GeoLog

Geochemistry, Mineralogy, Petrology & Volcanology

Imaggeo on Monday: Mount Elgon, a balance between fertility and destruction

Imaggeo on Monday: Mount Elgon, a balance between fertility and destruction

This colourful cropland patchwork is located on the fertile flanks of Mount Elgon, Uganda at an elevation of 2,400 metres above sea level. The extinct shield volcano, the oldest in East Africa, is mostly covered in clouds and provides an infinite flow of wonderful waterfalls.

Due to the climate at this elevation, the cultivated crops experience more temperate weather conditions compared to crops more typically grown in the tropics. This gives the region a less tropical outlook than what is observed at lower elevations, where the landscape views are dominated by banana trees.

Still the local communities intensely cultivate the land at these higher elevations since the soil is very fertile, a product of the mineral-rich volcanic material that was deposited during eruptions in the past twenty million years. The cultivation is only stopped by the steep cliffs that you can see in the background and the borders of the national park that encompasses Mount Elgon’s volcano top.

The image evokes a feeling of tranquility, but in reality, the environment is very prone to natural hazards, resulting in numerous fatalities within the densely populated communities every year.

Rockfall events in the Ugandan Mount Elgon area, such as this one pictured, have destructive and fatal impacts on local communities. (Credit: Jente Broeckx)

While the local lithology results in fertile fields, the area’s steep slopes and severe tropical thunderstorms make the region vulnerable to landslides. Mount Elgon’s steep cliffs pose a second risk as they can generate rockfalls, with big blocks as large as the houses at the foot of those cliffs. Both landslides and rockfalls often leave a trace of destruction on their path, sweeping away houses and causing fatalities.

Luckily, the view we see here on the north-facing side of Mount Elgon has rather gentle slopes, experiences milder storms and receives relatively low precipitation throughout the year.

My colleagues and I study the area’s susceptibility to landslides and the high risk this poses for its inhabitants, their livelihoods and the infrastructure. The picture was taken during one of our field work campaigns, where I was mapping landslides and landslide-free locations to calibrate the first landslide susceptibility map for the Mount Elgon region. At this year’s EGU General Assembly, I will give an oral presentation on this research.

This environment provides a duality that, on the one hand attracts people with its rich natural resources, but on the other hand poses a risk for their survival. It is one of the many places on earth with a fragile equilibrium between a growing human pressure and the forces of nature.

By Jente Broeckx, a PhD researcher at KU Leuven, Belgium

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/.

GeoTalk: How will large Icelandic eruptions affect us and our environment?

GeoTalk: How will large Icelandic eruptions affect us and our environment?

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Anja Schmidt, an interdisciplinary researcher at the University of Cambridge who draws from atmospheric science, climate modelling, and volcanology to better understand the environmental impact of volcanic eruptions. She is also the winner of a 2018 Arne Richter Award for Outstanding Early Career Scientists. You can find her on twitter at @volcanofile. 

Thank you for talking to us today! Could you introduce yourself and tell us a little more about your career path so far?

I was born and raised in Leipzig, Germany. I started my career completing an apprenticeship as an IT system engineer with the engineering company Siemens. I then decided to combine my interests in geology and IT by studying geology and palaeontology (with minors in Computing/IT and Geophysics) at the University of Leipzig in Germany. As part of my degree programme, I also studied at the University of Leeds’ School of Earth and Environment as an exchange student. I liked studying there so much I ended up returning to Leeds for a PhD.

My PhD on the atmospheric and environmental impacts of tropospheric volcanic aerosol again combined my interests in computing and volcanology, although I had to educate myself in atmospheric physics and chemistry, which wasn’t easy to begin with. However, I was embedded in a diverse,   supportive research group with excellent supervision, which eased the transition from being a geologist to becoming a cross between an atmospheric scientist and a volcanologist.

Initially, being neither one nor the other made me nervous. My supervisors and mentors all had rather straightforward career paths, whereas I was thought of as an atmospheric scientist when I presented my research in front of volcanologists and as a volcanologist when I presented to atmospheric scientists.

