Ngga Pulu is a peak in the western part of the island of New Guinea rising 4862 meters (15,951 ft.). Trigonometric measurements showed that Ngga Pulu was (and had been for many centuries before) the highest mountain of New Guinea and also the highest summit of the Australia/Oceania continent. The altitude of Ngga Pulu in 1936 about 4907m/16100’, and it was the highest and most prominent peak between Himalaya and the Andes. But due to glacial melting, Ngga Pulu lost a lot of altitude in the 20th century.
Loss of Altitude and Ice:
All prominence key cols in the inner Castensz area were entirely ice-covered, so Carstensz Pyramid, at this time was a just a sub-peak of Ngga Pulu with around 200m/656’ of prominence. But due to glacial melting, Ngga Pulu lost a lot of altitude in the mid-20th century. The Australian scientific expeditions of 1971-73 measured Ngga Pulu at 4862m/15951’, and the ice melting in the key col resulted in a prominence of around 300m/1000’. By the year 2000 all New Guinea glaciers outside the Carstensz area had disappeared. Inside the Castensz area, a former sub-peak, the now rocky summit of Sumantri, is now some meters higher than the still ice covered Ngga Pulu.
So now Ngga Pulu has less than 100m/328’ of prominence as a sub-peak of Sumantri (4870m /15,978’), which itself has a prominence around 350 m/1149’. The glacial melting has produced significant altitude changes for prominence key cols in the inner Carstensz area and it is also quite probable that other former big ice-capped peaks in New Guinea lost various meters in altitude, such as Puncak Mandala, East Carstensz Top, and Ngga Pilimsit. Scientists are monitoring this warming and estimate that by about 2020-2030 all New Guinea glaciers may disappear.