With the general distinctions well in mind,  we are able to explore the regional zones in which quake activity is taking place.

The maps at the top of this web page displays the distribution of major quakes around the world for periods ranging from 16 to 31 years.  The quakes all appear arrayed in a web of lines which circumnavigate the globe.  These lines in most cases define very well the margins of the Tectonic Plates.

We can focus on the boundaries of the Tectonic Plates which geologists have defined on maps and select specific areas.  As a possible aide, Google has an interactive map of the Tectonic Plates.  But frankly its execution and display is awkwardly slow. Google needs more time to get it right.  So for the time being let us stick with relatively recent efforts by the USGS.

The first map below displays the major boundaries fairly well for the "14 Tectonic Plate Model".  It offers the added advantage of informing us about how closely connected world volcanism is with the edges of the tectonic plates and thus also with earthquake activity.  The second map paints the plates in separate colors to make them easier to perceive as specific zones.

USGS Map of Active Volcanoes, Tectonic Plate Edges, & "Ring of Fire"
This map is clickable to expand into a larger size

Image Source: USGS -  http://vulcan.wr.usgs.gov/Imgs/Gif/PlateTectonics/Maps/map_plate_tectonics_world.gif

 

Map of Fourteen Tectonic Plates
This map is clickable to expand into a larger size

Image Source: http://geology.com/plate-tectonics.jpg
or see Wikipedia, public art in "Tectonic Plates"

The third map, immediately below, will take you into a giant wall-sized map over which you can fly to observe the various tectonics margins which have been painted on to show us how they snake around the Earth.  It summarizes the work of Peter Bird, who has outlined the edges of 52 Tectonic Plates based on current discussions and presentations in the scientific literature circa 2003.  These boundaries are used in Google Earth circa 2007.

Map By Bird Showing The Edges Of 52 Tectonic Plates
This map is clickable to expand into a larger size
The larger chart is high definition and over 10 megabytes in size.

File Link: http://element.ess.ucla.edu/publications/2003_PB2002/PB2002_wall_map.gif

Image Source:  Bird, P.: "An Updated Digital Model Of Plate Boundaries";
(2003) Geochemistry Geophysics Geosystems, 4(3), 1027, doi:10.1029/2001GC000252.
for links to these charts and a PDF of all his material, see also
 http://element.ess.ucla.edu/publications/2003_PB2002/2003_PB2002.htm

Perhaps a bit more practical is this fourth map, also by Peter Bird.  It presents the same 52 Tectonic Plates as does the giant map of plate edges and each plate is colored, as in the USGS Tectonic Plate Map.

Image Source:  Bird, P.: "An Updated Digital Model Of Plate Boundaries";
(2003) Geochemistry Geophysics Geosystems, 4(3), 1027, doi:10.1029/2001GC000252.
for links to these charts and a PDF of all his material, see also
 http://element.ess.ucla.edu/publications/2003_PB2002/2003_PB2002.htm

As can be readily seen in these four maps, there is considerable "tentativeness" about how to model the Earth...really.   The range of 14 to 52 tectonic plates is pretty extreme and Bird suggests that even more plate fragments will be identified on the basis of various morphological and behavioral analysis of actual geological structures.

In general, views and theories of plate tectonics vary widely and this IS NOT a field where the researchers are unified about the basic facts except for this one:  this is a "baby field" and it will take a long time to mature into a consistent story which is widely accepted.

The problem of tectonic modeling gets even worse when you attempt to deal with the directions of tectonic plate motion.  Every chart on the Iway and in the scientific literature seems to diverge in some details from the others, most especially with the details which the author is most focused on presenting.

Bird's direction arrows are all relative to Africa, which is most likely done to provide a sense of absolute motion relative to a large fixed location.  The masses may all have a net motion in the directions Bird indicates, but they are also moving in other directions against each other.  In other words, the plates are moving in two vectors at least simultaneously.  They may as well have three or even four vectors of motion.   By focusing on only the  absolute motion relative to Africa, one loses the net relative motion between many if not all the  plates.   Thus we also lose a sense of the direction and magnitude of the pressure vectors which may be present on the various edges and junctions.  So for the Gallery's purposes, Bird's arrows do  do not help much and some of them may be flatly misleading.  This is especially true with Eurasia, North America, the Carib Plate, and Antarctica. 

