Earthquake surface measurements reveal new revelations about how faults rupture

By Joanna P Faure Walker, on 12 November 2018

PhD student Francesco Iezzi (Birkbeck College), supervised by Prof Gerald Roberts (Birkbeck College) and Dr Joanna Faure Walker (UCL IRDR), has published a paper that could revolutionalise how geologists and seismic hazard modellers use long established scaling relationships between fault lengths and surface rupture parameters.

The paper is freely available to all and can be found here.

What new observations have been made?

For five earthquakes studied, the surface fault slip (the amount the fault surface moved during the earthquake) and the throw (the vertical component of the slip) was higher where there was a bend along the length of the fault.

Following the central Italy August and October 2017 earthquakes that ruptured the ground surface, we made detailed high spatial resolution measurements of surface fault displacement along the length of the surface fault ruptures. A study of the amount of vertical and horizontal displacement that occurred along the length of the fault revealed that the throw and slip that occurred during the earthquakes increased where there are bends in the fault. This result is critical and has not been identified before for individual earthquakes.

Damage in Amatrice from the August 2016 Earthquake. Photograph take during EEFIT fieldwork by Dr Joanna Faure Walker.

Why does this occur?

We hypothesis that this occurs in order to maintain the horizontal strain (change in length relative to the original length) across a fault during an earthquake and the long-term horizontal strain-rate that accumulates from multiple earthquakes over thousands of years.

Are there other examples of this?

We then went back and studied other examples earthquakes where there was enough information to determine whether a similar pattern of higher throw and slip could be seen across bends in the fault. In the three further events studied in USA Basin and Range, Greece, and Mexico, we found the same relationship. So it seems this phenomenon occurs worldwide in normal (extensional) faults.

This was the first time that the change in vertical component of slip during an earthquake has been shown to be predictable. However, the observed relationship of increased throw across fault bends has been identified previously in long-term displacements that have accumulated over 15 thousand years as a result of multiple earthquakes in Italy (Faure Walker et al., 2009, Wilkinson et al., 2015). Before now, it was not known whether this increase was caused by there being more earthquakes across the bends or more movement during individual events.  We now know that there can be more slip during individual events, however we do not know whether this is the only mechanism for creating a long-term higher throw-rate across the bends.

What does this mean for earthquake science?

This paper suggests that slip during an earthquake will change where there is a bend along the length of the fault and this change can be quantified and predicted using the proposed theory. This means that close to the fault, earthquakes may be more damaging near a bend in the fault. This finding suggests that we cannot use fault scaling relationships between fault length and expected slip in earthquakes without consideration of fault geometry. This paper can also explain much of the scatter seen in existing plots of maximum surface slip against fault length because when collecting the data as input for such relationships, consideration was not given about whether the measurements were taken across fault bends or not.

These changes in slip along faults in individual earthquakes related to the fault geometry should be included in probabilistic seismic hazard assessments (PSHA).

What other research in the IRDR relates to this?

This work contributes to the IRDR and colleagues’ work on investigating fault behaviour to improve our understanding of earthquake hazard. Recent papers have demonstrated the importance of including detailed fault geometry and slip-rates in seismic hazard calculations (Faure Walker et al., 2018) and Coulomb stress transfer calculations (Mildon et al., 2016, 2017).

Iezzi et al (2018), Coseismic Throw Variation Across Along‐Strike Bends on Active Normal Faults: Implications for Displacement Versus Length Scaling of Earthquake Ruptures, Journal of Geophysical Research, https://doi.org/10.1029/2018JB016732 

Launch event for the UCL IRDR Centre for Digital Public Health in Emergencies (dPHE)

By Saqar ' M Al Zaabi, on 8 November 2018

Blog post by Dr. Caroline Wood

The UCL Institute for Risk and Disaster Reduction held an evening event on Thursday 1st November 2018 to celebrate the launch of its newest transdisciplinary venture: the UCL IRDR Centre for Digital Public Health in Emergencies (dPHE). The event was attended by more than 120 people, including UCL senior managements, academics, researchers, students, industry specialists, entrepreneurs and policymakers from across a broad range of sectors and specialisms.

