Monday, 17 March 2014

Westwood Earthquake: Risk of Future Earthquakes-and-Landslides

At 13:25 UTC today on Monday 17th March a M4.4 earthquake occurred 9km NNW of Westwood, California, near to the city of Los Angeles. Whilst luckily no one was hurt, the earthquake serves as a reminder for those living within the region of the threat posed by the seismic faults beneath them. It is unknown or unreported at the moment whether any landslides or secondary hazards were triggered by the event. The epicentre of the earthquake is fairly close in proximity to the epicentre of the 1994 M6.7 Northridge earthquake which caused significant damage.

I am currently on holiday in San Diego at the moment, and hearing of the earthquake so close to me (in comparison to when I was in the UK) has prompted this blog post. My current research into earthquake triggered landslides has used the Northridge 1994 earthquake as a case study, investigating 'what-if' scenarios simulating the potential impact of such an event occurring in the present day. Unfortunately, I do not have my data or sources with me on holiday. But, I wanted to capture some of my thoughts on the event as soon as possible. I hope to update this post when I return to the UK for clarification and further details.

The area affected has been in a recent earthquake 'drought' with few earthquakes of significant magnitude occurring in recent years. The USGS suggest there is a potential for the recent M4.4 earthquake to be followed by another earthquake in the near future. Indeed, the entire region of Los Angeles is at risk of high magnitude earthquakes. The residents of Westwood and surrounding region are lucky the earthquake today was not of a higher magnitude and I can only hope this serves as a reminder for all those living in the region of the potential severity a bigger earthquake could cause.

There are currently no reports of landsliding in the area as a result of the earthquake. With a M4.0 the typically accepted threshold for triggering landslides, perhaps we may hear reports of landsliding coming in soon for more remote locations. The 1994 Northridge earthquake triggered tens of thousands of landslides in the surrounding region. Luckily, these landslides had minimal interaction with the population and infrastructure. However, where a landslide did affect a building, the damage from said landslide was approximately three times greater than the average damage caused by the earthquake shaking to similar buildings. Since 1994, there has been substantial development in Los Angeles, the San Fernando Velley and in the hillier areas surrounding Northridge.

Whilst I cannot go into specifics of the case study simulations I have run due to publication constraints, I can report that initial results suggest that even if the same earthquake occurred tomorrow as occurred in 1994 at Northridge, the potential impact of such an event would be greater than what was experienced in 1994. Even a smaller magnitude earthquake of, say, M6.0 could potentially cause as much damage as the M6.7 Northridge 1994 event, if it were to occur tomorrow. I will be able to give such statistics when/if the paper is accepted for publication in the near future.

The USGS PAGER estimates of losses due to secondary hazards states for today's event: "Recent earthquakes in this area have caused secondary hazards such as landslides and liquefaction that might have contributed to losses." This highlights a limitation of the PAGER loss estimates - the effect of secondary hazards are not currently accounted for in the report. This is an area the USGS is currently developing to be able to aid assessments of potential damage from the main shaking and secondary hazards for use in the future. Whilst secondary hazards such as landsliding do not always occur as a result of an earthquake, and in most cases, the majority of earthquake damages are caused by shaking, there are enough cases where the triggered landslides have caused a significant proportion of the damage to warrant concern. In some exceptional events, landsliding has caused the majority of losses as a result of an earthquake trigger. Development of a predictive tool for assessing landslide and liquefaction hazard and losses would be incredibly useful for emergency responders to get a more accurate picture of the disaster and locate areas of secondary hazard damage that may not be accounted for by earthquake shaking alone.

Whilst further research is required into the potential impact of secondary hazards, and the Southern California region provides an almost unprecedented amount of research and data to be of use in this area, I have respect and faith in the USGS and California research expertise in the area. From what I have learnt, California is one of the most regulated and highly prepared states for earthquake risk. By being located on active fault planes with high potential to experience the 'Big One' in multiple cities in the state, the officials and researchers have been forced to up their game. Whilst I hope that the region does not experience a high magnitude earthquake, the reality is that they are going to have one occur.