I suspect at the current time that any exact model of how the plates move is going to end up being a matter of whose research you chose to ignore. 

A superior model would be based on plate motions relative to the Great Rift which bisects the Arctic and/or the Atlantic Ocean.  Since the average angle of this portion of the Great Rift is close to a 90 angle with the equator, one has a fairly clean, highly defined point of universal reference which is built upon a primary generator of motion in the crust.  By triangulating points on Iceland, Falkland Island, the Great Pyramid at Giza, a peak in Switzerland, Soufriere Hills on Montserrat, something on the Southern tip of Africa, something such as a point near Boston Harbor, and, say, Mt. Baldy in Southern California, one could learn an enormous amount about the real tectonic dynamic at work and the real relative motion of the plates, at least for about 35% of the surface.  Something in the range of 300 points should define the entire planet, including the small "mystery areas" quite well.

Looking at the Earth purely behaviorally, we could avoid much of such work and many of the issues of measuring and recording.  By behaviorally, I mean by looking at the earthquakes and the volcanoes.  Their frequencies and magnitudes will tell us were the Earth's crust is moving the most rapidly and from this we can infer the vectors of relative motion, i.e. which plates are moving the most rapidly in what directions vis a vis their neighbors.  Absolute motion we could just ignore.

If this "anchoring" or "grounding" within the patterns of current quake activity is used consistently to infer primary tectonic motions, I predict that the data from other approaches for defining tectonic motion will fall into greater harmony and consistency.

What makes this most especially realistic is that for the most part we are not concerned with the Tectonic Plates as objects.  Not really. Our interest is mainly about their edges.  These are defined in this Gallery as Tectonic Activity Zones.

The grinding or spreading edges create the earthquakes, volcanoes, ocean climate oscillations, even Global Warming. What we need to do is focus on these edges and define them into distinct "zones" of activity which we can study, analyze, correlate with each other and then parallel with other data. 

As will be seen in the Gallery, this approach can give us  some real perspective.  But we will also see that the Earth is not nearly well enough wired and monitored to give us a full foundation for building the house of tectonics.  Too much essential data for many areas is simply missing.  So the best we can obtain at this time are some crude estimates.  They may not all be entirely correct, but you have to start somewhere.   This is where we start.

Digital Elevation Map From NOAA

Click here to Download 3 MB Digital Elevation Map From NOAA.  Use only  the darkest green color, such as on Florida or California Central Valley, to see what are the tectonic and Global Warming danger zones.  Unfortunately too much elevation is show in green tones. I am looking for a better, finer degree of gradation in elevation, one which clear demarcation at 50 meters, 100 meters, and 300 meters.   This will have too do at the moment.  It is a beautiful imaging job, very nice work, but I have my doubts about how useful it is with so much topography shown in hard to distinguish green tones.  Recommendations gratefully accepted.

This chart below is better for the U.S.

ftp://ftp.ngdc.noaa.gov/GLOBE_DEM/pictures/48USAcolshade.jpg

 

Modeling The Tectonic Activity Zones

The Earth is far too complex and old to categorize simply and easily.  Those who do so probably end up in illusions if not delusions.   In fact the Earth is so old that it has changed radically several times. Thus any inference about the changing Earth runs a difficult gamut of evidence which never completely fits into any scheme.  In other words, Plate Tectonics trends of today are most likely are not those of 500 million years ago, nor even of 20 million years ago. 

The evidence of radical shifts appears in every age, strata discontinuity, and continent, even throughout the last two million years.  Climate research through the ice on Antarctica and Greenland demonstrates that the Earth was radically different in many respects some 2 million years ago and has undergone 400,000 and 100,000 year cycles of deep climate shifts since then.

It does not appear that human science has a handle on this other than  large repositories of local research data which shows many trends and changes and shifts which are occasionally contradictory with other areas.  If you add in bizarro phenomenon,  such as entire blocks of crust which have turned in circles at the East Pacific triple junction, or such as blocks which have turned bellyside up in the interior of continents, you have a potpourri of diverse stories which are not easy to summarize into the same geological theories.  The more one looks, the more it seems that Earth history is stranger than we can imagine.

