{"id":8202,"date":"2019-01-15T16:25:17","date_gmt":"2019-01-16T00:25:17","guid":{"rendered":"http:\/\/earthjay.com\/?page_id=8202"},"modified":"2023-01-26T04:49:59","modified_gmt":"2023-01-26T04:49:59","slug":"plate-tectonic-fundamentals","status":"publish","type":"page","link":"https:\/\/earthjay.com\/?page_id=8202","title":{"rendered":"Plate Tectonic Fundamentals"},"content":{"rendered":"<ul>\n<li>For more on the graphical representation of moment tensors and focal mechnisms, check this <a href=\"http:\/\/www.iris.edu\/hq\/programs\/education_and_outreach\/animations\/25\" target=\"_blank\" rel=\"noopener noreferrer\">IRIS<\/a> video out:<\/li>\n<p><iframe loading=\"lazy\" width=\"420\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/MomVOkyDdLo\" frameborder=\"0\" allowfullscreen><\/iframe>\n<\/ul>\n<ul>\n<li>Here is a fantastic infographic from Frisch et al. (2011). This figure shows some examples of earthquakes in different plate tectonic settings, and what their fault plane solutions are. There is a cross section showing these focal mechanisms for a thrust or reverse earthquake. The upper right corner includes my favorite figure of all time. This shows the first motion (up or down) for each of the four quadrants. This figure also shows how the amplitude of the seismic waves are greatest (generally) in the middle of the quadrant and decrease to zero at the nodal planes (the boundary of each quadrant).<\/li>\n<p><a href=\"https:\/\/earthjay.com\/earthquakes\/fault_plane_solutions.pdf\" rel=\"noopener noreferrer\" target=\"_blank\"><br \/>\n<img decoding=\"async\" src=\"https:\/\/earthjay.com\/earthquakes\/fault_plane_solutions.jpg\" width=\"100%\" alt=\"\" \/><\/a>\n<\/ul>\n<ul>\n<li>Here is another way to look at these beach balls.<\/li>\n<blockquote class=\"twitter-tweet\" data-lang=\"en\">\n<p lang=\"en\" dir=\"ltr\">The two beach balls show the stike-slip fault motions for the M6.4 (left) and M6.0 (right) earthquakes. Helena Buurman&#39;s primer on reading those symbols is here. <a href=\"https:\/\/t.co\/aWrrb8I9tj\">pic.twitter.com\/aWrrb8I9tj<\/a><\/p>\n<p>&mdash; AK Earthquake Center (@AKearthquake) <a href=\"https:\/\/twitter.com\/AKearthquake\/status\/1029549068047900672?ref_src=twsrc%5Etfw\">August 15, 2018<\/a><\/p><\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script>\n<\/ul>\n<ul>\n<li>There are three types of earthquakes, strike-slip, compressional (reverse or thrust, depending upon the dip of the fault), and extensional (normal). Here is are some animations of these three types of earthquake faults. The following three animations are from <a href=\"http:\/\/www.iris.edu\/hq\/programs\/education_and_outreach\/animations\/2\" target=\"_blank\" rel=\"noopener noreferrer\">IRIS<\/a>.<\/li>\n<p>Strike Slip:<br \/>\n<iframe loading=\"lazy\" width=\"420\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/MrrLJ4vXHCs\" frameborder=\"0\" allowfullscreen><\/iframe><br \/>\nCompressional:<br \/>\n<iframe loading=\"lazy\" width=\"420\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/4b81nXSVA34\" frameborder=\"0\" allowfullscreen><\/iframe><br \/>\nExtensional:<br \/>\n<iframe loading=\"lazy\" width=\"420\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/tJDnfT1pqhQ\" frameborder=\"0\" allowfullscreen><\/iframe>\n<\/ul>\n<ul>\n<li>This is an image from the USGS that shows how, when an oceanic plate moves over a hotspot, the volcanoes formed over the hotspot form a series of volcanoes that increase in age in the direction of plate motion. The presumption is that the hotspot is stable and stays in one location. Torsvik et al. (2017) use various methods to evaluate why this is a false presumption for the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Hawaii_hotspot\" rel=\"noopener noreferrer\" target=\"_blank\">Hawaii Hotspot<\/a>.