al-Harif Aqueduct

Al Harif Aqueduct Seismic Events Fig. 13

Correlation of results among paleoseismic trenching, archaeoseismic excavations, and tufa analysis. In paleoseismic trenching, the youngest age for event X is not constrained, but it is, however, limited by event Y. In archaeoseismic excavations, the period of first damage overlaps with that of the second damage due to poor age control. In tufa analysis, the onset and restart of Br-3 and Br-4 mark the damage episodes to the aqueduct; the growth of Br-5 and Br-6 shows interruptions (I) indicating the occurrence of major events. Except for the 29 June 1170 event, previous events have been unknown in the historical seismicity catalogue. The synthesis of large earthquake events results from the timing correlation among the faulting events, building repair, and tufa interruptions (also summarized in Fig. 12 and text). Although visible in trenches (faulting event X), archaeoseismic excavations (first damage), and first interruption of tufa growth (in Br-5 and Br-6 cores), the A.D. 160–510 age of event X has a large bracket. In contrast, event Y is relatively well bracketed between A.D. 625 and 690, with the overlapped dating from trench results, the second damage of the aqueduct, and the interruption and restart of Br-3 and onset of Br-4. The occurrence of the A.D. 1170 earthquake correlates well with event Z from the trenches, the age of third damage to the aqueduct, and the age of interruption of Br-4, Br-5, and Br-6.

Sbeinati et al (2010)


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al-Harif Aqueduct Study

Introduction

This study was based on 4 paleoseismic trenches, 4 archeoseismic excavations, and 6 tufa cores taken from the aqueduct walls at a site close to Masyaf, Syria where the al-Harif Roman aqueduct crosses the north-trending ~90 km. long Missyaf fault segment. Displacement of the aqueduct revealed 13.6 ± 0.2 m of left-lateral offset since the aqueduct was first built.

Archaeoseismic Evidence

The date of initial construction of the aqueduct is not known any more precisely than that it was constructed during Roman times. It is therefore younger than 65 BCE. Two reconstruction and repair episodes were identified.

Event Date
1st 1st-6th century CE
2nd 7th-8th century CE
Tufa cores

30-83 cm. thick tufa deposits developed on the aqueduct walls from water which overflowed the aqueduct canal. Horizontal cores taken through the tufa deposits revealed discontinuities in tufa deposits which were interpreted as interruptions in tufa precipitation and markers of seismic and immediate post seismic conditions. Dates of two seismic events interpreted from the tufa cores are listed below:
Event Younger than Older than
1st 70-230 CE 410-600 CE
2nd 540-980 CE 770-940 CE
Sbeinati et. al. (2010) suggested that water overflow ended on the eastern aqueduct wall and bridge after the second damaging event while it continued on the western aqueduct wall. tufa accumulation probably ended sometime after 900-1160 CE indicating the final stoppage of water flow over the aqueduct.

Paleoseismic Evidence

Paleoseismic trenches identified 4 events summarized below:
Event Younger than Older than Comments
Z 960-1060 CE 1480–1800, 1510–1670, and 1030–1260 CE Trenches A and C
likely due to 1170 CE earthquake
Y 540-650 CE 650-810 CE Trenches A and C
X 350 BCE - 30 CE 650-810 CE Trench A
W 3400-300 BCE 800-510 BCE Trench C
Combined Analysis

Sbeinati et. al. (2010) combined the multiple strands of data to suggest 4 faulting events in the last ~3500 years
Event Date Comments
Z 1010-1210 CE likely due to 1170 CE earthquake
Y 625-690 CE
X 160-510 CE
W 2300-500 BCE

al-Harif Maps, Logs, Plots and Charts

Description Image Source Comments
Map showing site Sbeinati et. al. (2010) Figure 3
Google Earth View of Site Google Earth Figure 3
Plan View of site Sbeinati et. al. (2010) Figure 5
Schematic of
Aqueduct Faulting History
Sbeinati et. al. (2010) Figure 14
Trench A Log - N Wall Sbeinati et. al. (2010) Figure 10 A
Trench B Log - S Wall Sbeinati et. al. (2010) Figure 10B
Trench C Log - S Wall Sbeinati et. al. (2010) Figure 10C
Lithology Legend
for Trench Logs
Sbeinati et. al. (2010) Figure 10
Age Model Sbeinati et. al. (2010) Figure 12 A
Age Model - Big Sbeinati et. al. (2010) Figure 12 A
Aqueduct Wall
and Tufa Cores
Sbeinati et. al. (2010) Figure 7
Tufa Cores Sbeinati et. al. (2010) Figure 11
Archeological Evidence
of aqueduct rebuilding
Sbeinati et. al. (2010) Figure 9
Mosaic of Excavation 1 Sbeinati et. al. (2010) Figure 8 b and c

Calculator
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Strike-Slip Fault Displacement - Wells and Coppersmith (1994)

Variable Input Units Notes
cm. Strike-Slip displacement
cm. Strike-Slip displacement
Variable Output - not considering a Site Effect Units Notes
unitless Moment Magnitude for Avg. Displacement
unitless Moment Magnitude for Max. Displacement
  

References
References