Hawaii officials are warning residents of the Big Island that the world’s largest active volcano, Mauna Loa, is sending signals that it might erupt.

Scientists say an eruption isn’t imminent, but they are on alert because of a recent spike in earthquakes at the volcano’s summit. Experts say it would take just a few hours for lava to reach homes closest to vents on the volcano, which last erupted in 1984.

Hawaii’s civil defense agency is holding meetings across the island to educate residents about how to prepare for a possible emergency. They recommend having a “go” bag with food, identifying a place to stay once they leave home and making a plan for reuniting with family members.

“Not to panic everybody, but they have to be aware of that you live on the slopes of Mauna Loa. There’s a potential for some kind of lava disaster,” said Talmadge Magno, administrator for Hawaii County Civil Defense.

The volcano makes up 51% of the Hawaii island landmass, so a large portion of the island has the potential to be affected by an eruption, Magno said.

Mauna Loa, rising 13,679 feet above sea level, is the much larger neighbor to Kilauea Volcano, which erupted in a residential neighborhood and destroyed 700 homes in 2018. Some of its slopes are much steeper than Kilauea’s, so when it erupts, its lava can flow much faster.

During a 1950 eruption, the mountain’s Honokua lava flow traveled 15 miles to the ocean in less than three hours.

The Hawaiian Volcano Observatory, which is part of the U.S. Geological Survey, said Mauna Loa has been in a state of “heightened unrest” since the middle of September when the number of summit earthquakes jumped from 10 to 20 per day to 40 to 50 per day.

Scientists think more earthquakes are occurring because more magma is flowing into Mauna Loa’s summit reservoir system from the hot spot under the earth’s surface that feeds molten rock to Hawaii’s volcanoes.

The temblors have declined in frequency in recent days but could rise again.

More than 220 people attended a community meeting last weekend that county civil defense officials held in Ocean View, a neighborhood that lava could reach in hours if molten rock erupts through vents on Mauna Loa’s southwest flank.

Bob Werner, an Ocean View resident who didn’t attend the meeting, said it’s wise to be aware of a possible eruption but not to fear it. He’s not concerned that the neighborhood would be completely cut off if lava flows across the only road connecting it to the bigger towns of Kailua-Kona and Hilo, where many people do their shopping.

The “greater concern is it will be extremely annoying to drive an extra hour or two hours to get the same stuff,” he said.

Ryan Williams, owner of the Margarita Village bar in Hilo, said the volcanic unrest wasn’t worrying customers who are used to warnings.

There could still be a heightened sense of urgency since officials have been holding town hall meetings, urging people to prepare.

“But everything I’ve read or heard, they’re trying to kind of assure people that conditions have not changed,” Williams said. “There’s no imminent eruption, but just to be alert.”