Last week at the 2016 General Assembly Sara, one of the EGU’s press assistants, had the opportunity to speak toKoen Van Noten about his research into how crowdsourcing can be used to find out more about where earthquakes have the biggest impact at the surface.
Firstly, can you tell me a little about yourself?
I did a PhD in structural geology at KULeuven and, after I finished, I started to work at the Royal Observatory of Belgium. What I do now is try to understand when people feel an earthquake, why they can feel it, how far away from the source they can feel it, if local geology affects the way people feel it and what the dynamics behind it all are.
How do you gather this information?
People can go online and fill in a ‘Did You Feel It?’ questionnaire about their experience. In the US it’s well organised because the USGS manages this system in whole of the US. In Europe we have so many institutions, so many countries, so many languages that almost every nation has its own questionnaire and sometimes there are many inquiries in only one country. This is good locally because information about a local earthquake is provided in the language of that country, but if you have a larger one that crosses all the borders of different countries then you have a problem. Earthquakes don’t stop at political borders; you have to somehow merge all the enquiries. That’s what I’m trying to do now.
European institutes that provide an online “Did You Feel the Earthquake?” inquiry. (Credit: Koen Van Noten)
There are lots of these databases around the world, how do you combine them to create something meaningful?
You first have to ask the different institutions if you can use their datasets, that’s crucial – am I allowed to work on it? And then find a method to merge all this information so that you can do science with it.
You have institutions that capture global data and also local networks. They have slightly different questions but the science behind them is very similar. The questions are quite specific, for instance “were you in a moving vehicle?” If you answer yes then of course the intensity of the earthquake has to be larger than one felt by somebody who was just standing outside doing nothing and barely felt the earthquake. You can work out that the first guy was really close to the epicentre and the other guy was probably very far, or that the earthquake wasn’t very big.
Usually intensities are shown in community maps. To merge all answers of all institutes, I avoid the inhomogeneous community maps. Instead I use 100 km2 grid cell maps and assign an intensity to every grid cell.. This makes the felt effect easy to read and allows you to plot data without giving away personal details of any people that responded. Institutes do not always provide a detailed location, but in a grid cell the precise location doesn’t matter. It’s a solution to the problem of merging databases within Europe and also globally.
Underlying geology can have a huge impact on how an earthquake is felt. 2011 Goch ML 4.3 earthquake. Credit: Koen Van Noten.
What information can you gain from using these devices?
If you make this graph for a few earthquakes, you can map the decay in shaking intensity in a certain region. I’m trying to understand how the local geology affects these kinds of maps. Somebody living on thick pile of sands, several kilometres above the hypocentre, won’t feel it because the sands will attenuate the earthquake. They are safe from it. However, if they’re directly on the bedrock, but further from the epicentre, they may still feel it because the seismic waves propagate fast through bedrock and aren’t attenuated.
What’s more, you can compare recent earthquakes with ones that happened 200 years ago at the same place. Historical seismologists map earthquake effects that happened years ago from a time when no instrumentation existed, purely based on old personal reports and journal papers. Of course the amount of data points isn’t as dense as now, but even that works.
Can questionnaires be used as a substitute for more advanced methods in areas that are poorly monitored?
Every person is a seismometer. In poorly instrumented regions it’s the perfect way to map an earthquake. The only thing it depends on is population density. For Europe it’s fine, you have a lot of cities, but you can have problems in places that aren’t so densely populated.
Can you use your method to disseminate information as well as gather it, say for education?
The more answers you get, the better the map will be. Intensity maps are easier to understand by communities and the media because they show the distribution of how people felt it, rather than a seismogram, which can be difficult to interpret.
What advice would you give to another researcher wanting to use crowd-sourced information in their research?
First get the word out. Because it’s crowd-sourced, they need to be warned that it does exist. Test your system before you go online, make sure you know what’s out there first and collaborate. Collaborating across borders is the most important thing to do.
Interview by Sara Mynott, EGU Press Assistant and PhD student at Plymouth University.
Koen presented his work at the EGU General Assembly in Vienna. Find out more about it here.
