Active tectonics and seismic hazard assessment in Shaanxi, Gansu, and Ningxia Provinces, China

The provinces of Sha'anxi, Gansu, and Ningxia lie between the southern and western margins of
the Ordos block and the northeastern Tibetan plateau. The population of the region is about 70
million, of whom approximately half live within large cities, which have grown rapidly and recently
around the nuclei of much smaller cities that are known to have been destroyed by earthquakes
in the historical past. The remainder of the population is rural, and live in highly vulnerable buildings.
The region has suffered three of the most deadly earthquakes in recorded history; the 1556 Huaxian
earthquake was responsible for the deaths of over 800,000 people, and other historical earthquakes
are known to have killed over 100,000 people.

This project aims to make a significant improvement in the assessment of seismic hazard in the region,
and is particularly timely because the study area covers the most populous part of the Chinese end of
the Silk Road Economic Belt, a planned investment of hundreds of billions of dollars that will transform
communications, transport and trade across Eurasia.

Unlike countries around the Pacific Rim, where earthquakes occur quite frequently, on faults whose
locations are well known, China is exposed to hazards from earthquakes that occur on a widely
distributed system of faults, whose locations are poorly known -- or not known at all until an
earthquake occurs. The central aspect of this earthquake hazard is that the intervals between successive
earthquakes on the same section of fault are thousands of years. In order to characterize accurately
the deformation of a region, therefore, we need to determine the distribution, rate, and role
of the active faults across the region over the past 10,000 to 100,000 years.

We shall shall achieve this by combining techniques of field geology, geophysics, satellite-based mapping,
and measurements of the deformation of the Earth' surface using GPS and satellite radar. We shall
combine these observations into a coherent picture of the deformation of the region, which will be used
to make a new map of seismic hazard of the region that is both more accurate and more detailed than existing maps.

This project builds upon, and greatly increases the geographic extent of, a China-UK collaboration that was established as part of the NERC/ESRC-funded "Earthquakes without Frontiers" (EwF) programme. In this project, which works in China, Central Asia, and Nepal, natural and social scientists work together with policy makers, practitioners and local communities to identify and fill knowledge gaps, and to co-produce evidence-based approaches to reduce risk and increase resilience to earthquake hazard. Within China, EwF carries out research on seismic hazard around Xi'an, Sha'anxi province, and on the means whereby scientific understanding can improve the policy and practice of earthquake disaster risk reduction in the region.

The outcomes of our project will provide vital inputs for seismic hazard assessment and mitigation during the development of the wider region of northwest China. The project is driven directly by the goals of the China Earthquake Administration, the Ministry with responsibility for the assessment of seismic hazard. Because the Chinese investigators are drawn from senior levels within the China Earthquake Administration and the Provincial Seismological Earthquake Administrations, the results will feed directly into policy and practice at national and provincial levels.

Furthermore, because the EwF partnership emphasizes the exchange of information among all countries exposed to seismic hazards, this research will also be of benefit to developing nations in other parts of the world (e.g. Nepal, India, Central Asia).

The Earthquakes without Frontiers programme is fundamentally transdisciplinary in nature, by which we mean that its work is founded upon close collaboration between the different disciplines represented within the research team and between the team and local researchers, policymakers and operational agencies at provincial, national and international level. In a companion proposal to the present one (PAGER-O: Pan-participatory Assessment and Governance of Earthquake Risks in the Ordos Area) Su Guiwu of the CEA, John Young of the Overseas Development Institute, Timothy Sim of Hong Kong Polytechnic University, and Emily So of Cambridge University propose to improve policy and practice in earthquake disaster risk reduction (EDRR) by integrating national (top-down) and local (bottom-up) approaches. They will do this through close collaboration between researchers, policy makers, operational agencies, practitioners and local communities in the research itself and in the translation of results into immediately practical outputs. If the PAGER-O proposal is funded, the Investigators of this Proposal will engage fully in the programme of communication, stakeholder engagement and the uptake of the research into policy and practice that is contained in the PAGER-O proposal.