The evening started with a welcome address by Professor David Price (UCL Vice Provost for Research) outlining UCL’s Grand Challenges concept of bringing together academic expertise across disciplines to address the issues facing the society and the planet. Professor Peter Sammonds (Director of the UCL Institute for Risk and Disaster Reduction) gave an overview of the IRDR vision and highlighted how the new Centre forms a vital part of the UCL Faculty for Maths and Physical Sciences strategic 5-year development plan.

The Keynote Speaker Professor Virginia Murray (Head of Global Disaster Risk Reduction, Public Health England) kicked off the evening talks with an eye-opening keynote on global response to disasters and emergencies and the potential for science and digital health technologies to contribute. She illustrated her talk with reference to the United Nations Office for Disaster Risk Reduction (UNISDR) Sendai Framework for Disaster Risk Reduction (2015-2030); a tool developed to structure response and protect nations when disasters occur, and stressed the importance of improving accessibility and availability to key data.

The evening continued with Dr. Patty Kostkova (Director of the UCL IRDR Centre for Digital Public Health in Emergencies) outlining the history and vision of the Centre. She emphasised the Centre’s central mission to break down the limits of current health care systems’ capacity and communities’ resilience to improving health and wellbeing at national and international levels. A key part of the Centre’s research agenda will be to explore how use of digital technologies and improving access to data can build the ‘bridge’ between efficient emergency response, emergency activities and improved healthcare systems capacity and routine surveillance. The Centre will also seek to change the current dynamic of knowledge transfer and exchange between academia and policy, directly responding to the main global public health challenges identified by policy but also proactively bringing challenges to policy agendas.

With representation spanning five UCL faculties, involving multiple disciplines and chaired by Professor Ibrahim Abubakar (Director of the UCL Institute for Global Health, Faculty of Population Health Sciences), a panel then discussed the challenges faced by the global public health and potential ways in which digital technologies and community engagement could seek to address them. Professor Julio Davila (UCL Development Planning Unit, Faculty of the Built Environment) proposed that key challenges stem from the world’s continuing ambition to urbanise and from rapid increases in urban sprawl on a global level. He argued that improving infrastructure for capacity building is therefore crucial to efficient global public health response to disasters and emergencies.

Professor Kate Jones (UCL Centre for Biodiversity and Environmental Research, Faculty of Life Sciences) stressed that we need to better realise the state of our global ecosystems and the decreasing environmental diversity. Professor Jones proposed that digital technologies incorporating real-time prediction and big data would enable us to more fully understand links between ecosystem decline and human health. Major challenges surrounding data sharing, ownership and translation between sectors, organisations and disciplines were raised as significant barriers to more efficient ways of working by Professor Muki Haklay (UCL Extreme Citizen Science, Faculty of Social and Historical Sciences) and Dr. Patty Kostkova (UCL IRDR dPHE) stressing the opportunity to enhance big data-driven predictive disease analytics with routine surveillance data collected via mobile technology. Professor Haklay posited that citizen science has a large role to play in ensuring provision of digital tools direct to communities to improve data collection and guide usage of data for better public health response.

Professor Abubakar brought the panel to a close by stressing that it would be a crime not to exploit opportunities for addressing global public health using innovative digital technologies – especially given their growing global penetration, even in low to middle income countries (LMIC). He highlighted the importance of the IRDR Centre for dPHE’s role in bringing different disciplines and sectors together to address the bigger public health challenges and assess how to effectively drive innovation to global change. The role of human computer interaction science, behavioural science and education were specifically mentioned as being key disciplines in helping global public health to better understand how people interact with digital technologies and addressing how best to encourage uptake in communities. Initiatives expanding dPHE to more UCL Faculties beyond the core five represented at the panel were agreed at the event.

Professor David Lomas (UCL Vice Provost for Health) gave the closing address for the event reiterating cross Faculty and the UCL School of Life and Medical Sciences’ (SLMS) support for the new Centre and its importance in maintaining UCL’s role as a leader in improving global public health. A celebratory drinks and networking event showcasing several of the Centre’s collaborative research projects then took place in the Roberts Building Foyer.

