Antarctica: Regional Map and Introduction
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The southernmost section in the Pacific Ring of Fire is the continent of Antarctica. Although most people
know of only one volcano in this region, the famed Mount Erebus, there
are many large and spectacular volcanoes in Antarctica including one, Mount
Sidley, which is even higher than Erebus. The character and composition of the volcanoes of Antarctica
differ greatly from the rest of the Ring. Most of the Pacific Ocean is surrounded by subduction zones
where oceanic crust is being overridden by continental crust (or occasionally by other oceanic crust), thus
producing classic arc volcanism with its characteristic chains of stratovolcanoes. In contrast, the
Antarctic Plate is nearly completely surrounded by extensional zones, with spreading along the several
mid-ocean ridges which encircle it, and subduction is limited to a tiny section along the tip of the
Antarctic Peninsula (at the South Shetland Islands) and reaching eastward to the remote South Sandwich
Islands. Subduction zones produce viscous high-silica magmas (from the calc-alkaline sequence) which cause
explosive eruptions and tend to build mainly stratovolcanoes, while extensional zones and associated
intraplate volcanoes along rifts tend to produce alkaline magmas which are more fluid, resulting in a
majority of shield volcanoes. The alkaline magmas which also have a high silica content can produce
steeper stratovolcanic forms (for example, Mount Erebus).
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| Victoria Land and Ross Island
# The volcanoes of the Victoria Land region (longitude 150-175° E) are the best known in Antarctica, mainly because they are the most accessible. The major American base in Antarctica is located on Ross Island, just off the coast of southern Victoria Land at the edge of the vast Ross Ice Shelf. Much of Victoria Land is mountainous, forming the eastern part of the Transantarctic Mountains, and there are numerous scattered volcanoes including Mounts Overlord and Melbourne in the northern part. Farther south are two more prominent volcanoes, Mounts Discovery and Morning, which are on the coast across from Mounts Erebus and Terror on Ross Island. The volcanism of this region is caused by rifting along a number of rift zones extending mainly north-south parallel to the coast. |
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| Marie Byrd Land
# Marie Byrd Land (roughly longitude 100-150° W) contains the largest volcanic region in Antarctica, covering a length of almost 600 miles (960 km) along the Pacific coast. The volcanism is caused by rifting along the massive West Antarctic Rift, which stretches from the base of the Antarctic Peninsula to the vicinity of Ross Island, and the volcanoes are located along the northern edge of the rift. The West Antarctic Ice Sheet covers most of the region, with a thickness exceeding 2 miles (3000 m) in several areas. Protruding up through the ice are more than a dozen major shield volcanoes, including Mount Sidley, the highest volcano in Antarctica. Although several of the volcanoes are relatively young and possibly still active (Mounts Berlin, Takahe, Waesche, and Siple), others such as Mounts Andrus and Hampton are over 10 million years old, yet retain uneroded constructional forms. The desert-like environment of the Antarctic interior, along with a very thick and stable ice sheet which surrounds and protects the bases of the volcanoes, reduces the rate of erosion by a factor of perhaps a thousand relative to volcanoes in moist temperate or tropical climates. Marie Byrd Land is a very inaccessible region even by Antarctic standards, for there are no permanent bases closer than a few hundred miles. Several of these volcanoes are almost certainly unskied (and possibly even unclimbed), having been visited only once or a few times by volcanologists. Probably the only reasonable way to reach these areas for skiing or mountaineering is by flying with Adventure Network International, the largest private operator of aircraft in Antarctica. |
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  Select a mountain from the clickable map above |
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Antarctic Peninsula and Ellsworth Land
# Numerous volcanoes can be found along the west coast of the Antarctic Peninsula, and many of the islands just offshore are volcanic in origin. Several scattered volcanic fields can also be found in Ellsworth Land, which is located at the base of the Antarctic Peninsula. However, none of these volcanoes have yet been included here, since they are all relatively modest in elevation with the highest topping out at about 5000 ft (1500 m), and few seem to offer much in the way of skiing or mountaineering. I may include some of these in the future after further research. Of far more interest to skiers and mountaineers are the Ellsworth Mountains, the highest mountain range in Antarctica and a northerly offshoot of the Transantarctic Mountains. The highest summit, Vinson Massif, is now probably the most climbed mountain in Antarctica since the advent of private air support by Adventure Network International in 1985. (Erebus may be ascended by researchers in vehicles more often, but is less often climbed on foot or ski). |
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| Islands of the Southern Oceans
# There are numerous volcanic islands in the Southern Oceans, which consists of those parts of the Atlantic, Indian, and Pacific Oceans below about 45° S latitude. Many of these islands have permanent icecaps and are probably skiable, but access is extremely difficult and they are rarely visited. In some cases access is possible only by helicopter from nearby ships due to the lack of beaches and the steep rock and ice cliffs which encircle many of these islands. The highest and most spectacular of these volcanic islands is Heard Island, which is topped by the glacier-covered stratocone of Big Ben, and has reasonably good access in comparison. (Although Heard Island is in the Indian Ocean and thus not part of the Pacific Ring of Fire, I have included it here for lack of a better place to list it.) Other glaciated southern volcanic islands which may be skiable include Bouvetøya, Marion Island, Iles Kerguelen, the Balleny Islands, Peter I Island, and the South Sandwich Islands. The last of these is a classic example of subduction arc volcanism, the missing link in the Ring of Fire between South America and the tip of the Antarctic Peninsula despite now being offset almost 2000 miles (3000 km) to the east in the Atlantic Ocean by the creation of the Scotia Plate over many millions of years. There are about 10 glaciated stratovolcanic islands in the South Sandwich group, the highest of which reaches 4500 ft (1370 m). |
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