CVGHM reported that during 7-11 March instruments monitoring the Dieng Volcanic Complex detected carbon dioxide plumes from Timbang Crater drifting 50-200 m S; the concentration increased during 9-10 March. A strong sulfur odor was also reported, along with dead animals near the crater on 7 March. Observers noted white plumes rising from the crater that were diffuse during 7-8 March and dense during 9-10 March. Because of the increase of carbon dioxide emissions, CVGHM raised the Alert Level to 2 (on a scale of 1-4) on 11 March and warned the public not to approach Timbang Crater within a 500 m radius.

Geological Summary. The Dieng plateau in the highlands of central Java is renowned both for the variety of its volcanic scenery and as a sacred area housing Java's oldest Hindu temples, dating back to the 9th century CE. The Dieng Volcanic Complex consists of multiple stratovolcanoes and more than 20 small Pleistocene-to-Holocene craters and cones over a 6 x 14 km area. Prahu stratovolcano was truncated by a large Pleistocene caldera, which was subsequently filled by a series of cones, lava domes, and craters, many containing lakes. Lava flows cover much of the plateau, but observed activity has been restricted to minor phreatic eruptions. Gas emissions are a hazard at several craters and have caused fatalities. There are abundant thermal features and high heat flow across the area.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)