Further coverage of the event can be accessed via the dPHE Twitter account @UCL_dPHE or via the hashtag: #dPHELaunch. Recording of the event including the panel discussion will be available to view week beginning Nov 19th. Images with thanks to Dr. Ilan Kelman.

 

About the UCL Centre for Digital Public Health in Emergencies

The UCL IRDR Centre for Digital Public Health in Emergencies brings together experts from UCL and external stakeholders to lead on interdisciplinary research, training and policy advice to improve global public health through use of digital technologies and data systems.

Recent health emergencies – including the SARS, Zika and Ebola outbreaks, and the Haiti and Nepal earthquakes – have unnecessarily taken thousands lives and cost the global economy billions. These events have shown the limits of current health systems’ capacity and communities resilience to respond to emergencies at local, national and international levels.

The dPHE seeks to:

  • Strengthen response to public health challenges and emergencies
  • Lead cutting-edge research into mobile technologies, data science and policy
  • Harness expertise across sectors to strengthen national and international collaboration
  • Cultivate the next generation of experts through evidence-based teaching and training

Established in 2018 as part of the UCL Faculty of Maths and Physical Sciences five-year strategic plan, the vision is to develop the dPHE into a renowned and world-leading Centre in digital public health in emergencies to improve global capacity, preparedness and response to health emergencies.

Contact:  irdr.dphe@ucl.ac.uk

Office location:  Institute for Risk and Disaster Reduction, Wilkins South Wing – 2nd Floor, University College London, Gower Street, London WC1E 6BT

@UCL_dPHE

More data needed for better earthquake hazard and risk calculations

By Joanna P Faure Walker, on 6 November 2018

New research demonstrates the importance of having detailed measurements at multiple sites along a fault of how fast the fault is moving and how the surface orientation of the fault changes. To access the full paper click here.

Why do we need fault measurements?

Measurements of fault slip rate and the geometry of the fault (it’s 3d orientation) can be used to calculate earthquake recurrence intervals to give probabilities of how likely earthquakes of different magnitudes are to occur. We also need these measurements to model how much ground shaking there will be at given locations. Hazard maps of expected ground shaking can be used to inform building codes and identify where buildings including homes and schools might need retrofitting to improve their resistance to earthquake shaking.

There are other methods available for creating earthquake hazard maps, such as using historical records of earthquake shaking. However, these records unlikely go back far enough in time to capture all faults capable of hosting large earthquakes because some faults will not have hosted earthquake within the time period covered by such records. Therefore, the hazard from some faults would be missing in hazard maps based solely on historical seismicity leading to underestimations in earthquake hazard.

What new insights have been revealed in the research publication?

The paper, entitled “Variable fault geometry suggests detailed fault slip rate profiles and geometries are needed for fault-based probabilistic seismic hazard assessment (PSHA)” demonstrates that relying on only one or a few measurements of how fast the fault is moving along a fault and projecting these measurements along the entire fault may lead to underestimating the uncertainty in the earthquake hazard calculations. Crucially, there may be locations where the hazard is underestimated, meaning people could be at more risk than suggested by simpler models (the converse is also possible). Therefore, earthquake hazard assessments based on fault parameters need to either use detailed measurements including measurements of how fast the fault is moving at multiple sites along the fault or to incorporate how the lack of such data increases the uncertainty in calculated earthquake hazard assessments.

Why are detailed measurements not being already used?

In many regions it is difficult to constrain the fault slip rate (how much the fault has moved in a given time) or throw rate (vertical component of slip rate) along a fault at even one location, let alone several. However, there are regions where this is possible so as more data is collected, this detail should help to improve earthquake hazard assessments both in those regions and worldwide.

Where can I find out more?

Faure Walker J., Visini F., Roberts G., Galasso C., McCaffrey K., and Mildon Z., (2018) Variable fault geometry suggests detailed fault slip rate profiles and geometries are needed for fault-based probabilistic seismic hazard assessment (PSHA), Bulletin of the Seismological Society of America, doi: 10.1785/0120180137

The Fault2SHA Working Group is an ESC (European Seismological Commission) group of researchers in both universities and civil protection authorities collaborating to increase incorporation of fault data in seismic hazard assessments and to improve our understanding of how such data should be used.

