English: The Ulawun volcano rises steeply and dramatically on the north coast of New Britain, Papua New Guinea. This symmetric stratovolcano claims the position as highest of the 21 active volcanoes found in the 620 mile- (1000 km) long volcanic arc that begins with Rabaul volcano on the eastern peninsula of New Britain and ends near Wewak, on the northern coast of the island of New Guinea. It has been active in modern times, with the largest eruptions occurring in 1915, 1970, and 1980. While most eruptions are relatively mild, large, explosive eruptions have produced heavy pyroclastic (lava) flows which have caused damage to the immediate area. Ash plumes rising from this volcano can threaten air traffic routes. On January 1, 2018, the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite flew over New Britain and acquired a true-color image of a plume of ash rising from Ulawun volcano. No significant eruption was reported from monitoring agencies on that date, but it not unusual for light ash events to pass with little mention in media reports.