East Northwall Firn
{{Short description|Glacier in Indonesia}}
{{Infobox glacier
| name = East Northwall Firn
| photo = GrasbergMine ISS011-E-9620.jpg
| photo_caption = The East Northwall Firn is below the word "glaciers" in this 2005 image. The circular depression to the left is the Grasberg mine, the world's largest gold mine.
| type = Mountain glacier
| location = Puncak Jaya, Sudirman Range, Central Papua province, Indonesia
| coords = {{coord|04|03|54.82|S|137|10|49.87|E|type:glacier}}
| area = {{convert|0.11|km2|abbr=on}} in November 2024measurement of glaciers on [https://apps.sentinel-hub.com/eo-browser/?zoom=16&lat=-4.06612&lng=137.18444&themeId=DEFAULT-THEME&visualizationUrl=U2FsdGVkX19IWrUi8mqtpEH%2Fpl1MefMAOQzBFRWtim3Jgnuk%2F8l0FgvGrpzrbpNCosFT%2Fr8UYYGYfKsUOIGX3IbDOktNciyqYOO0AyWRn%2F3VgOur8v8eX5ha1vDkXNjQ&datasetId=S2L1C&fromTime=2024-11-18T00%3A00%3A00.000Z&toTime=2024-11-18T23%3A59%3A59.999Z&layerId=1_TRUE_COLOR&demSource3D=%22MAPZEN%22 satellite view from November 18, 2024]
| length = {{convert|406|m|abbr=on}} for the central patch
| thickness =
| terminus = Rockfall
| status = Retreating
| map = New Guinea#Indonesia
| label_position = top
| map_caption =
| embedded = {{Infobox mapframe |wikidata=yes |zoom=14|coord={{WikidataCoord|display=i}}}}
}}
The East Northwall Firn was a glacier on Mount Carstensz in the Sudirman Range on the island of New Guinea in Central Papua province, Indonesia. Situated at an elevation of approximately {{convert|4750|m}} {{convert|2.5|km}} NNW of Puncak Jaya, the highest summit in Oceania. It broke up in three patches in or before 2017.Kathryn Hansen, [https://earthobservatory.nasa.gov/images/91716/glaciers-in-the-tropics-but-not-for-long Glaciers in the Tropics, but Not for Long], at NASA Earth Observatory, February 13, 2018
File:Puncak Jaya icecap 1936.jpg region icecap in 1936.]]File:Puncak Jaya icecap 1972.jpg, and Carstensz Glacier. The first and third have now disappeared. See also animation.]]
Sometime between 1936 and 1962, a single Northwall Firn split into several separate glaciers, the largest being the East Northwall Firn and the West 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 East Northwall Firn had lost a further 4.5% of its surface area.{{cite web|last=Kincaid|first=Joni L.|title=Retreat of the Irian Jaya Glaciers from 2000 to 2002|url=http://www.easternsnow.org/proceedings/2004/kincaid_and_klein.pdf#search='meren%20glacier'|work=61st Eastern Snow Conference|accessdate=2011-11-03|author2=Andrew G Klein|pages=147–157|format=pdf|year=2004|archive-date=2017-05-17|archive-url=https://web.archive.org/web/20170517095529/http://www.easternsnow.org/proceedings/2004/kincaid_and_klein.pdf#search='meren%20glacier'|url-status=dead}} An expedition to the remaining glaciers on Puncak Jaya in 2010 discovered that the ice on the glaciers there is about {{convert|32|m}} thick and thinning at a rate of {{convert|7|m}} annually. At that rate, the remaining glaciers in the immediate region near Puncak Jaya were expected to last only to the year 2015.{{cite news|last=McDowell|first=Robin|title=Indonesia’s Last Glacier Will Melt ‘Within Years’|url=http://www.thejakartaglobe.com/home/indonesias-last-glacier-will-melt-within-years/383607|accessdate=2011-11-03|newspaper=Jakarta Globe|date=July 1, 2010}}{{cite news|title=Papua Glacier’s Secrets Dripping Away: Scientists|url=http://www.thejakartaglobe.com/news/papua-glaciers-secrets-dripping-away-scientists/383881|accessdate=2011-11-03|newspaper=Jakarta Globe|date=July 2, 2010}} Indeed, in or before 2017, the West Northwall Firn had completely disappeared and the eastern Firn had broken up in three small patches.
The East Northwall Firn glaciers are remnants of an icecap that in 1850 measured about {{convert|20|km2|abbr=on}} and had developed approximately 5,000 years ago. At least one previous icecap also existed in the region between 15,000 and 7,000 years ago.