Disaster Science is one of five key themes for partnership between UCL and Tohoku University

By Joanna P Faure Walker, on 21 October 2018

UCL and Tohoku University signed a Memorandum of Understanding on Thursday 11th October 2018 as part of the kickoff partnership event. President Arthur and President Ohno stated their commitment to continuing research exchange, following the agreement of the previous five years.

President Arthur and President Ohno sign memorandum of understanding Photo source: https://www.tohoku.ac.jp/japanese/2018/10/news20181018-02.html

Workshops for five key themes were held on the 11th and 12th October as part of the event that saw 50 delegates come to UCL from Tohoku University. The five themes were disaster science, data science, neuroscience, higher education and material science and spintronics.

The disaster science delegation (From left to right) Prof. Shinichi Kuriyama Dr Katerina Stavrianaki Dr Ilan Kelman Ms Anna Shinka Dr Tiziana Rossetto Dr Joanan Faure Walker Dr David Robinson Assist. Prof. Shuji Seto Prof Maureen Fordham Ms Miwako Kitamura Prof David Alexander Assoc. Prof. Anawat Suppasri

The disaster science delegation comprised representatives from UCL IRDR, Tohoku University IRIDes (International Research Institute for Disaster Science), and UCL EPICentre. The workshop has helped form new collaboration opportunities building on the existing relationship between these research institutions. Our collaboration cincludes joint publications in earthquake stress transfer (e.g. Mildon et al., 2016), disaster fatalities (Suppasri et al., 2016), and temporary housing (e.g. Naylor et al., 2018). We look forward to the next five years of working with all our colleagues at IRIDeS to enhance the field of disaster science.

Discussions during the disaster science workshop Photo source: https://www.tohoku.ac.jp/japanese/2018/10/news20181018-02.html

The disaster science workshop included the following talks, which prompted discussions of further questions we would like to research together:

  • Assist. Prof. Shuji Seto (IRIDeS)
    • New Research Project on the Fatality Process in the 2011 Tohoku Earthquake for Survival Study from Tsunami Disaster
  • Dr Ilan Kelman (UCL IRDR)
    • Disaster, Health, and Islands
  • Prof. Shinichi Kuriyama (IRIDeS)
    • Challenge of Public Health to Disaster – Using Public Health Approach and Artificial Intelligence Techniques
  • Prof Maureen Fordman (UCL IRDR)
    • Gender and Disasters
  • Ms Miwako Kitamura (IRIDeS)
    • Gender problems as seen from the oral history of the bereaved families of the deceased Tsunami in Otsuchi Town, during the Great East Japan Earthquake
  • Ms Anna Shinka (IRIDeS)
    • A questionnaire study on disaster folklore and evacuation behavior for human casualty reduction – Case of Kesennnuma City, Miyagi Prefecture.
  • Prof Tiziana Rossetto (UCL EPICentre)
    • Building response under sequential earthquakes and tsunami
  • Assoc. Prof. Anawat Suppasri (IRIDeS)
    • Building damage assessment considering lateral resistance and loss estimation using an economic model “Input-Output table”
  • Prof David Alexander (UCL IRDR)
    • A framework for Cascading Disasters
  • Dr Joanna Faure Walker (UCL IRDR)
    • Disaster Warning, Evacuation and Shelter

NHK, the largest broadcaster in Japan, reported the workshop with a focus on Miwako Kitamura and the UCL Gender and Disaster Centre:  NHK report (in Japanese)

New international panel promotes responsible resource extraction in the Arctic

By Rebekah Yore, on 19 October 2018

Blog post by Dr Emma Wilson and Professor Indra Overland

A pioneering new international panel is currently recruiting members to help promote better environmental performance in Arctic resource extraction industries, while pushing the boundaries of applied research.

The International Panel on Arctic Environmental Responsibility (IPAER) was introduced to London audiences on 17th October 2018 at University College London (UCL), at an event hosted by the London Polar Group and the Polar Research and Policy Initiative. The session was led by the architect of IPAER, Research Professor Indra Overland of the Norwegian Institute of International Affairs (NUPI) in Oslo, and Dr Emma Wilson, independent researcher and consultant, who is an IPAER Advisory Board member. The aim of the event was to raise awareness about the initiative, stimulate debate and encourage new members to join.