The mountainsides, severely weakened by last year’s Gorkha Earthquake, is more likely to give way, especially during monsoons and aftershocks. (Credit: Kristen Cook)
Jane Qiu, a grantee of the Pulitzer Center on Crisis Reporting, took to quake-stricken Nepal last month — venturing into landslide-riddled terrains and shadowing scientists studying what makes slopes more susceptible to failure after an earthquake. The journey proved to be more perilous than she had expected.
What would it be like to lose all your family overnight? And how would you cope? It’s with these questions in mind that I trekked with a heavy heart along the Langtang Valley, a popular touristic destination in northern Nepal.
The quake shook up ice and snow at five locations along a 3-kilometre ridge between 6,800-7,200 metres above sea level. They went into motion and swept huge amounts of loose debris and fractured rocks along their way — before crashing several kilometres down to the valley floor.
The avalanche generated 15 million tonnes of ice and rock, and sent powerful wind blasting down the valley, flattening houses and forests. Wind speeds exceeded 322 kilometres per hour and the impact released half as much energy as the Hiroshima nuclear bomb. Nothing in its path could have survived.
A pile of commemorating stones on the debris that buried Langtang and nearby villages last April, killing and leaving missing nearly 400 people. (Credit: Jane Qiu)
Where the villages used to stand is now a gigantic pile of debris, up to 60 metres deep. It’s effectively a mass grave where people pile up stones and put up prayer flags to mark where their loved ones used to live.
It’s hard to come to terms with the scale of the devastation. Everybody in the valley has lost somebody to the monstrous landslide. About two dozen children from 16 families, who were in schools in Kathmandu during the earthquake, lost all their family in the matter of a few minutes.
It’s a sombre reminder of how dangerous it can be in the Himalayas — where people live so close to ice and where population growth and the search for livelihood often push them to build in hazardous areas.
The only building in the village of Langtang that survived the avalanche. The rocky enclave protected it from the crushing debris and the powerful blast. (Credit: Jane Qiu)
The Langtang tragedy also reminds us how deadly landslides can be during an earthquake — a danger that is often under-appreciated. While earthquakes and landslides are like conjoined twins that go hand in hand, most of the resources go into building houses that can sustain strong shaking, and far too little into mitigating landslide risks.
In both the 2005 magnitude-7.6 Kashmir Earthquake in Pakistan and the 2008 magnitude-7.8 Wenchuan Earthquake in China — which killed approximately 26,000 and 90,000 people, respectively — a third of the fatalities were caused by landslides. While it’s certainly important to build earthquake-proof houses, it’s equally important to build them at safe locations.
In addition to the killer avalanche in Langtang, the Gorkha Earthquake unleashed over 10,000 landslides across Nepal, which blocked rivers and damaged houses, roads, and hydropower stations. Many valleys are totally shattered — with landslide scars running down from the ridge top like gigantic waterfalls, and numerous small failures marring the landscape like fireworks shooting across the sky.
Driving along the Aniko Highway that connects Nepal with Tibet, it’s not difficult to see that many houses had survived the shaking only to be crushed by debris flows and rock falls. The border remains closed because of continuing landslide hazards. The highway, which used to have some of the worst traffic jams in Nepal, is totally deserted.
A building in Kodari — which used to be a bustling trade town at the Nepal-Tibet border — was unscathed during the earthquake only to be damaged by large rock falls. (Credit: Jane Qiu)
A major concern is that Nepal will suffer from more severe landslides than usual for a long time. During the last monsoon, the landslide rate was about ten times greater than an average year. And my trek along the Langtang Valley was accompanied by frequent sound tracks of falling rocks and shifting slopes. A number of times, I had to run from boulders crushing down onto the trail — a clear sign that there are lots of instability in the system.
The instability could go on for years or even decades and will be exacerbated by rainfall and aftershocks. This enduring legacy is often not fully taken on board in quake recovery — with devastating consequences. Eight years after the Wenchuan Earthquake, for instance, settlements built after the disaster continue to be inflicted by a heightened level of landslides, which cause floods and destroy infrastructures.
This points to the importance of rigorous risk assessment before reconstruction and close monitoring afterwards. There is also an urgent need to better understand what makes mountainsides more susceptible to landslides after an earthquake and how they recover over time.
