On 18th May 1980, Mount St Helens erupted in Skamania County, Washington. The force was enough to blow down trees 16 miles away and it was seen on the Space Shuttle from outer space. The sound measured 163 decibels and the force blew windows out up to 200 miles away in Seattle!
How far could you hear Mt St Helens?
The eruption that morning mowed down some 200 square miles of forest and collapsed the mountain’s elevation from 9,677 feet to 8,365 feet. The explosion was heard more than 150 miles away.
How long had Mount St. Helens been quiet?
Mount St. Helens remained dormant from its last period of activity in the 1840s and 1850s until March 1980. Several small earthquakes, beginning on March 15, indicated that magma might have begun moving below the volcano.
How much volume did Mt St Helens lose?
3.4 billion cubic yards
On May 18, 1980, the volcano lost an estimated 3.4 billion cubic yards (0.63 cubic mile) of its cone (about 1,300 feet or 396 meters in height), leaving behind a horseshoe-shaped crater (open to the north), with the highest part of the crater rim on the southwestern side at 8,365 feet (2,550 meters) elevation.
Is Mount St. Helens explosive or quiet?
Helens and other volcanoes in the Cascades arc due to subduction of the Juan de Fuca plate off the western coast of North America. Over its rich and complex 275,000-year history, Mount St. Helens has produced both violent explosive eruptions of volcanic tephra and relatively quiet outpourings of lava.
What was the loudest volcano ever recorded?
of Krakatoa
On the morning of 27 August 1883, on the Indonesian island of Krakatoa, a volcanic eruption produced what scientists believe to be the loudest sound produced on the surface of the planet, estimated at 310 decibels (dB).
Where is the loudest volcano?
The loudest sound in recorded history came from the volcanic eruption on the Indonesian island Krakatoa at 10.02 a.m. on August 27, 1883. The explosion caused two thirds of the island to collapse and formed tsunami waves as high as 46 m (151 ft) rocking ships as far away as South Africa.
Did they know Mt St Helens was going to erupt?
In 1980, Mt St. Helens’ continued seismicity warned scientists at monitoring stations that the volcano might erupt, but the danger zone around the mountain turned out to be much too small.
What animal survived Mt St Helens?
Gophers were able to survive underground after the 1980 Mount St. Helens eruption and helped plants thrive again.
Will Mt St Helens erupt again 2022?
We know that Mount St. Helens is the volcano in the Cascades most likely to erupt again in our lifetimes. It is likely that the types, frequencies, and magnitudes of past activity will be repeated in the future.
How much bigger would the Yellowstone than Mt. St. Helens?
The three caldera-forming eruptions at Yellowstone (2.1 million years ago, 1.3 million years ago, and 640,000 years ago), were respectively about 2,500, 700, and 1,000 times larger than the 1980 eruption of Mt. St. Helens in the state of Washington.
How long did it take to clean up Mount St. Helens?
Mount St. Helens: 40 Years of Recovery | Earth And The Environment.
How deep was the ash from Mt. St. Helens?
2 inches
Ash and pumice piled 6 miles (9.7 km) northeast of the volcano to a thickness of 3 feet (0.9 m); 50 miles (80 km) away, the ash was 2 inches (5 cm) deep. Large pyroclastic flows and mudflows subsequently rushed down St. Helens’ west flanks and into the Kalama River drainage system.
What is the quietest volcanic eruption?
Quiet Eruptions
Volcanoes that have very hot, low-silica magma generally erupt quietly. In a quiet eruption, lava erupts in a stream of low-viscosity lava, called a lava flow. Lava flows from a quiet eruption can travel for great distances.
What is the quietest type volcano?
Shield volcanoes, those with broad, gentle slopes, produce the quietest eruptions. The Hawaiian Islands are not only home to active shield volcanoes, but the chain is actually built entirely by them. The two most common types of volcanoes known for producing explosive eruptions are cinder cones and stratovolcanoes.
Is Mt St Helens still active?
Mount St. Helens is the most active volcano in the contiguous United States, which makes it a fascinating place to study and learn about. Scientists receive many questions about the volcano.
Why is 194 dB the loudest sound possible?
At 194 dB, the energy in the sound waves starts distorting and they create a complete vacuum between themselves. The sound is no longer moving through the air, but is in fact pushing the air along with it, forming a pressurized wall of moving air.
What is the quietest sound ever recorded?
-20.6dB
-20.6dB. With a sound level of -20.6dB, Microsoft’s anechoic chamber holds the Guinness Record for “World’s Quietest Place.”
How loud is the Tsar Bomba?
224dB
Tsar Bomba (224dB)
The Hiroshima and Nagasaki bombs of 1945 destroyed cities in an instant – but the Tsar bomb was 3,300 times stronger than that and is considered the strongest sound every produced by mankind, with the most reliable figure suggesting it clocked at 224dB.
What is the loudest sound ever made by a human?
A noisy restaurant – 70 dB. An electric drill – 95 dB. Jill Drake, a teaching assistant who in 2000 won the Guinness World Record for the loudest individual’s shout – 129 dB.
What is the loudest place on Earth?
The Loudest Cities In The World
- Kolkata, India.
- Cairo, Egypt.
- New York City, United States.
- Delhi, India.
- Tokyo, Japan.
- Buenos Aires, Argentina.
- Shanghai, China.
- Karachi, Pakistan. With five million vehicles on the road, it’s no wonder that traffic is the main cause of noise pollution in Karachi.