Podcast
Lava Academy Podcast: The Volcanoes of Antarctica
When most people picture Antarctica, they imagine endless ice, extreme cold and perhaps a few penguins. Volcanoes are unlikely to be the first thing that comes to mind.
But beneath the continent’s vast ice sheet lies one of Earth’s most remarkable volcanic regions.
In this episode of the Lava Academy Podcast, host Iain MacKinnon and co-host Ragnhildur Ágústsdóttir are joined by Ann Sophie Bader, a member of the Lava Show team in Vík.
Ann Sophie divides her year between two extraordinary landscapes. She works at Lava Show in Iceland and, during the Northern Hemisphere winter, travels south to work at a remote tourism camp in Antarctica.
Her fascination with Antarctica began while working as a glacier guide in Iceland. After several years of trying to find a way onto the continent, she secured her first Antarctic job—cleaning facilities, setting up tents and doing whatever was needed. Today, she works there as a guest liaison, accompanying adventurous travellers, mountaineers and extreme athletes.
In this episode, Ann Sophie takes us beneath the ice to explore a volcanic world that remains largely hidden.
In This Episode about volcanoes and eruptions in Antarctica
Discover why Antarctica is far more volcanically active than it first appears. Ann Sophie explains:
Why so many Antarctic volcanoes are buried beneath kilometres of ice
How researchers identified 91 previously unrecognised volcanic features in West Antarctica
Why the West Antarctic Rift System is so geologically important
How Deception Island was created by an enormous explosive eruption
Why Mount Erebus contains one of Earth’s few persistent lava lakes
What makes Erebus’s phonolite lava so unusual
How the volcano releases microscopic particles of gold
Why Erebus produces spectacular volcanic bombs
How radar, gravity and magnetic measurements reveal what lies beneath the ice
How volcanic heat affects Antarctic glaciers
Why climate change—not volcanic activity—is the main cause of Antarctic ice loss
Watch the Podcast Episode
Watch the full conversation with Ann Sophie and discover the volcanic forces hidden beneath the coldest continent on Earth.
Is Antarctica Volcanic?
Antarctica is not volcanically uniform.
Much of the continent’s known volcanic activity is concentrated in West Antarctica, particularly around the West Antarctic Rift System. This enormous geological structure is an area where the continental crust has been stretched and thinned, allowing magma to rise more easily from below.
It is different from the volcanic setting in Iceland, where the North American and Eurasian tectonic plates are moving apart along the Mid-Atlantic Ridge. The West Antarctic Rift System lies within the Antarctic continent itself.
One major survey identified 138 possible volcanic structures beneath the West Antarctic Ice Sheet. Remarkably, 91 of them had not previously been recognised.
Many of these volcanoes are completely covered by ice. Instead of seeing the familiar cone-shaped mountains we associate with volcanoes, scientists must search for their shapes beneath a frozen surface that can be more than four kilometres thick.
Researchers believe there may still be more volcanic features waiting to be discovered.
A Continent 136 Times Larger Than Iceland
The scale of Antarctica makes volcanic research exceptionally difficult
The continent is approximately 136 times larger than Iceland. Reaching a potential volcano may involve travelling across vast distances in extreme cold, often through areas containing dangerous crevasses hidden beneath the snow.
Transporting scientists and equipment into these remote locations is also extremely expensive.
In Iceland, monitoring a glacier-covered volcano is already challenging. In Antarctica, researchers must investigate a much larger continent beneath an ice sheet that is several kilometres thick in places.
There is still no complete three-dimensional picture of everything that lies beneath the Antarctic ice. That leaves many unanswered questions about the continent’s volcanic history and its present-day activity.
How Do Scientists Find Volcanoes Beneath the Ice?
Researchers use several different methods to investigate Antarctica’s hidden landscape.
Aircraft can carry radar systems over the ice sheet, allowing scientists to map the shape of the bedrock below. Satellite observations can also reveal large-scale structures and changes in the ice surface.
Gravity measurements provide another clue. Volcanic rock is generally denser than many surrounding sediments, creating small differences in the local gravitational field.
Scientists can also use sensitive magnetic instruments because volcanic rocks often contain iron-rich minerals that affect magnetic readings.
Together, radar, satellite imagery, gravity surveys and magnetic measurements allow researchers to build a picture of a landscape that they cannot see directly.
A seal and two gentoo penguins at Whalers Bay, inside the flooded caldera of Deception Island—an active volcano near the Antarctic Peninsula.
Deception Island: A Volcano Disguised as an Island
One of the volcanic systems explored in the episode is Deception Island, located near the Antarctic Peninsula.
