Air quality advisories issued in 5 provinces, 1 territory
Air quality advisories are in effect across Western Canada as smoky conditions plague some areas, according to the latest forecasts. Here's where.
Lava is shooting 100 feet to 200 feet (30 to 60 metres) into the air as Hawaii's Mauna Loa, the world's largest active volcano, erupts for the first time in nearly 40 years.
For now, lava is not threatening any homes or communities and no evacuation orders have been issued. Lava could eventually reach neighbourhoods as it flows downhill though it could take a week or more for molten rock to reach populated areas.
Mauna Loa is spewing sulphur dioxide and other volcanic gases. They form volcanic smog, or vog, when they mix with vapour, oxygen and dust in sunlight. As a result, state health officials are urging people to cut back on outdoor exercise and other activities that cause heavy breathing.
Mauna Loa last erupted in 1984. Its smaller, more active neighbour, Kilauea volcano, has been erupting continuously for more than a year since September 2021.
Mauna Loa is one of five volcanoes that together make up the Big Island of Hawaii, which is the southernmost island in the Hawaiian archipelago. It's not the tallest (that title goes to Mauna Kea) but it's the largest and makes up about half of the island's land mass.
It sits immediately north of Kilauea volcano, which is well-known for a 2018 eruption that destroyed 700 homes and sent rivers of lava spreading across farms and into the ocean.
Mauna Loa last erupted 38 years ago. The current eruption is its 34th since written history began in 1843.
The Big Island is mostly rural and hosts cattle ranches and coffee farms but it is also home to a few small cities, including the county seat of Hilo, which has a population of 45,000.
It's about 200 miles (320 kilometres) south of Hawaii's most populous island, Oahu, where the state capital, Honolulu, and beach resort Waikiki are both located.
Mauna Loa's volume is estimated to be at least 18,000 cubic miles (75,000 cubic kilometers), making it the world's largest volcano when measured from the ocean floor to its summit.
The eruption began Sunday night at its summit after a series of large earthquakes. It then spread to vents that formed in a rift zone where the mountain is splitting apart and it's easier for magma to emerge.
These vents are on the mountain's northeast side and lava emerging there could head toward Hilo, which is on the east side of the island.
Ken Hon, scientist-in-charge at the Hawaiian Volcano Observatory, said he doesn't expect additional vents to form on the volcano's southwest rift zone during this eruption. That means communities to the west would be spared lava flows this time.
Mauna Loa also erupted from the northeast in 1984. That time, lava headed toward Hilo but stopped a few miles short of the city.
Historically, each Mauna Loa eruption has lasted a few weeks. Hon expects the current eruption to follow this pattern.
Mauna Loa is not exploding like Washington state's Mount St. Helens did in 1980, killing 57 people. That eruption sent ash soaring over 80,000 feet (24,384 meters) and raining down as far as 250 miles (400 kilometres) away.
The magma in Mount St. Helens tends to be stickier and traps more gas, making it much more likely to explode when it rises. It's of a variety called composite volcanoes, which form concave cones.
Mauna Loa's magma tends to be hotter, drier and more fluid. That allows the magma's gas to escape and lava to flow down the side the volcano the way it is starting to do now. Mauna Loa is a shield volcano, named because the long, broad flanks built by repeated lava flows give it the appearance of a warrior's shield.
In 1989, Alaska's Redoubt Volcano, another composite volcano, belched an 8-mile cloud of ash that clogged all four engines of a KLM Royal Dutch Airlines jet. The plane fell 13,000 feet before all engines restarted and the plane landed without injury to the 245 people aboard.
Mauna Loa released some ash this time but on a vastly smaller scale than these examples from composite volcanoes.
Lava: Molten rock could cover houses, farms or neighbourhoods, depending on where it flows. But lava from the northeast rift zone will likely take at least a week to reach populated areas, allowing people time to evacuate if needed.
Volcanic gas: Mauna Loa is releasing volcanic gases, mostly sulphur dioxide. The gases are present in their highest concentrations in the immediate area around the summit crater or vents. But they also combine with other particles to form vog, which can spread across the Big Island and even waft over to the state's other islands.
