GeoLog

Natural Hazards

Counting the cost of natural disasters

Counting the cost of natural disasters

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)

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: Friction in volcanic environments by Jackie Kendrick

GeoTalk: Friction in volcanic environments by Jackie Kendrick

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 the frictional 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)

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)

These approaches are also pertinent in understanding landslides and sector collapse events too – an interest of mine that was sparked during fieldwork at Mount St. Helens, which suffered one of the most infamous and catastrophic sector collapses ever documented in 1980.

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:

  1. 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(!)
  2. Volcanic rocks melt readily under friction – much more rapidly than most other rock types
  3. 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
  4. 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)

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)

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)

GeoSciences Column: Mapping floods with social media

GeoSciences Column: Mapping floods with social media

Picture this: you are on your commute home, smartphone or tablet in hand, surfing the internet. You might quickly catch up on the latest news, check in with your friend’s on Facebook, or take to Twitter to share a morsel of information with your followers.

This scenario is common in the modern era of technology. No doubt we are all guilty of indulging in a serious session of internet navigation every now and then (and nothing wrong with that!). But what if your online persona could also make a contribution to better natural disaster management?

One of the many challenges during, and in the immediate aftermath of, natural disasters is being able to provide local populations with timely and reliable information about the extent of damage and/or disruption expected. Flooding events are a prime example: minimising and managing the financial, human and emotional cost of floods is key for researchers, local communities, policy makers and authorities alike.

Contributing to this effort, a team of German researchers have designed a tool which harnesses our desire to share snippets of our lives via social media to support the creation of rapid inundation maps during flooding events. The research was recently published in the EGU open access journal, Natural Hazards and Earth System Sciences.

Currently, measurements of flood water heights made by river gauges, hydrodynamic-numerical models and remote sensing data – such as before and after images acquired by satellites – are used to create rapid response flood maps. Despite their successful and wide-spread use, they are not without limitations.  River gauges only allow for narrow point information on water heights during a flood and require detailed topographical data to be validated. Hydronamic-numerical models aren’t very flexible: it is difficult to build unforeseen incidents into them (e.g. a dike breach). Remote sensing techniques have limitations when it comes to providing real time information; it can take up to 48 hours for the images to be delivered and processed before they can be used.

The study authors argue that eyewitness information about flooding events shared via social media can fill in some of the gaps. Using quantitative data, such as geographical location and flood water height, held in images shared via Twitter and Flickr, can provide information to make more detailed and accurate flood maps in almost real-time. The researchers put the theory to the test for the June 2013 Dresden floods.

The city of Dresden, with its 800,000 inhabitants, sits on the banks of the River Elbe, known for its long history of flooding. This means the city’s population is more aware of the hazard and, being an urban area, likely has a large number of social media users, making it a good case study candidate.

Location of useful photos retrieved with PostDistiller and inundation depths estimates. (Photos by Denny Tumlirsch (@Flitz- patrick), @ubahnverleih, Sven Wernicke (@SvenWernicke) and Leo Käßner (@leokaesner). Taken from J. Fohringer et al. (2016))

Location of useful photos retrieved with PostDistiller and inundation depths estimates. (Photos by Denny Tumlirsch (@Flitz-patrick), @ubahnverleih, Sven Wernicke (@SvenWernicke) and Leo Käßner (@leokaesner). For instance, photos 1 and 2 show inundated roads but a dry sidewalk. This context en- ables the analyst to estimate inundation depth in the order of approximately 5 cm Taken from J. Fohringer et al. (2016))

The research team created an inundation map using only information from photos filtered from Twitter and Flickr. To collate the flood data from social media, the team designed a computer programme. In the first instance a search for key words (in both English and German) related to floods was ran: “Hochwasser”, “Flut”, “Flood”, “inundation”, to name a few. The results were then filtered by the time frame of interest (from May 5th to 21st June 2013) as well as the geolocation of the posts. This yielded a total of 84 posts from which five inundation depths were derived (see the figure caption for details of how the team achieved this), in the space of no more than four hours. The depths calculated were then used to create the inundation map.

