Iceland Glacial Outbursts Flashcards
What is the Icelandic term for glacial outburst floods, and what are some triggers for their occurrence?
The Icelandic term for glacial outburst floods is “Jökulhlaup” (yer-kul-hloyp).
What are some triggers for the occurrence of Jökulhlaups?
Triggers for their occurrence include increased flotation of ice as water levels rise, overflow of a melting ice dam, breakdown of an ice dam due to tectonic activity, irreversible overtopping of a moraine dam, failure of a moraine dam due to slow ice melt, and enlargement of pre-existing tunnels.
Where do glacial outburst floods commonly occur?
Glacial outburst floods commonly occur in the Andes, European Alps, Himalayas, Northern Canada, Alaska, and Siberia.
Which Icelandic volcano commonly causes glacial outburst floods, and what is the discharge pattern associated with it?
Grímsvötn volcano commonly causes glacial outburst floods as the Vanajökull Ice Cap lies directly above it. The discharge pattern ranges from 0.5 to 3.5 km sq every 3-6 years.
What significant event occurred in 1996 involving Grímsvötn, and what were the consequences?
In 1996, Grímsvötn broke through the ice, sending up a 10m column of ash.
On November 5th, meltwater burst through the glacier with a massive peak discharge, the largest since 1930.
Despite causing no damage to infrastructure, the event cost $15 million.