Hammerfest, Norway

The IPAER is an independent group of experts who have been tasked with assessing the environmental performance of oil, gas and mining companies in the Arctic, based on their professional or lived experience of these industries.

Issues to be considered by the Panel range from conservation to pollution prevention, from Indigenous rights to transparency and public reporting. Panel members are expected to be experts in some, but not all, of these questions. The IPAER aims to cover the full range of issues by recruiting a balanced and broad range of Panel members, including technical industry experts, local community and civil society representatives, academics, industry consultants, journalists and regulators.

Damaged forest at old drilling site, Komi Republic, Russia 

Panel members take part in a simple perceptions survey, which requires them to identify the companies they are familiar with and then rank them in relation to one another. The results will be published as an open-access ranking of companies.

Panel members are expected to base their perceptions on the facts and realities that they have encountered through their professional and lived experience. Where perceptions are not based on fact, but on lack of information or misinformation, this raises the issue of more effective, accurate and well-targeted communication on the part of industry, the government, the media and civil society. We hope the IPAER can trigger more of a debate around this question, and ensure that the right issues are discussed more objectively in the public domain.

The IPAER is an experiment in what could be called ‘governance without enforcement’, as a complement to legal and formal regulation. We hope that it will trigger public debate and dialogue, internal corporate thinking, and proactive responses from industry, stimulating an environmental ‘race to the top’. But its success depends on our ability to recruit as many Panel members as possible.

If you would like to become a member of the Panel, we would love to hear from you!

Please contact:

Research Professor Indra Overland: ino@nupi.no

Dr Emma Wilson: emma.wilson@ecwenergy.com

 

Hammerfest, Norway photo credit: Dr Ilan Kelman

Damaged forest at old drilling site, Komi Republic, Russia photo credit: Dr Emma Wilson

Newly Published Paper on Microinsurance for Disaster Recovery

By Rebekah Yore, on 4 October 2018

Joanna Faure Walker and I have recently published our paper entitled “Microinsurance for disaster recovery: Business venture or humanitarian intervention? An analysis of potential success and failure factors of microinsurance case studies” in the International Journal of Disaster Risk Reduction.

The paper is based around a review of a number of microinsurance case studies from the last 20 years and from around the world. Microinsurance as both a humanitarian and a development initiative has evolved significantly to incorporate new partners in the design, supply and delivery of more contextually appropriate and socially conscious financial products for lower-income markets. However, there is certainly no one-fix-all solution to the provision of financial services to low-income populations, particularly in relation to assisting with disaster relief, recovery and longer-term resilience building, and many either fail to deliver on their initial objectives to protect people or they simply fail to operate sustainably and cease their services.

In our paper, we begin exploring what factors may contribute towards the success and failure of global microinsurance products, and discuss whether microinsurance products can serve as effective humanitarian interventions in times of crisis, or better serve as viable business propositions, or serve their communities as a combination of the two, depending on the context. Our findings, along with our suggestions of minimum metrics for recording the performance of microinsurance programmes over time, are intended to help further the discussion on defining microinsurance, to inform microinsurance initiatives that may be set up to address the challenges of post-disaster transitions to recovery, and to aid in the tracking of longer-term community impact.

Visit here to read more and to download the paper.

 

Rebekah Yore

UCL Institue for Risk and Disaster Reduction

rebekah.yore.14@ucl.ac.uk (07732 174252)

Induced earthquakes – how and when they have occurred, and why should anyone care

By Joanna P Faure Walker, on 27 September 2018

Despite the high volume of material out there about induced earthquakes, it can be hard to separate fact from opinion. To help explain what induced seismicity is, how it is caused and what the risks are, a group of researchers from UCL Department of Chemical Engineering and Institute for Risk and Disaster Reduction have published “Addressing the risks of induced seismicity in subsurface energy operations”.

