*********************** Re: HOME REEF disclosed as the source vent for the extensive pumice rafts in the Tonga-Fiji area during late August to present (2006). www.matangitonga.to/article/tonganews/disasters/new_island061106.shtml *********************** Dear fellow Earth scientists, A few weeks ago we learned of extensive pumice rafts seen in the Tonga-Fiji region, which editors at the Smithsonian's Bulletin of the Global Volcanism Network tentatively thought had come from the Tongan submarine volcano Metis Shoal. This morning's news from the Tongan newspaper Matangi (Tonga online) had quotes from a fisherman who had been near the scene and had noted the emergence of a new island in vicinity of HOME REEF. Home Reef is the next known active volcano south of Metis Shoal. We have not yet received photos of the new island but it is apparently large. See known Holocene volcanoes arranged geographically (S to N) at http://www.volcano.si.edu/world/region.cfm?rnum=0403 . The eruptions themselves would have been considerably earlier than the rafts, perhaps mid- or early August. As discussed on our website, Home Reef constructed an island in 1984 that had an estimated size of 500 x 1500 m and a height of 30-50 m. Large amounts of floating pumice were later encountered by passing ships. http://www.volcano.si.edu/world/volcano.cfm?vnum=0403- 08=&VErupt=Y&VSources=Y&VRep=Y&VWeekly=N&volpage=photos&photo=016028 FURTHER RESEARCH. We have yet to see photos of the new island and the exact coordinates are also lacking. We hope to persuade colleagues in the aviation and remote-sensing fields to look for aerial and satellite views of the Home Reef region (18.992°S, 174.775°W; 18°59'30"S, 174°46'30"W) around the inferred time of eruption. We just found mariner's blogs that indicates strong eruptions were seen on 12 August, and the new island emerged from the sea by 13 August 2006. Here are few more key questions that quickly come to mind: How extensive were the rafts? At maximum how much surface area did they cover? We might then estimate a volume for the floating pumice. What volume of material piled up near the vent to form the island? What was the chemistry of the material erupted? How much material now litters the sea floor and is it fundamentally analogous to broad tephra deposits from larger eruptions (eg. for the Caribbean, the Los Chocoyos ash described by Drexler et al., 1980, Quat. Res., 13, 327-345). Better knowing the location and timing of the eruption, can we find one or more geophysical or satellite signals that may signify these eruptions? What atmospheric impact, if any, did the eruption have? What will be the fate and impact of the rafts? Previous rafts from this region have made it at least as far as Australia. We will have an initial report in the upcoming Bulletin. If you learn something about this event, please contact us. Thank you, Rick Wunderman and Ed Venzke wunderma@xxxxxx; gvn@xxxxxx Editors, Bulletin of the Global Volcanism Network Smithsonian Institution National Museum of Natural History 10th & Constitution Ave., NW Washington, DC 20560-0119 Web: www.volcano.si.edu Phone (202) 633 1800, 633-1827 ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
