Mount Sidley

{{Short description|Volcano in Antarctica}}

{{Infobox mountain

| name = Mount Sidley

| photo = MountSidleyCaldera.jpg

| photo_caption = Aerial view of the Mount Sidley caldera from the southwest

| elevation_m = 4285

| elevation_ref = . The map above showed the elevation as {{cvt|4181|m|ft|0}}.

| prominence_m = 2517

| prominence_ref = {{cite web |url=http://www.peaklist.org/WWlists/ultras/antarctica.html |title=Antarctica Ultra-Prominent Summits |publisher=peaklist.org |access-date=2013-12-24 |archive-date=2018-09-08 |archive-url=https://web.archive.org/web/20180908031353/http://www.peaklist.org/WWlists/ultras/antarctica.html |url-status=live }}

| listing = Volcanic Seven Summits, Ultra, Ribu

| location = Marie Byrd Land, Antarctica

| range = Executive Committee Range

| map = Antarctica

| map_caption = Antarctica

| coordinates = {{coord|77.04|S|126.10|W|type:mountain_scale:100000|display=inline,title}}

| 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, a member of the Volcanic Seven Summits, the highest volcanoes on each of the seven continents, with a summit elevation of {{convert|4181|-|4285|m|ft|0}}. It is a massive, mainly snow-covered shield volcano, which is the highest of the five volcanoes that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a {{Convert|5|km|4=-wide|adj=mid}} caldera{{cite journal |author1-first=Kurt S. |author1-last=Panter |author2-first=Philip R. |author2-last=Kyle |author3-first=John L. |author3-last=Smellie |date=September 1997 |title=Petrogenesis of a Phonolite-Trachyte Succession at Mount Sidley, Marie Byrd Land, Antarctica |journal=Journal of Petrology |volume=38 |issue=9 |pages=1225–1253 |doi=10.1093/petroj/38.9.1225 |issn=0022-3530}} on the southern side and stands northeast of Mount Waesche in the southern part of the range.

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.{{cite gnis |type=antarid |id=13802 |name=Mount Sidley |access-date=2013-12-24}} 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.{{cite book |title=Mountaineering in Antarctica: complete guide: Travel guide |url=https://books.google.com/books?id=TrHtBgAAQBAJ&q=Bill+Atkinson+Sidley&pg=PT251 |first=Damien |last=Gildea |publisher=Primento |year=2015 |isbn=9782511031346}}

File:MountSidleyWaescheMap.jpg

File:Sidley oli 2014324 lrg.jpg