Trying to model the motions of the Earth gets even more strange.  When we attempt to define the expansion and contraction zones of current Earth dynamics, we run immediately into the problem that some large sections of tectonic plates show evidence of moving in contradictory directions at the same time.  North America as a whole, for instance is moving to the West and South by some measurements, or more to the West and North by other measurements, yet the coastal zone of the Pacific Northwest is showing movement to the Northeast.  That's just for starters.  Any one for tea?

Then there is the strange case of the thin but quite long Baja Crumple (which slides along the coast of California and Northern Mexico.  Once called a tectonic plate it appears to have been downgraded to just the eastern edge of the Pacific Plate because no one can find a western edge for Baja except on the other side of the Pacific Ocean.  It is pushed from the south by the Cocos Plate which is subducted under Northern Mexico and perhaps along the Southern California Coast.  It is even yet still possible that the concept of a collision by an independent plate will be resurrected in the form of the the Cocos Plate under the Pacific Southwest.

For the time being,  it is convenient to think of the Baja Crumple as a unique segment of crust, a quivering sliver of ocean sediments turned into high piles of mountainous crust which is the product of both the Pacific and North American Plates grinding as they slide past each other, with the Cocos Plate and Rivera Platelet thrown against them from the south to keep everything confused.   This Crumple grinds against North America, producing Southern California’s high mountains as it goes.  As it passed, it produced the Santa Monicas with an offshoot through the Hollywood Hills,  the San Gabriels, the San Bernardinos, and of course several other major  mountainous crumples which form Southern California from Santa Barbara to Nevada and from San Diego to the Colorado River. 

Bird's Google Maps will tell you that the San Andreas Fault is connected to the East Pacific Rise, but sources in Mexico will tell you that the East Pacific Rise subducts under North America in lower Mexico.  Care for another cup of tea?

Then there is the matter of slowly moving crustal deformations (silent earthquakes), gradual subsidence or swelling which is measurable from year to year, and lunar (monthly) land tides which rise and lower the land each month by centimeters or millimeters.  All these motions are not easy to resolve in any general model of Earth's shape-shifting yet they all play a part in shaping the crust.   Since all the measurements of annual motion are in the range of a few millimeters to several centimeters, we are in any case dealing with measurements which are very hard to contrive with something the size of the Earth, which, above all, is moving ceaselessly.  Ever try to measure the height of a wave from your rowboat?  It is very hard to find a stable point of reference by which to even make a crude guess.  Subjectivity, error, mistaken presumptions, all can easily cloud our vision of such details.

Accordingly, exactly in what directions the crust, or better said, various portions of the crust, are moving, really, IN THE LONG TERM, or, AT THE CURRENT TIME, is a seriously open question.  It is probably practically impossible to answer such questions decisively  if the measurements come from short term data bases of less than 50 years.  Most of what we consider long term is just a brief flutter in geologic tectonic time.  A longer range cycle (more than 50 years) could begin to switch directions tomorrow.

And of course all humans have are databases which are generally less than 50 years deep, and incomplete for many areas.  They contain just enough "flutters" to give you a glimpse of some light and fuzzy outlines, but the devil is in the details which ellude us now and probably will for many centuries or more.   In other words, infant humanity and its play-pen science cannot yet obtain reasonable objectivity on long term issues and trends. 

The best we can do from the base of our existing empirical science is to speculate some basic concepts, such as "Plate Tectonics", and seek empirical means to refine them.  Therefore the Earth Changes Gallery begins with an empirical base of measurable earthquake activity which is organized into zones by some general concepts and data about plates tectonics such as seem to have been widely accepted. Most fortunately, despite the sadly incomplete and sometimes shallow data with which we must make do,  we are still able to make some reasonably clear observations.  From these we can make some reasonably real projections and speculations about the trends in geological and geophysical activity which are producing the changes in the Earth.  Already, this approach provides findings which are superior to the modeling on which the CO2 theory of Greenhouse Gas is built. 

The Use of Google

Where can we start, short of perfect objectivity?

Well, one thing we can do is use Google Earth.  Despite the criticisms above, Peter Bird has outlined more of less the latest quality definitions for various tectonic plate margins and built them into the "Google Earth" model.  (Simply google the name to acquire the latest best links which introduce it).

