Varves are annual layers of deposition in the sediments. If we can identify varves in an outcrop or a core we can count years of deposition just like we can count years of growth from tree rings.
A varve typically consists of one light and one dark layer of sediment. The light and dark layers are deposited during different times of the year. Thus, one pair of light and dark layers constitutes one year of time and by counting these couplets (i.e. varves), we can count years of deposition.
Varves are present in salty (aka evaporitic) lakes such as the Dead Sea. Unfortunately, the varves of the Dead Sea are not always well defined. Many of the Dead Sea varves are ambiguous. This means I can’t (for now) determine the exact year when this seismite was formed. At best, I can only define a time span of several years when the earthquake occurred.
To the right is a thin section (i.e microscope slide) created from a core taken near the town of Ein Gedi in 1997. It shows several years of varve couplets with one well defined varve couplet surrounded by a white rectangle. The whitish layer at the bottom of the rectangle is almost pure aragonite; a type of Calcite (CaCO3) that will precipitate out of the Dead Sea at the height of summer (e.g. in August). The darker top layer is flood deposit(s). In the winter and spring, a few rain storms cause the normally dry steams of Ein Gedi to flow with water and as they flow out to sea, they bring sediments with them which are deposited at the sea floor.
Using thin section slides from Ein Gedi, I counted varves from the top of the 31 BC earthquake to the top of this early first century earthquake I am trying to date. I also estimated the accuracy of my date for the earthquake. I concluded that this early first century earthquake appears to have occurred sometime between 26 and 36 AD; the years when Pontius Pilate was procurator of Judea and when the earthquake of the Gospel of Matthew is historically constrained. My best guess is that the earthquake in the sediments likely occurred sometime between 29 and 33 AD.
Along with some German colleagues, I published this research in 2012. The first page of this article is shown here. If you would like a complimentary copy, please download it from the link – >Quake Article
So, the earthquake in the sediments appears to have occurred more or less during the same time period when Jesus of Nazareth died but we still don’t know if the earthquake in the sediments is the same earthquake reported in Matthew. In fact, we still don’t know if Matthew’s earthquake is an accurate report of an actual geologic event. The description in Matthew could be pure allegory.
This leads to the current focus of my research; finding temporal patterns in the sediments.
While the biblical accounts are vague about the year of the crucifixion, they are specific about the time of year that the crucifixion occurred; the 14th or 15th day of the Jewish month of Nisan known as Good Friday.
If there is a way to determine what time of year the sediments immediately on top of this earthquake were deposited, we could determine if this was a spring, summer, winter or fall earthquake.
References and Links
- An Early First Century Earthquake in the Dead Sea. download here – >Quake Article
- J. William’s Masters Report (2004) modeling how earthquake shaking deforms the Dead Sea muds. Pages 21-25 cover the Jerualem Quake.
- Wikipedia entry on varves.
- Aragonite precipitation – Although the Dead Sea has been observed to “whiten” during August in particulalrly hot years, I cannot find a photo or a video of such an event. However, here is a link to a photo of a summer precipitation event in a salty lake in nearby Cyprus.
- Sediment Deposition from streams – Below is a YouTube video of a flash flood in Ein Gedi during the winter of 2009. Note the plume of muddy water going out to sea at the end of the video. As the sediments in that muddy plume drop to the bottom of the Dead Sea, they will leave a thin flood deposit.
Sediment Deposition from airborne Dust – The Dead sea also receives sediments in the form of dust that falls from the air onto to the Dead Sea itself. Such sedimentation is particularly pronounced during dust storms; of which half a dozen usually occur during the spring time.Click embedded links below to see :
- Satellite image of a dust storm in the Eastern Mediterranean that is moving towards the Dead Sea.
- dust storm photo taken from the Jordanian side of the Dead Sea.
- photo of a dusty day taken from the Israeli side of the Dead Sea.