For the first time found earthquakes according to ... seasons

The storms often appear seasonally, but no one thinks about earthquakes. Scientists have found in the Himalayas, they also appear in certain cycles and in the winter.

For years, seismologists have observed in this great mountain range of Asia, earthquakes appear more in the winter months than in the summer months, but they cannot find the cause of things. there. A new study using satellite data and a global positioning system has found an association between an increase in earthquakes and a monsoon season that rains this area every summer.

The Himalayas are areas of high earthquake activity due to the collision of two Indian and European lithosphere plates, while the Indian region continues to penetrate into Asia.

The Himalayan seasonal earthquakes are thought to be related to the monsoon activity that causes rain.(Photo: Theodora)

Philippe Avouac from the California Institute of Technology and colleagues analyzed the data of 1,000 Himalayan earthquakes and found double the number of occurrences in winter in the summer. For example, up to 150 level 3 earthquakes occur from December to February, but only 75 in the summer. The data is similar to the more intense earthquakes.

Satellite data on water levels in rivers in the Ganges Valley show strong fluctuations between winter and summer - when the monsoon starts to blow in May, water levels begin to accelerate strongly, and rise above 4. meters at the time of September, before the start of the recession until the next monsoon season.

According to the explanation of the research team, when monsoon rains brought the rivers in the valley of Ganges, they increased the pressure on the rock in the region. When the rain stopped and the river water began to seep into the ground, this pressure was relieved towards the front of the Himalayas. Redistribution of pressure led to horizontal compression in the mountains at the end of the year, and eventually triggered earthquakes in the winter.

Avouac also believes that earthquake mechanisms in the Himalayas are unique.

T. An