Questions remain nearly 100 years since the Tunguska Event of 1908 devastated the Central Siberian forest: Was it ball lightning? Did the event trigger climate change?

Stony Tunguska River

On June 30, 1908 in Central Siberia, a mysterious event occurred, leaving thousands of acres of forest burnt and charred and many people wondering just what had happened. Containing more energy than an atomic bomb, the explosion burst into luminous flames just 5 miles or 7.5 km above the Earth.

The explosion's energy has been compared to 20 million tons of TNT (BBC, 2007). The explosive event left 2,000 square kilometers of trees and vegetation knocked down and burned. A ring of destruction lies up to 34 km from the epicenter in every direction. Scientists estimate 60 million trees were thrust down by the blast, as reported by BBC. A 5.0 earthquake was registered by the nearest seismic station.

What Caused the Tunguska Event?

Many people believe a comet crashing onto the Earth’s surface caused the blast. The National Geographic News reported in November 2007 that scientists had found a crater, made by a cosmic object. The crater lies under the water of Lake Checko in Western Siberia. Yet, the scientists have found no object or material from the comet itself.

A Meteorological Event?

The closest weather station in Kezhma, located 214 km away from the epicenter, recorded earthquake-like vibrations during the event. Witnesses say the skies were clear that day. Yet, other meteorological factors point towards the possibility of a meteorological event occurring. There was evidence of strong cyclones near Siberia that summer. Significant increases in air pressure were associated with the area at that time. Increased thunderstorm activity and intensity inundated Russia. Witness accounts detail hearing thunder and seeing lightning as the event occurred. Perhaps there is some credit to the theory that the Tunguska event transpired as a meteorological occurrence.

Ball Lightning

One other possible cause of the Tunguska event is ball lightning. However, ball lightning is a phenomenon not consensually understood in the scientific world. A March 20, 2008 report by ABC Science of Australia, interviewed a leading ball lightning scientist, Emeritus Professor Bob Crompton, who says that currently there is no satisfactory explanation of the phenomenon.

Ball lightning is a spherical, luminous phenomenon that occurs most often during thunderstorms. It is considered a form of lightning. It can move horizontally, hover or in a zigzag motion, even witnessed to move through walls.

Ball lightning has been recorded as occurring during a thunderstorm, just after a lightning bolt strikes, which causes a high electrical field. Some scientists have been able to recreate ball lighting in laboratories. One scientist, Nikola Tesla, even mastered the production of lightning before the Tunguska event occurred. He is known as the "Master of Lightning".

Effects of Tunguska

Some climatologists and scientists concur that the Tunguska event caused major damage to the air layer of the mesosphere. These atmospheric changes resulted in an ozone depletion lasting up to four years after the event. A cooling trend in the years following the 1908 event was recorded in weather records around the Earth.

Several scientists even go so far as saying the Tunguska event triggered a natural climate change, resulting in the rising of the global temperature over the last one hundred years. The blast is said to have sent 30 million tons of nitric oxide into the stratosphere and mesosphere, leading to ozone depletion and climate change.

Sources:

BBC

National Geographic News