What causes “induced seismicity”? Induced earthquakes, those mainly caused by human action, can invoke strong feelings towards the processes that cause them, the most widely known among these is hydraulic fracturing (less favourably known as “fracking”). But hydraulic fracturing for shale gas extraction is not the only cause of induced earthquakes – several industrial activities are capable of inducing or triggering earthquakes, including mining, dams, conventional oil and gas operations, groundwater extraction, CO2 Capture and Storage (CCS), underground waste fluid disposal and the creation of geothermal energy systems. Rightly or wrongly, negative public perception and local public opposition to induced seismicity has led to numerous international projections having been suspended, delayed or curtailed.

How does industrial operation induce earthquakes? The Earth’s crust is believed to be in a state where it is critically stressed and only small stress changes in the right direction can cause an earthquake. Industrial action can alter the stress field in the most shallow part of the Earth’s crust, inducing a seismic event.

Are these events getting more likely? The number of documented cases of man-made earthquakes in different industrial activities is rapidly increasing: In 2017 alone, there were two reported record-breaking magnitude induced seismic events. One of the more well-known areas of induced seismicity is in the United States: The notable increase in seismicity within the last decade in the previously seismically quiet State of Oklahoma has been widely attributed to large scale waste water injection wells connected to the hydrocarbon production industry.

How big are induced earthquakes? Most induced earthquakes are low in magnitude (typically less than magnitude 4). However, even these small events are capable of causing structural damage to properties and evoking widespread fear and anxiety. We say most are small, but there are some examples where large magnitude earthquakes have been alleged to be caused by human activities. For example, in China in 2008, a dam was built that filled a reservoir behind it. A short time later, a magnitude 8 earthquake occurred in the region. Some scientists proposed this large earthquake was caused by the mass loading of the water in the dam and its penetration into rock, affecting the subsurface pressure in an underlying fault line and possibly setting off a series of ruptures that led to the earthquake.

So what is being done about it? Minimising seismic risk should be a high priority for industrial operators. All fluid injection processes should require detailed seismic hazard assessments for imaging and characterising faults prior to operations, with dedicated monitoring systems in addition to existing national seismic monitoring facilities. For assessing the risks, monitoring the operations, and designing mitigation strategies using predictive models that can characterise the spatiotemporal evolution of induced seismicity would be extremely helpful. Examples of best practice approaches show that maintaining a transparent dialogue between operator and the public, while adhering to the regulatory processes can allow safe operations in an atmosphere of public acceptance.

Where can I find out more? With all the controversy around such events, we need to understand what are the risks of induced earthquakes and how can we model them. In the published article in Wiley Interdisciplinary Reviews, Richard Porter, Alberto Atriolo, Haroun Mahgerefteh and Joanna Faure Walker provide a review of several alleged induced seismicity case studies that have occurred in the last 15 years covering a variety of causal mechanisms. We discuss issues relating to public perception and procedures and strategies that could be implemented to help prevent and mitigate future occurrences.

The above work was funded by Horizon 2020 research and innovation programme, Grant/Award Number: 640979

Fault2SHA has successful session at ESC 2018 in Malta

By Joanna P Faure Walker, on 7 September 2018

The Fault2SHA ESC (European Seismological Commission) Working Group hosted a session on Wednesday 5th September at the ESC 2018 Meeting held in Valletta, Malta. Oona Scotti represented the group in her keynote on the opening day of the conference, in which she addressed “Modelling fault systems in PSHA: Challenges Ahead”. The Fault2SHA Working Group, for which I am on the Executive Committee, links different researchers working on faults and seismic hazard assessment (SHA) in Europe and beyond. This collaboration has brought together field geologists, fault-modellers and probabilistic seismic hazard modellers. The group provides a forum in which data, results, modelling capabilities, and improvements in scientific understanding can be shared. If you want more information, and to join, see Fault2SHA. The next Fault2SHA workshop will be in Kaust, Saudi Arabia, in November 2018 and the next meeting will run on 3rd-5th June 2019 in Barcelona, Spain.

