During the past week, there have been a few small-magnitude earthquakes which occurred beneath the volcano at depths shallower than 3 miles (5km).
There were three felt reports of a magnitude 2.5 earthquake 0.6 miles southeast of Captain Cook at a depth of six miles on April 9.
The most recent earthquakes was reported on March 29 at 12.53am local time (10.53am BST) measuring magnitude 1.64 around 25km east of Honaunau-Napoopoo.
The current alert level is advisory and the colour code is yellow – ‘volcano is experiencing signs go elevated unrest above known background levels.’
Mauna Loa is the largest active volcano on the planet and measures 4,170m above sea level.
The enormous volcano covers half of the island of Hawaii and has erupted 33 times since its first historical eruption in 1843.
Its most recent eruption was in 1984.
People who live on the flanks of the world’s largest volcano face major hazards, including lava flows, explosive eruptions, volcanic smog, damaging earthquakes and tsunamis.
The last eruption in 1984 resulted in a lava flow which came within 4.5 miles of Hilo – the largest population centre on the island.
It is constantly monitored by the USGS as it has a tenacity to produce large flows of lava.
The USGS said: “Mauna Loa eruptions produce lava at a much higher rate than those of any other Hawaiian volcano, even the highly active neighbouring Kilauea volcano, resulting in fast-moving and long-travelled lava flows.
“Such high eruption rates require quick responses in order to protect life and property.”
David Rothery, professor of Planetary Geoscience, said: “Eruptions in Hawaii are of basalt, which makes for low viscosity (runny) lava.
“Unless it encounters seawater, basalt rarely erupts explosively, because the gases can escape without shattering the magma into fragments.”