When the Shaking Stops
The violent shaking in large earthquakes can have devastating impacts on lives, property and livelihoods of communities worldwide. Yet often overlooked in such disasters are a whole range of subtler changes to the land surface due to landsliding, destruction of vegetation and uplift or subsidence of the ground. These changes are hazards in their own right and can cause major long-term disruption to relief or rebuilding efforts over large areas. Rivers may become choked by landslide debris, vegetation loss may lead to persistent large-scale soil erosion, surface and groundwater flows may be disrupted or stopped completely and large landslides may block or even divert rivers away from their former courses. Importantly, these effects may occur irregularly in space and will persist for years or decades after the earthquake. In this programme, we seek to gauge the scope, distribution and impact of the secondary phenomena associated with large earthquakes. Are these less spectacular but longer-term effects as destructive as the earthquake itself? Are they comparable to the main event, in terms of surface change, direct economic cost, loss of resilience and decreased productivity? Is current practice in disaster response sufficiently flexible to cope with the chronic, long-term effects of earthquakes, as well as the acute short-term issues? To address these issues, we are (1) examining the controls on secondary earthquake phenomena, particularly landslides and river basin changes, in space and time; and (2) establishing dialogue with economists and social scientists, to explore the ways in which such phenomena exert pressure on affected communities and individuals.
Earthquake Research at Durham
Existing capacity in earthquake and post-earthquake research at Durham University is concentrated in the Departments of Geography and Earth Sciences and the School of Applied Social Sciences. In Geography, we have internationally recognised expertise on seismically triggered landslides, on large scale patterns and impacts of landsliding and on the geology and geomorphology of earthquakes, particularly in the area of the 2008 Wenchuan event. There is also considerable capacity in risk perception and communication, including pioneering work on upstream engagement of affected communities. Expertise in Earth Sciences is focused on earthquake and faulting processes and on active tectonics of various areas, including the Bam and Wenchuan regions. There is also experience of liaison with a variety of national and international organisations in the wake of large earthquakes. Expertise in the School of Applied Social Sciences is centred on resilience and the role of social work and social mechanisms in postdisaster recovery, again with experience in the Wenchuan event. In this programme we would seek to marry that experience with enhanced physical understanding of the longer-term phenomena, with the goal of eventually assessing the relative societal impacts.
Alexander Densmore (Geography) has worked on the role of earthquakes in building mountains and driving a range of erosional processes, including landslides and debris flows. He has examined the relationships between earthquakes, fault growth, erosion and sediment transport in a range of settings, including the western USA, China and northern India. Most recently he has looked at the surface rupture and landsliding associated with the 2008 Wenchuan earthquake in China and he has contacts with Chinese academic and government researchers working in this area. Mark Allen (Earth Sciences) has worked extensively on active tectonics and long-term deformation across much of Asia. His work has addressed the rates and patterns of continental deformation on both short and long timescales, with particular emphasis on the ongoing effects of the India-Asia and Arabia-Asia collisions. His experience with the direct and secondary effects of earthquakes comes largely from work in Iran, including regions affected by the 1990 Rudbar and the 2003 Bam earthquakes. He has excellent contacts with Iranian academia and the Geological Survey of Iran.