ANAK KRAKATAU VOLCANO EMERGENCY TSUNAMI EARLY WARNING SYSTEM

Abstract

On 22 Dec 2018 13:56 UTC a tsunami was generated from the area of the Anak Krakatau Volcano, with waves propagating in all directions inside the Sunda Strait - the sea portion between the islands of Java and Sumatra. The cause of this event seems to have a correlation with the ongoing volcanic eruption, which was particularly active since June 2018 [4]. At the time of the event, the Tsunami Early Warning System currently implemented in Indonesia, could not be used because there was no mechanism to activate the system on the basis of sea levels measurements or other information from the volcano activities. Given the situation, the Indonesian authorities decided to implement an Emergency Early Warning System that can timely inform if any sea level disturbance represents a tsunami from volcano activities and therefore be able to activate the warning sirens. The Joint Research Centre (JRC), in collaboration with the Indonesian Tsunami Society, the Marine Research Centre of the Ministry of Marine Affairs and Fisheries and the Meteorological, Climatological and Geophysical Agency of Indonesia (BMKG) worked together since the event in December in order to design and implement the new Emergency System. The new system will adopt the real time fast Tsunami instruments (Inexpensive Device for Sea Level Monitoring or IDSL), developed by JRC [ 1], to monitor in real time on a 24/7 the sea level and provide email, SMS alerts, CCTV images and inform about a potential event. The activation of the sirens in the area can be performed after human verification of the signals. The first two devices wereinstalled at the end of January 2018; other devices will be provided and installed in the near future. The present report illustrates the basic principle of the Early Warning System and reports about the first two months of operational activity since the new devices were installed.