To achieve that end, several research groups went into landslide-ridden areas in Gorkha’s immediate aftermath. They wanted to capture what happened to the landscape immediately after the quake, so they could track the changes in the coming years.
Last month, I joined one such team — consisting of Christoff Andermann, Kristen Cook and Camilla Brunello, of the German Research Centre for Geosciences (GFZ) in Potsdam, Germany, and their Nepalese coordinator Bhairab Sitaula — on a field trip along the Arniko Highway.
That was their fourth trip in Nepal since last June when they began to map the landslides and installed a dozen broadband seismometers, along with weather stations and river-flow sensors, over 50 square kilometres of badly shaken terrains.
The team often attracted a few curious onlookers when they worked away, but nothing provoked more excitement than the drone, says Cook. The crowd, especially kids, were thrilled to see the little robotic device buzzing around like a gigantic mosquito, she adds. A camera and sensors onboard can help them to locate the landslides and monitor debris movement, especially after rainstorms.
Christoff Andermann, Camilla Brunello and Bhairab Sitaula performing maintenance on a broadband seismometer and weather station near the village of Chaku on the Arniko Highway (Credit: Jane Qiu)
Another exciting aspect of their research is the use of seismology to probe geomorphic processes over a large area. Landslides are effectively earthquakes that occur near the surface, and produce signals that can be picked up by seismometers.
The team, led by Niels Hovius of GFZ, can detect precursory seismic signals days before a landslide happens. They also study ground properties by measuring how traffic vibrations travel through the ground.
Because seismic waves travel faster when subsurface materials are wet, the researchers are able to trace how rainfall penetrates into and through the ground. This determines the pressure of water in spaces between soil and rock particles, a key factor controlling slope stability.
Such studies will one day allow researchers to determine the rainfall thresholds that could precipitate a landslide and capture deformation precursors days in advance. This offers a real prospect of an effective early warning system, which is urgently needed in a country that is increasingly plagued by landslides.
Jane Qiu, an awardee of the 2012 EGU Science Journalism Fellowship, is a Chinese freelance science writer in Beijing. She is passionate about the origin and evolution of the Tibetan Plateau and surrounding mountain ranges—a vast elevated land also known as the Third Pole because it boasts the largest stock of ice outside the Arctic and the Antarctic.
Travelling extensively across the Third Pole, up to 6,700 meters above sea level (http://science.sciencemag.org/content/351/6272/436), Qiu has covered wide-ranging topics—from the meltdown of Himalayan glaciers, grassland degradation, the origin of woolly rhino, to the people of Tibet. Her work regularly appears in publications such as Nature, Science, The Economist, Scientific American, and SciDev.Net.
Qiu’s journey to the Third Pole began with Marine Biological Laboratory’s Logan Science Journalism Fellowship that allowed her to travel to the Arctic and the Antarctic and report climate change first hand. These experiences sowed the seeds for her later fascination with geoscience and environmental studies, and afforded her the insight to draw parallels between these geographically diverse regions.
Often, in the news, we are used to seeing disaster statistics reported as isolated figures, placed into context by the tragic human cost of floods, earthquakes and drought. The recent Ecuadorian earthquake that occurred on Saturday the 16th April, for example, was described as having an estimated economic cost of $820 million, which could rise as the scale of the disaster is revealed. But beyond the shocking levels of destruction that these numbers can represent, can they teach us anything of humanity’s resilience to natural disasters?
Well, according to Dr James Daniell, a civil/structural engineer and geophysicist from the Karlsruhe Institute of Technology (KIT) in Germany, by combining the data for disasters reported between 1900 and 2015, interesting trends in vulnerability across the globe are revealed. Dr Daniell, who presented his results to the European Geoscience Union this week, along with colleagues from KIT and the General Sir John Monash Foundation, Australia, has discovered that up to $7 trillion worth of economic losses have occurred globally since 1900. This value was revealed by comparing economic costs for various natural disasters including floods, earthquakes, volcanoes, storms and drought using a collection of socio-economic indicators called the CATDAT Damaging Natural Disaster database.
