The West Northwall Firn is a glacial body near the peak of Puncak Jaya (sometimes called Mount Carstensz or the Carstensz Pyramid) which is a mountain in the Sudirman Range, western central highlands of Papua province, Indonesia. The glacier is situated at an elevation of approximately and is north of the summit tower of Puncak Jaya.The Northwall Firn split into several separate glaciers since 1936, the largest two remnants being the West Northwall Firm and the East Northwall Firn. Research presented in 2004 of IKONOS satellite imagery of the New Guinean glaciers indicated that in the two years from 2000 to 2002, the West Northwall Firn had lost a further 19.4% of its surface area. An expedition to the remaining glaciers on Puncak Jaya in 2010 discovered that the ice on the glaciers there is about thick and thinning at a rate of annually. At that rate, the remaining glaciers in the immediate region near Puncak Jaya are expected to last only to the year 2015.The West Northwall Firn is a remnant glacier that was once part of an icecap that developed approximately 5,000 years ago. At least one previous icecap also existed in the region between 15,000 and 7,000 years ago, when it also apparently melted away and disappeared.