The 1996 eruption of Grímsvötn, Iceland
This is a short video recorded at the site of a former bridge, in the south of
Iceland, which was destroyed by a glacial lake outburst flood resulting from the
1996 eruption of the subglacial
Grimsvotn volcano. The Grímsvötn
Volcano is Iceland's most active volcano and it is situated underneath Vatnajökull which is
Europe's largest glacier. During the 1996 eruption the hot lava melted some 4 cubic km of ice. As the ice melted, the water drained rapidly along a narrow channel under the glacier into
Lake Grímsvötn.
Late on
November 4th 1996, a steady ground vibration signaled that the glacier on the south-eastern edge of Lake Grímsvötn had moved. Lake drawdown had started.
Beneath the Skediarár
Glacier the water crept at less than walking pace down the 50 km long tunnel. However, once it emerged from the end of the glacier, about
8 AM next day, the water swept down the alluvial plain in a flood wave. In less than two days, a volume of 3.6 cubic km discharged from the glacier, laden with sediment and transporting huge blocks of broken ice.
The
November 1996 GLOF was truly catastrophic compared with the usual mega-floods observed in the last 60 years. The peak discharge reached 55,
000 cubic m per second, making it the largest GLOF ever recorded in Iceland.
During this flood, huge volumes of ice-blocks were detached from the glacier and swept along in the raging waters. Depending on their size, some ice-blocks floated, others rotated, bounced, skipped and slid down-channel. The biggest were 10--15 m high and estimated to be up to 1,000 tonnes. Many huge 200-tonne blocks were strewn across the alluvial plain. Sediment up to 9 m thick was deposited over an area of
500 square km all in less than two days.
Collisions by moving ice-blocks caused considerable damage.
A 10 km segment of the premier highway that rings Iceland disappeared. The reinforced-concrete bridge over the Gígja
River was totally swept away. The 900 m
Skeidará River
Bridge was severely damaged, even though its foundations were buried to a depth of 15 m to withstand mega-floods. Iceland's main high-tension power-lines were severed, and the telephone cables ripped apart.
Source:
https://answersingenesis.org/geology/catastrophism/icelands-recent-mega-flood/