This tectonic plate structure on Google provides an excellent foil with which we can use some common sense deductions to generate our “zone” definitions for the primary tectonic quake zones.  Based on the lines drawn on the map, using the displayed quake activity as an underlay or overlay,  we can define a gridwork of Longitude and Lattitude numbers to encompass various active zones.  These definitions we can then feed into planet-scope earthquake catalog servers (such as ANSS Composite Catalog) to create a selected “database” for each of our zones.

This works quite well, as the Earthquake Storyboard demonstrates, but the data load is far in excess what Excel can process.  With existing servers and software, this works after a fashion but not as elegantly as one would prefer.  One has to go slowly and select partial data slices to get anything done. It definitely is not easy because of the collision of demands of KISS, the demands of the catalog servers, the inadequacies of the PC, and the nascent awkwardness of Google Earth (which is very young).  

Unfortunately  Google Earth is not nicely compatible with attempts to multi-process on a PC.  It is too imperious in resource use for the average PC of the first decade of Century 21.  That said, Google is a terrifically useful tool for visualization of data if you have the patience and computing ability to cope with it.

The Use Of NOAA World Surface Model

Poster - Surface of the Earth, March 2000 Revision

A FABULOUS DIGITAL MAP SYSTEM FOR EARTH.  High quality images of the zones, far superior to Google images, can be found by using the digital World Surface Model produced by NOAA.   GO HERE TO CLICK ON SECTIONS TO ZOOM IN ON IT.  One can quite easily define precision boundaries of the tectonic zones using this model as the final guide.

NOAA ETOPO2v2 Global Gridded 2-minute Database

Two-minute gridded global relief for both ocean and land areas are available in the ETOPO2v2 (2006) database.
http://www.ngdc.noaa.gov/mgg/image/2minrelief.html

Formal Citation:  U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Geophysical Data Center: "2-minute Gridded Global Relief Data (ETOPO2v2)", 2006; http://www.ngdc.noaa.gov/mgg/fliers/06mgg01.html
 

The Use of Polygon Parameters and Map Coordinates

 The zones all use coordinates of Longitudes and Latitudes, often comprised of multiple sets to define “polygon” structures or  zones of many sides to encompass large unsymmetrical areas of the Earth.  Almost none of the activity zones come in convenient rectangles or circles which can just defined as four points on a map or as one point plus a distance radius.    To create our activity zones we have to use what have become called "polygon parameters".  In a few cases we will have to add two blocks together.

The ANSS Composite Catalog defines the task this way:

You may specify a polygonal search area with the polygon parameter. This takes the strict grammatical software structure of:

polygon=lat_1,lon_1,lat_2,lon_2,,...,lat_N,lon_N

where lat_i,lon_i specify the latitude and longitude of the i-th vertex of the polygon. In other words, you can define as many pairs as you  want in order in the same consistent direction to outline any complex shape you want. The last point is identical to the first point in order to "close" the polygon. Blanks are not allowed.

For example

  polygon=37.4,-122.7,37.9,-122.75,37.9,-122.3,37.0,-122.0,37.4,-122.7

    This defines a polygon which encloses that Bay Area Peninsula.

All south latitudes are negative numbers, all north latitudes are positive numbers.  You do not use N or S to specify which side of the Equator you are on.

All longitudes east of Greenwich Meridian, are positive, all to the west are negative.

The polygon you describe must NOT cross the -180/180 degree longitude boundary, THE INTERNATIONAL DATELINE because the algebra will meltdown.  This little gem is a huge headache and needs to be solved by using a grown-up and mature non-anglo-centric 360 degree coordinate system for the Longitudes.  Why scientists in Century 21 are still pissing around with this antique West and East system invented for use by euro pirates is beyond me.

Conventions of Numbers, Lats, & Longs

For describing the zones, since I cannot focus on numbers nor abstract directions as proper cognitive objects by which to process information, the following convention is used to describe points on the Earth as intersections of our reference lines.  Longitude or Latitude is always specified first.  This gives me the imaginary Proper Noun object to process.  Then comes the qualifier which tells me which direction into which half the Earth to look,  West or South   or North or South.  Then come the numbers which specify exactly where the intersections come together.  It is very simple, very clear.  One never makes a mistake with it.  It is nearly the opposite of the scheme used by academics.

 Model Specifications

For All World Quakes, use these scales where ever possible:

All Earth =>6

All Earth =>4 & <6

All Earth =>2.5 & <4  (desirable but not practical with PC)

Unless highly qualified, do not use data prior to 1973.  Do not use data younger than 60 days.

