Report on Zubair Group (Yemen) — 14 December-20 December 2011
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 14 December-20 December 2011
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2011. Report on Zubair Group (Yemen) (Sennert, S, ed.). Weekly Volcanic Activity Report, 14 December-20 December 2011. Smithsonian Institution and US Geological Survey.
15.05°N, 42.18°E; summit elev. 191 m
All times are local (unless otherwise noted)
According to local news, fishermen from the port city of Salif on the western Red Sea coast of Yemen reported an off shore eruption from the island of Jebel Zubair, about 60 km SW, with lava fountains rising 20-30 m above the summit on 19 December. On 19 December a SO2 cloud was detected in an OMI satellite image. MODIS imagery from 20 December shows a plume rising from a submarine eruption about 1.5 km SW of Haycock and N of Rugged (near the N end of the Az-Zubair island group), and about 12 km NE of Jebel Zubair island. A bathymetric sketch map made in 1973 indicates a water depth of about 100 m in that area.
Geological Summary. The 5-km-long Jebel Zubair Island is the largest of a group of small islands and submerged shoals that rise from a shallow platform in the Red Sea rift. The platform and eruptive vents forming the islands and shoals are oriented NNW-SSE, parallel to the rift. An early explosive phase was followed by a brief period of marine erosion, then by renewed explosive activity accompanied by the extrusion of basaltic pahoehoe lava flows. This latest phase of activity occurred on the morphologically youngest islands of Zubair, Centre Peak, Saba, and Haycock. Historical explosive activity was reported from Saddle Island in the 19th century. Spatter cones and pyroclastic cones were erupted along fissures that form the low spine of Zubair Island. Eruptions that began in late 2011 built two new islands, increasing the total number in the group to 12.