September 9, 2026 | 07:04 pm

Incandescent lava from Mount Anak Krakatau is visible from Pasauran, Serang Regency, Banten, Indonesia, on September 5, 2026. ANTARA/Muhammad Bagus Khoirunas

TEMPO.CO, Jakarta - Indonesia's Mount Anak Krakatau in the Sunda Strait remains active, with an eruption detected early Wednesday, September 9, 2026, as authorities continue to monitor changes in its volcanic activity.The eruption occurred at 12:47 a.m. local time, according to an alert issued by the Lampung Regional Disaster Management Agency (BPBD) through its official Instagram account. The eruption was recorded by a seismograph with a maximum amplitude of 51 millimeters and lasted 28 seconds.Later that afternoon, Lampung Governor Rahmat Mirzani Djausal said the volcano remained at Level III, or Alert (Siaga).He said its activity had visibly declined compared with about three days earlier, with the frequency and intensity of magma emissions decreasing, the intervals between eruptions becoming longer, and volcanic ash becoming less visible.Djausal made the statement after monitoring Mount Anak Krakatau directly from the Indonesian Navy warship KRI Lepu 861, approaching to within about three kilometers of the volcano.The monitoring involved the Indonesian Navy, BPBD, the National Search and Rescue Agency (Basarnas), the Lampung Marine and Fisheries Agency, the Environmental Agency, and the Institut Teknologi Sumatera (ITERA).Declining Activity Does Not Mean the Eruption Has EndedAccording to the latest update posted by BPBD Lampung on Instagram at 4 p.m. local time, Djausal also stressed that the decrease in volcanic activity should not be interpreted as the end of the eruption.Authorities cannot yet determine when the eruption will stop because its duration depends on the volcano's activity and the supply of magma beneath it.“Mount Anak Krakatau is still erupting and remains on alert. We must stay calm but not let our guard down,” Djausal said, as quoted by Antara.Volcanic Ash Remains Relatively ThinDjausal said winds were blowing toward the northwest on Wednesday, while volcanic ash in the area was relatively thin.Air quality across all 15 regencies and cities in Lampung was also gradually improving, he said, allowing outdoor activities to continue.Authorities nevertheless urged the public to remain calm but vigilant, avoid the volcano's eruption sector, and follow official information and instructions.Volcano Appears to Be Expanding HorizontallyVisual observations during Wednesday's monitoring also showed that the body of Mount Anak Krakatau appeared to be expanding horizontally rather than increasing significantly in height.Djausal said the observation still needs to be confirmed through technical data from the relevant authorities.Authorities will continue monitoring the volcano as its activity evolves.