Glacier death

The glacier Okjökull in Iceland died in 2014.

We all know why the glaciers are in retreat, and why they’re likely to continue to shrink in the years to come. Although glaciers have been weakening since the end of the little ice age in 1850, global warming has pushed that trend into overdrive. One of the victims: Okjökull, the glacier on top of Ok volcano in western Iceland.

Glaciers form when snow and ice accumulate faster than they melt, and then get so heavy that they begin to move under their own weight. A measure called the glacier mass balance represents the ratio between accumulation and melting of a glacier: if it’s positive, the glacier grows; if it’s negative, the glacier retreats. Almost all glaciers are currently in retreat.

Sometimes the glacier retreats so much that it stops moving entirely: the weight is not enough to propel it forward. This is known as dead-ice, and it’s a strong indicator that the glacier is dead.

Okjökull stopped moving in 2014. It’s gone now, and this year they unveiled a plaque to commemorate its loss:

A letter to the future
Ok is the first Icelandic glacier to lose its status as a glacier. In the next 200 years all our glaciers are expected to follow the same path. This monument is to acknowledge that we know what is happening and what needs to be done. Only you know if we did it. August 2019 415PPM CO₂

That last number is a measure of atmospheric carbon dioxide.

• Okjökull
• Ok
• Retreat of glaciers since 1850
• Glacier mass balance
• Dead-ice