2 - After Shocks
by Jefferson Williams
1After the Sabbath, at dawn on the first day of the week, Mary Magdalene and the other Mary went to look at the tomb.
2There was a violent earthquake, for an angel of the Lord came down from heaven and, going to the tomb, rolled back the stone and sat on it.
- Matthew Chapter 28
Approximately 36 hours after the first earthquake, Matthew reports another earthquake; what today might be called an aftershock. The quote from Matthew mentions a Rolling Stone being jarred open and revealing an empty tomb. The picture to the right shows a Rolling Stone from around the time of Jesus. It is possible to calculate the amount of force you would feel if this aftershock event was real. If you were near to the tomb, you would have experienced a jolt that felt like ~25% of your body weight just got slammed against you.
Another small seismic shock is written about by a different author. Perhaps 8 weeks after the crucifixion, the author of Luke writes
31And when they had prayed, the place was shaken where they were assembled together; and they were all filled with the Holy Ghost, and they spake the word of God with boldness.- Acts Chapter 4
It appears that the people present viewed the seismic shock as having a divine origin. This was a common belief in antiquity among Jews and other peoples. It is strange however that they are reported as viewing it in a positive light. That was not how most people viewed earthquakes in Antiquity.
When the author of Matthew reports a second earthquake in Chapter 28, he mentions that a Blocking or Rolling Stone was jarred open; revealing an empty tomb . The relevant passage is repeated below.
1 After the Sabbath, at dawn on the first day of the week, Mary Magdalene and the other Mary went to look at the tomb. 2 There was a violent earthquake, for an angel of the Lord came down from heaven and, going to the tomb, rolled back the stone and sat on it.A force balance calculation can be made to determine the minimum peak horizontal ground acceleration required to move the stone. At equilibrium conditions the disturbing force FH is balanced by the resisting force FR. When FH exceeds FR, the Rolling Stone will begin to move. A diagram and the calculation is shown below.
To visualize this, a force of 0.25 g is equivalent to feeling a jolt equal to about 25% of your body weight. If you weighed 100 pounds (45 kg.), you would feel a jolt of ~25 lb (11 kg.). If you weighed 200 pounds (90 kg.), you would feel ~50 lb (11 kg.). This is discussed in a bit more depth in the collapsible panel titled Rolling Stone Calculation in the Earthquake Encyclopedia Entry for the Jerusalem Quake.