Mauna Loa’s seismic activity puts Hawaiians on alert – The Ticker

Recent earthquakes and seismic activity have put residents near Mauna Loa, the world’s largest active volcano, on high alert, but scientists say the volcano won’t erupt anytime soon.

Located in Hawaii, Mauna Loa is one of five volcanoes on the Big Island. Although Mauna Loa is not the tallest volcano, it is the largest and makes up half of the island’s landmass.

According to the Hawaiian Volcano Observatory US Geological Survey, or USGS, the volcano is under a “yellow” warning, meaning Mauna Loa is showing signs of “increased unrest as indicated by increasing earthquake activity and peak inflation.”

The HVO has detected low-magnitude earthquakes about two to three miles below the Mokuʻāweoweo Caldera due to new magma inflow.

“The disturbances are likely caused by the re-entry of magma into Mauna Loa’s summit reservoir system,” the observatory said. “As the reservoir expands, it triggers small earthquakes just below the Mokuʻāweoweo Caldera and in a region just northwest of the caldera.”

The series of earthquakes has been occurring since June, ranging from 10 to 20 per day to more than 40 to 50 per day in September. According to this, it reached a peak of 100 earthquakes per day on September 23 and 29 CNN.

Unlike Kīlauea, which is on the southeast coast of the Big Island, Mauna Loa is larger and therefore eruptions can involve faster lava flow due to its altitude. It also has a larger magma reservoir, resulting in larger lava flows and longer pauses between eruptions.

Also unlike Mount St. Helens — a stratovolcano — Mauna Loa is a shield volcano, meaning the lava flows eventually form mountains that look like a “warrior’s shield,” according to the Associated Press.

The Hawaiian volcano won’t have the same explosive eruption as its Washington counterpart because its magma is hotter and more fluid, according to geophysicist Hannah Dietterich of the USGS Alaska Volcano Observatory.

The Hawaii Volcanoes National Park closed Mauna Loa Summit is open to visitors until further notice due to increased activity, but Mauna Loa Road and the Mauna Loa Lookout remain open to the public.

While the increased activity is cause for concern, it does not yet indicate that the volcano will erupt any time soon.

“In this case, we increased the seismicity, and the deformation, the ground is changing, but not fast enough to trigger an alarm,” says Frank Trusdell, an HVO geologist. said.

According to Trusdell’s comments during Volcano Awareness Month in 2021, HVO has been preparing for Mauna Loa’s potential eruption, including adding new instruments, upgrading monitoring equipment, and coordinating response plans with various agencies, including NPS, Civil Defense, and FEMA.

Since the volcano’s first documented eruption in 1843, it has erupted 33 times. During its last eruption in 1984 a lava flow came within 4 miles of the city of Hilo, the largest population center on the island.

Luke Meyers, the administrator of the Hawaii Emergency Management Agency, said that at the current alert level, officials are advising to “look cautiously at what may come” and that it is always “better to be prepared and ready”.

The Hawaii Civil Protection Agency recommended that residents in the area prepare a holdall filled with groceries and identify a pre-selected location where they can safely evacuate and meet their family members.

“Not to panic everyone, but you have to realize that you live on the slopes of Mauna Loa. There is a possibility of some kind of lava disaster,” Talmadge Magno, Hawaii County Civil Protection Administrator said.