Overview: We request funds to make measurements of the elapsed time since major earthquakes on active faults in central Italy using 36-Cl cosmogenic dating, and calculate stress transfer from historical/palaeoseismic earthquakes. This will allow (1) knowledge transfer to at-risk communities in the region so they can prepare for future earthquakes if a fault with a long earthquake elapsed time has had stress transferred onto it by a neighboring earthquake(s), and (2) communication of this process to other regions with similar earthquake hazard. Technical Summary: Active faults experience earthquake rupture due to stress transfer from neighboring earthquakes only if the fault in question is close to its failure stress. We lack knowledge of which faults are close to their failure stress and thus cannot interpret calculations of stress transfer in terms of the probability of impending earthquakes. We propose, for an active normal fault system in central Italy, to measure the elapsed time since the last earthquake normalised to fault slip-rates using in situ 36-Cl cosmogenic isotope dating, because this is a proxy for how close a fault is to its failure stress. We will combine this with calculations of stress transfer from historical and palaeoseismic earthquakes in order to calculate which faults have the highest probability of rupture. Background: When an earthquake ruptures an active fault, stress is transferred onto neighboring active faults. This transfer of stress may cause a neighboring active fault to rupture in a subsequent earthquake. For example, the 2004 Boxing day earthquake on the subduction plate boundary near Sumatra caused severe loss of life on that day, but also triggered subsequent earthquakes in 2005, 2007, 2009 and 2010, each of which caused major loss of life. Such triggered earthquakes also occur on active faults within plates, such as the three 9th September > Mw 6 earthquakes in 1349 A.D. in central Italy, which occurred on the same day, but on different active faults; this has increased concern for the possibility of a future mainshock to follow the 2009 L'Aquila earthquake (Mw 6.3) whose ongoing aftershocks have transferred onto a neighboring fault (Fig. 1). A key point is that, despite the above examples, earthquakes do not always trigger subsequent earthquakes. Subsequent earthquakes only occur if the neighboring fault(s) are already close to failure due to long-term loading from motions in the crust or between plates. Identification of such faults could inform local populations and civil protection agencies in advance of a future earthquake allowing location-prioritised mitigation efforts. However, unfortunately, we cannot directly measure stress on a fault at 12-15 km depth where intra-plate mainshocks nucleate and so cannot identify such faults. However, we can measure a proxy for stress-through-time, that is elapsed time since the last earthquake, using cosmogenic isotopes (36-Cl). In the sub-surface, 36-Cl concentrations accumulate through time mainly due to hits on calcium atoms by cosmic particles. With 1-2 m slip in each earthquake on active normal faults, and with knowledge of 36-Cl production rates at depth, 36-Cl concentrations measured at 1-2 metres depth quantify elapsed time since the last earthquake. We can dig trenches to expose the fault plane to 1-2 metres depth and measure 36-Cl concentrations on the fault planes. If a neighboring earthquake has loaded/stressed a location with a high 36-Cl concentration, and hence a long elapsed time, we will be able to inform civil protection agencies responsible for planning mitigation; no such data are available at present. We can make such measurements, and have ongoing links with government civil protection project partners who make the seismic hazard maps for central Italy, and who are involved in communicating seismic hazard worldwide.

