People-Centered Tsunami early Warning for the INdian coastlines (PCTWIN)

The United Nations has called for every person on earth to be covered by warning systems. Tsunami events are responsible for greatest of losses compared to other more frequent hazards. The Indian coastlines, which are some of the most populated areas in the world, are prone to tsunamis generated from subduction zones such as Makran, the northern part of the Sunda trench and submarine landslides. The arrival time for these events could range between 15 minutes for the Andaman Nicobar Islands to 2-3 hours for the mainland. This is a time scale where effective warning and being prepared to act can save many lives. The Indian Tsunami Early Warning Centre (ITEWC) is an official tsunami service provider for 25 countries along the Indian Ocean Coasts. Through achieving improvements to the practical and operational capacities of ITEWC, grounded in local participation, PCTWIN takes concrete steps towards ensuring communities are more disaster resilient.

The objectives of PCTWIN are aligned with the pillars of people-centred early warning: improving disaster risk knowledge; improved detection, observation, and forecasting of tsunamis; more effective and more inclusive tsunami warning communication; increased preparedness.

Knowledge of the physics of tsunamigenic sources provides invaluable insights into the expected features and frequency of future large megathrust earthquakes. PCTWIN will use the GNSS stations in the Sumatra-Andaman region to tackle fundamental questions regarding post seismic deformation and strain accumulation 20 years after the great 2004 Sumatra Earthquake.

Non-seismic and atypical tsunami sources have been responsible for deadly, near-source, tsunamis that have left no time for the affected populations to safely evacuate. Examples are the 2018 Sulawesi and Sunda Strait Tsunamis. PCTWIN pushes boundaries of frontier research by comprehensive characterization of tsunamigenic submarine landslide sources. This will pave the way for tsunami forecasting to include the landslide sources.

There are several operational and technical challenges related to tsunami forecasting and early warning, such as high uncertainties in early source characterizations, gaps related to timely assimilation and post-processing of data, and effective communication of uncertainties. PCTWIN promotes a paradigm shift, from deterministic to probabilistic tsunami forecasting with flexible scenario building for the next generation of Indian tsunami early warning system. This entails co-design of communication of uncertainties in warnings and uncertainty reduction through real-time multi-channel data assimilation, especially through implementation of geodetic data for fast source characterization within 5 minutes. PCTWIN strives to forecast not only the hazard but also the impact, at different scales, from lower resolution national scale to higher resolution local scale at selected hotspots as pilot sites for the future.

For near-source tsunamis with short arrival times, preparedness and readiness to act can save many lives. Situational awareness and risk perception gaps, especially related to inclusion of vulnerable groups, are serious barriers towards community resilience to tsunamis. PCTWIN embraces inclusive, local, and participatory methods for increasing the preparedness of the communities at tsunami risk. This is facilitated by synergies with UNESCO initiatives in the Indian Ocean region such as the Tsunami Ready Recognition Program. PCTWIN complements the Tsunami ready preparedness indicators by introducing markers measuring the inclusivity of the tsunami response plans devised by the local communities and engagement of the private sector.

Striving to render tsunami readiness accessible to all communities at risk, PCTWIN will co-design and co-develop best practice guidelines for making communities tsunami ready and tsunami resilient.