Sciency Thoughts: Himalayan Orogenic Belt

Monday, 22 January 2024

Magnitude 7.1 Earthquake on the border between China and Kyrgyzstan.

The China Earthquake Networks Center recorded a Magnitude 7.2 Earthquake at a depth of 22 km beneath Wushi County in western Xinjiang Province, China, close to the border with Kyrgyzstan slightly before 2.10 am local time on Tuesday 23 January 2024 (slightly before 6.10 pm on Monday 22 January, GMT). The are no reports of any damage or injuries associated with this event at the time of writing, although people have reported feeling it across much of eastern Kyrgystan.

The approximate location of the 23 January 2024 Xinjiang/Kyrgyzstan border region Earthquake. USGS.

The Tian Shan Mountains stretch for 2500 km across Xinjiang, Kazakhstan, Kyrgyzstan and Uzbekistan. The Tian Shan are part of the Himalayan Orogenic Belt, mountains in Central Asia pushed upwards by the collision of India and Asia. The Indian Plate is currently pushing into the Eurasian Plate from the south at a rate of 3 cm per year. Since both are continental plates, which do not subduct, the Eurasian Plate is folding and buckling, causing uplift in the Himalayas and other mountains of Central Asia. This is not a smooth process, the rocks will remain effectively stationary for log periods of time while pressure builds up, then give suddenly, releasing large amounts of energy in the form of Earthquakes.

The movement of India relative to Asia, and the blocks within the eastern part if the Eurasian Plate. University of Wollongong.

Magnitude 5.2 Earthquake in western Kyrgyzstan.

The United States Geological Survey recorded a Magnitude 5.2 Earthquake at a depth of 28.0 km, in western Kyrgyzstan, 66 km to the northwest of the city of Shakhimardan an enclave of Uzbekistan surrounded by Kyrgyzstan, slightly before 4.30 pm local time (slightly before 10.30 am GMT) on Saturday 26 December 2020. There are no reports of any damage or casualties associated with this event, but it may have been felt locally.

The approximate location of the 26 December 2020 Kyrgyzstan Earthquake. USGS.

The quake occurred in the Pamiro-Alai Mountains, which form the border between Kyrgyzstan, Khazakhstan and China, and form a western extension of the the greater Tian Shan range. The Tian Shan are part of the Himalayan Orogenic Belt, mountains in Central Asia pushed upwards by the collision of India and Asia. The Indian Plate is currently pushing into the Eurasian Plate from the south at a rate of 3 cm per year. Since both are continental plates, which do not subduct, the Eurasian Plate is folding and buckling, causing uplift in the Himalayas and other mountains of Central Asia.