Statement I : The Indian Ocean Tsunami of 2004 occurred along a subduction zone along west coast of Sumatra Statement I : Along the Sumatra coast the Indo-Australian Plate converges below the Eurasian Plate

Statement I is true as the 2004 Indian Ocean Tsunami was caused by a megathrust earthquake (magnitude 9.0-9.3) with its epicenter near the western boundary of Sumatra [3]. This event occurred along the Sunda Trench, a major subduction zone [1]. Statement II is also true and provides the correct explanation: the earthquake was triggered by the subduction of the Indo-Australian Plate beneath the Eurasian Plate (specifically the Burma and Sunda microplates) [1]. This convergence causes the denser oceanic plate to plunge beneath the less dense plate, leading to stress accumulation [2]. The abrupt release of this stress during the 2004 event caused a vertical displacement of the seabed, which pushed the water column upward and generated the devastating tsunami waves [2].

Sources

1. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 15: Tsunami > Disturbance > p. 191
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 15: Tsunami > 15.3. 2004 Indian Ocean Tsunami > p. 193
3. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 8: Convergent Boundary > Formation of The Indonesian Archipelago > p. 112