Of this $7 trillion, the majority of financial costs have been from flooding disasters, which accounted for just over a third of losses. Since the 1960’s, however, this trend has started to shift, with storms and storm surges accounting for 30% of the losses. Storm and flooding damages have presented an interesting challenge for Dr Daniell and his team, as it can be difficult to separate the financial costs of these similar and often connected disasters. Luckily, the database has amassed over 30,000 sources in over 90 languages to attempt to clarify the various sources of economic loss.
Deaths due to natural disasters since 1900 (Credit: James Daniell, KIT)
As well as looking at trends over the last 115 years, by examining the relationships between disasters, socio-economic losses and vulnerability, Dr Daniell has come to a surprising realisation. Although the total number of deaths in disasters appears to be increasing, in comparison with the total global population the percentage of deaths is actually in decline, and so too is the associated economic cost for society.
“Here there is a clear trend, that many (but not all) countries are protecting themselves better against disasters by building better, and therefore and are reducing their risk of high losses.”
Dr Daniell also says that his data highlights the noticeably positive impact that flood prevention infrastructure, education and communication is having on resilience to flooding.
“Over the entire time period, half of people died due to flood. However, with better planning, warnings and preventive measures, the death rate due to floods is significantly decreasing.”
An additional benefit of this database is the rapid assessment of the potential economic consequences for future natural disasters it can provide, making it easier for communities and governments to plan for large scale natural disasters. It is clear the benefits of this study and the CATDAT database will continue to assist us into the future, in our attempts to manage the risks of our planet’s most destructive forces.
By Hazel Gibson, EGU General Assembly Press Assistant and Plymouth University PhD student.
Hazel is a science communicator and PhD student researching the public understanding of the geological subsurface at Plymouth University using a blend of cognitive psychology and geology, and is one of our Press Assistants this week.
Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Jackie Kendrick, a volcanologist at the University of Liverpool, and winner of the 2016 GMPV Outstanding Young Scientist Award. The occasion will be marked during the upcoming General Assembly, where you’ll be able to listen to Jackie speak in session GMPV 1.1 on the topic of friction in volcanic environments.
First, could you introduce yourself and tell us a little more about your career path so far?
My name is Jackie Kendrick, and I’m a post-doc in volcanology at the University of Liverpool. I studied for an MSci in Geology at University College London, where I conducted my research project in the Rock and Ice Physics Laboratory. This was an insightful experience for me, I had always been passionate about volcanoes, but having the opportunity to work hands-on in a research environment taught me that I wanted to focus on a career an academia.
I then went on to an Internship at the USGS Cascades Volcano Observatory in Washington State (USA), where I worked on processing of seismic data and had the chance to do a huge amount of fieldwork in incredibly varied settings – for example I installed seismometers at Crater Lake, deployed rapid-response monitoring systems (termed spiders!) at Mount St. Helens and performed landslide simulations at a debris flow flume.
I then moved to Munich, where I undertook my PhD in the Department of Earth and Environmental Sciences at Ludwig Maximilian University. During my PhD I was fortunate enough to largely choose the direction of my studies, as such my research focused on lava dome eruptions from an integrated field, monitoring and experimental approach. Lava dome eruptions have always held a huge fascination for me, and their unpredictable behaviour, with rapid changes from effusive to explosive eruptions, continues to enthral the volcanological community. My PhD opened up possibilities I could not have imagined, and I visited breath-taking volcanic landscapes and state-of-the-art laboratories, where I met so many inspirational scientists – I knew the research community was something I could not turn my back on.
Upon completing my PhD in early 2013 I secured a post-doctoral position at University of Liverpool, funded by the European Research Council. During this position I have worked on a great variety of topics, including experimental studies of magma rheology, rock deformation and friction experiments as well as learning new volcano monitoring strategies like infrasound. Importantly, I have also helped design and develop bespoke high-temperature equipment for the rapidly growing Experimental Volcanology Laboratory, which has allowed me to target specific conditions not previously explored, and once again focus my attention toward the behaviour of dome-building volcanoes, which I find so dynamic in both activity and dormancy.
My primary goal in my research is to strive for the integration of multiple strategies, be it geophysics, geochemistry or geodynamics to try to better understand volcanological processes, and that’s something I hope to continue to pursue throughout my career.
