10 things you need to know about the 2022 Mauna Loa Eruption
1 | When did Mauna Loa start erupting?
Mauna Loa volcano began erupting on November 27, 2022, at approximately 11:30 p.m.
2 | Will we see a cataclysmic eruption like we saw at Mt. Saint Helens back in the 1980’s?
Not likely, thank goodness. The magma at Mauna Loa has less dissolved gases than the magma at Mt. Saint Helens which makes these Hawaiian eruptions significantly less explosive than what we see in the Cascades of the western USA.
This image, taken during an early morning overflight, shows the Mauna Loa's Northeast Rift Zone fissure 3 vent and lava channel. Fountain heights of 130 feet (40 meters), with bursts over 330 feet (100m) were measured by HVO field crews. USGS image by L. Gallant.
3 | What kind of economic impact could we expect to see from this latest eruption?
Volcanic eruptions are big business for tourist centric Hawaii and this new eruption has people from all over the world flocking to see new Earth born right before their eyes. The 2022 Mauna Loa eruption will without a doubt boost the economy of the state of Hawaii.
Unfortunately, there is a distinct possibility that the main road used for commerce on the Big Island of Hawaii is at risk of being cut off by the incoming lava flow. If this occurs, the residents of the island will be forced to lengthen their daily commutes by hours. Beyond commuters, this is also anticipated to negatively impact emergency response capabilities and hurt businesses who relied on this vital route. While the boom in tourism is great, some residents are wondering how the island will cope with this until the roads are repaired. As of December 5th the road remained open.
4 | When did Mauna Loa last Erupt?
Mauna Loa last erupted in 1984. After being mostly silent for 38 years, the volcano woke up in November 2022.
This image, taken midday during a helicopter overflight of Mauna Loa's eruption on December 5, 2022, shows a lava flow branching after it cuts across the Mauna Loa Access Road. The large blocks in channel are called lava boats. These are termed lava balls or lava boats and form when portions of the fissure 3 cone or levees break away and are rafted down stream. As they move along in the channel, additional lava can cool to their surface to form accretionary lava balls. USGS image by L. Gallant.
5 | Are people and property in danger?
Thankfully people and private property are not at risk as of December 6th 2022 as the lava flow is still in a rural, uninhabited area at high elevation but this could change at any time. Residents and visitors should stay in communication with their local authorities to get the latest news on the flow.
6 | Did the Mauna Loa eruption cause earthquakes?
Yes! Lots of them. The biggest earthquake was a magnitude 4.2 the day after the eruption began.
Map of Hawaiian Earthquakes November 6-December 6th 2022 (USGS)
7 | Is Mauna Loa really the largest active Volcano in the world?
Yes! Mauna Loa is absolutely enormous.
Mauna Loa is more than 4 km (2.5 mi) above sea level, Hawaii’s Mauna Loa is the largest active volcano on our planet. Below the ocean’s surface, Mauna Loa extends another 13 km (8 mi). This means the volcano's summit is about 17 km (10.5 mi) above its base which makes Mauna Loa not only the biggest volcano in the world, it is also the tallest mountain too. Mt. Everest from summit to base is only 8.85 km (5.5 mi).
8 | What is “vog” and why is it dangerous?
Volcanic + Fog = Vog
Vog is a naturally occurring phenomenon where toxic and sometimes deadly volcanic gasses mix with the atmosphere or fog in a similar way to smog. Vog is directly affected by current weather conditions in addition to volcanic gas output. Unlike lava, Vog can quickly travel to inhabited areas and become a danger. Residents and visitors should stay in contact with local authorities to learn more about the risks of Vog in Hawaii.
Aerial image of the distal end of a lava flow from Mauna Loa's Northeast Rift Zone the morning of November 30, 2022. As of 12:30 HST p.m. on November 30, the flow front remained about 3.6 miles (5.8 km) from the Daniel K. Inouye Highway (Saddle Road). USGS image by K. Mulliken.
9 | Where does Mauna Loa’s magma come from?
Unlike most volcanos that are a result of tectonic subduction, the magma chamber that feeds Hawaiian volcanos is sourced by a Hot Spot in Earth’s crust. Hot Spots are defined as exceptionally hot regions of contact between Earth’s crust and mantle. The Hot Spot below Hawaii is stationary and does not move. New Hawaiian Islands are formed when the Pacific plate moves across this stationary hotspot giving us a somewhat linear chain of islands.
10 | When can we expect this eruption to end?
This depends on several factors and it is too soon for scientists to be sure. Many of Mauna Loa’s previous eruptions only lasted for 2-4 weeks but the volcano has never had a period of rest this long in recorded history so who knows what we can expect other than a magnificent show by Mother Nature.
Update: Mauna Loa has stopped erupting as of December 12th 2022 and efforts to survey the damage caused by the volcano have now begun.