I hope the M4.4 experienced today has provided a timely reminder to all those living there of what they could face, and causes them to prepare and be able to respond appropriately if and when a future big earthquake comes their way.

Friday, 6 December 2013

Interacting UK Hazards - Impacts and Origins PhD

Loughborough University has recently advertised for a PhD opportunity: "Interacting UK Hazards - Impacts and Origins". It's great to see the field and funding is starting to get on board with multiple and interacting natural hazards!

Interacting UK Hazards – Impacts and Origins

Dr John Hillier, Geography, Loughborough
Dr Gregor Leckebusch, School GEES, Birmingham
Dr Kate Royse, British Geological Survey

An excellent, inquisitive and highly-numerate student is sought to combine novel and industry-based GIS methods (i.e., catastrophe modelling) to understand the origins and impacts of interacting hazards as they afflict the UK.

The UK is affected by several natural hazards (e.g., floods in 2007). These are currently considered independently, but they could interact. A pilot study by the supervisors, using a novel way of examining past data, has robustly shown that interactions can alter likely ‘worst case’ losses by ~£50 million. This is of immediate interest to insurance companies and with much potential to contribute to policy making about the resilience of the UK as climate changes.

Objectives & Methodology:
A core of the work is low risk, building directly upon the pilot study, but scope exists for a student to innovate and excel. A key objective is to understand the origin of the interaction between shrink-swell subsidence losses for clay soils and other risks. This will be done by relating loss data (Zurich Insurance) to recorded weather patterns and developing published work linking subsidence and climate using British Geological Survey (BGS) data (e.g., GeoSure). The strength of interaction between physical processes required to explain the observed impacts will be quantified by generating catastrophe models [e.g., Donat & Leckebusch, 2011; Royse & Hillier In Press] (new QuickCat code). ‘Catastrophe modelling’ is relatively little used in academia, giving potential for exciting developments, and the last stage of this project is a new use for the technique.

A secondment to Zurich Insurance Plc. (3-6 months) has been negotiated, and engagement with the BGS is anticipated. Catastrophe modelling underpins all financial risk assessment, and is becoming critical in Disaster Risk Reduction and humanitarian efforts, ideally placing the student for a range of careers. Training will include fieldwork, integrated modelling, GIS, and relevant programming giving the student skills identified as ‘most wanted’ for environmental jobs; ‘modelling’, ‘multi-disciplinarity’, ‘risk and uncertainty’.

Thursday, 7 November 2013

Multi-Hazards Summer School 2014

The Association of Pacific Rim Universities are hosting a Multi-Hazards Summer School in July 2014 at Tohoku University (date to be announced).

The Multi-Hazards Summer School objectives are to:
  • Increase knowledge of the Hyogo Framework for Action (168 countries adopted at the UN World Conference on Disaster Reduction in 2005) and DRR initiatives in Japan; 
  • Share lessons and experiences on effective disaster preparedness from the Great East Japan Earthquake and Tsunami; 
  • Discuss the roles of universities/research institutes in DRR and their challenges; and
  • Identify collaborative synergies among APRU universities in DRR and develop strategies to harness these.


The Multi-HazardsSummer School consists of a 2-day seminar and a site visit to the affected area impacted by the Great Eastern Japan Earthquake and Tsunami.

Summer School topics will include:
  • Hyogo Framework for Action ~ International framework for DRR ~ 
  • DRR initiatives and history in Japan 
  • Lessons-learnt from the Great East Japan Earthquake and Tsunami
  • Campus safety 
  • Good practices of DRR initiatives by academia
  • Future roles of academia in DRR

Friday, 25 October 2013

EGU 2014: Multi-type hazard and risk assessment: Concepts and methodologies

Details of the 2014 EGU multi-type hazard and risk session for you all. Really disappointed I won't be able to attend this year. Once again, Kevin Fleming from the MATRIX project convening the session. Really nice to see this topic being pushed forward. Hope there are some good and relevant presentations for 2014!