From the outside, it appears to be an ordinary horseshoe-shaped island. However, a narrow entrance leads through the outer wall and into a flooded volcanic caldera, forming a vast natural harbour.
This hidden entrance is the source of the island’s name. Early explorers sailing past could easily be deceived into believing that they were looking at a solid island rather than the rim of a volcano.
Deception Island is still active. It experienced several eruptions during the 20th century, including its most recent confirmed eruption in 1970.
It is also known for geothermal activity, including areas where volcanic heat warms the ground and coastal water.
The Enormous Eruption That Created Deception Island
The flooded caldera was created by one of the largest confirmed Antarctic eruptions of the Holocene.
Research now places the caldera-forming eruption at approximately 4,000 years ago. Scientists estimate that it released between 30 and 60 cubic kilometres of magma.
For comparison, the 2010 Eyjafjallajökull eruption in Iceland produced only a fraction of one cubic kilometre of volcanic material.
The Deception Island eruption was powerful enough to cause the volcano’s central structure to collapse, creating the large caldera that seawater later flooded. Evidence of the eruption has been found thousands of kilometres from the volcano in Antarctic ice and sediment records.
Despite the scale of this ancient event, Deception Island’s more recent eruptions have been considerably smaller.
Mount Erebus rises 3,794 metres above Ross Island in Antarctica. Beneath its ice-covered summit lies one of Earth’s few persistent lava lakes, which has remained active for decades.
Mount Erebus: Antarctica’s Lava-Lake Volcano
The episode also explores Antarctica’s most famous active volcano: Mount Erebus.
Rising 3,794 metres above sea level on Ross Island, Erebus is considered the southernmost active volcano on Earth. It stands close to McMurdo Station and New Zealand’s Scott Base, giving researchers in the area a dramatic volcanic neighbour.
Unlike most of Antarctica’s hidden volcanic structures, Erebus looks exactly like the volcano many people drew as children: a huge, unmistakable cone rising above the surrounding landscape.
Its most remarkable feature is found inside the summit crater.
Mount Erebus contains one of the world’s few persistent lava lakes.
What Is a Persistent Lava Lake?
A lava lake is an exposed body of molten rock held within a volcanic crater or vent.
Temporary lava lakes can form during eruptions, including eruptions in Iceland. Most eventually drain away or cool and solidify.
The lava lake at Mount Erebus is different. It has persisted for decades and has been observed continuously since at least 1972.
Scientists believe the lake is maintained by a circulating system of magma and volcanic gases. Hot magma rises towards the surface while cooler, denser magma sinks back into the volcanic system. This creates a cycle similar to convection in a pot of heated liquid.
Gas bubbles also rise through the lake and burst at the surface. This regular release of gas helps prevent pressure from accumulating continuously, although Erebus can still produce sudden explosive bursts.
Phonolite: The Unusual Lava of Mount Erebus
Most of the lava produced in Iceland is basalt. Basaltic lava is extremely hot and relatively fluid, allowing it to form flowing rivers of molten rock.
Mount Erebus contains a much rarer type of magma known as phonolite.
Phonolite is rich in alkali elements such as sodium and potassium. It is generally more viscous than basalt, making the survival of an open, circulating lava lake especially unusual.
The name phonolite means “sounding stone”. Some pieces of phonolite can produce a ringing sound when struck, almost like a bell.
The phonolite at Erebus also contains large feldspar crystals. These crystals can become trapped inside material thrown from the volcano, providing scientists with clues about what is happening within its magmatic system.
Volcanic Bombs from the Lava Lake
Mount Erebus regularly produces volcanic bombs.
A volcanic bomb forms when an explosive burst throws molten or partly molten rock into the air. The material begins cooling and changing shape as it travels before falling back onto the volcano.
At Erebus, large gas bubbles rise through the lava lake and burst at the surface. These bursts can propel fragments of lava hundreds of metres into the air.
Although the lava lake releases pressure frequently, Erebus remains an active volcano. Its sudden explosions are an important reminder that even relatively steady volcanic activity can be unpredictable.
The Volcano That Releases Gold
Mount Erebus has another surprising characteristic: it releases microscopic particles of gold.
The gold is carried from the volcano with its gases. As those hot gases enter the freezing Antarctic atmosphere, tiny particles can condense and become dispersed through the air.
Gold originating from Erebus has been detected far from the volcano. However, there is no realistic opportunity for Antarctic gold mining. The particles are microscopic, widely scattered and present in extremely low concentrations.
The phenomenon is scientifically fascinating rather than commercially valuable. It demonstrates how the complex magma beneath Erebus concentrates and transports unusual elements.
