CHARLOTTE, NC (WBTV) – On this date in 1980,
Mt. St. Helens violently erupted in Washington state, sending millions of tons
of ash into the atmosphere.
The area had seen
approximately 10,000 smaller earthquakes around the volcano before the
eruption, and the USGS had been monitoring it for months before the eruption on
May 18. Even though there had been
warnings, fifty people were killed.
The eruption was so
violent, that a large part of the mountain slid away, creating the largest
landslide in Earth's documented history.
An 80,000 foot high
cloud of ash developed and began to spread.
A complete blackout was reported in Spokane, nearly 250 miles away. Ash was deposited in eleven states, and after
three days ash had traveled to the East coast.
In just over two weeks, it had circled the Earth.
Prior to the
eruption, Mt. St. Helens was 9677 feet tall. Afterwards, Mt. St. Helens was only
8363 feet tall, a change of 1314 feet.
Multiple lightning
strikes were recorded as plumes of ash were forced higher into the
atmosphere. While the exact cause of
these strikes is still debated among scientists, most generally agree that particles
traveling at such high rates of speed can break apart or collide with one
another.
Some form of
aerodynamics causes the negatively charged particles to be separated from the
positively charged, just as we would see in a thunderstorm. Lightning will occur when the charge
separation is too great for air to resist the flow of electricity.
While spectacular,
this is a fairly regular occurrence for this volcano. Mt. St. Helens has erupted nearly every one
hundred years since 1400 A.D.
