During the last couple of weeks, the Redoubt Volcano in Alaska, Semeru Volcano in Indonesia and the Chaiten Volcano in Chile have seen considerable volcanic activity.В Mild earthquakes and some seismic activity were seen in the areas the volcanoes were located.В Every year potential eruptions are being monitored in order to save lives and better understand volcanic eruptions and its effects on the environment.
Scientists already know that huge volcanic eruptions have a considerable effect on the global climate.В Huge and destructive eruptions actually help cool temperatures around the world.В However, due to global warming eruptions during the last 2 decades has had little or no effect on the climate.
In 1816 for example, a year after Indonesia Tambora volcano erupted, there were crop failures in Europe and the United States.В Tambora caused the temperature to drop considerable especially in the higher latitudes.В Tree rings were also considerable thinner suggesting that trees tend to grow thinner when the temperature rises.
Aside from causing climate change by cooling temperatures around the world, volcano eruptions also cause havoc on the immediate vicinity where they are located.В In 1991, Mt. Pinatubo erupted in the Philippines.В Days before the massive explosion, water around Zambales, Tarlac and Pampanga was undrinkable due to sulfur contamination.В Ash obscured sunlight which damaged crops and killed farm animals.
Years after the explosion, lahar or mudflow composed of pyroclastic material and water during the rainy season, caused the displacement of thousands of residents.В Agriculture and farming was also at a standstill due to damage sustained by the eruption.В What was once fertile and arable land became ash covered and deemed infertile destroying the livelihood of thousands of farmers around the region.
Mt. Pinatubo eruption coupled with Mt. Hudson in Chile reduced the amount of sunlight to reach the earth by 10%.В It also accelerated the depletion of the Ozone layer.
Volcanic eruptions also have good effects.В Decades after volcanic eruptions, soil which was once destroyed by ash actually become fertile once again because ash contain minerals which enrich the soil.В Underground steams may also form which can be harnessed for energy.В Copper and nickel can also be mined from volcanic rocks which are ejected during eruptions.В Natural glass, sulfur and pumice also form during eruptions.