Mount Sidley

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title: "Mount Sidley" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["volcanic-seven-summits", "polygenetic-shield-volcanoes", "calderas-of-antarctica", "volcanoes-of-marie-byrd-land", "four-thousanders-of-antarctica", "executive-committee-range", "pliocene-shield-volcanoes", "shield-volcanoes-of-antarctica", "ultra-prominent-peaks-of-antartica"] description: "Volcano in Antarctica" topic_path: "general/volcanic-seven-summits" source: "https://en.wikipedia.org/wiki/Mount_Sidley" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Volcano in Antarctica ::

::data[format=table title="Infobox mountain"]

Field	Value
name	Mount Sidley
photo	MountSidleyCaldera.jpg
photo_caption	Aerial view of the Mount Sidley caldera from the southwest
elevation_m	4285
elevation_ref
prominence_m	2517
prominence_ref
listing	Volcanic Seven Summits
Ultra
location	Marie Byrd Land, Antarctica
range	Executive Committee Range
map	Antarctica
map_caption	Antarctica
coordinates
coordinates_ref
type	Shield volcano
volcanic_field	Marie Byrd Land Volcanic Province
first_ascent	1990 by Bill Atkinson (New Zealand)
::

| name = Mount Sidley | photo = MountSidleyCaldera.jpg | photo_caption = Aerial view of the Mount Sidley caldera from the southwest | elevation_m = 4285 | elevation_ref = | prominence_m = 2517 | prominence_ref = | listing = Volcanic Seven Summits Ultra | location = Marie Byrd Land, Antarctica | range = Executive Committee Range | map = Antarctica | map_caption = Antarctica | coordinates = | coordinates_ref = | topo = | type = Shield volcano | volcanic_field = Marie Byrd Land Volcanic Province | age = | last_eruption = | first_ascent = 1990 by Bill Atkinson (New Zealand) | easiest_route =

Mount Sidley is the highest dormant volcano in Antarctica, and a member of the Volcanic Seven Summits (the highest volcanoes on each of the seven continents) with a summit elevation of 4181 -. It is a massive, mainly snow-covered shield volcano, and the highest of the five volcanoes that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a 5 km caldera on the southern side and stands northeast of Mount Waesche in the southern part of the range.

History

The mountain was discovered by Rear Admiral Richard E. Byrd on an airplane flight, on November 18, 1934, and named by him for Mabelle E. Sidley, the daughter of William Horlick who was a contributor to the 1933–1935 Byrd Antarctic Expedition. Despite its height, the volcano's extremely remote location means that it is little known even in the mountaineering world compared to the much more accessible Mount Erebus, the second-highest Antarctic volcano which is located near the U.S. and New Zealand bases on Ross Island.

The first recorded ascent of Mount Sidley was by New Zealander Bill Atkinson on January 11, 1990, whilst working in support of a United States Antarctic Program scientific field party.

::figure[src="https://upload.wikimedia.org/wikipedia/commons/8/8e/MountSidleyWaescheMap.jpg" caption="Topographic map of Mounts Sidley and Waesche (1:250,000 scale)"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/b/b5/Sidley_oli_2014324_lrg.jpg" caption="Landsat 8 image of Mount Sidley and the Executive Committee Range"] ::

Notes

References

References

1. . The map above showed the elevation as {{cvt. 4181. m. ft. 0.
2. "Antarctica Ultra-Prominent Summits". peaklist.org.
3. (September 1997). "Petrogenesis of a Phonolite-Trachyte Succession at Mount Sidley, Marie Byrd Land, Antarctica". Journal of Petrology.
4. {{cite gnis
5. Gildea, Damien. (2015). "Mountaineering in Antarctica: complete guide: Travel guide". Primento.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::