Mauna Loa, the world’s largest volcano in the United States, erupted for the first time since 1984, spewing lava.
Lava flows below the volcano at temperatures of 1,000C. Experts say it does not yet pose a major threat to local residents.
How big is a volcano?
Mauna Loa means ‘long mountain’ in Hawaiian. It is the largest active volcano in the world.
The Mauna Loa volcano is located on the island of Hawaii along the Pacific Ocean to the west of the United States.
It covers an area of 2,035 square miles (5,271 square kilometers) among the five volcanic ranges that make up the Big Island of Hawaii.
This one volcano alone occupies half of this island.
The summit of Mauna Loa is 13,680 feet above sea level. But, its bottom is on the sea floor.
It is 30,085 feet (9,170 meters) from the sea floor to the summit, making it taller than Mount Everest.
Why is Mauna Loa volcano erupting?
Debris and gases of super-hot material called magma are rising from the hottest part of the Earth deep beneath Mauna Loa and nearby volcanoes.
Dr Carmen Solana, a volcanologist at the University of Portsmouth, said: “Nobody knows exactly why this hot spot exists, but it could be caused by the decay of radioactive material in the Earth’s crust.”
“The debris and gas from this magma formed all the islands in Hawaii.” When Mauna Loa erupts, magma first fills the caldera, the bowl-shaped crater at the top of the volcano, says Dr. Solana. It has an area of 6 square miles (15 sq km) and a depth of 600 feet (180 m).
How do volcanoes erupt?
Magma comes out in fountains from “fissures” or fissures in the rock on the side of a volcano. Some of these springs break 40m high.
It flows down the mountainside as liquid lava with a temperature of 1,000C.
Lava is ejected into the air, some of which stretches out into fine glassy strands like what is said to be the hair of the goddess Pele.
“Pele is the name of the deity who is said to live in Hawaii, and these petals are brownish-golden in color,” says Dr. Solana.
Why is Melana Loa’s explosion so important?
Melana Loa has erupted 33 times since it was first recorded in 1843. It has erupted on average once every five and a half years.
However, the last volcanic eruption occurred about 40 years ago.
In the past 10 years there have been some signs of magma filling up, but no eruption has yet occurred, says Andrew Sacooper, professor of geophysics at the University of Wits in Britain.
The fact that Mauna Loa is now erupting has given a new generation of scientists the opportunity to study how the volcano works, says Professor Cooper.
“It will be interesting for us to see where the magma is stored inside Mauna Loa — between the time it rises well up from the Earth’s mantle and the way it comes out of the volcano’s surface,” he says.
Is Mauna Loa Volcanic Eruption Dangerous?
Mauna Loa volcano’s debris and gas does not really erupt like many other volcanoes that are exposed high in the air.
In contrast, lava flows very slowly down the flanks of the volcano.
“Lava lava flows are not life-threatening because you can get out of the way,” says Professor Hooper.
“Also, the lava flow is not moving down the volcano toward nearby towns, but toward the northeast. It has to travel far in that direction before it can cause serious damage to property.”
However, local people may be at risk from the gases emitted by the Mauna Loa volcano.
“Volcanic gases, including sulfur dioxide… react with moisture in the air to form ‘volcanic fog’,” says Dr. Solana.
“It can cause problems for people living below this volcanic area. It can cause eye irritation and respiratory problems for some people.”
Local health officials say air quality is still good, but warn it could get worse.
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