Ron Schott‘s attempt to get revenge at us wily newcomers with a little keelhauling didn’t go as well as planned, I don’t think. I was able to surmise the undersea location fairly quickly as being in the Juan de Fuca Ridge off the coast of Washington and Oregon, USA. It just happened that being a “Left Coaster” I took an interest in the undersea topography off the west coast of North America in Google Earth and knew this to be one of the few areas to have enough resolution for such a tight zoom. Although I missed the specific detail that the focal object is a volcanic caldera on the Axial Seamount, I knew just enough of the geologic significance of the area to pass muster with Captain Ron. <whew! I live to swab the decks another day!>
My selection for WoGE 284 I know is going to be a tough one. It’s a deep zoom, although not quite down to that single sand dune we keep hearing threats about. Also, it’s an oblique image. For these reasons, no ‘Schott Rule’. Oh, I forgot to leave the compass in the image, but north is approximately to the left. I have several clues prepared, so don’t be afraid to speak up if after a several days this one starts making you want to throw me overboard.
Because the area and angle lends itself well to the idea, I also created a cross-eye stereogram of the view for your enjoyment. No glasses required, just cross your eyes until the two images merge. You may have to sit back from your monitor in case your eyes don’t want to cooperate.
For those unfamiliar with Where on Google Earth, the goal is simply (ha-ha) to find this place in Google Earth, report back the latitude and longitude and describe the geologic significance of the location. Felix Bossert has an excellent page detailing the rules on his blog, as well as hosting a pretty up-to-date KML file of previous locations.
Posting time is 0200 UTC May 2nd, 2011.
Good luck!!
Brian
Where on Google Earth #284
Where on Google Earth #284 3D
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40.3N, 117.6W
The Pleasant valley earthquake rupture of 1915, looking pretty fresh. It was obviously a west facing fresh fault scarp, and the high-res + USDA meant I was concentrating on the western US. Besides, I was there several times…
More detailed explanation soon, I got to go to work.
Neta
The pleasant valley earthquake occurred along a fault on the eastern side of Pleasant Valley, Nevada in 1915. The combined length of the scarps was 59 kilometers, the average vertical displacement 2 meters, and the maximum displacement of 5.8 meters. Several northwest-striking segments of the scarps had a right-lateral component of displacement, generally less than 1 meter.
One of the most striking effects of this earthquake was the large increase (and decrease) in the flow of springs and streams throughout northern Nevada. Cracks formed in unconsolidated materials for considerable distances. Felt from the State of Oregon to southern California and from the Pacific coast to beyond Salt Lake City, Utah. Two foreshocks and many aftershocks occurred.
The range front is Tobin range, which is composed of Paleozoic metamorphic rocks, lower Triassic volcanic rocks, Triassic limestone, the upper Triassic-lower Jurrasic Humboldt assemblage, and capped by Tertiary basalts, andesites and ash.
Sources:
Geologic map of Nevada
http://www.nbmg.unr.edu/Pubs/Misc/Stewart&Carlson500K.pdf
Quaternary faults in google earth:
http://earthquake.usgs.gov/hazards/qfaults/google.php
I saw that my comment is not visible yet, probably because I put links in it to some sources… So here’s just the geological explanation, in the hopes it will pass the spam filter:
The pleasant valley earthquake occurred along a fault on the eastern side of Pleasant Valley, Nevada in 1915. The fault is part of the basin and range province, where E-W extension creates a series of N-S trending mountain ranges, in this case the fault is on the western front of the Tobin range. The combined length of the scarps was 59 kilometers, the average vertical displacement 2 meters, and the maximum displacement of 5.8 meters. Several northwest-striking segments of the scarps had a right-lateral component of displacement, generally less than 1 meter.
One of the most striking effects of this earthquake was the large increase (and decrease) in the flow of springs and streams throughout northern Nevada. Cracks formed in unconsolidated materials for considerable distances. It was felt from the State of Oregon to southern California and from the Pacific coast to beyond Salt Lake City, Utah. Two foreshocks and many aftershocks occurred.
Tobin range is composed of Paleozoic metamorphic rocks, lower Triassic volcanic rocks, Triassic limestone, the upper Triassic-lower Jurrasic Humboldt assemblage, and capped by Tertiary volcanics.
Congrats, Neta!!! I guess this wasn’t so hard after all. I hemmed and hawed over leaving the copyright notices in the image as a clue. It seems there’s no telling if a particular location will be difficult or not. Seems like somebody just happens to know the area in question and gets it right away.
In Google Earth, you can see the fault scrap all up and down the valley, this image being towards the southern end. The location is approximately the same as that in a photo on the USGS page for this quake.
http://earthquake.usgs.gov/earthquakes/states/events/1915_10_03.php
http://libraryphoto.cr.usgs.gov/cgi-bin/show_picture.cgi?ID=ID.%20Earthquake%20Information%20Bulletin%20%2015
I thought about making it a ground level view matching the image, but thought that would be a bit much.
In any case, WoGE 285 is yours!
Yes, I currently have posts with links requiring approval due to comment spam. My blog was online less than a month and it was already getting hammered. ‘Tis ok, though, I have plans for these pests.
Brian
Thanks Brian, it was a very cool location. WoGE 285 (my first!) will be online here:
http://frenchise.wordpress.com/2011/05/04/woge-285/
On May 4th, 00:00 UTC/GMT.
Neta
Well, my comment was filtered again, so to get to the next WoGE you can click on my name. WoGE 285 (my first!) will be online on May 4th, 00:00 UTC/GMT.