After my PhD, I spent just under 2 years at one post-doc before securing an independent research fellowship at the University of Leeds. The first year of total independence and responsibility as principle investigator was very challenging, but after a while I began to appreciate the benefits of the situation. I also really started to embrace the fact that I would always sit between the disciplines. I spent my summers in the United States at the National Centre for Atmospheric Research, helping them to build up their capability to simulate volcanic eruptions in their climate model. These research visits had a major impact on my career as they generated a lot of new research ideas, opened up opportunities and strengthened my network of collaborators greatly.

I considered myself settled when, shortly before the end of my fellowship, a lectureship came up. It had the word ‘interdisciplinary’ in its title and I simply couldn’t resist. Since September 2017, I have been an interdisciplinary lecturer at the University of Cambridge in the UK.

At this year’s General Assembly, you will receive an Arne Richter Award for Outstanding Early Career Scientists for your work on the environmental impacts of volcanic eruptions. What brought you to study this particular field?

I have always been fascinated by volcanic eruptions, but my first active volcano viewing wasn’t until college, where I had to chance to travel to Stromboli, a volcanic island off the coast of Sicily. While studying at the University of Leipzig, I used every opportunity to join field trips to volcanoes. I ended up spending 10 weeks in Naples, Italy to work with Giovanni Chiodini, a researcher from the National Institute of Geophysics and Volcanology in Rome, and his team on CO2 degassing from soils at the Solfatara volcano. Later on I was awarded a scholarship from the University of Leeds, which allowed me to delve deeper into the subject, although I ended up learning as much about atmospheric science and computer modelling as about volcanology.

Anja in front of the 2010 Fimmvörðuháls eruption in Iceland. Fimmvörðuháls was the pre-cursor eruption to Eyjafjallajökull. Credit: Anja Schmidt.

My PhD work focused on Icelandic volcanism and its potential effects on the atmosphere as well as society. In 2010, during the 3rd year of my PhD studies, Eyjafjallajökull erupted in Iceland. While an eruption like this and its impacts did not really come as a surprise to a volcanologist, I personally considered it a game-changer for my career. I had an opportunity to witness the pre-cursor eruption in Iceland and present my research. Within a matter of months, interest in my work increased. I even started to advise UK government officials on the risks and hazards of volcanic eruptions in Iceland.

In August 2014, an effusive eruption started at the Holuhraun lava field in Iceland. To this date, analysing field measurements and satellite data of the site and modelling simulations keeps me busy. Many of my senior colleagues told me that there is one event or eruption that defined their careers; for me that’s the 2014-2015 Holuhraun eruption.

At the General Assembly you also plan to talk about your work on volcanic sulphur emissions and how these emissions can alter our atmosphere as well as potentially affect human health in Europe. Could you tell us a little more about this research?

On average, there is one volcanic eruption every three to five years in Iceland. The geological record in Iceland also reveals that sulphur-rich and long-lasting volcanic eruptions, similar to Iceland’s Laki eruption in 1783-1784, occur once every 200 to 500 years. Sulphur dioxide and sulphate particles produced by volcanic eruptions can have detrimental effects on air quality and human health. Historical records from the 1780s imply that the Laki eruption caused severe environmental stress and contributed to spikes in mortality rates far beyond the shores of Iceland. While these long-lasting eruptions occur much less frequently than more typical short-duration explosive eruptions (like Grímsvötn 2011), they are classified as ‘high-impact’ events.

I was always interested in investigating how a similar magnitude eruption like Laki’s would affect modern society. By combining a global aerosol microphysics model with volcanological datasets and epidemiological evidence, I led a cross-disciplinary study to quantify the impact that a future Laki-type eruption would have on air quality and human health in Europe today.

