Above is a diagram of the boundaries of the supposed tectonic plates from the US Geological Survey (USGS), the federal source in the US for science about the earth.
Simply looking at it should raise some intuitive questions, such as "if the continents once fit together, how did they ever slide apart, seeing that there is so much material between them (and, in at least one case, an entire Pacific Plate between them)?" Another intuitive question would be how the Pacific Plate ever moves at all, especially in the northern region where the words "Ring of Fire" are located with three red arrows pointing northwards -- the "arc-and-cusp" pattern of trenches in that area (discussed briefly towards the end of this previous post) would seem to create a pretty solid lock on movement, besides being very difficult to explain via plate motion (is the plate somehow expanding in all three directions indicated by those red arrows?).
Another major piece of evidence that there are grave problems with the tectonic theory are the earthquakes that take place in the middle of huge plates, far from plate boundaries. The tectonic theory seems to provide a compelling explanation for earthquakes by arguing that they are primarily caused by the rubbing and colliding that takes place along plate boundaries, and indeed many earthquakes do take place along such boundaries. However, there are numerous earthquakes which take place far from boundaries, some of them quite severe. These pose a serious problem for adherents of tectonics.
For example, in the diagram above, the North American plate is shown as one of the largest plates on the globe, and many earthquakes take place along its western edge. However, scientists recently have been issuing warnings about severe earthquakes in the past taking place right in the middle of it, and saying that the midwest might be due for another one in the near future.
This recent article discusses the debate among scientists over the danger for another major earthquake in Missouri based upon the history of several fairly large quakes there during the 19th century. Major earthquakes have also been noted in the interior of Antarctica, which have caused scientists to scratch their heads due to their location in the middle of a plate.
The hydroplate theory of Dr. Walt Brown does not have a problem explaining earthquakes in the middle of plates the way the tectonic theory does. As the name implies, Brown's theory does not deny the existence of plates, but argues that they were created by the forces surrounding a catastrophic global flood and that they slid apart as a result of the chain of events he describes in greater detail in his book. Since that time, they have not been "drifting," but there is a fairly common incidence of "shifting," as described in the post on earthquakes linked previously.
Brown's theory holds that water trapped under the earth built up pressure and eventually led to a rupture, which allowed the high-pressure water to escape with enormous power, leading to a worldwide flood. The removal of the water and sediments above the line of this rupture allowed the basement crust to spring upwards, initiating the slide of the plates away from this rupture. Some water (although only a small percentage of the original) remained trapped beneath, and remains there to this day.
As Dr. Brown explains, this sequence of events helps explain the cause of earthquakes. In the 7th edition of his book, published in 1999, he writes:
Trapped, subterranean water, unable to escape during the flood, slowly seeps up through cracks and faults formed during the crushing of the compression event. The higher this water migrates through cracks, the more its pressure exceeds that in the walls of the crack trying to contain it. Consequently, the crack spreads and lengthens. (So before an earthquake, the ground often bulges slightly, water levels sometimes change in wells, and geyser eruptions may become irregular.) Simultaneously, stresses build up in the crust, again driven ultimately by gravity and mass imbalances at the end of the flood. Once the compressive stress has risen enough, the cracks have grown enough, and the frictional locking of cracked surfaces has diminished enough, sudden movement occurs. The water then acts as a lubricant. (Therefore, frictional heat is not found along the San Andreas Fault.) Sliding friction instantaneously heats the water, converts it to steam at an even higher pressure, and initiates a runaway process called a shallow earthquake. 108.
This theory also explains why earthquakes can be caused by injecting high-pressure water deep into the ground and by filling huge man-made reservoirs with water (as happened in India in 1967 and 1998 and in China in 2008 and possibly 2010). In his 1999 book, Brown noted: "The plate tectonic theory claims earthquakes occur when plates rub against each other, temporarily lock, and then periodically jerk loose. If so, why are some powerful earthquakes far from plate boundaries? Why do earthquakes occur when water is forced into the ground after large reservoirs are built and filled?" (91).
Here is a recent story describing the possibility that the injection of high-pressure water into the ground could be responsible for earthquakes in Arakansas. All of these examples accord perfectly with the predictions of Brown's hydroplate theory.