Sea-level and land-level change in Southeast Asia: a geological approach to quantifying hazard from rising seas and earthquakes

Like many places around the world, Singapore faces a threat from sea-level rise; however, local projections for the anticipated amounts and rates of sea-level rise are poorly constrained, owing to a lack of high-quality data from the region. A separate but related problem is the potential earthquake hazard in Singapore: despite the commonly-held belief that Singapore does not have earthquakes, tectonic faults cut across the island, and the earthquake potential of those faults is not known. Both sea-level rise and the possibility of earthquakes and tectonic deformation are hazards that must be assessed and mitigated, and both lead to changes over time in relative sea level (RSL), the difference in elevation between the sea surface and land.

For those who aim to address questions of coastal tectonics, sea-level change, or the local isostatic response to the load of glacial meltwater, it is imperative to quantify the contribution of each of those processes to overall RSL change. An insufficient understanding of tectonic deformation can result in under-appreciation of the risk for coastal flooding, and insufficient constraints on RSL can allow us to overlook evidence for past tectonic deformation. Anticipating the future risk from both hazards requires geological observations that spatially and temporally constrain land deformation and sea-level change over thousands of years, and it requires modeling that will allow us to tease apart the signals of the various processes that drive RSL change. Until now, the few studies of RSL change near Singapore have been based on low-precision data and have simply assumed that the region is tectonically stable; none of these studies were capable of testing whether faults near Singapore were active recently.

I aim to improve our understanding both of RSL and of tectonic hazards in Southeast Asia foremost by improving the available RSL data. By choosing sites strategically, using high-quality proxy data, and collaborating with modelers, I will address both the sea level and potential earthquake problems facing the Singapore region.