This colourful image of Hawaii island shows the flanks of Mauna Loa or ‘long mountain’, one of the largest and highest (over 4 km above sea level) volcanoes in the world. This active shield volcano is routinely monitored by the Hawaiian Volcano Observatory of the US Geological Survey and last erupted in 1984. North of Mauna Loa, with small red spots, lays the higher and dormant Mauna Kea volcano.