<\/li>\n<p><a href=\"http:\/\/earthjay.com\/earthquakes\/20180504_hawaii\/USGS_Hawaii_hotspot_cross_sectional_diagram.jpg\" rel=\"noopener noreferrer\" target=\"_blank\"><br \/>\n<img decoding=\"async\" src=\"http:\/\/earthjay.com\/earthquakes\/20180504_hawaii\/USGS_Hawaii_hotspot_cross_sectional_diagram.jpg\" width=\"100%\" alt=\"\" \/><\/a><\/p>\n<blockquote><p>A cutaway view along the Hawaiian island chain showing the inferred mantle plume that has fed the Hawaiian hot spot on the overriding Pacific Plate. The geologic ages of the oldest volcano on each island (Ma = millions of years ago) are progressively older to the northwest, consistent with the hot spot model for the origin of the Hawaiian Ridge-Emperor Seamount Chain. (Modified from image of Joel E. Robinson, USGS, in \u201cThis Dynamic Planet\u201d map of Simkin and others, 2006.)\n<\/p><\/blockquote>\n<li>Here is a map from Torsvik et al. (2017) that shows the age of volcanic rocks at different locations along the Hawaii-Emperor Seamount Chain.<\/li>\n<p><a href=\"http:\/\/earthjay.com\/earthquakes\/20180504_hawaii\/torsvik_etal_2017_pacific_plate_motion_fig_01.JPG\" rel=\"noopener noreferrer\" target=\"_blank\"><br \/>\n<img decoding=\"async\" src=\"http:\/\/earthjay.com\/earthquakes\/20180504_hawaii\/torsvik_etal_2017_pacific_plate_motion_fig_01.JPG\" width=\"100%\" alt=\"\" \/><\/a><\/p>\n<blockquote><p>\nHawaiian-Emperor Chain. White dots are the locations of radiometrically dated seamounts, atolls and islands, based on compilations of Doubrovine et al. and O\u2019Connor et al. Features encircled with larger white circles are discussed in the text and Fig. 2. Marine gravity anomaly map is from Sandwell and Smith.\n<\/p><\/blockquote>\n<li>Here is a great tweet that discusses the different parts of a seismogram and how the internal structures of the Earth help control seismic waves as they propagate in the Earth.<\/li>\n<blockquote class=\"twitter-tweet\" data-lang=\"en\">\n<p lang=\"en\" dir=\"ltr\">Today, on <a href=\"https:\/\/twitter.com\/hashtag\/SeismogramSaturday?src=hash&amp;ref_src=twsrc%5Etfw\">#SeismogramSaturday<\/a>: what are all those strangely-named seismic phases described in seismograms from distant earthquakes?  And what do they tell us about Earth\u2019s interior? <a href=\"https:\/\/t.co\/VJ9pXJFdCy\">pic.twitter.com\/VJ9pXJFdCy<\/a><\/p>\n<p>&mdash; Jackie Caplan-Auerbach (@geophysichick) <a href=\"https:\/\/twitter.com\/geophysichick\/status\/1099343267752116226?ref_src=twsrc%5Etfw\">February 23, 2019<\/a><\/p><\/blockquote>\n<p><script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script><\/p>\n<li>Have you ever wondered how seismologists determine the depth of an earthquake? This thread helps us learn this.<\/li>\n<blockquote class=\"twitter-tweet\">\n<p lang=\"en\" dir=\"ltr\">***THREAD*** How can we compute the depth of earthquakes? Here&#39;s an example from yesterday&#39;s M7 offshore north Japan quake. Earthquakes produce P and S waves that travel through the Earth. For distant earthquakes, P-waves travel through Earth&#39;s mantle from the source to a station<\/p>\n<p>&mdash; Stephen Hicks &#x1f1ea;&#x1f1fa; (@seismo_steve) <a href=\"https:\/\/twitter.com\/seismo_steve\/status\/1228340873202749440?ref_src=twsrc%5Etfw\">February 14, 2020<\/a><\/p><\/blockquote>\n<p> <script async src=\"https:\/\/platform.twitter.com\/widgets.js\" charset=\"utf-8\"><\/script>\n<\/ul>\n<ul>\n<h2><strong><font color=\"orange\">References:<\/font><\/strong><\/h2>\n<li>Frisch, W., Meschede, M., Blakey, R., 2011. Plate Tectonics, Springer-Verlag, London, 213 pp.<\/li>\n<li>Hayes, G., 2018, Slab2 &#8211; A Comprehensive Subduction Zone Geometry Model: U.S. Geological Survey data release, <a href=\"https:\/\/doi.org\/10.5066\/F7PV6JNV\" rel=\"noopener noreferrer\" target=\"_blank\">https:\/\/doi.org\/10.5066\/F7PV6JNV<\/a>.