I lead the Fault2SHA Central Apennines Laboratory. Our team comprises researchers from Italy (Paolo Boncio, Bruno Pace, Laura Peruzza, Francesco Visini), France (Lucilla Benedetti, Ooona Scotti) and the UK (Joanna Faure Walker, Gerald Roberts). At ESC in Malta, I introduced the central Apennines Laboratory and our current activities to the wider working group. The Central Apennines, as well as being a beautiful place to conduct fieldwork with the opportunity to obtain detailed datasets, suffers from large magnitude earthquakes. Indeed, earthquakes in the Central Apennines have featured widely in the UK press due hosting the two deadliest earthquakes in Europe of the last ten years: the 2009 L’Aquila sequence and the 2016 Amatrice-Norcia sequence.

 

The Fault2SHA Central Apennines Laboratory, which formed in January 2018, held an in-person meeting in July at the University of Chieti-Pescara, Italy. The photograph shows (from left to right) Oona Scotti, Francesco Visini, Joanna Faure Walker, Bruno Pace, Laura Peruzzi, Lucilla Benedetti, and Paolo Boncio.

During the Fault2SHA ESC session, I presented a second talk and a poster about my research investigating the importance of incorporating detailed fault geometry for understanding seismic hazard. The oral presentation demonstrated the importance of incorporating detailed fault geometry and loading on faults between earthquakes in Coulomb Stress Transfer modelling, a process that causes the stress on faults to change in response to an earthquake on a neighbouring fault. This was based on work carried out by Zoe Mildon (former IRDR PhD student, now a lecturer at the University of Plymouth) in collaboration with Gerald Roberts, Shinji Toda and myself (see Midon et al. 2016 and Mildon et al. submitted preprint). The poster displayed the importance of detailed fault geometry and slip-rate data for calculating earthquake probabilities and ground shaking intensities. I further represented Zoe for her poster within the session on earthquakes in regions of distributed deformation, that showed surface ruptures from the 1997 Colfiorito Earthquake in the central Apennines was due to primary earthquake slip (see Mildon et al., 2016 for details).

I thank all those at the conference with whom I had interesting discussions and I look forward to seeing all of our research progress.

Report of the 43rd Natural Hazards Workshop, Colorado

By Rebekah Yore, on 30 July 2018

Blog post by Justine Uyimleshi and Emmanuel Agbo

 

The natural hazard workshop is an annual event organised by the Natural Hazard Centre in collaboration with the University of Colorado Boulder around the field of disaster management and emergency response to trigger interactions and contributions from different experts in the field of disaster management and humanitarian responses. This year’s workshop, which was held in Omni Interlocken Hotel Boulder, Broomfield Colorado, from 8 – 11 July 2018 attracted over five hundred participants including disaster managers, emergency response personnel, practitioners and academia from around the world with different expertise in interactive sessions around pertinent issues that globally result in loss of lives, property damage, loss of economic values and human displacement. As a part of the IRDR strategy for promoting continuous research around disaster risk reduction (DRR) and expansion of networks in strengthening collaborations with other disaster management and emergency response entities across the world, the Institute through its research assistance funding provided support for two of its PhD researchers, Justine Uyimleshi and Emmanuel Agbo, to take part in this international event. Our participation in the workshop availed us the opportunity of interaction amid experts with different knowledge about disasters and present our research to the international communities.

Presenting our research

The workshop was full of several concurrent sessions that created opportunities for vast interaction around social media and disasters, data and partnership need for improved disaster response, cascading disasters, institutional settings, community impact and recovery from disasters, Health and wellbeing of disaster respondents, among others which enriched our understanding of the different thematic areas of disaster management. Most interestingly, the workshop further availed us the opportunity during the researcher’s meeting to moderate sessions of paper presentations as efforts in promoting the IRDR commitment in global events.  Also, of great attention from the workshop was our meeting with Jim Murphy, project director, Civil/Water Resource Engineering, DC Metro Area. Jim in admiration of our presence in the workshop and presentation during the workshop sessions demonstrated a benevolent act towards us and offered us a tour to the wild fire and flood devastating sites in Broomfield.

On this tour, we were able to see the available response facilities, and measures that are in place to quell the likely impact from future occurrence of these hazards. Finally, we extended the exploration of Colorado to the Gold hill town, where the coal exploit took place and the city mountains, which are part of the historical features of Colorado. Resulting from our experience of this workshop, we wish to express our profound appreciation to the IRDR for their continuous support. The workshop was greatly an event worth attending.