The biggest uncertainty in predictions of sea-level rise is what the contribution will be from the great ice sheets on Antarctica and Greenland as climate warms. The West Antarctic Ice Sheet and the Antarctic Peninsula Ice Sheet are the cause of greatest concern, as they are showing signs of significant ice loss and there are theoretical reasons for expecting them to be most vulnerable. Important sources of information for helping to predict how these ice sheets will change as climate warms are records of their response to past climate changes contained in sea bed sediments around Antarctica. Such records extend further back in time than ice cores from the ice sheets themselves. They can also show how the margins of the ice sheets interacted with changes in ocean temperature and circulation, which recent studies have identified as having an important influence on ice sheets. Although sedimentary records in the shallow seas close to Antarctica have been periodically disturbed or removed by past expansions of the ice sheets, there are places in the nearby deep ocean where sediments have accumulated continuously over millions of years. The international Integrated Ocean Drilling Program is considering a proposal to send a drilling ship to collect long sediment cores from some of these places. However, before this is done additional survey data are needed to find the sites that will provide the most continuous, detailed records and to make sure that it will be safe to drill those sites. In this research proposal we are seeking funding to collect this essential survey data. On the same expedition we also propose to collect short sediment cores for pilot studies to confirm that the analytical methods we intend to apply to the longer drill cores will provide reliable information about sediment ages, past climate and past ice sheet behaviour. One of the major difficulties in studying sediment records from the sea bed around Antarctica has been obtaining reliable ages from the sediments. This is because the types of microfossils that are analysed to determine sediment ages in drill cores from most of the world's oceans are rare or absent in many sediment cores collected near Antarctica. By carrying out detailed survey and studying short cores we hope to identify sites where there are sufficient numbers of these microfossils to apply the standard dating techniques. We also plan to test whether a new method of dating sediments that is based on analysis of their magnetic properties will work in the area of the proposed drill sites. It has recently been shown that in many places analysis of the magnetic properties of sea bed sediments can provide records of past changes in the intensity of the Earth's magnetic field, and comparison of these records to well-dated reference records allows ages to be assigned to sediments throughout a core. By comparing ages obtained using this method with ones obtained from microfossils, where they are present, we will be able to find out how well the magnetic dating method works in the study area. If the magnetic method works well, we will be able to establish detailed age models for drill cores without dependence on microfossils, which will greatly extend the area that can be studied by drilling and allow more detailed records of past changes to be derived from the drill cores.

Earthquake prediction, (where? how big? and when?) is currently not possible but recent, rapid developments in earthquake science have made progress on identification of regions of high seismic hazard on which mitigating actions and scarce resources can be focused. For many scientists, the goal of earthquake prediction has been superseded by the goal of targeted preparation of at-risk populations. Integrated earthquake science, much of it established and uncontested, has produced effective disaster risk reduction preparedness programmes which can be shown to work. In western Sumatra, for example, the city of Padang lies broadside on to the Mentawai Islands segment of the Sunda megathrust which has been shown to be advanced in its seismic cycle and nearing failure in a large earthquake. This event will likely generate a destructive tsunami and, without preparation, a death toll on the same scale as the 2004 Indian Ocean tsunami is thought possible. The population of the city have been the subject of intensive preparedness work based on the current insights from integrated earthquake and tsunami science. On 30 September 2009 an earthquake of magnitude 7.6 hit the city killing some 1200 people. Interestingly, this earthquake ruptured deep in the crust and did not cause any vertical movements of the seafloor and therefore did not generate a tsunami but no one in Padang knew this, it was perfect dry run for the expected earthquake. Later forensic studies of the response of Padang residents show that large numbers of people evacuated the city according to the evacuation plan and many lives would have been saved had the earthquake been tsunamigenic. Unfortunately in developing countries, where the risk to lives is highest, examples of excellent practice in utilising uncontested earthquake science are too rare, and thus avoidable loss of life to earthquakes and their associated hazards is too common. The 12 January 2010 Haiti earthquake is a case in point, here, despite several publications in international earthquake science journals warning of the impending threat of an earthquake of magnitude around 7, the population and NGO's working with them remained completely ignorant of the threat and more than 230000 people died when the earthquake (M=7.1) occurred. We aim to change this balance. In this project we will put together an international team of earthquake scientists, NGO actors and government agencies and develop a large consortium project aimed at the integration and demonstration of cutting-edge, hybrid methods in earthquake science in parallel with the development of partnerships and methodologies for dissemination, utilisation and contextualisation of the best methods for disaster risk reduction programming in developing countries. The consortium project will do cutting-edge applied science by taking the best of current methods from different earthquake science fields, all of which have been shown to work, and combine them to produce protocols to identify regions of highest earthquake hazard. We will then take examples of international best practice, like Padang, in preparedness and work with social scientists and end users in the NGO and government agencies to ensure that the lessons from these examples are learned on a global basis so that the at-risk populations can fully avail of the state-of-the-art earthquake science. To enable appropriate use of earthquake science, the consortium will identify the most effective forms of science policy dialogue and develop innovative approaches which best support the effective communication and application of earthquake science for ARCs. This science policy learning will be of enormous transferable value, enabling learning from across scientific fields concerning future vulnerability to directly inform and support at risk communities.