Our work suggests that such an eruption could significantly degrade air quality over Europe for up to 12 months, effectively doubling the concentrations of small-sized airborne particles in the atmosphere during the first three months of the eruption. Drawing from the epidemiological literature on human response to air pollution, I showed that up to 140,000 cardiopulmonary fatalities could occur across Europe due to such an eruption, a figure that exceeds the annual mortality from seasonal influenza in Europe.

In January 2012, this discovery was used by the UK government as contributing evidence for including large-magnitude effusive Icelandic eruptions to the UK National Risk Register. This will help to mitigate the societal impacts of future eruptions through contingency planning.

Anja and her colleague Evgenia Ilyinskaya from the University of Leeds carrying out measurements during the 2014-2015 Holuhraun eruption in Iceland. Credit: Njáll Fannar Reynisson.

Since then, we have done more work on smaller-magnitude effusive eruptions such as the 2014-2015 Holuhraun eruption in Iceland, showing that this eruption resulted in short-lived volcanic air pollution episodes across central and northern Europe and longer-lasting and more complex pollution episodes in Iceland itself.

Something that you’ve touched on throughout this interview are the challenges of ‘sitting between the disciplines.’ From your experience, what has helped you address these issues throughout your career?

Indeed, it is often challenging to sit between the disciplines, but it can also be very rewarding. It helps to ignore boundaries between disciplines. I also tend to read a lot and very widely to get an idea of key concepts and issues in specific fields. In addition, I think collaboration and a willingness to challenge yourself are key if you want to make progress and break traditional disciplinary boundaries.

Anja, thank you so much for speaking to us about your research and career path. Before I let you go, what advice do you have for aspiring scientists? 

Be curious and never hesitate to ask a lot questions, no matter how ‘stupid’ or basic they may seem to you. The latter is particularly true when it comes to cross-disciplinary collaboration and work.  I also didn’t always follow the conventional route most people would advise you to take to achieve something. Never be afraid to take a chance or work with some level of risk.

I also have two or three close mentors that I can approach whenever I require some advice or feedback. No matter what career stage you are at, I think it almost always helps to get an outsider’s perspective and insight not only when there are problems.

Finally, never forget to have fun. Some of my best pieces of work were done when I was surrounded by collaborators that are really fun to be with and work with!

Interview by Olivia Trani, EGU Communications Officer.

References: 

Ilyinskaya, E., et al.: Understanding the environmental impacts of large fissure eruptions: Aerosol and gas emissions from the 2014–2015 Holuhraun eruption (Iceland), Earth and Planetary Science Letters, 472, 309-322, 2017

Schmidt, A., et al.: Satellite detection, long-range transport, and air quality impacts of volcanic sulfur dioxide from the 2014–2015 flood lava eruption at Bárðarbunga (Iceland)Journal of Geophysical Research: Atmospheres12097399757, 2015

Schmidt, et al.: Excess mortality in Europe following a future Laki-style Icelandic eruption, Proceedings of the National Academy of Sciences, 108(38), 15710-15715, 2011

Imaggeo on Mondays: Chilean relics of Earth’s past

Imaggeo on Mondays: Chilean relics of Earth’s past

As Earth’s environment changes, it leaves behind clues used by scientists to paint portraits of the past: scorched timber, water-weathered shores, hardened lava flows. Chile’s Conguillío National Park is teeming with these kind of geologic artifacts; some are only a few years old while others have existed for more than 30 million years. The photographer Anita Di Chiara, a researcher at Lancaster University in the UK, describes how she analyses ancient magnetic field records to learn about Earth’s changing crust.

Llaima Volcano, within the Conguillío National Park in Chile, is in the background of this image with its typical double-hump shape. The lake is called Lago Verde and the trunks sticking out are likely remnants from one of the many seasonal fires that have left their mark on this area (the last one was in 2015).

The lake sits on pyroclastic deposits that erupted from the Llaima Volcano. On these deposits, on the side of the lake, you can even track the geologic record of seasonal lake level changes, as the layers shown here mark the old (higher) level of the lake during heavy winter rains.

