A powerful undersea earthquake south of Japan has shaken buildings in Tokyo. The US Geological Survey said the 7.8-magnitude earthquake was centred 874km (543 miles) from the Japanese capital, at a depth of almost 700km. It struck at 18:30 local time (11:30 GMT). Buildings in the capital swayed for almost a minute as the quake built in intensity, AFP news agency says. There are no reports of serious damage or casualties. No tsunami warning has been issued.The unusual thing about this quake is its depth. What scientists call deep-focus earthquakes are an anomaly, they aren't supposed to be able to happen. At least, according to the scientific theories of why quakes occur.
Deep Earthquakes: About.Com Education- Geology
Deep earthquakes were discovered in the 1920s, but they remain a subject of contention today. The reason is simple: they aren't supposed to happen. Yet they account for more than 20 percent of all earthquakes.And so all the articles go on and try and explain it.
Shallow earthquakes require solid rocks to occur more specifically, cold, brittle rocks. Only these can store up elastic strain along a geologic fault, held in check by friction, until the strain lets loose in a violent rupture.
The Earth gets hotter by about 1 degree C with each 100 meters of depth on average. Combine that with high pressure underground and it's clear that by about 50 kilometers down, on average the rocks should be too hot and squeezed too tight to crack and grind the way they do at the surface. Thus deep-focus quakes, those below 70 km, demand an explanation.
A Psalm of David. The earth is the LORD’s and the fullness thereof, the world and those who dwell therein, (Psalm 24:1)
Who has a claim against me that I must pay? Everything under heaven belongs to me. (Job 41:11)
Shallow-focus earthquakes are quakes that occur between depths of 0 and 70KM below the surface.
Intermediate-focus earthquakes are quakes that occur between depths of 70Km and 300KM below the surface.
Deep-focus quakes are quakes that occur between depth of 300-700KM. (source)
So we can see that the Japan quake was the deepest of the deep-focus quakes. It was the deepest this year, being exactly 677.6 KM. There were 4 deep-focus quakes 4 in Fiji this year at 600-613 depth. All the other deep quakes that have occurred so far were shallower than 600KM.
There have been 23 deep-focus quakes this year so far. Here is a screen shot from my search on USGS for quakes between the magnitudes of 5.0-9.9 this year thus far exceeding a depth of 300K, AKA deep focus quakes at a meaningful magnitude. Click to enlarge.
The United States Geological Survey (USGS) data presents an average number of annual quakes.
In the 6.0-6.9 range so far this year there have been 52.
In the 7.0-7.9 range so far this year there have been 8.
In the 8.0-8.9 range so far this year there have been 0.
This article, Greatest Earthquakes of the Bible, by Dr Steven Austin at the Institute for Creation Research, is excellent. I recommend it. Here is Dr Austin's conclusion:
A review of the 17 earthquakes listed above shows that virtually the entire story of the Bible can be summarized by its association with earthquakes. Biblical events emphasized by earthquakes are creation, Noah’s Flood, separation of Abraham and Lot from judgment of the wicked cities, the giving of the Law on Mount Sinai, authentication of the leadership of Moses, God’s provision in the conquest of Canaan, vindication of the messages of Hebrew prophets, the crucifixion of our Lord in Jerusalem, the resurrection of our Lord, the ministry of the apostles and the church, the modern “birth pangs” sign of the end times, the national conversion of Israel, and the Second Coming of the Lord Jesus Christ. History, archaeology, and geology appear to confirm independently many earthquakes mentioned in the Bible.
Earthquakes have been used distinctively by God to highlight some of the most important events of the Bible. The three main purposes for biblical earthquakes are judgment, deliverance, and communication. The lesson is obvious—God does not do anything really big without emphasizing it with an earthquake! In our fast-paced, man-centered, technology-based society of the twenty-first century, God would have us pause and consider His sovereign nature and the program He has been accomplishing in the world.