Sprat Issue 4 – Volcanic Activity

By James Donahue

In his list of concerns, the person identifying himself as Jack Sprat lists increased volcanic activity. While we have been made aware of more volcanic eruptions in recent years, especially along the "Ring of Fire" surrounding the Pacific Ocean, there is a clear difference of opinion among scientists as to whether the world is experiencing more eruptions now than in the past.

Some are saying we are simply more aware of the volcanic activity because of the Internet and the fact that all world volcanos are plotted and recorded daily. Also true is that because of an increase in the world population, more people are today living under the shadow of volcanos that have remained dormant for hundreds of years.

One report claims that there has been no significant increase in volcanism since comprehensive reporting began in the 1960s and shows a chart that indicates a linear regression line that indicates world volcanism has been relatively constant.

There is another chart, however, by Simkin and Siebert, taken from the Smithsonian Institute Catalog of world volcanos that suggests a significant increase in volcanic activity from 1875 to 1990. Interesting enough, the spike in volcanism began in about 1960. While there have been more volcanic eruptions since about World
War II, the number of major eruptions has remained somewhat constant.

Overall this may account for the reason that ash from the extra volcanism has not collected in the upper ionosphere of the planet and thus blocking out the sunlight and causing a general cooling of the Earth.

The 1815 eruption of Mount Tambora in Indonesia, the largest spewing of ash and volcanic gasses known to have occurred in over 1,300 years, was blamed for a global temperature drop that caused 1816 to be remembered as the "Year Without a Summer." Seasonal frosts across the Northern Hemisphere caused a major food shortage and thousands died from the cold and starvation.

Can it happen again? Indeed there exist numerous major volcanos on the planet that have been known for causing the same kind of havoc. We all remember the 1980 eruption of Mt. St. Helens that spewed ash across much of North America, but that was relatively small in comparison to some of the other big explosions that have occurred within recorded human history.

There was the eruption of Mt. Vesuvius in 79 AD that buried the entire city of Pompeii. Then there was the eruption of Krakatoa, Indonesia in 1883 that blew the entire mountain away and sent a super shock wave and tsunami that left an estimated 32,000 people dead on the surrounding islands.

Mt. Pelee, Martinique exploded in 1902 killing 29,000 people, and Colombia’s Nevada del Ruiz erupted in 1985 killing another 23,000 people.

Also rumbling and believed to have the capacity to do as much damage are Mt. Rainier near Seattle, Washington, Mt. Fuji near Tokyo, and Mt. Popocatepeti that looms over Mexico City.

Then there are the six known world "super volcanos" that are so mammoth in size, and their vaults of steam and lava reaching so deep in the earth that volcanologists fear that if any of them ever erupt they may have the capability of destroying all life on the planet.

Each of these monsters are located in places where hot steam vents and bubbling mud pits signal lots of energy escaping from under them. The areas are referred to as calderas. They are located at Yellowstone National Park in North America; Long Valley, a 200-square-mile caldera in East-Central California, Valles in Northern New Mexico; the 1,080-square-mile Toba caldera in North Sumatra, Indonesia; the Taupo caldera in New Zealand and the Aira caldron in Southern Japan.

That three of these monster volcanos lie in the United States is fearsome enough. It is said that the Yellowstone caldera sits on a subterranean chamber of molten rock and gasses so vast that it is believed to be one of the largest active volcanoes in the world.

Yes Mr. Sprat, there appears to have been an increase in world volcanic activity since about 1950, but most of them were small and they did not threaten the world. The big ones are rumbling once in a while, and smoldering just enough to let us know they are still active. The Mother Earth could awaken them at any time.