Understanding that long-term sea-level variability is the key to recognizing future variability, a Research Grant awarded in 2014 to a team led by Dr Pradeep Nalaka Ranasinghe of Department of Oceanography & Marine Geology, University of Ruhuna was successfully completed in 2018 contributing to the development of a long sea-level record for the Central Indian Ocean and to identify forcing mechanisms.
Warming of the atmosphere due to greenhouse gases and melting of polar ice is causing a significant rise in the sea-level. Reconstructions of sea level history in the Central Indian Ocean do not run beyond Holocene due to lack of long-term records. Further, available sea-level history for the Central Indian Ocean runs into doubts due to inconsistency of available records for the Holocene.
There have been several unresolved issues on Holocene reconstructions of the region. Accordingly, this study was carried out with the objective of finding solutions to the said unresolved scientific problems as it would explain the impacts of global anthropogenic sea level rise to the coastline of Sri Lanka as well as South India.
According to the results, three phases of island formation during the Miocene, Pleistocene, and Holocene could be recognized in the Palk Strait area. Changes in sea level have resulted in these island formations. It was recognized that future anthropogenic sea level rise could submerge a large area of coastal lowlands in the South and in the Jaffna peninsula. This study also glimpsed the coastal landscape changes at the anthropogenic sea-level rise. According to the gathered data, coastal lowlands including Jaffna peninsula will be at risk with the rising sea level. This information can be used for urban planning and coastal zone management as modeling the coastal areas with accurate levelling data is essential to predict flooding areas at different levels of sea level rise in future.