Vog can give healthy people burning eyes, headaches and sore throats. It can send those with asthma or other respiratory problems to the hospital.
Glass particles: When hot lava erupts from a fissure and rapidly cools, it forms glass particles named "Pele's hair" and "Pele's tears" after the Hawaiian goddess of volcanoes.
The particles tend not to travel far from volcanic vents -- maybe only a few hundred yards or a mile -- and won't threaten many people, said Aaron Pietruszka, an associate specialist at the University of Hawaii's Department of Earth Sciences.
"It just literally looks like hair strands. And that's where the fluid lava is stretched by the wind to make long, thin strands," said Pietruszka.
The glass bits -- as short as a few millimetres or as long as a few inches -- can be sharp.
"You wouldn't want to be digging your hands in it because you could get a cut," Pietruszka said.
An N95 or KF94 mask would protect against these glass particles but not against volcanic gas, said Dr. Libby Char, the director of the state Department of Health.
"Pele's hair" specimens from Kilauea volcano's eruption are visible at Hawaii Volcanoes National Park.
Mauna Loa released about 15,000 tons of carbon dioxide per day during its 1984 eruption, according to USGS data.
That's equivalent to the annual emissions from 2,400 sport utility vehicles.
Scientists say all of Earth's volcanoes combined emit less than one percent of the carbon dioxide that humans produce each year.
This story has been updated to correct figure for Mauna Loa's volume.
Air quality advisories are in effect across Western Canada as smoky conditions plague some areas, according to the latest forecasts. Here's where.
After receiving a DNA kit one Christmas from his son-in-law, Hugh McCormick soon discovered that he had six unknown siblings, with whom he shared the same birth parents.
Four years on, the controversy over whether airlines owed refunds to passengers after cancelling hundreds of thousands of flights during the pandemic continues to simmer, aggravated by a sluggish, opaque complaints process.
Many foods fall under the category of ultraprocessed foods, depending on their exact ingredients. This type of food has been studied a lot lately, and the results aren’t great.
Dozens of Ontarians are expressing frustration in the province’s health-care system after their family doctors either dropped them as patients or threatened to after they sought urgent care elsewhere.
A new study projecting declining rates of cancer cases and deaths in Canada demonstrates the success of prevention and early detection programs, but also highlights areas where more work is needed to save and prolong lives, researchers say.
The star prosecution witness in Donald Trump's hush money trial is set to take the stand Monday with testimony that could help shape the outcome of the first criminal case against an American president.
Millions of Indians across 96 constituencies began casting their ballots on Monday as the country's gigantic, six-week-long election edges past its halfway mark. Prime Minister Narendra Modi is seeking a third straight term with an eye on winning a supermajority in Parliament.
An Ottawa pizzeria is being recognized as one of the top 20 deep-dish pizzas in the world.
English, history, entertainment, math and geography: high school trivia teams could be quizzed on any of it when they compete at the Reach for the Top Nationals in Ottawa in June.
An Ottawa pizzeria is being recognized as one of the top 20 deep-dish pizzas in the world.
A family of fifth generation farmers from Ituna, Sask. are trying to find answers after discovering several strange objects lying on their land.
A Listowel, Ont. man, drafted by the Hamilton Tigercats last week, is also getting looks from the NFL, despite only playing 27 games of football in his life.
The threat of zebra mussels has prompted the federal government to temporarily ban watercraft from a Manitoba lake popular with tourists.
A small Ajax dessert shop that recently received a glowing review from celebrity food critic Keith Lee is being forced to move after a zoning complaint was made following the social media influencer’s visit last month.
The Canada Science and Technology Museum is inviting visitors to explore their poop. A new exhibition opens at the Ottawa museum on Friday called, 'Oh Crap! Rethinking human waste.'
The Regina Police Service says it is the first in Saskatchewan and possibly Canada to implement new technology in its detention facility that will offer real-time monitoring of detainees’ vital health metrics.
Just as she had feared, a restaurant owner from eastern Quebec who visited Montreal had her SUV stolen, but says it was all thanks to the kindness of strangers on the internet — not the police — that she got it back.