There is a pressing need for a homogonous tsunami catalogue for the Indian Ocean as nearly 20 per cent of tsunami events worldwide affect the region. Any study on tsunami hazard assessment necessitates a homogenous tsunamigenic earthquake catalogue. The existing records of strong tsunamigenic earthquakes have the magnitudes expressed in Moment magnitude (M W ), Body wave magnitude (m b ), Local magnitude (M L ) and Surface wave magnitude (M S ). This study deals with developing regional magnitude correlation equations for tsunamigenic earthquakes of the Indian Ocean.The present investigation estimates the threshold magnitude and focal depth for an earthquake to turn tsunamigenic. It is found that earthquakes above M W ≥ 5.2 and focal depth ≤ 80 km have the potential to generate a tsunami in the region. Since the moment magnitude is the most scientific and reliable scale that describes earthquakes' physical size, equations have been developed to convert surface wave magnitude (M S ) to moment magnitude (M W ). Three types of regression models have been used, viz. Orthogonal Standard Regression (OSR), Standard Regression (SR) and Inverse Standard Regression (ISR). The efficacy of these models has been compared in terms of R-Squared and residual analysis. This study indicates that OSR (Orthogonal Standard Regression) is the best-suited regression model for developing magnitude correlation equations for the region. Magnitude conversion equations for three zones of the Indian Ocean have been created. Additionally, a single unified conversion equation for the whole of the Indian Ocean has also been derived with rational accuracy. Article Highlights The magnitude and focal depth ranges have been identified for the earthquakes to turn potentially tsunamigenic. Magnitude conversion equations have been developed for the Indian Ocean Region. Orthogonal standard regression has been identified as the best fitting regression model.

There is a pressing need for a homogonous tsunami catalogue for the Indian Ocean as nearly 20 per cent of tsunami events worldwide affect the region. Any study on tsunami hazard assessment necessitates a homogenous tsunamigenic earthquake catalogue. The existing records of strong tsunamigenic earthquakes have the magnitudes expressed in Moment magnitude (MW), Body wave magnitude (mb), Local magnitude (ML) and Surface wave magnitude (MS). This study deals with developing regional magnitude correlation equations for tsunamigenic earthquakes of the Indian Ocean. The present investigation estimates the threshold magnitude and focal depth for an earthquake to turn tsunamigenic. It is found that earthquakes above MW ≥ 5.2 and focal depth ≤ 80 km have the potential to generate a tsunami in the region. Since the moment magnitude is the most scientific and reliable scale that describes earthquakes' physical size, equations have been developed to convert surface wave magnitude (MS) to moment magnitude (MW). Three types of regression models have been used, viz. Orthogonal Standard Regression (OSR), Standard Regression (SR) and Inverse Standard Regression (ISR). The efficacy of these models has been compared in terms of R-Squared and residual analysis. This study indicates that OSR (Orthogonal Standard Regression) is the best-suited regression model for developing magnitude correlation equations for the region. Magnitude conversion equations for three zones of the Indian Ocean have been created. Additionally, a single unified conversion equation for the whole of the Indian Ocean has also been derived with rational accuracy.

<p>The Pacific Ring of Fire, stretching over 15 countries, is one of the earth's most Tsunami-prone regions. 80 Percent of the Tsunami Occurrences could be directly or indirectly associated with this region. This study deals with the development of Conditional Probability and Total Probability based approaches for estimating the probability of Tsunami Occurrence in the study area. This study suggests ten regions with a high probability of tsunami occurrence in the region. The prediction results are validated by computing the occurrence probabilities of the known tsunami events in the region. The study reveals that East Asian Countries like Japan, North and South Korea and Parts of China have a probability, more than 75 per cent, of experiencing a strong tsunami (Mw > 7.5) in the next three years from now. Also, certain South American countries like Peru, Chile and Ecuador, Southeast Asian Counties like Indonesia and South Pacific Countries like Papua New Guinea, Australia, and the Solomon Islands have a high probability of tsunami occurrence (90 Percent and above) in the next five years.  Based on this methodology, it has been possible to predict the Indonesian Tsunami of December 14th, 2021, with a probability of 83 Percent.</p>

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