Exception Number One:  Southern California, use from 1932, 3+

 

We will begin with the Expansion Rifts, which are composed of essentially four great parts:  the west to east running Antarctic Rifts around the southern end of the Earth, the north to south running Arctic-Atlantic Rifts, the south to north running East Pacific Rifts, and the south to north Indian (Bharatian) Rifts.  Many names have been given to various parts of the Great Rifts but for the most part this Gallery ignores them to concentrate on the largest scale units of Earth's dynamics.  We are striving to find the simplest level, not the most complex.

The Expansion Rifts, or course, are where the crust of the Earth is separating apart.  This allows new crust to slowly form from out of the Earth's deep liquid magma beneath the crystallized shell of the outer surface (which is typically called the lithosphere).  Curiously, the Expansion Rifts do not produce very many major quakes, their activity is generally in the lower magnitudes (under Class 4). 

xxx edit below this definitional portion of the storyboard is fairly raw.  formats, links, and grammatical structure need major editing

It runs west to east around the southern end of the Earth. As can be seen in the charts above, the Antarctic Rifts comprise by far the longest rifts.  The Antarctic Tectonic Plate is huge, much larger in aggregate than the very large continent of Antarctica which composes the middle of the Plate. The Antarctic Plate is in essence the entire bottom of the Earth 360 degrees in round through all the Longitudes, mostly everything south of Latitude South 50.  That is an enormous chunk of the Earth.

 The margins of the vast plate are not easy to define, have not been completely defined, and almost certainly are not understood by a single human well enough to define with precision.  Part of the problem is its remoteness.  Almost all of the margin lies deep under oceans far to the south over which almost no one sails nor flies.  Thus is it not much observed and there is about zero incentive to want to observe it.

It is said to be mainly a spreading rift zone with some areas looking like transform (horizontal) slip faults (as under the tip of South America associated with the Scotia Plate and the Falkland Islands). It also is said by some to be moving in a circle, mostly moving, relative to all the other plates, in the same direction as the Earth Spins.  If this is so, then the spreading rift which encircles Antarctica must be largely produced as a result of the Indian Ocean Bottom and the Pacific Ocean Bottom Plates moving to the north while Antarctica remains virtually static in its north-south movement. 

At the bottom of South America, the Atlantic Ocean, and Africa, the margin mainly appears to behave more like a vast transform slip fault zone than a spreading rift. There is relatively little north-south motion between them.  Antarctica can be said to be scraping past them, or perhaps South America is scraping past the edge of Antarctica.  According to recent high technology measurements made by the JPL, there is not much net movement in Antarctica.  JPL indicates a small net easterly migration, much slower than the active areas to the north of it. 

To avoid stultification by the complexity, we begin by simply making the assumption that the margin of this plate  is all an expansion rift at the bottom of the Earth.  We ignore the issue of how much of  some portion of it may be more like a transform slip zone. 

So we dive in and use the Google plate margin boundaries around Antarctica to define the entire zone as an expansion rift.  Since there are few recorded quakes above 2.0 for the entire interior portion of the Antarctic Plate, we can simply block the entire continent into this zone.  (Quakes up to 3.99 may occur there in the interior but they simply are not being recorded and logged circa 2007).

For various reasons we have to get complex in a polygon structure to encompass the zigs and zags which shoot alternatively to the  north and south in the Indian Ocean and the Pacific.

Because of international dateline and software limitations, we cannot specify a zone which passes through the dateline.  Thus we are forced to model these quakes into at least two polygon files

Partly to keep the polygons manageable and partly to observe the possible existence of different behaviors,  this vast rift is best divided into at least three major sections:

Antarctica-Bharati  Definition

Lat South 52, Long East 180

Lat South 52, Long East 145

Lat South 45, Long East 145

Lat South 45, Long East 100

Lat South 24, Long East 100

Lat South 24, Long East 50

Lat South 35, Long East 50

Lat South 40, Long East 40

Lat South 40, Long East 0

Lat South 90, Long East 0

Lat South 90, Long East 180

Lat South 52, Long East 180

polygon=-50,0,-60,0,-60,180,-50,180,-50,145,-45,145,-45,100,-25,100,-40,40,-25,40,-40,10,-50,10,-50,0

The first portion along the date line is a little problematic near the Triple Junction of the East Indian Rise. 

