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An active volcano for centuries, the mountain Hekla is one of the most famous in the world.
Old tales tell of the belief that the souls of the condemned travelled through Hekla's crater on their way to hell. Others belived that the witches met with the devil on its top. It has been compared with Brocken and Vesuvius and the trio were thought to be the gateways down to hell.
The whole mountain ridge of Hekla is about 40 km long. The fissure which splits the mountain ridge is about 5,5 km long. The mountain is about 1491 m high (4890 ft).
It is thought that Hekla has had at least twenty eruptions since the settlement of Iceland. The biggest eruption was in 1104 when it erupted without warning ejecting millions of tonnes of tephra. Hekla has erupted four times in the 20th century, the last time in 2000. Hekla has erupted more often than any other volcano on the island since the settlement. Some eruptions have been so powerful and violent that its ashes has reached as far as mainland Europe.
In the 1947 eruption, the last really big one, 14 m (46 ft) were added to its summit. In that eruption the volcano spewd up a column of ash as high as 28 000 meters into the atmosphere. The ash fell as far away as Russia.
Year |
Duration |
Lava and |
Destruction |
|
|
ash, km³ |
|
1104 |
Unknown |
2,5 |
Much |
1158 |
Unknown |
0,15 |
Some |
1206 |
Unknown |
0,03 |
Some |
1222 |
Unknown |
0,01 |
Little |
1300-01 |
12 mo. |
1,0 |
Much |
1341 |
Unknown |
0,08 |
Much |
1389-90 |
Unknown |
1,0 |
Some |
1440 |
Unknown |
Unknown |
Little |
1510 |
Unknown |
0,32 |
Some |
1554 |
Unknown |
Unknown |
Little |
1597 |
6 mo. |
0,24 |
Little |
1636 |
12 mo. |
0,08 |
Little |
1693 |
7-12 mo. |
0,03 |
Much |
1725 |
Unknown |
Unknown |
Little |
1766-68 |
24 mo. |
1,7 |
Some |
1845-46 |
7 mo. |
1,0 |
Some |
1878 |
Unknown |
Unknown |
Little |
1913 |
4-5 mo. |
Unknown |
Little |
1947-48 |
13 mo. |
1,0 |
Some |
1970 |
2 mo. |
0,3 |
Little |
1980-81 |
2 weeks |
0,25 |
Some |
1991 |
2 mo. |
0,15 |
Little |
2000 |
11 days |
0,11 |
Little |
The quiet (or repose) period between Hekla's eruptions has ranged from 16 years to 121 years. A tendency toward longer repose intervals has occurred between the later eruptions.
Eruptions in Hekla are extremely varied and difficult to predict . Some are very short (a week to ten days) whereas others can stretch into months and years (the 1947 eruption started March 29, 1947 and ended April 1948).
Over the past 7000 years Hekla has had five big fissure eruptions. The biggest eruptions were 4000 and 2800 years ago. Traces of these two eruptions can be found in the soil in the North and the North-East of Iceland. The biggest layer of tephra from one eruption fell in the eruption 2800 years ago. It covers about 80% of the country and its volume was around 12 cubic km. Traces of it has been found in various places in Scandinavia.
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