NH9.9 Multi-type hazard and risk assessment: Concepts and methodologies

Convener: Kevin Fleming
Co-Conveners: Alexander Garcia-Aristizabal , Nadejda Komendantova

Losses arising from natural hazards are increasing worldwide, and are expected
to continue to do so, often as a result of the increased  exposure and vulnerability
of human society.  Scientists, engineers,  regional and local planners, civil
protection authorities and disaster  managers usually treat natural and
anthropogenic hazards and risks  individually; however, such a framework leads
to the neglect of the  frequent spatial and temporal relationships that exist between
hazards  and their associated risks.  This potentially leads to the situation where
simply summing the individual risks may result in an  underestimation of their true
impact, while identifying the different  types of risk, i.e., direct versus indirect, and
tangible versus  intangible, remains a challenge.  There is therefore an
increasing  realisation that a multi-hazard and risk framework is necessary if 
one is to effectively assess the consequences of natural and  anthropogenic
disasters, and to optimise the available resources for  mitigating against such
events.  Such a framework would need to consider  the various interactions
between different hazard types, and hazards  and risks, while also considering
the different loss types in order to  gain a complete view of how disasters impact
upon the broader society.

This session aims at presenting the latest developments in the area of  multi-type
hazard and risk assessment. The issues of particular concern  are cascade effects,
including the interactions between natural and  NaTech events, uncertainty
propagation and temporal dependency, which  requires examining short-term
sequences where hazards occur almost  simultaneously or are triggered by one
another, to longer-term scenarios  that may cover several months or years.  Case
studies where a  multi-type framework has been applied (for better or for worse) or
could  have been beneficially applied are also of interest.

Landslide scenarios for a large Seattle earthquake: Blog Post Share

A quick share to let you know of a recent post on the Institute of Hazard, Risk and Resilience Blog about an electronically released paper on landslide scenarios for a large Seattle earthquake. Post here, written by Dave Petley reviews the paper. For access to the paper, click here.

This paper is very close to my research in simulating earthquake-triggered landslide occurrences and the potential damages from them.

9th Multi-Hazards Symposium 2013

The APRU symposium series on Multi-Hazards around the Pacific Rim is having its ninth symposium from 28 to 29 October 2013 at National Taiwan University in Chinese Taipei.

Unfortunately, I have only just become aware of this event so will not be attending. It is unlikely I would have had time at this stage of my PhD to travel there to present in any case.

The 9th APRU symposium is hosted by the Center for Weather Climate and Disaster Research (WCDR) at National Taiwan University. For general information, please refer to the website.

The 9th APRU symposium aims to convene scholars and experts from countries around the Pacific Rim. The inter-disciplinary knowledge on multi-hazard researches can be exchanged and shared through APRU collaboration. The symposium will focus on related topics of multi-hazards induced by extreme weather, earthquake, volcanic activity and haze pollution. Other issues are also included such as advanced monitoring and forecasting techniques, risk assessment, disaster health and emergency management, as well as education on disaster reduction.


1.Multi-hazards induced by extreme weather; Multi-hazards induced by earthquake; Multi-hazards induced by volcanic activity; Air pollution and haze related issue

2.Disaster risk assessment and impact analysis; Advanced research on monitoring, sensing, nowcasting and forecasting

3.Disaster management and education; Post-disaster recovery and reconstruction; Disaster health and emergency management

Sunday, 15 September 2013

Foresight Review Case Study: Global Multiple Hazard and Risk Mapping

The Foresight Review commissioned in 2012 has a section (co-written by me) on multiple hazard and risk mapping. I forgot to post something about it at the time. Click on the links below for access to the documents.

Reducing Risks of Future Disasters: Priorities for Decision Makers.

Evidence base document for download: State-of-the-Art in Risk Mapping
CASE STUDY: Global Multiple Hazard and Risk mapping (p49)
Authors: Mirianna E.A. Budimir, Peter M. Atkinson and Hugh G. Lewis

A quote from the document for you all:

"Multi-hazard risk assessment should also take into consideration the interaction between multiple hazards affecting an area. Natural hazards act in a natural system and as such are complex and affect each other. The cascading effects of natural hazards and their impact on resultant risk is an important area of research which has received little attention to date."