Tuesday, November 2, 2010

The big rebound of Life- Napolean`s exile

Mount St. Helens is most famous for being Napolean`s last exile and where the die hard spirit breathed his last and then for its catastrophic eruption on May 18, 1980, at 8:32 am PDT which was the deadliest and most economically destructive volcanic event in the history of the United States. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles (24 km) of railways, and 185 miles (298 km) of highway were destroyed. A massive debris avalanche triggered by a earthquake measuring 5.0 on the Richter scale, caused an eruption, reducing the elevation of the mountain's summit from 9,677 ft (2,950 m) to 8,365 ft (2,550 m) and replacing it with a 1 mile (1.6 km) wide horseshoe-shaped crater.The earthquake was caused by a sudden surge of magma from the Earth's mantle. [3] The debris avalanche was up to 0.7 cubic miles (2.9 km3) in volume. The Mount St. Helens National Volcanic Monument was created to preserve the volcano and allow for its aftermath to be scientifically studied.

As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted. The largest of the dacite domes formed the previous summit, and off its northern flank sat the smaller Goat Rocks dome. Both were destroyed in the 1980 eruption.
When Mount St. Helens blew its top in 1980, it wasn't a surprise that it happened, but even today the extent of the damage is hard to fathom. The eruption knocked down 100-foot trees like matchsticks and killed just about everything in its path. There have been several smaller eruptions since then, but nothing like what happened in 1980.

Today, dead tree trunks still litter the landscape. But, if you take a closer look, you'll see another kind of eruption; an eruption of life on the mountainside. For Bishop, it's a blessing. "It's a rare opportunity for scientists to get to study a devastated area and how it comes back from scratch in such detail," he says.


With help from the National Science Foundation (NSF), Bishop is documenting the return of living things to the once lifeless mountain. "Up until the last 10 years, the landscape has been completely dominated by lupins," says Bishop. He says these flowering lupin plants are able to create new soil from volcanic ash. That new soil has created a habitat for the Sitka willow. But, Bishop says there is a problem. "One of the things we've realized about these willows is that they're not getting big. And that's important because they create habitat for birds and mammals."


The culprits are small invasive weevils that are on the attack. They've taken up residence inside the willows' stems, stunting the plants' growth or killing them. Bishop says there is a lesson in all of this. "Seemingly insignificant organisms, like insects that consume plants, play an extraordinarily important role in the sorting out process of deciding, essentially, which plants are going to stay in the landscape and which ones are going to disappear."
Bishop points out that the imbalance between plants and insects on Mount St. Helens should be expected in rudimentary systems and will cause instability until a more complex community of plant and animal species is sustainable, or until the day Mount St. Helens itself changes the equation once again ,like its famous resident Napolean ,who never gave up



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