation. My contemporaries and I came into play towards the end of the “straight line plan” era, we went to university with grand expectations of long term employment, careers and success in our chosen fields. However, the onset of the international banking crisis in the late 2000s, meant that despite our hard work, many of us found ourselves last in and first out. No job, no career, no funding. And so we began to think outside the box. We used our skills, knowledge, talents and contacts to develop our own jobs, our own careers and our own pathways. Some have carved out career pathways that have stayed relatively similar to the original straight line plan, while others have wiggled around a bit, gaining new skills and experiences from a wide range of opportunities. Being open to new ideas has allowed us to develop our own pathways and to succeed. Below are four examples of how career pathways have developed for my contemporaries and I.

Jo: the industrial straight linerhi_1

Jo is a classic straight liner. Jo graduated with a BSc in Applied and Environmental Geology and gained employment in the Hydrocarbon industry, where she has worked for the past ten years in geosteering. However, due to the current down turn in oil production, Jo has been made redundant. While Jo is investigating what to do next, she has been undertaking a part-time MSc and is open to the idea of moving sideways into a new field which would utilize the transferable skills she gained during her geosteering work.

Rhian: the academic wiggler

rhi_2

This is me! I am an academic wiggler! I initially followed a straight line career; I graduated with an MGeol in Geology and completed a PhD focussing on physical volcanology and geochemistry. I decided that academia wasn’t for me and wiggled sideways into science communication working for an international science festival both in Scotland and in the United Arab Emirates. While I loved the communication work, I felt I had to give academia one more chance and I went back to complete a one year post doc in tephrochronology. Although the post doc confirmed that a career in scientific research wasn’t for me, I discovered the teaching-focussed academic pathway where I could use my communication skills. I’ve now been teaching for four years. The figure above has a two way arrow between teaching and science communicating as I’m still involved with communication and do outreach, accessibility work and TV / radio work to promote my subject whenever possible. I have no major plans to leave my role in the near future, but academia can be a very fickle place. I am therefore continuing to develop my skills and interests to ensure that I am able to wiggle again should the need arise.

Laura: The wiggling communicator

rhi_3

Laura graduated with an MGeol in Geology and worked as an Environmental Consultant before returning to academia to complete a PhD in Geomagnetism. While completing her PhD, Laura began blogging about geosciences and her research and developed a passion for science communication and social media. Upon completion of her PhD, Laura gained employment at the European Geosciences Union as the Communications Officer, and is now responsible for managing and developing content for the EGU blogs, social media accounts, online forums and Early Career Researcher activities. Laura is a perfect example of how to use your interests, skills and passions to create new opportunities.

Kate: the chaotic accumulator

Kate is a chaotic accumulator, and I mean that in the best possible way. Kate is someone who tries everything and has developed a portfolio of transferable skills and interests from each experience.  Although slightly chaotic to the untrained eye, there are underlying themes in the figure above: Geography, Textiles and Education. Each job or qualification has built on one or more of those themes and in her current job as a university lecturer in Human Geography, Kate uses all three themes in her modules. There is an additional theme that does not show up on the figure: Language. Kate is a fluent Welsh speaker and in each position or qualification, the Welsh language has been central from museums to coaching to teaching to lecturing.rhi_4

And so in my future discussions with applicants and their parents, I will introduce the idea of straight lines, wiggles and all out chaos (although perhaps not in those exact words). I will explain that an undergraduate degree will train and prepare them, but that we should all be open to new opportunities and new experiences.

And as life becomes more complicated once again – the down turn in the oil industry, the impact of the UK leaving the EU, an overly qualified labour market – it’s becoming more important than ever for us all to adapt, to think outside the box, to wiggle.

By Rhian Meara, Geology & Geography Lecturer at Swansea University.

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