Earthquakes in Jerusalem: A Historical and Seismological Perspective

Introduction

The destruction in Jerusalem from the
earthquake that occurred in 1927

Approximately 3000 years ago, Jerusalem was captured by King David, who established it as the capital of the united Kingdom of Israel: "The king and his men marched to Jerusalem" (2 Samuel 5:6). Since then, the city has been continuously inhabited, making it one of the oldest cities in the world with a continuous history of human settlement. Today, Jerusalem is the capital of Israel and holds religious significance for Judaism, Christianity, and Islam. Throughout its history, Jerusalem has experienced numerous changes in governance, destruction by human actions, and damage caused by earthquakes (Killebrew, 2011). Earthquakes are not rare in Jerusalem due to its proximity to the Dead Sea Transform (DST), the primary cause of earthquakes in the region, and the numerous faults crossing the city (Garfunkel, 1981; Zohar et al., 2016).

Historical Earthquakes and Their Impact

Seismic Activity in the Region

Zohar et al. (2016) identified that 54 settlements in Israel and its surroundings were affected by earthquakes at least twice in the last 2000 years. Jerusalem has the highest number of documented incidents, with at least 14 occurrences (Zohar et al., 2017). The most destructive earthquake in recent history occurred in 1927, with a magnitude of M=6.25, centered near the northern Dead Sea. This event caused significant damage across the region, with hundreds of casualties and injuries. In Jerusalem, notable damage was reported in areas such as the Bukharan Quarter, Mahane Yehuda, Jaffa Gate, the Armenian Quarter, the Old City, Hebrew University, the Governor's House, Talpiot, and other locations (Avni, 1999).

Importance of Studying Historical Earthquakes

The epicenters of the earthquakes,
 intensity and year

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Studying the cumulative damage from historical earthquakes in ancient cities is crucial for understanding the existing risk and for enabling authorities and communities to prepare for and mitigate future earthquake damage. For instance, research on the city of Rome (Italy) mapped earthquakes that affected the city over the last two thousand years, starting from 15 CE. The study examined potential epicenters, assessed their magnitudes, classified different areas according to the severity of cumulative damage, and identified recurring damage patterns (Galli & Molin, 2014). In Israel, however, the extensive knowledge of historical earthquakes, including archaeological and paleo-seismic findings and historical documents, has not yet been translated into detailed mapping and analysis of cumulative damage at a high resolution. Particularly, there is a lack of identification and classification of damage to structures, evaluation of damage severity, and the ability to assess damage to structures and landscapes that no longer exist, with evidence found only in historical documents or archaeological excavations.

Research Objectives

Given the extensive material and evidence accumulated regarding historical earthquakes that affected Jerusalem, it is an appropriate target for such research. In this context, the following research questions are raised:

1. What are the spatial and temporal damage patterns from earthquakes in Jerusalem and its surroundings over the last two thousand years?

2. What is the cumulative chronological damage profile of selected buildings and sites across the city and its surroundings? The aim is to identify specific buildings or sites that have been damaged multiple times.

Data Collection and GIS Analysis

The study involved the interpretation of sources and literature, archaeological findings, precise mapping of damage, and GIS-based analysis to identify areas with high risk. Sources included literary documents, historical records, and archaeological reports. The reliability of these sources was carefully evaluated to ensure accurate representation of seismic events. GIS technology enabled detailed mapping and analysis of damage distribution, helping to identify patterns and high-risk areas.

Findings

Temporal and Spatial Damage Distribution

The study found that Jerusalem has been affected by 16 different earthquakes over the past 2000 years. Sites within the city experienced damage between one and five times during this period. The highest intensity recorded was 9 on the EMS-98 scale, indicating relatively moderate damage. The spatial distribution of seismic intensities was uneven: southeastern areas experienced higher average intensities compared to western areas.

The different impact strengths

Data Density and Sensitive Areas

The highest data density was found in the central research area, around the Old City. This can be attributed to the concentration of historical and archaeological sites, greater accessibility for researchers, and a wealth of historical documentation. Sensitive areas to seismic intensity were identified as the geological formations of Shabta and Netzer, which showed higher seismic intensities, while the Veredim formation exhibited greater resilience.

Discussion and Conclusions

Impact of Geological Formations

The varying seismic intensities observed are linked to the distance from the epicenter and the strength of the earthquake. Shabta and Netzer formations displayed higher intensities due to differences in rock structure and lithological characteristics. Conversely, the Veredim formation showed lower intensities, likely due to its structural properties that reduce seismic wave amplitudes.

Seismic Intensity Gaps

The study observed gaps in seismic intensity data, particularly for the first millennium CE. This indicates the existence of additional earthquakes for which there is no archaeological or historical evidence, suggesting the need for further research.

Recommendations for Further Research

To fill these gaps, it is recommended to:

1. Continue archaeological excavations in underexplored areas.

2. Re-examine historical documents for additional evidence.

3. Use advanced technologies such as seismic imaging to identify subsurface structures indicative of past earthquakes.

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Summary

Jerusalem has experienced numerous earthquakes over the past 2000 years, with relatively moderate seismic intensities. The study highlights the importance of geological formations in determining seismic vulnerability and emphasizes the need for further research to fill historical data gaps. Understanding the impact of geological formations on seismic intensities is crucial for future preparedness and the resilience of new structures in the area.

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References

- Avni, G. (1999). "The Earthquake of 1927 in Jerusalem." Tel Aviv University Press.

- Garfunkel, Z. (1981). "The Dead Sea Transform and Its Implications for Geology and Seismicity in the Region." Geological Survey of Israel.

- Galli, P., & Molin, D. (2014). "Earthquake Damage Patterns in Rome Over Two Millennia: From Historical to Recent Events." Journal of Seismology, 18(2), 357-376.

- Killebrew, A. E. (2011). "Biblical Jerusalem: An Archaeological Assessment." In: The City of David: Revisiting Early Excavations, New Studies, (pp. 45-78). Jerusalem: Israel Antiquities Authority.

- Zohar, M., Marco, S., & Agnon, A. (2016). "Historical Earthquakes in Jerusalem: Data Collection and Analysis." Journal of Archaeological Science, 65, 1-12.

- Zohar, M., Marco, S., & Agnon, A. (2017). "Seismic Hazard Assessment of Jerusalem." Earthquake Spectra, 33(4), 2309-2331.