<\/li>\n<li>Holt, W. E., C. Kreemer, A. J. Haines, L. Estey, C. Meertens, G. Blewitt, and D. Lavallee (2005), Project helps constrain continental dynamics and seismic hazards, Eos Trans. AGU, 86(41), 383\u2013387, , <a href=\"https:\/\/doi.org\/10.1029\/2005EO410002\" rel=\"noopener noreferrer\" target=\"_blank\"> https:\/\/doi.org\/10.1029\/2005EO410002<\/a>. \/li>\n<li>Kreemer, C., J. Haines, W. Holt, G. Blewitt, and D. Lavallee (2000), On the determination of a global strain rate model, Geophys. J. Int., 52(10), 765\u2013770. <\/li>\n<li>Kreemer, C., W. E. Holt, and A. J. Haines (2003), An integrated global model of present-day plate motions and plate boundary deformation, Geophys. J. Int., 154(1), 8\u201334, , <a href=\"https:\/\/doi.org\/10.1046\/j.1365-246X.2003.01917.x\" rel=\"noopener noreferrer\" target=\"_blank\">https:\/\/doi.org\/10.1046\/j.1365-246X.2003.01917.x<\/a>. <\/li>\n<li>Kreemer, C., G. Blewitt, E.C. Klein, 2014. A geodetic plate motion and Global Strain Rate Model in Geochemistry, Geophysics, Geosystems, v. 15, p. 3849-3889, <a href=\"https:\/\/doi.org\/10.1002\/2014GC005407\" rel=\"noopener noreferrer\" target=\"_blank\">https:\/\/doi.org\/10.1002\/2014GC005407<\/a>.<\/li>\n<li>Meyer, B., Saltus, R., Chulliat, a., 2017. <a href=\"https:\/\/www.ngdc.noaa.gov\/geomag\/emag2.html\" rel=\"noopener noreferrer\" target=\"_blank\">EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution) Version <\/a>3. National Centers for Environmental Information, NOAA. Model. <a href=\"https:\/\/doi.org\/10.7289\/V5H70CVX\" rel=\"noopener noreferrer\" target=\"_blank\">https:\/\/doi.org\/10.7289\/V5H70CVX<\/a><\/li>\n<li>M\u00fcller, R.D., Sdrolias, M., Gaina, C. and Roest, W.R., 2008, <a href=\"http:\/\/www.earthbyte.org\/people\/dietmar\/Pdf\/Muller_etal_age_rate_asym_G3_2008.pdf\" rel=\"noopener noreferrer\" target=\"_blank\">Age spreading rates and spreading asymmetry of the world&#8217;s ocean crust<\/a> in Geochemistry, Geophysics, Geosystems, 9, Q04006, <a href=\"https:\/\/doi.org\/10.1029\/2007GC001743\" rel=\"noopener noreferrer\" target=\"_blank\">https:\/\/doi.org\/10.1029\/2007GC001743<\/a><\/li>\n<\/ul>\n<h2><font color=\"orange\"><strong>Return to the <a href=\"http:\/\/earthjay.com\/?page_id=3218\">Earthquake Reports page<\/a>.<\/font><\/strong><\/h2>\n<ul>\n<li>Sorted by <a href=\"http:\/\/earthjay.com\/?page_id=3219\">Magnitude<\/a><\/li>\n<li>Sorted by <a href=\"http:\/\/earthjay.com\/?page_id=3220\">Year<\/a><\/li>\n<li>Sorted By <a href=\"http:\/\/earthjay.com\/?page_id=3226\">Region<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<div class=\"entry-summary\">\nFor more on the graphical representation of moment tensors and focal mechnisms, check this IRIS video out: Here is a fantastic infographic from Frisch et al. (2011). This figure shows some examples of earthquakes in different plate tectonic settings, and&hellip;\n<\/div>\n<div class=\"link-more\"><a href=\"https:\/\/earthjay.com\/?page_id=8202\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &ldquo;Plate Tectonic Fundamentals&rdquo;<\/span>&hellip;<\/a><\/div>\n","protected":false},"author":3,"featured_media":0,"parent":6951,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/pages\/8202"}],"collection":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8202"}],"version-history":[{"count":3,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/pages\/8202\/revisions"}],"predecessor-version":[{"id":10765,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/pages\/8202\/revisions\/10765"}],"up":[{"embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/pages\/6951"}],"wp:attachment":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}