Randy Mann: Volcanic activity enough to give us pause

Volcanic activity across the planet may be showing signs of increasing. Within the last month, a new lava flow and moderate emissions of white steam were seen at the Mayon Volcano in the Philippines. Indonesia’s Mount Sinabung has been erupting with smoke and lava flows, forcing hundreds to flee from the huge blasts. In Japan, Mount Ontake erupted, killing at least 31 people; and southern Japan is showing signs of activity in this country that has over 100 active volcanoes.

In 2010, the eruption of Iceland’s Eyjafjallajokull volcano halted flights in Europe and other areas causing more than $7 billion in lost revenue for the airlines. In a remote area in central Iceland, the Bardargunga volcano erupted on Aug. 31; it was bigger than the one in 2010.

Predicting a major volcanic eruption has not quite become a reality, but much progress has been made. It seems that eruptions tend to come in bunches. Many explosions often are preceded by earthquakes, a swelling of the ground, the formation of cracks and the release of gases. There are also thermal infrared sensors in satellites to help detect the hot spots.

If we were to see several major eruptions within a short period of time, it’s possible that the Earth would be cooled by at least 1 to 3 degrees as all the dust and ash in the upper atmosphere would partly shield the sun’s rays and greatly disrupt worldwide weather patterns. Temperatures did cool rather dramatically during the “Year without a Summer” following the major eruption of Mount Tambora in 1815. Snow fell every month in 1816 at the higher elevations in the interior Northeast while freezes blackened crops that summer in the valleys of northeastern New York state, interior New England and much of southeastern Canada.

In June 1991, Mount Pinatubo erupted in the Philippines. The Earth’s temperature temporarily fell 1 to 2 degrees the following year, but quickly rebounded. This eruption was much smaller than Mount Tambora’s.

There has been concern over the huge supervolcano in Yellowstone National Park. Although a major eruption there would throw the Earth into sustained winterlike conditions almost immediately, a significant explosion is not expected for at least thousands of years.