Historical Earthquakes

Over the past thousand years, earthquakes have occurred along the borders of Saudi Arabia that were felt by the population. Locating the areas, where they occurred was approximated because of the low number of inhabitants and the lack of written records in the past. The current statistics indicate that historical records on seismicity are largely incomplete, even in regard to earthquakes of magnitudes 6 or higher. However, one of the well-documented events on seismic activities in Saudi Arabia is the occurrence of a volcanic eruption in Harrat Rahat near Madina in 654 H (1256 AD), which was accompanied by a significantly high seismic activity. This area is still experiencing low seismic activity to date. The last important seismic event in Saudi Arabia was the 1995 Haql earthquake in the Gulf of Aqaba (7.3 MW), which caused significant damages to the cities on both sides of the Gulf of Aqaba, and it was felt hundreds of kilometers away from its epicenter. Earthquakes with magnitude 6, taking place along the axis of the Red Sea are usually not felt by the population of the cities on both sides of the Red Sea. However, they may pose a pronounced threat to the infrastructures.

Recently, a moderate earthquake, measuring 5.4 in magnitude occurred in 2009 in Harrat Al-Shaqa (Lunayyir) to the north of Yanbu, which was linked to the activity of a magma chamber at shallow crustal depths. Although it only caused minor damages to properties, it implies that the Arabian Shield can be potentially subjected to earthquake hazards.