Kilauea volcano active since 1983, some perspective on volcanoes
HAWAII COUNTY, Hawaii — The most active volcano on Earth has captured our fascination again. Not to mention our fear and respect: 1,700 people had to flee their homes as lava broke the surface near their community Thursday and Friday. The activity appears to be continuing into the weekend, with strong earthquakes of up to a highly unusual preliminary magnitude of 6.9, more ground cracks opening, and new vents opening within residential areas.
Kilauea volcano, on the Big Island of Hawaii, has been erupting continually along its East Rift Zone since 1983. Most of the time, the lava flows south toward the ocean, threatening nobody. But occasionally it goes in a different direction.
Clearly, the events that have happened on the island since Friday dictates a much more active time now:
Let’s put this volcanic activity into some perspective with this background information about volcanoes.
More than 80% of the Earth’s surface, both above and below sea level, is of volcanic origin.
Lava is molten rock from a volcano that reaches the Earth’s surface. The liquid rock below the Earth’s surface is referred to as magma.
There are more than 500 volcanoes that have erupted at least once in the world and 50 of them are located in the United States.
More than 50 percent of the world’s active volcanoes above sea level encircle the Pacific Ocean, forming the “Ring of Fire.” The ring stretches from New Zealand to the coast of South America, running along the west coast of the United States.
In 2010, a volcano eruption in Iceland disrupted air travel for days across Europe. The eruption expelled an ash cloud 30,000 feet into the air. The International Air Transport Authority estimated that the airline industry lost $1.7 billion in revenue due to the disruption.
Deadliest Volcanic Eruptions since 1500 AD.
Volcanic Explosivity Index (VEI): The Volcanic Explosivity Index, which measures the relative explosiveness of volcanic eruptions, was devised in 1982. On a scale of 0-to-8, each number represents a tenfold increase in explosive power.
The VEI uses several factors to determine a number, including volume of erupted material, height of eruption column and duration in hours.
Major eruptions: Selected VEI 4 and above (1902 – current): Sources: NOAA Significant Volcanic Eruption Database and Smithsonian volcano database
Note: Dates listed cover the day of peak explosive activity.
May 6, 1902 – Soufrière St. Vincent on the island of Saint Vincent erupts, resulting in about 1,680 deaths. (VEI 4)
May 8, 1902 – Pelée on Martinique erupts, killing about 28,000 people. (VEI 4)
October 24, 1902 – Santa Maria in Guatemala erupts, resulting in about 2,500 deaths. (VEI 6)
June 6, 1912 – Novarupta volcano erupts in Alaska, killing two people. It is the largest volcanic eruption of the 20th century. (VEI 6)
January 20, 1913 – Colima in Mexico erupts. The number of deaths is unknown. (VEI 5)
May 19, 1919 – Kelut in Indonesia erupts, resulting in 5,110 deaths. (VEI 4)
January 21, 1951 – Mount Lamington in Papua New Guinea erupts and kills nearly 3,000 people. (VEI 4)
March 17, 1963 – Agung in Indonesia erupts, killing more than 1,000 people. (VEI 5)
March 29 1982 – El Chichón in Mexico erupts, resulting in 1,879 deaths. (VEI 5)
May 18, 1980 – Mount St. Helens in Washington erupts, killing 57 people. (VEI 5)
June 15, 1991 – Pinatubo in the Philippines erupts, killing about 350 people. (VEI 6)