Talk:Rano Kau

Steam Crack

This link shows a steam crack coming out of the crater wall. Does this mean that the volcano is not extinct and geothermal activity continues? --Guanlong wucaii 15:34, 13 March 2010 (UTC)

Easter hotspot, so the magma chamber is active and the volcanic complex too, it is certainly not extinct, how about dormant? "Easter Island". Global Volcanism Program. Smithsonian Institution. Retrieved 2010-0-13. {{cite web}}: Check date values in: |accessdate= (help) says Rano Kau, Poike volcano, and Terevaka are Pleistocene volcanoes. Quote: "The latest lava flows, at Hiva-Hiva near the west-central coast, are thought to be less than 2,000 years old." But if a vent will ever erupt again, nobody can tell. --Chris.urs-o (talk) 17:05, 13 March 2010 (UTC)--

Were seems to be no submarine volcano on the interactive map of http://mineralsciences.si.edu/tdpmap/

--Chris.urs-o (talk) 14:19, 16 March 2010 (UTC)

So it's somewhat like Hawaii? --Guanlong wucaii 14:43, 16 March 2010 (UTC)

Right, I think so; but Hawaii is the strongest hotspot. --Chris.urs-o (talk) 15:51, 16 March 2010 (UTC)

I thought the Easter hotspot was now a bit further west, nearer Pukao (seamount). It is possible that Easter Island is dormant rather than extinct, but we'd need a source that said that. Alternatively is it possible for an extinct volcano to still have geothermal heat? Perhaps we should get one of our vulcanologists into the discussion? ϢereSpielChequers 17:43, 16 March 2010 (UTC)

Quote: "Compared with the relatively mafic submarine samples, the more fractionated lavas on Easter Island suggest the presence of another, more shallow magma chamber." The distance of the seamounts and Easter Island is around hundert km, not much. Hawaii is as big. Lava that is 2,000 years old (GVP), this is not much indeed too. Easter Island and Galapagos are near the border of the Plate. Ok, Tupa, Ahu & Umu volcanic field are younger, then Pukao Seamount and Moai Seamount. Quote: "activity apparently ended with the emplacement of trachytic and rhyolitic intrusions at Poike and Rano Kau" and Roiho field lavas are younger than two samples of Pukao & Moai. I think "activity apparently ended" does not equal extinct. How about it? "Poike and Rano Kau are inactive." Haase, Karsten M. (October 1997). "The Petrogenetic Evolution of Lavas from Easter Island and Neighbouring Seamounts, Near-ridge Hotspot Volcanoes in the SE Pacific". Journal of Petrology. 38 (06): 785–813. Retrieved 2010-03-16. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help) --Chris.urs-o (talk) 18:48, 16 March 2010 (UTC)

Hi, I was asked to chip in here. If I remember correctly, Easter Island volcanism has extended as far as Chile. Therefore, it's likely that this volcano could be active. Before making a decision, though, I'd suggest finding a reliable or maybe even official (GVP or USGS) source supporting that. If that isn't available, feel free to contact me and I'll do some research. ceranthor 22:16, 17 March 2010 (UTC)

I know. Overview: Karsten M. Haase (1997), Quote I: "The 2,500 km long and 100 km wide Easter Seamount Chain (ESC), or Sala y Gomez Ridge, stretches to the east of the island. The ESC is bounded to the east by the Nazca Ridge, a 300 km wide aseismic ridge extending to South America. The ESC shows an age progression, with the youngest volcanoes occurring in the west near Easter Island." So the seamounts East of Easter Island are extinct. Quote II: "activity apparently ended with the emplacement of trachytic and rhyolitic intrusions at Poike and Rano Kau". So, Poike and Rano Kau are clogged and apparently inactive, and Maunga Terevaka is apparently dormant. Tupa, Ahu & Umu volcanic fields (around 150 km west of Easter Island) are younger, then Pukao (seamount) and Moai (seamount), all apparently active. As I see it. Quote GVP: "The latest lava flows, at Hiva-Hiva near the west-central coast, are thought to be less than 2,000 years old." Quote (Vezzoli L, Acocella V, 2009. Easter Island, SE Pacific: an end-member type of hotspot volcanism. Geol Soc Amer Bull, 121: 869-886): "The comparison to other intraoceanic volcanic islands suggests that, because of its tectonomagmatic features (low eruptive rate, scattered rift zones, and scarce lateral collapses), Easter Island represents an end-member type of hotspot volcano that is contrary to Hawaii, which represents the opposite end member." --Chris.urs-o (talk) 12:04, 18 March 2010 (UTC)

Another citation, Active_volcano#Volcanic_activity "...with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists." "Examples of extinct volcanoes are many volcanoes on the Hawaiian Islands in the U.S. and Paricutin, which is monogenetic." It'd be better if we do not use the word extinct for the othe types of volcanos. --Chris.urs-o (talk) 06:46, 29 March 2010 (UTC)