Speed of the Continental Plates

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Plate tectonics is a relatively new theory in the field of geology. It statesthat the lithosphere of the earth is divided into a small number of plates whichfloat on and travel independently over the athenosphere, which lies over the mantle.Much of the earth's seismic activities occurs at the boundaries of these plates.It is a relatively slow movement, driven by thermal convection currents and othergeological activity originating deep within the earth's mantle. This theory ofplate tectonics replaced the previous one of continental drift, where it was thoughtthat just the continents themselves drifted over the earth's surface. There arebasically eight large plates -- African, Antarctic, Eurasian, Indian-Australian,Nazca, North American, Pacific and South American; and various smaller ones --Anatoliah, Arabian, Caribbean, Cocos, Philippines, Somali, and Juan de Fuca (toname a few).

Most of my research turned up theories and not hard experimental data and thosemeasurements that I was able to obtain were averages or estimations. The numbersfound in each source did not exactly agree with each other but their ranges werereasonably similar. The majority of the research showed that the plates movedat the average rates between approximately 0.60 cm/yr to 10 cm/yr. Somesources stated that in the North Atlantic, the rate of movement is only about1 cm (about 0.4 in) per year, while in the Pacific it amounts to more than4 cm (almost 2 in) annually, while two others said the plates, in general,traveled from 5 to 10 cm/yr.

However, the velocities, in some sources, of the plates are measured as absoluteand/or relative motion. I found the absolute velocities to some of the platesfrom one source. They are as follows:

I obtained the relative velocities of the plates by combining the data fromtwo sources. With some help, I discovered a great calculation program on the Internet(see bibliography) specific for this purpose. I used the coordinates from anothersource (see bibliography) that calculated the relative rotational motions of theplates to the Pacific plate. The relative velocities of some of the plates relativeto the Pacific plate using this method are as follows:

The relative and absolute velocities can be calculated using the Internet programbut the coordinates are crucial, for very different results may be obtained ifthe coordinates are not correct. Due to various activity on different points onand below the earth's surface, the movement of one plate is not uniform. One platecan have many velocities depending upon the location. However, due to my lackof knowledge in this topic and the conflicting numbers of scientists, my valuesmay be off. I suppose there's no agreeable data because there is probably no realefficient method of measuring all the tectonic plates on earth. There are manyfactors involved with plate tectonics; they don't just move in one path, but theyindividually take many different paths. They interact with each other and affectthe motions by applying various types of stress and pressure, etc. at differentpoints on the earth. Also, the earth is constantly changing and so there is noexact number to reflect the velocities of the plate tectonics.

Zhen Shao Huang -- 1997

Editor's Supplement -- 2001

External links to this page:

• CyberSleuthkids: Science - Geology
• Earth's Continental Plates - EnchantedLearning.com
• Earth's Continental Plates - LittleExplorers.com
• Earth's Continental Plates - ZoomSchool.com
• The Earth Will Reel from Its Place: Scientific Confirmation for Bible Prophecies of Geological Upheaval, Dan Graves

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