The world's largest active volcano, Mauna Loa, is showing signs of unrest, displaying inflation on the monitoring system, I4U news reports.

However the eruption of Mauna Loa volcano is not imminent or certain, according to scientists at U.S. Geological Survey Hawaiian Volcano Observatory.

Volcano observatories employ the monitoring system to describe the current status of volcanoes. The alert levels of the volcanoes range from 'normal' to 'advisory' to 'watch' and 'warning'.

Mauna Loa last erupted in 1984, more than 30 years ago. Mauna Loa is among the five volcanoes forming Hawaii. Mauna Loa is showing unrest since 2014 but it is difficult for the experts to predict anything with certainty.

Geologist Frank Trusdell said that the geologists would wait for "the seismicity to grow steadily and be more consistent and persistent and even the rates to change before we forecast an eruption."

"It is possible that the increased level of activity at Mauna could continue for many months or years, without even leading to an eruption," said Tina Neal, HVO scientist in-charge. "It is also possible that the current unrest could be a precursor to the next eruption of Mauna Loa. But at this early stage, we cannot determine precisely which possibility is more likely."

Previous studies on the volcano suggest that Mauna Loa erupts once every five years. A total of 33 eruptions have been recorded since 1843.