The Mauna Loa, the world's largest active volcano, has been reported Monday to be erupting for the first time in nearly 4 decades. Webcam footage released by the U.S. Geological Survey (USGS) Monday showed lava on the summit.
Hawaii's Emergency Management Agency said on Twitter that the eruption, for the moment, was limited to the caldera area of the volcano and posed no risk to communities at the base of the mountain. However, some shelters have been opened as a precautionary measure.
About half of the recorded eruptions of Mauna Loa have been confined to the caldera area without posing any danger to nearby populations, the bureau explained.
The U.S. National Weather Service said a remnant of ash less than a quarter-inch may accumulate in some parts of the island, so people with respiratory problems were advised to stay indoors so as not to inhale airborne particles.
The Mauna Loa volcano is just a few kilometers from the Kilauea volcano, which in 2018 suffered an eruption that destroyed more than 700 homes, forcing several residents to relocate.
In addition to the Mauna Loa, the world is on alert for other possible volcano eruptions in Russia, Chile, and El Salvador are also watching two volcanoes closely. Indonesia and Japan, which occupy the third region with the most volcanoes in the world, are safe for the time being.
For a volcano to be active it must have erupted or shown activity in the last 10,000 years. Eruptions come after magma heating due to a difference in pressure or density between the molten mass so the encasing rocks seek an exit. Eruptions are often preceded by seismic shocks and the emission of gases and vapors that rise to the surface through the outer cracks of a volcano.
Mauna Loa, in Honolulu, Hawaii, 4,169 meters above sea level, is the most active volcano in the world. After 40 years of dormancy, it erupted Monday around midnight, the U.S. Geological Survey (USGS) reported after upping the alert level from advisory to warning. It had last erupted in 1984. It lasted 22 days and produced lava flows that reached as far as about seven kilometers from Hilo, a town where about 44,000 people currently reside.
The United States leads the list of the country with the most volcanoes in the world, with 180. The largest number of volcanoes are on the Alaska Peninsula and the Mariana Islands.
Russia is the country with the second most volcanoes in the world: 152. The Institute of Volcanology of the Russian Academy of Sciences, Sunday warned that the Kliuchevskói and Shiveluch volcanoes on the Kamchatka peninsula had erupted Saturday after a strong earthquake.
Institute Director Aleksey Ozerov explained that the intensity of the eruption will increase and the explosions of Klyuchevskoye could last from several weeks to a year. The greatest risk is to Klyuchi, a town of 5,000 inhabitants, which is nestled between the two volcanoes, separated by about 30 and 50 kilometers. The only major city on the Kamchatka peninsula, Petropavlovsk-Kamchatsky, is located 450 kilometers from the volcanoes.
Chile is the Latin American country with the most volcanoes and ranks fifth in the world. There are 104 on this list, although several of them are on the dividing line with Argentina, so they belong to both territories. But the Villarica volcano is 100% in Chilean territory and experts deem the situation to be on yellow alert.
Meanwhile, the Chaparrastique volcano in El Salvador Sunday went into green alert (preventive) due to the repeated expulsion of gases and ashes. It last erupted in 2013 and 1976 before that.