The lake also overlaps the Liquiñe-Ofqui Fault, which runs about 1000 kilometers along the North Patagonian Andes. The fault has been responsible for both volcanic and seismic activity in the region since the Oligocene (around 30 million years ago).

I was there as field assistant for Catalina Hernandez Moreno, a geoscientist at Italy’s National Institute of Geophysics and Volcanology, studying ancient magnetic field records imprinted on rocks. We examined the rocks’ magnetised minerals (aligned like a compass needle to the north pole) as a way to measure how fragmented blocks of the Earth’s crust have rotated over time along the fault.

From this fieldwork we were able to examine palaeomagnetic rotation patterns from 98 Oligocene-Pleistocene volcanic sites. Even more, we concluded that the lava flows from the Llaima Volcano’s 1958 eruption would be a suitable site for studying the evolution of the South Atlantic Anomaly, an area within the South Atlantic Ocean where the Earth’s magnetic field is mysteriously weaker than expected.

By Anita Di Chiara, a research technician at the Lancaster Environment Centre in the UK 

References

Hernandez-Moreno, C., Speranza, F., & Di Chiara, A.: Understanding kinematics of intra-arc transcurrent deformation: Paleomagnetic evidence from the Liquiñe-Ofqui fault zone (Chile, 38-41°S), Tectonics, https://doi.org/10.1002/2014TC003622, 2014.

Hernandez-Moreno, C., Speranza, F., & Di Chiara, A.: Paleomagnetic rotation pattern of the southern Chile fore-arc sliver (38°S-42°S): A new tool to evaluate plate locking along subduction zones. Journal of Geophysical Research: Solid Earth, 121(2), https://doi.org/10.1002/2015JB012382, 2016.

Di Chiara, A., Moncinhatto, T., Hernandez Moreno, C., Pavón-Carrasco, F. J., & Trindade, R. I. F.: Paleomagnetic study of an historical lava flow from the Llaima volcano, Chile. Journal of South American Earth Sciences, 77, https://doi.org/10.1016/j.jsames.2017.04.014, 2017.

 

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submittheir 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/.

Imaggeo on Mondays: Snow folded by advancing lava

Imaggeo on Mondays: Snow folded by advancing lava

The photograph shows the interaction of the first snow and an active lava flow during the 2014 / 2015 Holuhraun eruption in Iceland. The first snow fell onto a ground covered by fine black ash on 26 September 2014. While the meter thick lava flow advanced a few meters per day, it neither melted the snow nor flowed on top of it. Instead, it pushed a layer of centimetre-thick snow and millimetre-thick ash out of the way, folding it like icing on a cake.

The photograph was taken on September 27, when the lava flow field had covered an area of more than 44.2 km2. This is the size of nearly 6200 football fields or more than half of the total size of Manhattan (water and land area). By the end of the eruption the area covered by lava had almost doubled this and was the largest recorded in Iceland in 200 years.

Prior to the eruption, increasing and migrating seismicity was detected from 16 August 2014 in the location of the Bárðarbunga volcano, beneath the Vatnajökull ice cap. Small sub-glacial eruptions were also inferred based on observations on the ice surface and research on long-lasting ground vibrations (called volcanic tremor). The eruption then started sub-aerially on 29 August 2014 and continued (with a small break on 30 August) until March 2015.

A multidisciplinary approach [1] [2] was used to study the growing lava flow. This included the use of GPS instruments, satellites and seismic ground vibrations recorded by an array of seismometers. The research was conducted through a collaboration between University College Dublin & Dublin Institute for Advanced Studies in Ireland, the Icelandic Meteorological Office & University of Iceland in Iceland and the GeoForschungsZentrum in Germany.

The FP7-funded FutureVolc project financed the above mentioned research and further research on early-warning of eruptions and other natural hazards such as sub-glacial floods.

By Eva Eibl, researcher at the GeoForschungsZentrum

If you pre-register for the 2018 General Assembly (Vienna, 08–13 April), you can take part in our annual photo competition! From 15 January until 15 February, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

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/.