The destructive earthquake that struck Morocco in conjunction with the floods in Libya, in addition to the earthquake in Turkey and Syria and the subsequent successive tremors on February 6, 2023, have prompted research into the geological situation and tracking the seismic and volcanic map of Yemen, based on reports, research, and studies issued by the Yemen Geological Survey and Mineral Resources Board and the National Information Center.
Yemen is affected by a number of parallel and perpendicular fault systems in both the Red Sea and the Gulf of Aden. Consequentially, this leads to the occurrence of earthquakes as a result of reactivation or movement at the levels of these faults due to other new forces and in any direction, causing movements in different directions and with varying displacements.
Additionally, the recorded events in the Red Sea and the Gulf of Aden constitute most of what is observed at Yemeni seismic monitoring stations, as the toll of the Gulf of Aden earthquakes exceeds 50% of the total seismic activity and about 25% in the Red Sea. So, this indicates that both—the Red Sea and the Gulf of Aden—are affected by the tectonic situation resulting from fractures in the marine crust and the movement of the subterranean magma flowing from cracks resulting from fault systems in the marine crust, according to geologists.
Earthquakes Map, Their Areas, and Consequences
Based on the records of the seismic history in Yemen, which began to be documented with the earthquake in the Sheba Desert in the city of Ma’rib in the seventeenth century, and by tracking the occurrence of earthquakes in Yemen in terms of their areas of origin, method of recurrence, periods of occurrence, and recurrence, it is noted that seismic activity in Yemen does not occur randomly but rather is associated with major fault zones at plate boundaries or secondary faults within those tectonic plates or areas of active volcanic fields. Some historical studies also indicate that the recurrence of earthquakes in the southern Arabian Peninsula, the Red Sea, and the Gulf of Aden occurs every four years and every 20–30 years.
The 1982 Dhamar earthquake is one of the largest and main seismic events in the south of the Arabian Peninsula. It left more than 2,500 people dead and damaged more than 12,000 homes, as well as a large number of facilities and services. Likewise, the Saada earthquake in 1941 is considered one of the strongest earthquakes that struck Yemen, where it left about 1,200 people dead and destroyed 17,000 homes. The tremors continued to reverberate for nearly three months.
In addition to the earthquake in Al-Odain in 1991, which caused great damage to lives and property, the number of deaths reached 12. On the other hand, during the past years, Yemen has witnessed many slight tremors and earthquakes of less than two magnitudes.
These rocks occupy an area of 50,000 square kilometers, which is about 10% of the total area of the Republic of Yemen, and equivalent to 28% of the total area of the volcanic rocks in the Arabian Plate.
Yet, Yemen has recently been exposed, from time to time, to hurricanes and floods that continuously hit the country, causing relatively high material and human damage. In recent years, since 2015, Yemen has been struck by several hurricanes, including: Chapala, Mekunu, and Layan, causing widespread floods that killed dozens of people and resulting in billions in losses in material and human property.
In this context, the newest volcanoes in Yemen, in terms of age and composition, are classified in the framework of dormant volcanoes, because it has been a long time since they erupted.
What are volcanoes?
Volcanoes are ruptures, cracks, and openings—vents—on the Earth's surface, through which lava, volcanic ash, molten rock, and gases escape.
As for the rifting, it is depressions that arose as a result of the complete crushing and breakup of the thickness of the rocky area under the influence of the expansion factors of the plate parts. Thus, the Gulf of Aden is the oldest in formation. It began to rift from the east to the west. Then was followed by the rift of the Red Sea, which began to rift from south to north; as a result of the relative movements of Africa, specifically in the Nubian shield, Somalia, and the Sinai Peninsula.
Introduction
The newest volcanoes in Yemen are classified in terms of age and composition as dormant volcanoes. Because it has been a long time since their eruption, for example, the volcanoes of the coastal strip of the Gulf of Aden, including Kharaz, and the line connecting the Amran region and Aden, since it has been millions of years since they were active,
Accordingly, perhaps the most recent activity of the Shuqra volcano in Abyan took place about 260 thousand years ago. So, this is the case with the volcanic fields in the Hamdan region (northwest of Sanaa), the Surwah-Ma’rib region, and even the Dhamar-Radaa region, all of which are theoretically considered dormant volcanoes.
Trap Series of Yemen
Trap Series of Yemen (Geology of Yemen), which are called "tertiary volcanoes,", is penetrated in the west, with an area estimated at approximately 42,000 square kilometers and a thickness of up to 2,000 meters.
The volcanic rocks are located within the framework of the Arabian Plate in the west of the Arabian Peninsula, extending over a distance of 3,000 km from Yemen through Saudi Arabia, Jordan, and Syria. Together, these rocks form one of the largest alkaline volcanic ranges in the world, covering an area equivalent to a third of the area of Yemen.
While the large volumes of volcanic eruptive rocks are the subsequent results of several subterranean processes in the Earth’s interior, which led to the formation of continental extension through the splitting and rifting of the Gulf of Aden and the Red Sea in the western part of Yemen, where the terrain of the highlands is formed. The highest elevation is 3666 meters above sea level, represented by the “Jabal An-Nabi Shu'ayb” mountain in Sana’a, which is the highest peak in Yemen.
Further, these rocks occupy an area of 50,000 square kilometers, which is about 10% of the total area of the Republic of Yemen, and equivalent to 28% of the total area of volcanic rocks in the Arabian plate.
Geographic Distribution of Volcanoes in Yemen
It appears in five fields, as follows: Sana'a, Dhamar, Ma'rib, Aden, and Shuqra, on an area estimated at about 9,000 square kilometers, consist of basalt, rhyolite, and tuff rocks, and their age dates back to the Upper Miocene and up to the modern era (8–700 million years).
Volcanoes are divided into two groups:
The first group contains the volcanoes located between Perim island and Aden, which are relatively older, and were formed during the time period from 10 million years to 5 million years.
The second group is located east of Aden and includes Shuqra, Bir Ali, Ataq, and others. In addition to this group are the internal volcanic fields, which are: Surwah, Ma’rib, Sana’a, Amran, Dhamar, and Radaa (Jabal Isbil, Jabal Al-Lassi, and what is in between). This group is relatively newer than the first, and it arose between 5 million years ago and the present.
The largest and main volcanoes that occurred in Yemen are: Jabal al-Marha in Sanaa; Bir Birhout in Hadramaut; Balhaf Field in Shabwa; Dhamar Field; Harat Al-Sawad in Abyan; and the Hanish Islands.
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