Significance

• Mauna Loa is the largest volcano on the planet. It is located in the Hawaiian Islands and has been erupting for at least 700,000 years according to scientists. The first eruption of Mauna Loa that was documented by science occurred in 1843, although it has erupted countless times before that. Since 1843 it has erupted 33 more times. The last one came in 1984 when the volcano erupted from March 24th to April 15th, a total of 23 days. Volcanoes such as Mauna Loa, which is just one of many in that region, both above and under the water, are significant because their lava created the islands.
  
  

Effects

• Mount Vesuvius in Italy has erupted many times. Its most famous came in 79 AD when over a period of two days it erupted violently and destroyed the cities of Pompeii and Herculaneum. This catastrophic eruption lasted for only 18 to 20 hours according to the eyewitnesses that survived. There was much seismic activity prior to the eruption, with earthquakes of major proportions years before and a series of strong tremors for weeks preceding the eruption. This eruption killed thousands, many whose preserved remains have been found and extensively studied.
  
  

History

• The human race got a rare look at the actual birth of a volcano in Mexico in 1943. From out of a farmer's field the Paricutin volcano rose. It began as a fissure on February 20th, 1943 and began to spew ash and stones at first. The eruption continued for weeks and the volcano grew in size, burying nearby villages under metric tons of debris. Paricutin would erupt for more than eight years, finally going dormant in 1952 when it had attained a height of 424 meters. It has not erupted since.
  
  

Time Frame

• No volcanic eruption in modern times was more cataclysmic than that of Krakatoa in 1883. Located in the Indonesian island chain it began to show signs of something brewing in the years before. Steam began to vent from Krakatoa in May of 1883 and it erupted on July 20th of that year but nothing out of the ordinary. Larger eruptions took place on August 11th and from August 26th through the 27th it culminated in a volcanic eruption and explosion that was heard almost 2,000 miles away. The resulting tsunamis are thought to have killed as many as 120,000 people in the region and the volcanic ash sent into the atmosphere from the blast decreased the average temperature of the entire planet for a year afterward by reflecting sunlight back into space.
  
  

Considerations

• The deadliest volcanic eruption in U.S. history came on May 18, 1980 when Mt. St. Helens in Washington State blew its top. fifty-seven people were killed by this event and damage was in the billions of dollars to surrounding areas. There were earthquakes leading up to the eruption and scientists were deployed to study it but none could have been prepared for the final conclusion. The eruption lasted for a bit more than a day and took more than 1,300 feet off the top of the mountain.