US Geological Survey's Hawaiian Volcano Observatory said Mauna Loa has been in a state of "heightened unrest" since mid-month due to daily earthquake swarms jumped from 10-20 per day to 40-50 per day. 

"Scientists believe 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," AP said.

Hawaii's civil defense agency held a meeting earlier this week to educate residents on preparing for a possible eruption. 

"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, Hawaii County Civil Defense administrator.

Mauna Loa is about half of the Hawaii Island landmass. So any eruption would immediately impact residents. There are about 200,000 people on the island. It last erupted in 1984, and lava flows took out homes in under two hours. 

USGS data shows hundreds of quakes have rattled the island in the last 30 days.