Saturday, December 31, 2022

The volcanoes: Kīlauea reinflating, Mauna Loa resting

Two weeks after their double eruption, Kīlauea and Mauna Loa are handling the holidays differently, although neither is erupting.

Mauna Loa appears to be resting, according to the U.S. Geological Survey’s Hawaiian Volcano Observatory.

At Mauna Loa, “deformation rates have decreased significantly, and there is no sign of inflation at this time. The Hawaiian Volcano Observatory continues to closely monitor the earthquake and deformation rates at Mauna Loa. We expect additional shallow seismicity and other signs of unrest to precede any future eruption, if one were to occur,” the observatory reported.

At Kīlauea, there is more activity. Seismologists’ instruments show that Kīlauea is re-inflating, its upper area expanding as magma pumps into underground chambers near the surface.

The smaller mountain has been inflating since November 29—meaning it was inflating at the same time it was erupting during the early days of the Mauna Loa eruption. A seismic swarm, indicating magma movement underground, shook the volcano Friday (December 30).

“These earthquakes are typical as the summit of Kīlauea repressurizes after the end of the last eruption.  The earthquakes are generally dispersed beneath and around the south side of Halemaʻumaʻu,” the HVO reported.

It is normal for Mauna Loa to take a longer break between eruptions than Kīlauea.

Kīlauea’s most recent eruption lasted a little more than 14 months from September 29, 2021, to December 9, 2022. It was entirely within the crater at Halema’uma’u. The volcano erupts frequently, often a couple of times a year, and sometimes continuously for years.

Mauna Loa’s recent eruption lasted from November 27, 2022, to December 10, 2022. The volcano for the past couple of centuries has erupted every five years or so, but pauses between eruptions can be months to decades long.

© Jan TenBruggencate 2022

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