The Department of Geography is delighted to announce the latest in its lecture series from current members of staff, showcasing some of the exciting research that is happening within the department.

Subduction zones are the source of the largest earthquakes on Earth and commonly produce high tsunami that devastate coastal environments and populations. The instrumental record provides accurate information on parameters such as magnitude and shaking intensity, with additional lower resolution data often available via historical records. However, the instrumental and historical records are almost always too short, typically less than a hundred years, to provide useful information on recurrence intervals or to answer questions on variability in magnitude between events, including the existence of patterns or cycles. One solution to this is to develop reconstructions of past earthquake and tsunami from geological records that can extend the record to millennial timescales. The importance of such palaeoseismic records has been highlighted in recent years by unexpected M8.5+ subduction zones earthquakes in places where hazards was previously underestimated. As such, palaeoseismic records that span beyond the instrumental/historical era remain the best way to quantify variations in the size of past earthquakes and to assess the variability of recurrence intervals. Earthquake-induced changes in land-level at coastal locations can be measured using sedimentary or coral archives that record changes in environment due to subsidence or uplift and from deep sea and lake records that retain evidence of high intensity shaking. Tsunami can be reconstructed from the deposition of anomalous sand sheets in typically low energy, fine grained environments.

In this talk, I will provide the background to using geological archives to document pre-instrumental/historical earthquakes at global subduction zones. Building from this introduction, I will then discuss how work that has been ongoing in the Geography department at Durham since the early 1990s has improved our understanding of subduction zone earthquakes along the west coast of the United States and Canada at the Cascadia and Alaska-Aleutian subduction zones.

Please register by clicking on the 'booking tab' above.

Previous talks can be downloaded from our website https://www.durham.ac.uk/departments/academic/geography/alumni/alumni-lecture-series/