For the next edition of WOGE I will try to keep things simple (but interesting) so that the game will move along quickly. The Schott rule will be in effect. The posting time below is in UTC. As always, find the coordinates of the Google Earth image and tell us something about the geology of the location. The winner gets to host the next challenge. Have fun!
Here is a larger "historical view" that shows more of the key feature.
This is not another location to search for, just a hint about the geology seen above.
Here is another historical view that might reveal something about the climate at this location.
Also, if the detail were greater you would be able to find more than two dozen small boats in the second image above. Must be a popular place for day trips. Maybe a larger view will help.
It's Kuei Shan Tao ("Turtle Island" because of it's shape) volcano island northeast of Taiwan.
ReplyDelete24°50'31"N, 121°57'10"E
The volcano belongs to a series of volcanic islands on the Okinawa trough back-arc which is developing behind the Ryukyu trench (where the Philippine plate is subducting below the Eurasian plate).
Trench roll-back causes extension of the crust in the back-arc basin. Extension, and therefore thinning, of the crust creates a rift with volcanic activity.This is very roughly similar to mid-ocean ridges, but the processes is of course different. The magma is basaltic, too. But because the location is close to the subduction zone, the magma contains more water.
Congratulations to Effjot for winning another edition of WOGE. I had not intended to offer a difficult location, but in retrospect I should probably have included a bit of the coastline to begin with.
ReplyDeleteThank you for a good summary of the geology that created Kuei-shan Tao. The feature that drew my attention to this spot was the long plume of discolored water created by underwater fumaroles and solfataras. An interesting paper at http://www.terrapub.co.jp/journals/GJ/pdf/3905/39050469.pdf reviews a study of the gasses being released and what they suggest about the tectonic setting of the volcano.
I can't wait to see what bizarre landscape Effjot will give us to search for next.
[Different ID, same person: fj = effjot. It's always interesting to see how and when Blogspot fails or fails not at OpenID…]
ReplyDeleteI the hurry to get my answer posted, I think I mixed up the magma types. Keui Shan Tao should be andesite, not basalt.
I must admit that I completely didn't get the plume (but at least the volcano and climate/latitude…). The bright blue looked a bit like most shallow does water on Google Earth and so from the second picture I got the impression of a arc-shaped shallow area close to deep water.
That's quite embarassing, given the various clues you left in the text (But who reads when he can look at nice pictures...) about “historic” views, indicating that the thing had changed rather quickly over time. And on closer inspection, some boats are cutting through the plume, leaving trails. This would of course not happen if it were just shallow water.
As the saying goes, in hindsight you're always smarter. :-/
WoGE 332 will be here soon (today or tomorrow).
Because this WoGE has stayed around for so long, I'd like to offer a possibility for people to catch up and delay my WoGE Monday aftenoon 15:00 UTC on my blog. (I hope that's a time that accomodates the different timezones at least a little bit.)
ReplyDeleteMy WoGE will be rather easy (I hope), and Schott's Rule will be in effect, so newcomers should have a chance.
WOGE331 is at http://blog.effjot.net/en/2012/02/where-on-google-earth-332
ReplyDelete