Research Seminar: Multi-proxy approaches toward a long view of past coastal disasters

Risk assessments for coastal hazards such as sea level rise, tsunamis or storm surges are often based on short-term instrumental records that in many cases fail to reflect the full range or magnitude of possible events. The global growth of human populations in many hazard-prone coastal areas mean accurately assessing natural hazard risk is increasingly important globally. To date, most risk assessments do not incorporate long-term and/or prehistoric records of extreme events and coastal development continues to rely on short historical records as a reflection of the long-term behaviour of a hazard. In some locations such as southern Europe, China, Japan or the Philippines, historical records may be appropriate as consistent records have been kept for several centuries or longer. However, for much of the world, the historical archives rarely stretch beyond World War II. Clearly, such short records are inadequate for determining the natural variability of a hazard at multi-decadal timescales and for the extrapolation of extreme events. Without integrated long-term records, we cannot make realistic assessments of coastal vulnerability and exposure, and in fact, we might even increase the likelihood of providing an erroneous estimate of the risk of that hazard. The ability to safeguard communities and reduce future economic losses is dependent upon our understanding of each hazard. Long-term records present the only option for uncovering the frequency and spatial variability of natural hazards over time. It is well known that historical records are usually fragmented, incomplete and limited in spatial balance. However, despite these limitations, historical records provide a key link between instrumental datasets and the prehistoric records for detailed reconstruction of past events. The integration of non-instrumental datasets such as archaeological, indigenous and geological records is a rapidly advancing discipline that is based on a variety of data including structured approaches to historical datasets, sedimentary techniques applied to coastal sequences and emerging techniques such as speleothem and tree ring geochemistry. In this presentation I highlight some past work on known events and examine the potential for new techniques and proxies. I conclude with some statements on future research directions for coastal hazard studies with the aim of preparing coastal populations for future events. The utility of the integrated approach must become familiar to those outside of academia, as familiarity breeds awareness and it is through awareness and adoption that the true potential of integrating across disciplines will be recognized.

Poster