Antarctica : a new active volcano discovered in Marie Byrd Land

A new active volcano was discovered under the ice sheet in West Antarctica, as revealed by a study published in November in the journal Nature Geoscience .

Under the draft POLENET research, two lines of sismo were installed in 2010 in Marie Byrd Land to take pictures of the rocky underbody , using the disruption caused by distant earthquakes .

Two seismic swarms were recorded in January 2010 and March 2011 , near the Executive Committee Range , about fifty km. south of Sidley and Waesche mts . Located 25-40 km . beneath the surface , these earthquakes DPLs - Deep , long-period - are linked to outbreaks of magmatic fluids, or other, fracturing the rocks and opening new avenues to the surface.

An overview radar confirmed the presence of a rise in the topography of the subglacial bed at the same location as seismic swarms. Radar images also show a layer of ashes buried under the ice. These ashes could come from Mount Waesche , near Mt Sidley volcano , located at a depth of 1400 meters. This layer of ash is 8,000 years old ... which would make enter the Mt Waesche in the GVP list of active volcanoes .

                                   Waesche mt. - photo Skimountaineers

                               Antarctica - the Mt.Sidley - Photo Doug Wiens

These observations demonstrate the presence of a magmatic activity and a volcanism that continued to migrate south along the Executive Committee Range, at the slow speed of 9.6 km . per million years .

This  migration is perpendicular to the direction of movement of the Antarctic tectonic plate, which does not validate the feeding of volcanoes by a mantle plume or an hot spot. The regional magmatism is connected to a wide area of ​​rifting, and the volcanic chain is located on the northern edge of the rift.

Location of Mary Byrd Land and Transantarctic mts. - doc . USGS

    The West Antarctica rift system and the location of volcanoes - doc . Timothy S. Paulsen

It is illusory to believe that an eruption here can break away 1.2 to 2 km of overlying ice, but it could generate a large amount of meltwater ( in the manner of Icelandic jökulhlaups ) affecting the flow of the MacAyeal ice flux towards the sea.

Sources :

- Nature Geoscience 17.11.2013 - Seismic detection of an active subglacial magmatic complex in Marie Byrd Land, Antarctica - By Amanda C. Lough & al.

- Preliminary stratigraphy of volcanoes in the Executive Committee Range, central Marie Byrd Land – by J.L.Smellie & al. 

- Evolution of Neogene volcanism and stress patterns in the glaciated West Antarctic Rift, Marie Byrd Land, Antarctica - By Timothy S. Paulsen & al.