Mauna Loa on Friday offered up a prodding reminder that it very much remains an active volcano capable of unleashing as much, or more, damage as its neighbor, Kilauea.

A 4.1-magnitude earthquake that originated deep below the western flank of the 13,861-foot colossus shook Hawaii island Friday morning.

The 7:44 a.m. temblor was felt across the island, as 130 people responded to the U.S. Geological Service’s “Did you feel it?” survey within an hour afterward. A couple of aftershocks followed.

Hawaiian Volcano Observatory geophysicist Jefferson Chang said the earthquake about 24 miles east-southeast of Kailua- Kona had no apparent effect on Mauna Loa or Kilauea volcano.

“We’re continuing to monitor the situation,” he said late Friday afternoon.

Chang said the morning’s temblor occurred in an area that has experienced consistent seismicity over the past five years or so, but normally the quakes are much smaller in size.

It was only the fourth recorded earthquake of this magnitude to strike in that area of the mountain, he said. The last one was in November 2011. Previously, there were two in September 1983.

“This spot has been lively, but it is a mystery why it is happening,” Chang said. The area is not a rift zone, he said, and there are no cracks that run deep in that area.

Mauna Loa’s last eruption happened in the spring of 1984, when fast-moving lava came within 4 miles of Hilo.

The volcano has remained silent for the past 36 years. That’s in contrast to Kilauea, which had been erupting continuously since January 1983, until it fell idle following its spectacular but destructive Puna eruption in 2018.

Chang said the alert level for Mauna Loa remains at Advisory, or Yellow, which means the volcano is showing signs of “elevated unrest” compared with the usual long-term background levels.

Mauna Loa is the only U.S. volcano with such an elevated alert level right now.

HVO scientists Thursday posted their weekly update for Mauna Loa, saying rates of deformation and seismicity have not changed significantly over the past week, but remained above long-term background levels.

In addition, global positioning system measurements continue to show slow, long-term summit inflation, consistent with magma supply to the volcano’s shallow storage system.

As for Friday’s earthquake, HVO officials said it occurred at a depth of about 3 miles below sea level and produced enough movement for light shaking felt across the island.

It was not enough movement, however, to generate a tsunami, according to the Hawaii County Civil Defense Agency.

Mauna Loa, the world’s largest active volcano, has erupted 33 times since 1843, with intervals between eruptions ranging from months to decades, according to HVO.

Scientists say that when Mauna Loa does erupt, it tends to produce lots of fast-moving lava that can flow into communities on both sides of the island. Hilo has been threatened by seven Mauna Loa lava flows over the last century and a half, according to HVO, while flows have reached the south and west coasts of the island eight times.