Indonesia is arguably the most geomorphologically diverse and expansive archipelago in thernworld, consisting of more than 17,500 islands, 6,000 of which are inhabited. It straddles thernequator and extends almost 5,000 km eastwards from Sabang in northern Sumatra (5°38’ N,rn94°44’ E) to the West Papua–Papua New Guinea border (141°37’ E) and for 1,770 km southwards to Roti off West T…