Details of Award
NERC Reference : NE/I00503X/1
Sediment signatures of the 2010 Chile Mw 8.8 earthquake
Grant Award
- Principal Investigator:
- Professor I Shennan, Durham University, Geography
- Co-Investigator:
- Dr SA Woodroffe, Durham University, Geography
- Grant held at:
- Durham University, Geography
- Science Area:
- Terrestrial
- Marine
- Overall Classification:
- Terrestrial
- ENRIs:
- Environmental Risks and Hazards
- Science Topics:
- Land - Ocean Interactions
- Geohazards
- Abstract:
- Great earthquakes (Magnitude 8 and above) and related tsunami, generated where the Earth's tectonic plates collide, produce major hazards for both the earthquake area and heavily populated coastlines across much of the adjacent ocean. On 27th February 2010, a Mw 8.8 earthquake struck central Chile. This is the 5th or 6th largest earthquake ever recorded and resulted in over 500 deaths, with 500,000 homes significantly damaged and initial estimates of the financial cost ranging from $15bn to $30bn. We seek urgency funding to make a rapid field assessment of the sedimentary record of land uplift and subsidence at the coast. We shall collect sediments deposited by the tsunami and those deposited later by daily tides. Laboratory analyses of these sediments will provide, for the first time, the modern equivalent of geological records used to investigate the long-term record of these large earthquakes, not just in Chile but coasts in similar tectonic settings, e.g. Alaska, Washington, Oregon, British Columbia, Japan, Indonesia and Tonga. Evaluating future earthquake and tsunami risk around the Pacific and Indian Oceans requires knowing how frequently great earthquakes occur, at what intervals and how the patterns of land movement vary in different events. We can only obtain the long term patterns from the geological investigations of sediments accumulating of the last 5000 years. Land and sea-level motions, as well as coastal sedimentation (and restoration / reconstruction efforts) mean that field observations from the immediate post earthquake event are critical to our palaeoseismic reconstructions. This has been recently shown in the contemporary sampling that followed the Indian Ocean tsunami but this took place in a markedly different coastal and climate regime to that in Chile. Analysis of the sediments from Chile will help us to validate methods used and applicable to all these other areas. The results will help validate methods to (1) estimate the amount of uplift and subsidence in previous earthquakes over the past few thousand years in these areas; (2) determine the area affected by uplift or subsidence in each great earthquake, and (3) determine whether similar sized areas rupture each time, or can we have even greater earthquakes when two adjacent parts of the tectonic plate boundaries rupture at the same time. There are three key reasons for urgency. First, as restoration takes place in Chile we expect to see the loss of pristine sediments as farmland is recovered and grazing resumes on intertidal salt marshes. Second, sediment traces of medium sized tsunami are often ephemeral, where the run-up extends into the supratidal zone. Heavy rainfall, which is common in this area of Chile, will likely destroy sedimentary evidence of the tsunami within a few months. Third, sites at the southern end of the rupture will potentially preserve the overlap, mixing or separation of evidence of the 1960 Chile earthquake (Magnitude 9.5, the largest ever recorded by instrumentation) as these sites lie in the area potentially recording two earthquakes 50 yr apart. This will provide unique sedimentary evidence for testing methods and models for separating multi-segment from single-segment great earthquakes preserved in the sedimentary record for the last few thousand years. This is a critical debate in assessing earthquake hazard, tsunami generation and the long-term development of the boundaries where tectonic plates collide.
- NERC Reference:
- NE/I00503X/1
- Grant Stage:
- Completed
- Scheme:
- Small Grants (FEC)
- Grant Status:
- Closed
- Programme:
- Urgency
This grant award has a total value of £51,729
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Investigators | DA - Estate Costs | DI - Staff | DI - T&S |
|---|---|---|---|---|---|
| £4,849 | £19,399 | £6,025 | £2,495 | £11,853 | £7,106 |
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