This morning we heard that Mauna Loa, Big Island’s second largest volcano, is erupting. Should you be concerned? What does this mean for your Maui vacation?
Where is Mauna Loa?
Let’s start with geography. The Hawaiian Islands are comprised of seven main islands. Southeast most in the island chain is the Island of Hawaii, also known as Big Island. Did you know, it is larger than all other islands combined? Hence the name. It is home to five shield volcanos, including two active ones (Kilauea and Mauna Loa). Maui is located to the west of Big Island, followed by Lanai and Molokai, Oahu (home to Honolulu ~ incidentally not on the largest island, though many think it is), Kauai and Ni’ihau. The distance between the summit of Mauna Loa and Kihei is 104 miles. Less to Hana (92 miles).
The Hawaiian islands are all volcanos, formed when the tectonic plate moved over a hot spot plume. I took the (above) photo at the interpretive center at Kilauea’s caldera a number of years ago.
Have a look at the livecam from Mauna Loa’s NW rim caldera.
What is a shield volcano?
Hawaii’s volcanos are shield volcanos. They actually look relatively unimpressive because of their gentle slopes. Mauna Loa, the volcano that just started its eruption, is 13,681 ft above sea level. Haleakala, Maui’s Eastern volcano, is 10,023 ft above sea level. Shield volcanos have these gentle slopes because of the way they erupt – the basalt lava is relatively runny, so it just spreads out, rather than chunky lava would. For much more (scientific) information about Hawaii’s volcanos, please check out the National Park Services website.
More volcano lingo
The news story today mentioned a caldera ~ this is a collapse depression where magma has shifted from a shallow magma chamber underneath. They are usually near the top of the shield volcano. The floor of these calderas can break open (fissures or rifts) and allow a lava lake to form. Mauna Loa currently has a lava lake forming in its caldera. This lava lake may or may not spill out of the caldera and start making its way down the slopes. The news story also mentions Pele’s hair. Pele is the Hawaiian Goddess of Fire. Pele’s hair is volcanic glass formed during eruptions. It is very brittle and sharp.
How will Mauna Loa’s eruption impact your Maui stay
As with Kilauea’s eruption in 2018, you will not be able to see the lava flow from Maui. It will not heat up the ocean (significantly enough for you to notice), you should not be in any additional danger from ash or Pele’s hair. You will experience vog depending on the wind direction. Vog is volcanic air pollution. When the trade winds are blowing, they blow the vog west and away from us. However, every now and then trade winds subside and we experience a Kona weather pattern which brings the the vog from Big Island to us. We currently have a wet weather system coming in from the West, causing Kona weather, and yes, I did faintly smell vog this morning on my walk. If you have asthma, you may experience some symptoms.
How to get the most accurate information
The news media make their money by the way they tell stories. This morning I checked various media outlets to see what stories they were telling. Hawaii news stations (KHON, Hawaii News Now and the likes) were the tamest/most accurate, some mainland stations told a bit more drama than what was actually happening. Big Island’s mayor is directing residents to Big Island’s County’s Civil Defense site for the most up-to-date information.
How to go see the lava flow?
Well, this is really early days. Who knows what will happen with this current eruption. It may stay contained within the lava lake, it may start flowing. It may fizzle out in a few weeks, or it may be a longer event. There is a road that leads to the summit of Mauna Loa (which also has an observatory/research station). In 2016 I took our boys to Big Island on a helicopter tour to see Kilauea in action. We flew into Hilo with Hawaiian Air and booked the Circle of Fire tour with Blue Hawaiian Helicopters. We stayed overnight at the Hilo Hilton and drove to Kilauea’s summit to see the (at the time small) lava lake in the caldera. It was such a neat experience for us. Incidentally, Kilauea currently also has a lava lake.
If you are interested in doing something like this, do your research, see what kind of volcanic activity is going on much closer to your trip. When Kilauea erupted in 2018 and the lava flow inundated homes in Puna district, helicopter tours stayed well away from that area, both for their own safety but also to protect residents’ privacy. At the time the lava inundation areas were closed off with even residents not being allowed in. Please be respectful of residents whose lives may be dramatically impacted by nature.