Move over Iceland: Tavurvur in Papua New Guinea is the volcano to watch
Last week, the eyes of volcanologists-and presumably a few nervous pilots-were fixed on Iceland.
Join the discussion below, or Read more at Ars Technica.
“Geologist [I'm Climate Change]”
Since: Mar 07
#1 Sep 3, 2014
Early eruption in Rabaul area appears to have been from Tavui caldera which is off the NE part of Tavui point North of rabaul.
The Rabaul area appears to have been a cluster of stratovolcanoes in the early Holocene with the norteasthern pair outside of the rim being the current highpoints of the Rabaul area.
The current Blanche bay caldera is the result of an unroofed pluton which appears to have been developing throughout the early Holocene S. of the remnant stratovolcano group. This pluton appears to have unroofed at or slightly after 535AD (probably slightly affter) as a result of the crust relaxing with big quake & tsunami as a result of a shockwave from the impact of 2 small asteroids into the Gulf of Carpentaria (Australia) in 535AD with a dust pall from that event resulting in the dark ages. the 14*8 Km diameter blanche bay caldera (Dacite) appears to have been a VEI 7 event in the realm of 120 to 140Km3 erupted as a sillar, adding to the dark ages dust pall and elongated in the same direction as the Rabaul stratovolcano group. Most of the products of this event appears to be deposited as submarine ash flow tuffs of Krakatau type as a nonwelded mass, with most of the fine ash winnowed out.
The current (post 535AD) activity appears to involve re intrusion of basalt into the caldera rim erupting through Tavurvur, and Rabalankaia (slightly older). In repose periods the basalt solidifies with a result being that there is a block to new eruptions & as a result basalt intrudes into the cooler de gassed dacite remaining in the caldera. Eruptions of dacite have occurred at sulphur creek, over a resurgent dome, and Vulcan 1 and vulcan 2 interior to the W. caldera rim on the other side of the resurgent dome.
Good news is that the last major eruption (tavurvur & Vulcan 2) re formed the conduit at tavurvur with the result that the freshly arriving basalt is now erupting directly out of tavurvur leaving the dacite bypassed. The basalt (as seen in the pics) is definitely rather gassy, having been sitting around in fractures @ the base of the crust since 535AD, and crystallising out, exsolving gas into the remaining liquid.
This eruption is rather less spectacular than the last one,(column height 18Km as opposed to 40Km last time. Should now (at time of typing) have subsided to steaming & vulcanian explosions.
The descending plate is still descending and as a result there is still a fair amount of recompression to go in the new Britain arc. Should therefore be a fair chunk of volcanism to come in that dot on the map.
Will keep watching that space.
have a nice day: Ag
Add your comments below
|Fort McMurray pastor and firefighter: confronti...||5 hr||Reverend Laidlaw ...||1|
|Number of Lyme disease cases more than triples ...||7 hr||9403zoe||1|
|Global warming made Paris floods far more likel...||8 hr||Earthling-1||113|
|Beyonc and Kendrick's BET Awards Smash||9 hr||larryX||3|
|The Latest: Obama pledges federal support in fl...||21 hr||WasteWater||10|
|Rainelle natives and mayor uncertain of what's ...||Sun||Dennis Neathawk||1|
|At gay pride parades, large crowds and increase...||Sun||OUCH||4|
Find what you want!
Search Natural Disasters Forum Now
Copyright © 2016 Topix LLC