Report on Yasur (Vanuatu) — 15 July-21 July 2020
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 15 July-21 July 2020
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2020. Report on Yasur (Vanuatu) (Sennert, S, ed.). Weekly Volcanic Activity Report, 15 July-21 July 2020. Smithsonian Institution and US Geological Survey.
19.532°S, 169.447°E; summit elev. 361 m
All times are local (unless otherwise noted)
Based on webcam images and satellite data the Wellington VAAC reported that on 19 July ash plumes from Yasur rose to 1.5 km (5,000 ft) a.s.l. Diffuse ash plumes rose to 1.2 km (4,000 ft) a.s.l. and drifted NNE.
Geological Summary. Yasur has exhibited essentially continuous Strombolian and Vulcanian activity at least since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island in Vanuatu, this pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide open feature associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century.