Mount Erebus, Ross Island and the Age of Exploration

Satellite image: NASA/JPL. Released under US Gov Common

Satellite image: NASA/JPL. Released under US Gov Common

This is a reposted article from December 3, 2011.

I have always had a love of the beauty of the Antarctic. When I discovered that a cousin of my grandfather had joined Shackleton’s Trans-Antarctic expeditionof 1914 to 1917 as the official photographer, this love morphed into an enduring interest in the early explorations of the Antarctic and then increased to developing an interest in volcanoes due to the descriptions I read of Mount Erebus erupting.

Mount Erebus is classified as a polygenetic stratovolcano. The bottom half of the volcano is a shield and the top half is a stratocone.  It is is currently the most active volcano in Antarctica and is the current eruptive zone of the Erebus hotspot.  Inside the crater is a persisting lava lake and shows up well in the NASA satellite image above.

Mount Erebus overlooks the McMurdo research station on Ross Island and is the largest of three major volcanoes on the island. We see above in the Nasa picture the lava lake which has been monitored since 1972, this activity has been continuous since then with many minor explosions and occasional larger strombolian explosions that throw up lava bombs to the rim of the crater. Although this activity has been noted since 1972 it is more than likely that it has occurred for most of the volcanoes recent history, because the volcano was active when discovered in 1841 and also when other later explorations took place.

The summit of Mount Erebus rises to 3,794 metres of 12,447 feet. Quite a height when you consider this volcano rises from sea level.

Ross Island

Mount Erubus is situated on Ross Island which was formed by four volcanoes  in the Ross Sea, only one of which Erebus is still active today. Because the ice sheet is so thick and persistent it appears as if it is part of Antarctica.

It was discovered in 1841 by Sir James Clark Ross who perhaps not realising it was an island did not name it after himself, the naming of the island in honour of him came many years later by the polar explorer Robert Falcon Scott. Ross did however name the two largest volcanoes on the Island after the names of his two expedition ship, the Erebus and Terror.

Ross Island was the base for many of the early expeditions to Antarctica. It was very suitable as a base for explorations as it is the southernmost island reachable by sea.  Scott and Shackleton both built huts on the island as bases for their polar expeditions. These are still standing and are now preserved as historical sites.

Today Ross Island is home to New Zealands Scott Base and also the largest Antarctic settlement, the U.S. Antarctic Program’s McMurdo Station.

Erebus and the Age of Exploration

Map showing the four volcanos of Ross Island.

Map showing the four volcanos of Ross Island.

Erebus was first discovered by James Clark Ross and named after his ship. Here is an interesting description of the awe it inspired in these early explorers.

Robert McCormick, the surgeon, described the discovery as “a stupendous volcanic mountain in a high state of activity“. Dr. Hooker ran to grab his notebook and quickly wrote down his reaction: “All the coast one mass of dazzling beautiful peaks of snow which, when the sun approached the horizon, reflected the most brilliant tints of golden yellow and scarlet; and then to see the dark cloud of smoke, tinged with flame, rising from the volcano in a perfectly unbroken column, one side jet-black, the other giving back the colors of the sun….This was a sight so surpassing everything that can be imagined…that it really caused a feeling of awe to steal over us at the consideration of our own comparative insignificance and helplessness, and at the same time, an indescribable feeling of the greatness of the Creator in the works of His hand“. The peak was 12,400 feet above sea level and was belching flame and smoke. Ross named it Mount Erebus and the smaller extinct volcano to the east, Mount Terror.

Members of Shackleton’s later Trans-Antarctic expedition also reported of the feelings caused by the beauty and grandeur of the volcano.

By that time the returning sun was touching with gold the peaks of the Western Mountains and throwing into bold relief the massive form of Erebus. The volcano was emitting a great deal of smoke, and the glow of its internal fires showed occasionally against the smoke-clouds above the crater. Stevens, Spencer-Smith, and Cope went to Cape Royds on the 20th, and were still there when the sun made its first appearance over Erebus on the 26th. Preceding days had been cloudy, and the sun, although above the horizon, had not been visible.

The morning broke clear and fine,” wrote Mackintosh. “Over Erebus the sun’s rays peeped through the massed cumulus and produced the most gorgeous cloud effects. The light made us all blink and at the same time caused the greatest exuberance of spirits. We felt like men released from prison. I stood outside the hut and looked at the truly wonderful scenery all round. The West Mountains were superb in their wild grandeur. The whole outline of peaks, some eighty or ninety distant, showed up, stencilled in delicate contrast to the sky-line. The immense ice-slopes shone white as alabaster against dark shadows. The sky to the west over the mountains was clear, except for low-lying banks at the foot of the slopes round about Mount Discovery. To the south hard streaks of stratus lay heaped up to 30 degrees above the horizon. . . . Then Erebus commenced to emit volumes of smoke, which rose hundreds of feet and trailed away in a north-westerly direction. The southern slopes of Erebus were enveloped in a mass of cloud.”

NEWBY

16 thoughts on “Mount Erebus, Ross Island and the Age of Exploration

  1. Great post, deserves another look. And I’m thinking that Erebus deserves another post itself; with its comsitionally peculiar lava lake and anomalous location: hotspot volcano or continental rift valley volcano|?

    • I mentioned a few posts back that the entirety of Antarctic volcanism is a bit peculiar. As strange as Erebus is, the continental volcanic lines are even more anomalous to me with no overtly known subduction arcs or rifting zones (although that doesn’t mean they don’t exist).

  2. I have a question regarding this recent swarm of EQs north of Reno, NV:

    There’s been a swarm happening north of there near the Oregon border (Sheldon Antelope etc) for over a year. It still continues.

    The lastest quake has data here:

    http://www.seismo.unr.edu/Events/main.php?evid=543016

    the question is this: what causes these swarms when there are no nearby faults?

    • These quakes have me stumped too. I don’t think anyone
      really has a good theory. Tectonic/volcanic/a bit of both?
      My guess is there has got to be something magmatic in
      the mix, strange.
      There is a mix of basin and range faults in that whole area.
      South East Oregon to oh, Mexico…
      But not there..

  3. A celebration of Harmonic tremor. Fluidic movement (air) through a large structure=lower notes. Through smaller structures = higher notes.

    The difference is that here, the size of the structures is controlled (tuned) so that the vibrations fall into specific note structures. In a volcano, the tuning is chaotic.

    https://youtu.be/ho9rZjlsyYY

    • Large earthquakes along the San Andreas are inevitable. You can’t predict the times well, it could easily be 100 years off. But it takes many decades to properly prepare and that is the main point of these kind of news releases. A fault being quiet should not be confused with it being safe: people tend to ignore slow dangers, and by the time someone wakes up there may be too little time left to prepare. So no panic, and no imminent disaster, but a wake-up call. Don’t take the world for granted.

    • I am skeptical that the southern end of the San Anreas fault has over 300 years of charge. It appears to me that the true plate boundry between points A and B is the San Jacinto fault, which seems to be slipping every day and would be better described as a creeping section.

      • Could be that the sliver of land between the two faults is a microplate, in which case it can move independently of both American and Pacific Plates. There could then be stress building on both faults. Or even more interesting things, like small-scale rifting, which if present could one day result in volcanism in the region. (Wasn’t there a movie where that happened?)

  4. There will not be a weekly update today: Hobbes’ work is interfering with pleasure. So any volcano with plans, including St Helens, is kindly requested to hold off until next week.

    Instead we will have a volcano-free post later today on Portuguese earthquakes.

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