During EGU 2016, you will receive the Outstanding Young Scientist Award from the GMPV Division for your work on understanding what role friction plays in volcanic eruptions. For instance, you’ve carried research out which tries to decipher what role thefrictional properties of volcanic rocks and ash play in controlling the run-out distances, and associated risk, of pyroclastic density currents. Could you tell us a bit more about your research in this area and its importance?
This is something that I have really just started working on in the last year – it’s a new direction for me and that’s really exciting! To be recognised by the community, in receiving this award, is a great honour, and I do hope that I can continue to push frontiers with the research I undertake in the future.
This new endeavour into pyroclastic flows developed naturally, logically from work I was doing on sector collapse at volcanoes – where a volcano becomes unable to support its own weight and fails and collapses. We have just recently acquired the capability to study the frictional properties of rocks at high temperature, something which has been really lacking in volcanology previously, and so this opened up a whole realm of possible applications – one of which is looking at the dynamics of pyroclastic flows. Supported by colleagues at University of Liverpool, our approach is to constrain the frictional properties of a range of volcanic materials at realistic temperatures, for example, pyroclastic flows can reach several hundreds of degrees, even as high as 1000oC. The accurately constrained material properties that we get through laboratory experiments can then be integrated into models using accurate topography, which can predict for example, run-out distance, i.e. how far a flow will travel away from the volcano.
This type of study is hugely important at lava dome volcanoes especially, where pyroclastic flows can be triggered by even small collapse events on the lava dome or at lava flow fronts – events that may have no warning at all. Never has this been more apparent than standing on the lava dome at the summit of Mount Unzen (Japan), observing the precipitous drop to the small, vulnerable suburbs of Shimabara town, where tragically, 44 people lost their lives in a pyroclastic flow in 1991. Hopefully, via our efforts to accurately predict flow dynamics, as well as actively tackling real-time monitoring targeted directly at pyroclastic flows (currently underway at Santiaguito volcano, Guatemala), such tragedies can be avoided in future.
The view down over Mount St. Helens crater from the summit, in the centre the lava dome has grown in the collapse scar from the 1980 eruption. The collapse devastated the proximal land and vegetation, dead trees still float like matchsticks in the calm waters of Spirit Lake and the event left the inner workings of the volcano open to scrutiny. In the background, the glacier-capped Mount Rainier lies dormant. (Credit: Jackie Kendrick)
It seems like Mount St. Helens has been a pretty inspirational place for you over the years! Can you tell us more about the work it’s stimulated?
Absolutely- I’ve been lucky enough to visit this spectacular volcano on numerous occasions, sometimes for work and always for pleasure!
My MSci research looked at the strength of rocks that make up the volcanic edifice rocks (usually layered lava flows that give volcanoes their familiar cone-shape), but the real defining moment in my career path was during fieldwork in 2010. During a visit organised between Ludwig Maximilian University of Munich, University College London, University of British Columbia and with the USGS we had the chance to study the crater lava domes up close for almost a week, to conduct thorough structural investigation of the internal lava dome characteristics. The domes, formed during eruptions in 1980-86 and 2004-08 are surrounded by the so-called Crater Glacier, which forms a ring around the domes, and which prevents access by foot – instead, we had to fly in by helicopter and camp in the crater!
There I began to appreciate lava domes for what they are, huge, rigid masses of near-solidified rock that are forced through the crust by buoyant magma below. This is especially true of Mount St. Helens, where the magma during the 2004-08 eruption was already crystallised at a depth of about 1 km and the dome is formed of a series of solid magma spines that rose up during the eruption, like arching whalebacks from the crater floor. These whalebacks are mantled by the products of friction, shear zones with powdery gouge, complex fracture networks and distorted crystals. It became suddenly apparent to me how important frictional processes were during these types of eruption, and how exciting it could be to push my research in a new direction endeavouring to understand it!
So since your career defining visit to Mount St. Helens in 2010, it’s been your goal to understand how frictional properties come into play in different volcanic scenarios, including the conduit?
Exactly, I’ve always had a passion for new and exciting research directions – and looking at the frictional properties of volcanic rocks in the context of erupting magma was something only touched upon experimentally before.
