The Island of Hawaii is on alert as seismic activity continues underneath Mauna Loa, suggesting that magma bodies may be shifting under the giant volcano. Despite the mounting quake activity — with the number of tremors beneath the summit having increased from 10–20 per day to 40–50 last month, reaching magnitude 5.0 two weeks ago — experts have said that an eruption is not likely to be imminent. Hawaii, also known as The Big Island, is home to a population of around 201,500 people who could be at risk in the event of a volcanic eruption.
Mauna Loa, which reaches an elevation of 13,679 feet above sea level at its summit, is the largest land-based volcano on the planet.
The mountain is an example of shield volcano — so named because the runny, non-explosive nature of the magma that formed it resembles a large shield on the ground.
Geologists believe that Mauna Loa has been erupting for at least 700,000 years — peaking about the sea surface some 400,000 years ago — fuelled by magma from the underlying Hawaii hotspot, which is responsible for the creation of the whole Hawaiian archipelago.
Mauna Loa last erupted in 1984, when a narrow flow of ʻAʻā — a basaltic lava that formed a rough of rubbly surface as it cools — passed within four miles of Hilo, close enough for the glow from the molten rock to illuminate the town at night.
Dr Ken Hon is an earth scientist and the chief scientist at the US Geological Survey’s Hawaiian Volcano Observatory, which has been monitoring the rumblings under Mauna Loa science September.
He said: “Mauna Loa continues to be in a state of heightened unrest.”
However, he added, “the current increase in activity does not suggest that a progression to an eruption is certain.”
Nevertheless, data from the Hawaiian Volcano Observatory as well as snapshots and recaps of Mauna Loa’s seismic activity are being posted to social media daily by the Hawaii County Civil Defense Agency.
Hawaii County civil defense administrator Talmadge Magno reiterated Dr Hon’s assessment, saying: “Under current conditions an eruption from Mauna Loa is not imminent.
“We’re reminding people to take this opportunity to register for county emergency alert messages and prepare or review their plans to be ready for any disaster.”
Last Saturday, Mr Magno and Dr Hon met with local residents at the Ocean View Community Centre on the south of the island to discuss the latest scientific observations and emergency preparedness measures.
Another local information session is being planned for 5.00–7.00pm tonight, local time, at the Robert N. Herkes Gymnasium in the neighborhood of Pāhala.
