20th anniversary of the great eruption

2000/05/23 Roa Zubia, Guillermo - Elhuyar Zientzia

• Geologia

Santa Helena Volcano is located between the cities of Seattle and Portland. In 1980 the typical explosions in the crater were occurring. On May 18, at eight and a half in the morning, coinciding with the magnitude 5.1 earthquake, a large eruption occurred that calmed the next day.

The data obtained are surprising. Before it was a mountain of 2,949 meters, but after the eruption it was 2,549 meters. 400 meters side. In total the volcano lost 2.8 billion cubic meters. The propagation wave spread at a speed of 475 kilometers per hour at 350 ° C.

Calming the needle

In nine hours it was a column of ashes and fumes on the volcano. The column was 20-25 kilometers high. The ash spread 95 kilometers per hour to the east. In fact, the volcano was more violent than the nuclear explosion of the cities of Hiroshima and Nagasaki.

Since then there have been research on geology and local biology. The eruption destroyed the surrounding ecosystems, including bacteria and microscopic beings. Washington University biologist John Bishop and his colleagues have continued to recover these ecosystems.

In 1981 a copy of the Lupinus Lepidus legume plant was found alive in the fields around the volcano. Amazing. In addition, this type of plant increases soil nitrogen, so it is important for the cultivation of other plants.

Stones were later discovered around the roots of these plants. Bishop's team discovered that worms were conducting vegetation control. For Bishop, the effect of Lupinus is reflected in a few generations. However, if it occurs on a larger scale, it would be an effect to consider.

Research is open. Other trophic levels are currently being studied. For example, why are there no herbivorous communities? But it is clear that nature has resources to deal with major catastrophes.