The final portion is even more problematic.  It truncates at Long 0 and thus ignores a section of the margin between the Falklands Fragment and the Triple Junction which is formed with the Atlantic Rise nearly dead on the Prime Meridian.  Rather than song and dance this into the Ant. Margin, this zone is simply added to the expansion zone of the South Atlantic.  It is, after all, in the middle of the South Atlantic and most of the interpreted activity is characterized as transform slippage due to the expansions of the central Great Rift in the South Atlantic. 

Antartica-Pacific  Definition

Lat South 30, Long West 77

Lat South 30, Long West 130

Lat South 50, Long West 180

Lat South 90, Long West 180

Lat South 30, Long West 77

polygon=-30,-77,-30,-130,-50.-180,-90,-180,-30,-77

Atlantic Zone of Ambiguity

From the East Pacific Triple Junction (near the Easter Islands), the Antarctic Margin past the tip of South America and into to the bottom of the Atlantic Ocean, to the Scotia Triple Junction, at approximately Long. West 2,  shows very complex mechanisms involving subduction, transform slippage, crustal deformation, and crustal rifting.  Here what we see as the tip of South America is more or less slipping to the West (relatively speaking) past the edge of the Antarctic Plate.

To accommodate the complex collisions in this area of the Pacific, South American, and Antarctic Plates, exclude Long West 77 to Long West 50 from the Antarctic Margin and incorporate into the South American Compression Zone.

It is not likely that there is significant subduction between the two plates of South America and Antarctica, though the volcanoes on the Scotia Plate are likely the tattletales of such a zone.  Evens so, we will categorize all the remaining activity in the Atlantic as part of the Antarctic Rifts.

The leg of the margin which runs from the  lower Triple Junction of the East Pacific Rise is probably NOT a boundary of Antarctica.  This section of ocean bottom is probably best described as a separate fragment, like the Nasca and Cocos Plate Frags to the north of it.  But since this is reputably a classic expansion rift, and since the edge of Australian plate below is virtually tectonically silent, thus locked with little or no actual relative motion in class 4+, we can treat this as the de facto statistical edge of of the Antarctic Plate.

This famous artist's drawing of the ocean bottom displays most of this vast rift very well.  Here is about the best image yet of  Loki's Dragon breaking the bounds of Hel.

Heezen Artist's Map
NOAA - USGS

Arctic Definition

Click On This For Gorgeous Expanded Version

NOAA NEW IBCAO RP-2, 2004 Poster

 

For our purposes, this portion of the Great Rift begins at the shores of Siberia in the Artic, runs past the North Spin Axis, down to the east of Greenland, and over Iceland (which is actually a part of the spreading Earth) .  In the north we begin at Lat North 77 (+22m) at Long. East 126 (+58m).  We define a zone which encompasses a major portion of the Arctic and head south. 

The coordinates for this zone are a simple circle to Latitude 75.  The search parameter is written as such:

search criterion: delta=0 km to 1600 km from (90,0)

This is the entire Arctic centered on the geographic north pole and  extending out to Latitude 75 all the way around.  This overlaps both Siberia and the Canadian Arctic islands slightly but not much and avoids the complexities of eastern Siberia and Alaska zone, which are handled separately. It is nearly certain that virtually all recorded quakes in this zone are directly connected to lateral expansion pressure forcing the growing of the crust through the Atlantic.

North Atlantic Definition

This portion runs down through the middle of the North Atlantic past a "triple junction" (which is west of Spain) down to near the Equator where it passes another triple junction with a vast transform fault connected to the Carib Plate.  At the Equator we pass to the next segment.

The coordinates for this zone cut cleanly close to the central Great Rift to avoid most of the compression slip zone between Africa and Europe

The polygon overlaps Greenland a small amount, but this is statistically insignificant.

A great deal of "staircasing" is required in our polygon to bypass Europe.

polygon=75,-50,75,10,65,10,65,-10,40,-10,40,-24,10,-24,10,-56,40,56,40,-40,65,-40,65,-50,75,-50

South Atlantic Definition

polygon=10,-54,0,-55,0,-34,-50,-34,-50,-20,-65,-20,-65,0,10,0,10,-54