Could a Volcano Erupt Without Breaking Through the Ice?
With many Antarctic volcanoes buried beneath thick ice, it is possible that an eruption might not reach the surface.
Magma could melt some of the surrounding ice and create water beneath the ice sheet without producing a visible eruption plume. The activity would still be expected to generate warning signs such as earthquakes, changes in heat flow or movement within the ice.
Detecting those signs is difficult. Seismic instruments work best when they are placed on solid bedrock, which may lie beneath kilometres of ice. Antarctica’s enormous size also makes it impossible to monitor every potentially volcanic area as closely as scientists monitor active regions in Iceland.
Does Volcanic Heat Cause Antarctica’s Ice to Melt?
Geothermal heat does melt ice from below in some parts of West Antarctica.
This can affect the stability and movement of individual glaciers. Water beneath a glacier can reduce friction between the ice and bedrock, allowing the glacier to move more quickly towards the ocean.
However, Ann Sophie emphasises an important distinction in the episode: volcanic and geothermal heat are not the main causes of Antarctica’s present ice loss.
The greatest threats are the warming atmosphere and, particularly in West Antarctica, warmer ocean water reaching beneath floating ice and the edges of glaciers.
One example is Thwaites Glacier, sometimes dramatically nicknamed the “Doomsday Glacier”. Its retreat matters because it helps hold back a much larger section of the West Antarctic Ice Sheet.
Scientists estimate that the complete loss of Thwaites itself would raise global sea levels by around 65 centimetres. The loss of the entire West Antarctic Ice Sheet would have a much greater effect, although such changes would unfold over a far longer period and remain the subject of intensive research.
Could Melting Ice Affect Future Volcanic Activity?
Ice places an enormous amount of pressure on the crust beneath it.
When a large ice sheet becomes thinner, that pressure is reduced. In some volcanic regions, unloading the crust in this way may influence magma production or make it easier for magma to move upwards.
This relationship has been studied in Iceland and other formerly glaciated volcanic regions. However, Antarctica’s volcanic systems remain poorly understood, and scientists cannot yet say exactly how future ice loss might affect volcanic activity beneath the continent.
It is another reason why mapping and monitoring Antarctica’s hidden volcanoes is important.
Should We Worry About Antarctic Volcanoes?
There is currently no evidence that Antarctica is approaching a continent-wide volcanic crisis.
Most of its volcanic structures are buried, poorly understood or have shown no signs of an imminent eruption. The continent’s active systems are scientifically important, but they do not currently represent an immediate threat to the rest of the world.
That does not make them unimportant.
Antarctica offers researchers a rare opportunity to study how volcanoes, glaciers, oceans and the atmosphere interact in one of Earth’s most extreme environments. Its ice also preserves a record of ancient eruptions, including eruptions that took place thousands of kilometres away.
The more scientists learn about Antarctica, the clearer it becomes that the continent is not a static block of ice. Beneath the frozen surface lies a dynamic geological landscape shaped by rifting, magma, geothermal heat and moving glaciers.
A Personal Connection to Antarctica
What makes this episode especially engaging is Ann Sophie’s personal connection to the continent.
Her work takes her to Union Glacier, where she lives in a tent between mountain ranges and spends the Antarctic summer as part of a close-knit international team.
She describes Antarctica as a pristine place dedicated largely to peaceful purposes and scientific research. Its isolation makes working there difficult, but it also allows researchers to investigate landscapes unlike almost anywhere else on Earth.
Her enthusiasm reveals a continent full of contrasts: a frozen desert containing enormous stores of ice, a seemingly empty landscape filled with hidden geology, and active molten lava surviving in one of the coldest environments on the planet.
Listen to the Full Episode About Antarctica’s Volcanoes
Want to learn more about the fire hidden beneath the Antarctic ice?
Listen to the full Lava Academy Podcast episode with Ann Sophie Bader and discover Deception Island, the extraordinary lava lake of Mount Erebus and the volcanic landscape concealed beneath the world’s largest ice sheet.
Listen now or download the episode through your favourite podcast app.
Lava Academy Podcast episodes mentioned in this episdoe
Experience Real Molten Lava
Antarctica may contain one of the world’s rare persistent lava lakes, but reaching Mount Erebus is beyond the plans of most travellers.
At Lava Show, you can experience real molten lava safely and much closer to home. Watch lava flow just metres away, feel its intense heat and hear it crackle as it begins to cool.
Plan your visit:
Experience Lava Show Reykjavík – Watch real molten lava flow in Iceland’s capital.
Experience Lava Show Vík – Visit Ann Sophie’s Icelandic home and experience the world’s only live lava show on Iceland’s South Coast.
