Dammam and Alkhobar cities and nearby areas in the Eastern Province experienced tremors measuring 4 on the Richter scale last month.
“The Eastern Province is not an earthquake-prone zone by nature. The impact of large scale extraction of petroleum on the Earth’s plates could be the cause for these tremors,” said Abdullah Al-Amri, supervisor of tectonic studies at King Saud University.
A number of tremors in many parts of the world are man-made, Al-Amri added. “Subterranean rocks, particularly lime rocks, collapse after interaction with water. This creates fissures leading to the weakening of the upper layers of earth and a rise in water levels,” Al-Eqtisadiah daily reported Wednesday quoting the scientist.
Wave-like movements in the Arabian Gulf, caused by tremors, create ripples, said Al-Amri. These worsen the weakness of the Earth’s layers in some areas in the Eastern Province. Dammam and Alkhobar have also experienced the phenomenon of earth sinking in recent years.
Coastal regions are the most exposed to such subterranean activities, said Al-Amri. “Recent studies in the province have shown that the thickness of the earth’s plate is 48 kms while the depth of the basalt rocks is 8.5 kms,” he said. Although the tremors in the region are of low intensity, the region’s geographical proximity to the quake-prone areas in Iran’s Zagros Mountains is a matter to worry, he said.
Al-Amri stressed the need to conduct thorough studies on the impact on Saudi Arabia of the tectonic activities in Turkey, Iran, the Arabian Shield and submarine rifts in the Red Sea, and the transform faults of the Dead Sea.
The subterranean tremors in the Arabian Peninsula are focused at the Gulf of Aqaba, southwestern and southern Red Sea, Yemen and the Makkah region, he said. Central and eastern regions are comparatively safer from tectonic activities.
Chairman of the Saudi Geological Survey Zuhair Nawab agreed with the theory that the Kingdom’s western region is prone to earthquakes and volcanic activities. There is a tremor belt extending from the western region to the Gulf of Aqaba and further north to Turkey, Nawab said. The Arabian Peninsula moves on the Arabian plate at a rate of 1.5 cms a year.
The collision between the Arabian Plate and the Eurasian Plate is pushing up the Zagros Mountains of Iran and causes earthquakes in Iran and Turkey.
Low-level earthquakes are continuously registered in the western region on the Arabian Shield while noticeable activities were experienced in the recent past, in the Harrah Al-Shaqqah region 120 kilometers northeast of Yanbu, he said.