During an eruption, magma (called lava after it reaches the surface) is carried from the subterranean magma chamber to the surface in a conduit. Some conduit models have proposed a friction criteria to explain certain seismic signals, but parameters were derived theoretically or from friction experiments on other rocks. I started performing friction experiments in 2011. In these experiments 2 cylindrical rock cores are placed end-on, while a load (force) is applied from one end, and the other end is rotated at a desired velocity to create a simulated fault. I’ve looked at the frictional behaviour of volcanic glass, of ash, and of crystalline lavas – and I always try to integrate these studies with geophysical observations of real processes. You can watch one of these experiments in this video:
Another important aspect is examining microstructures and performing geochemical analysis, to make sure that the experiments recreate elements of natural examples. So far these investigations have led to a number of important findings:
That the heat that can be generated by friction can be immense – just try rubbing your hands together for a few seconds and then imagine this process in magma(!)
Volcanic rocks melt readily under friction – much more rapidly than most other rock types
The heat generated by friction can make the magma degas – volatiles in magma are only stable under certain pressure-temperature conditions, and if rapidly changed the gas will try to escape – we term this thermal vesiculation, and cite it as the driving force of some explosive eruptions
When some lavas melt due to friction, the viscosity (stickiness) of the melt is abnormally high – this melt “glues” the slip zone together (a phenomena called viscous braking) and it can actually control the rate of an eruption.
The list goes on, and there are many applications beyond the conduit, in terms of volcanoes, faults and even material sciences. But even after several years, nothing beats the excitement of seeing a molten magma form between volcanic rocks rubbed together for just a fraction of a second!
The product of our first successful friction experiment at University of Liverpool in 2014 – we created frictional melt in a pair of andesites from Volcán de Colima (Mexico). (Credit: Jackie Kendrick)
We can’t argue, volcanoes are possibly one of the coolest things in the Earth sciences, but what about them sparked your interest and the willingness to dedicate your research to them? In particular, why did you choose this interdisciplinary field at the crossroads between structural geology, seismology and volcanology?
For me, volcanoes hold such intrigue because of the power they possess – the unharnessed raw energy expelled during an eruption is something just fascinating to watch. The fact that they hold the potential to wreak havoc, and that we don’t yet really understand all the processes involved, just adds to my desire to study them, to know them inside and out.
There’s no doubt in my mind that this can be best achieved using an interdisciplinary approach, it’s all about monitoring, detailing and simulating the process. That is, we see something in real-time via geophysics, we simplify the system so that we can explore individual processes experimentally, and then we integrate our findings back into models to see if we can recreate a phenomena – there’s no point explaining one aspect if it can’t tie in all the others.
Fortunately I’ve had a pretty varied background, nonetheless it’s impossible to be an expert at everything – only highlighting the need to work together, to integrate knowledge from different fields in order to start deciphering complex earth processes.
This was the goal of the recent NSF-funded Workshop on Volcanoes 2016, held at Quetzaltenango (Guatemala), near the ever-active Santiaguito volcano, where we shared best practices and methodologies in monitoring and research – something I believe should be at the forefront of our minds moving forward.
To finish, what advice would you give students fascinated by volcanoes wanting to pursue a career in academia studying volcanology?
Well, first off, I’d say go for it! There are so many great post-graduate options nowadays, and you can really go down any route you choose – be it remote monitoring (like InSAR), proximal monitoring (including seismicity, gas measurements), laboratory experiments (such as friction described here) or you can approach volcanology from the social sciences, looking at influences on people and the environment. There are so many ways that you can get into volcanology, and what’s important is drive and passion, more than a specific academic prerequisite.
That said, I would certainly advise getting some experience before committing to post-graduate study, not least to find out exactly where your interests lie! You can get involved in monitoring by volunteering at volcano observatories, or in research by contacting professors and other academics for short internships and research opportunities. If you’re still doing your undergraduate studies, ask around, speak to graduate students to get advice and learn about the options open to you, and if you can, go to conferences, they are excellent for meeting influential people that can help shape your career!
An explosion at the dynamic Santiaguito volcano (Guatemala) in January 2016 – the volcano offers a unique monitoring opportunity as the ancestral Santa Maria volcano sits just a few km away and several hundred meters higher – the perfect vantage point. (Credit: Jackie Kendrick)