Antarctica: 85,000 earthquakes caused by underwater volcano

85,000 earthquakes hit Antarctica in 2020 over a three month period

Scientists think they have discovered the mystery behind why 85,000 earthquakes hit Antarctica in 2020.

Experts believe they were all caused by a previously dormant underwater volcano called "Orca Seamount" which has awakened.

The volcano is found deep under the sea near King George Island and some of the quakes were felt by scientists working there in research stations.

The event was the strongest earthquake activity ever recorded in Antarctica.

Everything you need to know about volcanos

The Big Question: Why do volcanoes erupt?

La Palma lava fizzes and steams as it hits ocean

What did scientists find?

Experts examined equipment used to measure earthquakes here at Carlini Base in Antarctica

Antarctica is absolutely enormous - it is about 58 times the size of the UK and it's also the world's highest continent!

Researchers from the German Research Centre for Geosciences used seismometers and remote sensing techniques to find out how long the 'swarm' of earthquakes lasted, and what caused it.

They found that the tremors took place over a three month period between August to November 2020.

Lead author of the study, Simone Cesca, said: "In the past, seismicity in this region was moderate. However, in August 2020, an intense seismic swarm began there."

"It represents the largest seismic unrest ever recorded there," he added.

• Seismicity: The occurrence or frequency of earthquakes in a region.

• Seismometer: An instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions

The team was able to find out more information by piecing together data from the closest research stations on Antarctica, along with satellite information and data from seismic stations which monitor earthquakes located further away.

Researchers say the earthquakes were caused by a very quick transfer of magma from the Earth's mantle nearly up to its surface.

The two largest earthquakes which occurred were a 5.9 magnitude quake in October 2020 and a 6.0 magnitude earthquake a month later.

Earthquakes: What are they and what causes them?

After November, they found that the earthquake activity decreased.

They also discovered that during the swarm, the quakes moved the ground on King George Island by 11cm!

Scientists say that their study shows that volcanic events can still be studied in close detail, despite the fact that it occurred on such a remote part of Earth.