To test the robustness of the map, the team created a second map relying only on online data acquired from the Dresden river gauge. Comparing the two maps shows that the social media created map overestimates inundation height by decimetres as well as the geographical extent of the flooding. Despite that, the study authors argue that the errors are acceptable when it comes to providing rapid inundation maps, particularly in situations when no other information is available.

Inundation maps and inundation depths derived from online water level observations (a) and social media content (b) ; inundated area derived from the reference remote sensing flood footprint (c) ; and differences between inundation depths for overlapping areas in scenarios (a) and (b) (panel d ). J. Fohringer et al. (2016))

Inundation maps and inundation depths derived from online water level observations (a) and social media content (b); inundated area derived from the reference remote sensing flood footprint (c); and differences between inundation depths for overlapping areas in scenarios (a) and (b) (panel d). J. Fohringer et al. (2016))

The case study also highlighted some of the method’s shortcomings. It will be important to improve the vertical and horizontal accuracy of the social media created maps by supplementing them with more detailed topographical terrain data. The current method of acquiring data via social media is relatively passive and relies on users sharing images from a flooding event. Crowdsourcing data, where citizens are actively encouraged to share images, would improve the reliability of the data as well as the spatial coverage.

So when you next take a selfie or capture a stunning landscape to share on social media, who knows, the data held in your images and geolocation could have even more value than you might have originally thought!

By Laura Roberts Artal, EGU Communications Officer

 

 

 References

Fohringer, J., Dransch, D., Kreibich, H., and Schröter, K.: Social media as an information source for rapid flood inundation mapping, Nat. Hazards Earth Syst. Sci., 15, 2725-2738, doi:10.5194/nhess-15-2725-2015, 2015.

Rimkus, S. et al.  A Century of UK Flood Losses (conference abstract) Geophysical Research Abstracts Vol. 18, EGU2016-11905, 2016, EGU General Assembly 2016

Trejo Rangel, M.A., et al. How Can Flood Affect the Real Estate Market? (conference abstract) Geophysical Research Abstracts, Vol. 18, EGU2016-8977, 2016, EGU General Assembly 2016

Imaggeo on Mondays: Fire Watch Constellation

Imaggeo on Mondays: Fire Watch Constellation

Wild fires: raging walls of flames, capable of burning down swathes of pristine, sometimes protected and ancient, landscapes have been causing havoc around the globe. Managing and controlling them is no easy task; they can unexpectedly change their course with the wind and jump across rivers, roads and man-made fire breaks.

The significant threat they pose, and damage they can cause, to valuable ecosystems worldwide has been recently evidenced by the destruction of 180 million year old forests in Tasmanian; so unique they are a designated United Nations World Heritage wilderness land. Not only that, wildfires can have sever effects on air quality, directly impacting human health, while at the same time contributing hefty amounts of greenhouse gases to the atmosphere. As recently as the end of last year (2015), forest fires in Indonesia were hailed as a ‘crime against humanity‘, after causing over 500,000 cases of acute respiratory tract infections.

This week’s Imaggeo on Mondays photograph highlights an emerging field of research where scientists are developing new methods to try and better understand the past impact of wildfires and how they contributed (or not) to climate change.

Of his image, Egle Rackauskaite writes: This composite shows a constellation of combined visual and infrared imaging of a smouldering combustion front spreading radially over a thin sample of dry peat. The central watch is created by a series of twelve wedges. Each wedge is extracted from a photo taken every 5 min from an elevated view looking down into the sample during the one-hour lab experiment. The circular peat sample (D=22 cm) was ignited on the centre by an electrical heater. The average radial spread rate was 10 cm/h and the peak temperature 600°C. The top figures show the virgin peat (left) and the final residue (right). The bottom figures show the wedges in visual (left) and infrared (right) imaging. Smouldering combustion is the driving phenomenon of wildfires in peatlands, like those causing haze episodes in southeast Asia and Northeast Europe. These are the largest fires on Earth and an extensive source of greenhouse gases, but poorly studied. Our experiments help to understand this emerging research topic in climate-change mitigation by characterizing the dynamics of ignition, spread and extinction, and also measure the yield of carbon emissions.

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 April), you can take part in our annual photo competition! From 1 February up until 1 March, 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/.

 

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