EARTH WOBBLE RELATED EARTHQUAKE TRIGGERING

This is most of the text of a report that I just posted to a number of Newsgroups including sci.geo.earthquakes

Questions for discussion:

*** What do we know about the Earth wobble?

*** Has anyone tried to link the Earth wobble with earthquake triggering?

EARTH WOBBLE RELATED EARTHQUAKE TRIGGERING THEORIES

I believe that my data indicate that earthquake triggering processes are linked with one or more time cycles which are about 30 days in length, and one which is about 24 hour and 50 minutes in length. And I believe that my data might also be indicating that many earthquakes could at times be tending to occur during time windows which are several months in length. However up until now I have not been able to form any distinct theories to explain what processes might be controlling those several month duration time windows.

Perhaps they are being controlled by crustal strain linked with an "Earth wobble."

Basic Earth Wobble Theory - The Earth rotates once each day on its North - South Pole axis. And some researchers believe that there can be a certain amount of "wobble" associated with that rotation.

Popular theories propose that the Earth is composed of layers which include a relatively solid crust, a somewhat fluid layer of molten rock beneath the crust, and a solid core. One or more of those layers can start to rotate on an axis which is slightly out of alignment with the Earth's normal North - South Pole rotation axis. And that can cause a wobble to occur. The Earth becomes something like a spinning top which is not perfectly balanced. It tends to wobble. And when it does it causes strain to appear in the crust at different locations around the world. That strain can add to the strain which results from the movement of tectonic plates relative to one another etc. and strain associated with the daily flexing of the crust due to the Solid Earth Tide and ocean tides etc. And those combined amounts of strain can help trigger earthquakes.

Why would the Earth wobble like that?

If you know the answer to that question then you might offer an explanation. For discussion purposes I am going to outline the following theories:

1. Earth Layer Rotation Around A Sun - Earth - Moon Barycenter

Once each month the different layers of the Earth rotate around a sun - Earth - moon barycenter (center of mass) which is located a certain distance down inside the Earth. It is in the general vicinity of the Earth - moon barycenter. But depending upon where the sun is in the sky relative to the moon its position constantly shifts to latitudes to the north or south of, longitudes to the east or west of, and depths above or beneath the Earth - moon barycenter. Because the Earth is not a truly rigid body its different layers attempt to rotate around that sun - Earth - moon barycenter somewhat independently of one another.

The speed of rotation of those different Earth layers is affected by factors or phenomena such as the following:

A. The positions of the sun and the moon in the sky relative to one another

B. How close the moon is to the Earth during its monthly rotation cycle

C. The latitude of the moon during its monthly journey from being above northern latitudes to being above southern latitudes, and back again

A result of those three factors etc. is that the different layers of the Earth are being constantly pulled in different directions as they attempt to rotate around the sun - Earth - moon barycenter which is constantly changing its location. And that can help cause earthquake triggering strain to appear in different locations of the Earth's crust.

As the following GIF file shows, those three factors etc. have slightly different time lengths. And they can reinforce one another and enhance earthquake triggering processes for different parts of the Earth's crust for a while before they get "out of sync" with one another. (Compare moon gravity, moon latitude, and Sun - Earth - moon angle)
http://www.freewebz.com/eq-forecasting/90-03w.html

2. Ocean Tide Drag On The Earth's Crust

As the Earth rotates on its North - South Pole axis each day our oceans are being constantly pulled toward the positions of the sun and the moon in the sky. This results in ocean tides.

That water movement produces a "drag" on the ocean floor and pressure on the edges of continents as the tides push against them. The amount of drag etc. and its direction is constantly changing. This results in the Earth's crust being pulled in different directions relative to its inner layers which are not directly affected by that ocean water related drag etc. And that can produce a certain amount of Earth wobble and related earthquake triggering strain which appears at different locations in the crust.

3. Centrifugal Force Related Factors

Centrifugal force resulting from the daily rotation of the Earth on its North - South Pole axis causes the Earth to bulge outward near the equator and to be flattened to a certain degree near the North and South Poles. A certain amount of the Earth's rotation energy is invested in the mass shifts which result from that.

As the Earth wobbles as a result of processes 1 and 2 etc. those bulges and flattened locations try to slowly shift to other locations in order to reestablish an Earth rotation equilibrium. And those shifts can result in additional changes in the Earth wobble patterns and increased or decreased earthquake triggering strain at different locations around the Earth.

Final Question: Assuming theories 1 and 2 are accurate, can anyone propose how much Earth wobble those two processes would produce compared with one another?

My own guess would be that wobble associated with rotation of the different Earth layers around the sun - Earth - moon barycenter would be stronger.

The information in this report represents expressions of personal opinion.