inversion of focal mechanism solutions along nine subsectors (I-IX) reveals a relatively complex stress pattern. The Andaman-Sumatra-Sunda subducting lithosphere experiences nearly NNE trend. The average orientation of stress remains incomparable in both before and after the mega event, having been induced by the mega event. Compressive stress orientation before the mega event in nine sub-sectors had gone through significant change in orientation after the event. The result suggests that the stresses rotated due to co-seismic activity and post-seismic deformation. Dominance of thrust faulting in subsectors I, II and III indicates the orientation of compressive axis along NE-SW direction. The stress states reveal a NE-SW trending compression that affects all the broad sectors and subsectors creating E-W trending compression in southern part of the rupture. We then compare the sector wise reconstructed stress regime with the available information about geodetically determined displacement. Depth vs. Dip angle relation indicates successive increase in the depth of flexing of subducting slab along the subsectors. It is revalidated that NE-SW shortening refers to arc-parallel shortening in the slab which is normal to the trench in the fore-arc. The aftershocks caused by the main shock changed the stress distribution in the crust and subducting slab which came up as a regional stress change along rupture area. The thermal contrast between Asian landmass and southern Indian Ocean drives seasonally reversing Indian monsoon which is one of the most spectacular features on Earth. During summer (June-August), the warmer land mass drives wet and strong southwest (SW) monsoon winds, whereas during winter (December-February) the winds are northeasterly (NE monsoon) dry and variable. The summer and winter monsoon winds impact several parts of the Indian Ocean and its surrounding regions, driving important changes in ocean productivity and land vegetation. The Indian monsoon constitutes a critical resource for the region's largely agrarian economies, as almost two third of India's food production depends on summer rains, so are the rivers that cater to the domestic needs of the Himalayan and adjoining regions. The Indian monsoon has varied on orbital and suborbital time scales. While long term changes in the Indian monsoon have been linked to the phased uplift of the Himalaya-Tibetan plateau superimposed by orbital changes, small scale, rapid changes as documented in late Quaternary and Holocene proxy records from marine sequences, speleothems, peat deposits, runoff in the Bay of Bengal, and fluvial sediments have been related to boundary conditions including Himalayan-Tibetan snow, North Atlantic variability, Eurasian temperatures, tropical sea surface temperatures, solar activity, vegetation changes, and linkages with the El Nino Southern Oscillation, Indian Ocean Dipole or North Atlantic Oscillations. The late Quaternary and Holocene records of the monsoon from the Arabian Sea indicate presence of North Atlantic events including Bond, Dansgaard-Oeschger (DO) and Heinrich events, indicating that North Atlantic variability brings pronounced changes in the Indian monsoon on millennial time scales.