Los Volcanos En La Isla Kasatochi

The Effects of the Volcanic Eruption on Kasatochi Island and its
Surrounding Ecosystem

Volcanoes are one of the most destructive forms of natural disasters, with some of the most extreme and varied consequences (Talbot et al. 2010). Although volcanoes do not occur as frequently as most other natural disasters, they are probably the most harsh to the surrounding ecosystems. After a volcanoerupts, the local area around it is generally affected very negatively. The extremeness of these destructions varies depending on how severe the eruptions are and the type of substrate that is exuded from the volcano. This can be shown in the recent studies that have been done on the eruption at Kasatochi Island, Alaska that occurred on August 7th, 2008. Kasatochi Island is a small volcanicisland located in the central Aleutian Islands right outside of Alaska (Del Moral 2010). This was one of the first times that there was already significant information on the pre-existing ecosystem of the area before the eruption occurred. This made Kasatochi Island it an excellent source for the scientific study of how an ecosystem reassembles itself (Del Moral 2010). From these extensive studiesof Kasatochi Island we can see that the success of an ecosystem, after a volcanic eruption, is generally based on several factors that determine its recovery rate. In this case these factors are: the effects that the material erupted from the volcano have on the surrounding landscape, how the changed habitats of the local terrestrial and marine life are able to restore themselves, and theimportance of the different dispersal methods in reassembly of the ecosystem.
In general, the amount of destruction from a volcano is very dependent on the type of substrate that is released from the volcano during the eruption. For instance, how quickly an ecosystem can recover is directly affected by how fast a substrate can be broken down or eroded away so that new or surviving vegetation can startto re-grow (Del Moral 2010). The most common substrates that are dispersed from a volcano are lava, pyroclastic rocks, ash, and debris or lahars. In the eruption at Kasatochi Island a thick layer of pyroclastic deposits covered all of the land, while ash was spread into the ocean and nearby islands (Bronwen et al. 2010). The flow and thickness of the pyroclastic deposits were dependent on thedifferent topographic positions of the land. In some areas the thickness of the pyroclastic deposits were greater than 1 meter deep, and no less than 1 meter of ash covered all the surrounding area too (Bronwen et al. 2010). From the evidence of the aftermath, it had seemed that there was no surviving trace of the old terrestrial ecosystem. One of the factors that would determine if theecosystem would be restored was by finding how deep the pre-eruption soil was buried under the new deposits. On the island, the hills that were steeper than forty percent had the least amount of deposits on them and were where pre-eruption soils were found. These hills, along with some gullies on the island, are where scientist predicted will be the most likely places for new terrestrial re-growth(Bronwen et al. 2010).
In contrast to the destructiveness of the substrates produced from the eruption, evidence was found that they had some positive affects on the marine ecosystems and possibly on the ozone too. For example, the deposits that had flowed into the oceans were extremely rich in iron and were found to be one of the causes for a huge increase in the phytoplankton population thatoccurred in the North East Pacific Ocean that year (Bronwen et al. 2010). Also, eruptions such as these contain certain materials and gases that are released into the air in the form of particles, and are distributed when they comes in contact with water (Crowely and Hyde 2000). The affects of these vary, but evidence shows that these particles and gases in the air could possibly reduce some of the...