Post by thread:[OT] quake activity

Any particular reason? Funny N. Au Group Electronics, New Bedford, MA, http://www.AuElectronics.com ----- Original Message ---- From: David VanHorn <spam_OUTmicrobrixTakeThisOuTgmail.com> To: Microcontroller discussion list - Public. <.....piclistKILLspam@spam@mit.edu> Sent: Saturday, April 26, 2008 12:02:24 PM Subject: [OT] quake activity A lot of quakes in the Reno Nv area lately, 230+ in the last week. (!) Also, quite a few in southern illinois. Interesting.

> A lot of quakes in the Reno Nv area lately, 230+ in the > last week. (!) > Also, quite a few in southern illinois. > Interesting. > Any particular reason? Crude summary of popularish theory: Often it's when two Tectonic plates sliding past each other load up an energy storage system (bits of bending rock) to the stage where the resistance to slippage is overcome by the forces involved. The stalled slippage then occurs in 1 or more "jumps" as parts that reduce the slippage are overcome by the forces involved. If you live nearby you hope that the value of "1 or more" is large. ie many small quakes and not 1 very large one. You often get a "swarm" of small quakes preceding a larger one as the system starts to fail and then "lets go". Wikipedia knows I'm sure. Russell

> http://ap.google.com/article/ALeqM5gS-Ci5Mg_3qzF4HK8o9c8qjvj2tgD909RRDO0 > > Seems I'm not the only one.. Not too near a major plate boundary (as you know) http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/map_plate_tectonics_world.html They say they'd be surprised if the biggest quake was over about 6.1 Note the two red "dots" on a curve on the Antarctic plate to the right of South America. That's NZ :-). Where I am we are off the plate edge proper - my city is instead over a volcanic hot-spot (such as created and is creating the Hawaiian chain.) Our next volcano is overdue. Russell

>Note the two red "dots" on a curve on the Antarctic plate >to the right of South America. That's NZ :-). Sheesh, you can't get Kiwis to describe their country position right ... I think you meant to the right of Australia - NZ can be quite clearly seen on the map. The ones to the right of South America are definitely not NZ ... !!!

> >Note the two red "dots" on a curve on the Antarctic plate >>to the right of South America. That's NZ :-). > Sheesh, you can't get Kiwis to describe their country > position right ... I > think you meant to the right of Australia - NZ can be > quite clearly seen on > the map. The ones to the right of South America are > definitely not NZ ... > !!! "Well held, Sir" He's right :-(. http://vulcan.wr.usgs.gov/Glossary/PlateTectonics/Maps/map_plate_tectonics_world.html The volcanoes shown in NZ are arguably not correctly placed, although the scale does not lend itself to good positioning. Bottom dot is probably Ruapehu. http://www.wikimapia.org/#lat=-39.318097&lon=175.538521&z=12&l=0&m=a&v=2 Just above (< 15 km?) away is Tongariro aka Mt Doom for those who have seen LOTR. http://www.wikimapia.org/#lat=-39.163342&lon=175.68718&z=12&l=0&m=a&v=2 Above and right is White Island - out to sea. http://www.wikimapia.org/#lat=-37.527154&lon=177.203979&z=8&l=0&m=a&v=2 WI steams regularly and erupts harmlessly usually. Tongariro erupts ?5- 20 yearsly? and has hot spots and thermal vents lower down. (Nice for glove warming during "The Tongariro Crossing" at about 0C. Ruapehu is a variable feast. Little eruptions 2-10 yearsish and a good lava flow every ?50+? years. It's has all our major North Island ski fields on it so skiing sometimes gets interrupted. Nearby and unseen coz it's so very very very large is Mt Taupo. Nobody but me calls it that. Largest eruption on earth in last 20,000 years. Larger the time before. 30km x 20 km crater !!! :-) http://www.wikimapia.org/#lat=-38.673717&lon=176.105347&z=10&l=0&m=a&v=2