Geology And Geophysics

Why the Volcanoes of Java are particularly Devastating



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"Why the Volcanoes of Java are particularly Devastating"
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When people talk about a devastating eruption, it is often in reference to the amount of damage caused for mankind. Volcanoes are vehicles for both destruction and creation, however almost all can be devastating, even when they aren't close to a populated area. The volcanoes of the Java area are among the most destructive, for good reasons.

History

In spring of 1883, arguably the loudest sound ever experienced by modern man was unleashed when Krakatoa erupted. The explosion was one of several that ended up destroying much of the Indonesian island. The sound of the explosion was so loud that it was reported by some to have been heard thousands of miles away. Millions of cubic feet of rock was blasted out, though the total amount is still not known for sure. The bang was certainly reported in many areas of Australia. And yet, this was but one of the volcanoes in the area of Java. The area is volcanically active.

Explosiveness

As shown by Krakatoa, the volcanoes can be quite explosive. Unlike places like the Hawaiian Islands, these volcanoes don't often produce fluid magma, low in gases. Instead, the magma is thick and doesn't seem to want to release the gases it contains. This is rather like a pressure cooker that is capped. Given time, something has to give, to allow the gases out. The result is often many times greater than would be produced by thousands of tons of TNT. In the case of Krakatoa, it was enough to destroy most of the island.

Land and altitude

Virtually all of the land around Java consists of islands. Most are volcanic in origin. A few of the volcanic mountains tower above sea level, but this is actually rare. The greater portion of the habitable land is low, scarcely over 20 feet above sea level. This plays an important part in how destructive the volcanoes in the area can be and are. This is especially true since the ocean isn't especially deep in this area. 

Population

Nearly all of Indonesia is heavily populated. The best, and most fertile land tends to be close to the coastlines. What is more, the coast is where there is access to the fish that largely sustain the people. For this reason, a lot of villages are built close to the shore. Many men, women and children live in this low-laying area.

Tsunamis

When a major eruption occurs in the Java region, since much of the mountains are underwater, the water is displaced. Water rushes in to fill the void. This creates a huge surge of water that spreads outward in all directions, like a pebble thrown into a pond, only on a vastly greater scale. When the ocean waves reach shallower water, the friction against the ocean bottom causes them to pile up. The tsunami slams into lower elevation areas. A 50 foot wave flowing over a village creates the type of destruction that can be scarcely imagined.

During the Krakatoa eruption, no accurate death toll was created, because there was no point. Whole villages were swallowed by the extremely powerful tsunamis that followed the eruption. Details are sketchy, but it is likely that several hundred people and their belongings were destroyed during the actual eruption. Tens of thousands were swept away by the enormous waves that were produced. A good guess put the death toll at around 200,000. 

The same recipe for disaster still exists in the Java islands, though it happens over and over again. The devastation that is unleashed is a combination of the volcanic eruption and the location. This can be one of the most destructive places on Earth for volcanic eruptions.

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ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://www.geology.sdsu.edu/how_volcanoes_work/Krakatau.html
  • InfoBoxCallToAction ActionArrowhttp://www.asianinfo.org/asianinfo/indonesia/pro-geography.htm
  • InfoBoxCallToAction ActionArrowhttp://www.indonesiapromo.com/java.html
  • InfoBoxCallToAction ActionArrowhttp://www.ess.washington.edu/tsunami/index.html