Development of Tsunami Mode Algorithm for Tsunami Coastal Acoustic Tomography

Tsunami Coastal Acoustic Tomography or TCAT operates in 2 modes of observation, namely normal mode, and tsunami mode. The normal mode has an interval recording of 10 minutes and the tsunami mode has an internal recording of 30 seconds. TCAT’s system requires input parameters in order to shift into tsunami mode. In tsunami mode, the TCAT system data acquisition is more frequent and it is expected to record the changes of flow velocity in more detail. Parameter input is derived from external or internal sources. The external data is collected from earthquake data, whereas the internal data are observation data. The earthquake data provide some information, namely information of epicenter, magnitude, and depth. This data can be derived into several parameters such as distance into the sensor, location of the events. Algorithmically, the system will turn a tsunami mode if the equation parameters result from more than or equal to 6.5 MW as the earthquake magnitude threshold, the depth is under 100 km, the distance from the sensor is within 150 km, and the earthquake epicenter located at the sea. Internal factors are based on the anomaly of a sudden change in travel time difference higher than the normal condition with the limitation of more than 34s deviation. The algorithm is running well enough and able to switch the tomographic observation mode from the normal mode in the tsunami mode. It still needed an improvisation to increase the execution time and some improvements for the algorithmic calculations.