Andaman Islands and its mangroves still reeling from effects of 2004 tsunami

On December 26, 2004, the Andaman and Nicobar Islands changed forever. A tremor stirred 30 kilometres deep beneath the ocean floor in the Sunda trench off the coast of Sumatra, Indonesia. It reverberated into a deadly earthquake of 9.1 magnitude. Massive waves engulfed the entire archipelago. At least 250,000 people were severely affected. A tsunami, the result of this tremor, was witnessed across South and Southeast Asia, and even distant East Africa. Human and socio-economic losses were brutal. To this day, we are yet to understand the full impact of this tragic event on the Andaman archipelago.

The tsunami also impacted mangroves along the coast of the Islands. While initial reports recorded a 60%-70% loss of mangrove cover, detailed studies reported a 97% loss. Twenty years after the devastation, the archipelago and its mangroves are still reeling from the aftermath.

A study published in May 2024 monitored the long-term response of mangroves to the geomorphological changes left in the wake of the tsunami. North Andaman experienced coastal uplift (sea level drop or SLD) of approximately 1.3 metres, while South Andaman experienced coastal subsidence (sea level rise or SLR) of about 1.1 metres. Little to no changes were observed in Middle Andaman.

Mangrove species are changing slowly but surely in the...

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