Grímsvötn
Grímsvötn is one of Iceland’s most active volcanic systems,
located deep beneath the
Vatnajökull
ice cap, the largest glacier in Europe.
The volcano lies in the southwestern part of the glacier
and has played a major role in shaping the landscape
of Southeast Iceland through eruptions and glacial floods.
The system consists of a powerful central volcano,
a large caldera and extensive fissure zones.
Geothermal heat beneath the glacier melts the ice,
forming subglacial lakes known as Grímsvötn.
When pressure builds up,
these lakes drain suddenly in massive glacial outburst floods,
which flow across
Skeiðarársandur.
Grímsvötn is among the most frequently erupting volcanoes
in Icelandic history.
Notable eruptions occurred in 1996,
when a powerful jökulhlaup destroyed sections of
the Ring Road,
and again in 2011,
when a large ash plume rose high into the atmosphere
and disrupted air traffic across parts of Europe.
Subglacial eruptions at Grímsvötn are often accompanied
by extreme natural forces.
As magma rises,
ice melts rapidly,
water accumulates beneath the glacier,
and is eventually released in sudden floods.
This dramatic interaction between fire and ice
is a defining feature of Iceland’s geology.
Although Grímsvötn itself is rarely visible to visitors,
hidden beneath hundreds of metres of ice,
its influence extends far beyond the glacier.
Repeated jökulhlaups have reshaped river systems,
built vast outwash plains
and directly affected infrastructure
and settlements in South Iceland.
Grímsvötn stands as one of the clearest examples
of Iceland’s active plate boundary.
Here, volcanic heat, glacial ice and flowing water
interact continuously,
reminding us that Iceland’s landscape
is dynamic and ever-changing.