Ein Rahel

Introduction
Introduction

Korzhenkov and Erickson-Gini (2003) report that the fort at Ein Rahel was first constructed and occupied in the 3rd century BCE followed by a hiatus in occupation from ~100 BCE until the early first century CE after which it was re-occupied. The fort was then, according to the authors, re-abandoned in the early second century CE. The abandonment came after the fort's destruction due to what the authors beleive was a seismic event.

Maps and Plans
Maps and Plans

  • Fig. 5 - Plan of the Fort with marked types of deformations from Korzhenkov and Erickson-Gini (2003)
  • Plan 1 - Plan of the Fort from Shamir (1999)

Chronology
Early 2nd Century CE Earthquake

Korzhenkov and Erickson-Gini (2003) describe archeoseismic evidence for an early second century CE earthquake as follows:

In the surrounding casemate rooms the latest occupational phase (dating to the early 2nd cent. A.D.) was sealed by the collapse of the upper floor of the fort. Sections excavated in these rooms revealed clear collapse of the ceiling of the lower floor and the upper floor debris sealed by the upper floor roof. The ceiling and roof of the structure were made from woven organic matting and mud and were supported by wooden beams.

A rich ceramic assemblage was discovered in the fort as well as extensive organic finds and included reed-matting and wooden beams, almond shells, nuts and olive and dates stones. Several wooden lice combs and other wooden objects were found in excellent condition, as well as many shreds of textiles and leather. Two camel bones were found bearing inscriptions in black ink in the Nabataean script.
Shamir (1999:92) examined the textiles, basketry and cordage and reported that
Preserved by the arid climate, the perishables from `En Rahel include about 300 textile and basketry fragments, cordage, spindle whorls and needles. The Early Roman date of the material, provided by its archaeological context, differs slightly from its radiocarbon dating (Carmi and Segal 1995:55).1
Footnotes

1 In the fall of 1991, a brown goat-hair textile fragment from L13, Basket 129 was submitted to I. Carmi and D. Segal at the 14C laboratory of the Weizmann Institute of Science, in order to verify the archaeological conclusions. Their results suggest the fabric was manufactured in the Roman period:

Sample d14C d13C yrs BP* Calendaric Age**
RT-1596 -209.2 ± 3.9 -15.95 1885 ± 40 82-204 CE
* Conventional radiocarbon years before 1950.
** Calculated using CALIB 3 (Stuiver and Reimer 1993).

The description of the Calendaric Age distribution reported in Carmi and Segal (1995:55) which is referenced in Footnote 1 above is a bit different and earlier. See the table below from Carmi and Segal (1995:55).
Sample d14C d13C yrs BP* Calendaric Age**
RT-1596 -209.2 ± 3.9 -15.95 1885 ± 40 66-145 CE (87%), 165-186 CE (13%)
* Conventional radiocarbon years before 1950.
** Calculated using CALIB 3 (Stuiver and Reimer 1993).

Seismic Effects
Early 2nd Century CE Earthquake

Korzhenkov and Erickson-Gini (2003) list the following seismic effects:

  • inclination of walls
  • collapse of walls (upper floor collapsed)
  • collapse of lintels
  • roof collapse
Detailed discussion of some of these effects are shown in the table below:
Seismic Effect Plan Figure(s) Comments
The Inclination of Building Elements 8 Earthquake events that have occurred in other parts of the world have produced a large number of structural elements that were found to be preferentially inclined toward the epicenter. However, in some cases the inclination was in the opposing direction. Similar destruction features were found in the ancient fort at Ein Rahel where preferentially inclined walls were observed (see Fig. 5 - Plan).

As seen in Fig. 8, the eastern wall in Room 13 (see Fig. 5 - Plan), oriented N16°, inclines to the east. In contrast the perpendicular walls are slightly inclined to the north and south with no preferential direction. This would indicate that the seismic shock arrived approximately from an E-W direction with the wall oriented roughly normal to the seismic wave direction was inclined, whereas walls oriented parallel to the seismic waves lost support and were tilted on both sides.
The Collapse of Door Lintels 9
10
Collapsed door lintels found in the ruins of the Ein Rahel fort exhibited an oriented collapse. The seismic wave approaching the lintel perpendicular to its orientation caused an oriented collapse which can be recognized by a significant shift of the collapsed lintel on the ground in relation to its original position (Fig. 9. 10). Thus the lintel above the entrance to Room 10 (see Fig. 5 - Plan) was thrown eastwards (Fig. 9). The door lintel located between Rooms 20 and 9 was thrown southwards (Fig. 10) and was broke upon impact. These observations would indicate that the propagation of the seismic waves causing the destruction was from the SE.

Archaeoseismic Analysis
Early 2nd Century CE Earthquake

Figures

Figures

  • Fig. 5 - Plan of the Fort with marked types of deformations from Korzhenkov and Erickson-Gini (2003)
  • Fig. 8 - Eastward tilt of eastern external wall from Korzhenkov and Erickson-Gini (2003)
  • Fig. 9 - Oriented collapse of door lintel from N-S wall from Korzhenkov and Erickson-Gini (2003)
  • Fig. 10 - Oriented collapse of door lintel from E-W wall from Korzhenkov and Erickson-Gini (2003)

Discussion

Korzhenkov and Erickson-Gini (2003) provided the following analysis:
Studies of destruction in Ein Rahel fort also reveal a systematic nature of dislocations (see Fig.5):
  1. NS-trending walls revealed tilt (see Fig. 8) and collapse toward east, whereas perpendicular trending walls tilted and failed down without a noticeable systematic pattern. These observations indicate that the seismic shock arrived approximately along the east-west axis, most probably from the east.
  2. The door lintel on the N-S trending wall was thrown eastward (see Fig. 9), but the lintel on the E-W trending wall was thrown southward (see Fig. 10). This fact indicates that the propagation of the seismic energy was along the SE-NW axis, making it likely that the seismic waves came from the SE direction.
Thus, the epicenter was located somewhere ESE or WNW of Ein Rahel. The strong degree of destruction at the fort indicates that the epicenter was located in the vicinity of the site. Absence of systematically rotated building elements did not allow us to precisely locate the source of seismic waves. A WNW source could bring about the collapse of the fort along the western shoulder of the Dead Sea Rift, but the site is located just inside the zone of the Western shoulder fault. The occurrence of an earthquake in this area would not create a systematic picture of deformation. In the case of the fort at Ein Rahel the epicenter was apparently located along the Dead Sea Transform, located several kilometers ESE (~125°) of Ein Rahel. The degree of destruction found in the fort corresponds to an earthquake intensity of I = VIII–IX (MSK-64 scale).

Intensity Estimates
Early 2nd Century CE Earthquake

Effect Location Intensity Comments
Tilted Walls VI +
Collapsed Walls VIII +
This archaeoseismic evidence requires a minimum Intensity of VIII (8) when using the Earthquake Archeological Effects chart of Rodríguez-Pascua et al (2013: 221-224).
Earthquake Parameters from Korzhenkov and Erickson-Gini (2003)

Korzhenkov and Erickson-Gini (2003) hypothesize that the epicenter of the causative earthquake was located in the vicinity of the site either to the WNW or ESE (~125 degrees). The proximity of the Arava Fault led them to consider ESE more likely. They estimated a local seismic intensity of VIII–IX.

Notes and Further Reading
References