A Short Tale of Fieldwork

By Claudia Sgambato, on 26 July 2018

Fieldwork represents a fundamental part of my PhD research, and, as a geologist, it is also my favourite part of the job. In June 2018, I flew to Italy for the first of many fieldtrips, with Joanna Faure Walker, my primary supervisor. Together we worked for five days to conduct detailed mapping of and data collection from the Auletta fault, located in Campania, Southern Italy.

The Italian Apennines are undergoing a southwest-northeast extension, associated with earthquakes of moderate and large magnitudes, occurring on active normal faults. The exact location of these faults and rates of movement across them represents an important factor for the seismic hazard.

The fault studied is located in the Vallo di Diano, one of the extensional intramontane basins that characterise this sector of the Southern Apennines; the basin, filled by river and lake fan and slope deposits, is bordered on the East side by a major fault system, terminating to the North with the 3 km long fault strand that was the object of this study.

The Auletta fault scarp seen about half way up the slope as a grey line that offsets the topography, where my fieldwork was focussed. This fault scarp crosses the Cretaceous carbonates of Mt. San Giacomo for about 3km (photograph credit: Claudia Sgambato).

Many large magnitude earthquakes have struck the Southern Apennines in the past 1000 years, with an average of one event every 50 years. For instance, in 1694, a M=6.9 event with epicentre in Irpinia caused about 6000 casualties; in the same area, in 1980, a M=6.9 earthquake caused about 3000 deaths. Some events had damage consistent with them possibly occurring on the Auletta fault, like the two events in 1561 (M=6.7) that caused 600 casualties. Moreover, there is a debate on the location and nature of the structure responsible for one of the strongest earthquakes in the area, which occurred in 1857 in the Northern Vallo di Diano and Val d’Agri, causing between 10,000 – 20,000 casualties.

The main aim of my fieldwork on this trip was to collect detailed data along the fault scarp of the fault geometry (strike and dip), together with offset and slip direction data, to understand how these vary along what we consider the termination, or tip, of the fault. In fact, my research project investigates how the geometry of both individual faults and fault arrays in the Central and Southern Apennines influences the seismic hazard. All these data collected in the field, such as the fault orientation, length, strike and dip, slip to length ratios, will be used to study what controls the variability in slip-rates along the faults and how the fault geometry and faults interaction can affect earthquake recurrence intervals.

Joanna is taking measurements of the strike and dip of the fault (photograph credit: Claudia Sgambato).

Our typical day in the field started with an early breakfast, to avoid the heat and to reach the fault scarp at an elevation of 750m, as soon as possible. Then we walked along the scarp, taking measurements of strike and dip and slip vector, and where possible, measuring the throw using a meter ruler, which requires lying on the ground and sliding through the slope for about 100m.

You would think that the best part of fieldwork is the immersion in nature, with the fresh breeze and the warm sun of an early summer in Italy. Indeed, growing up in southern Italy means I have many such memories. But, there is the other side of the coin: imagine starting a day by facing some steep, slippery, muddy, slopes, covered in thistles, the kind that grows taller than you! Then later in the day, while working in the sun, suddenly heavy clouds cover the sky and rain, loud long-lasting thunders, and all the things you don’t expect from an Italian summer, happen, every day over those five days. And while you are trying to save your precious maps and notebook from the pouring rain, your legs and arms experience all kinds of thorns and stings. Well, this is fieldwork! The joy of working in the best “office” in the world, and all the (mis)adventures that come with it.

Negotiating through the thistles on my way up to the fault scarp – the Vallo Di Diano in the background – my “office” view (Photograph credit: Joanna Faure Walker).

Even if this field trip wasn’t exactly as expected, I learned a lot thanks to Joanna. We had a fun time, enjoying the stunning views, and more importantly, we brought back some interesting data that will keep me busy while I am already organising my next trip.

Happy to have escaped the thunderstorm, after anticipating its coming and climbing to the top (Photograph credit: Joanna Faure Walker).