Cheb, West Bohemia, May 22 (CTK) – The Cheb area, the westernmost in the Czech Republic, experienced an earthquake of up to magnitude 4.4 on Monday night, another within an earthquake swarm that hit the region earlier this month.

The epicentre was near the town of Luby, some 20 km north of Cheb and close to the German border. The tremor could be registered by people across a half of Bohemia, including the northern districts of Prague, and also in the adjacent Bavaria.

According to the automatic localisation data of the European Mediterranean Seismological Centre (EMSC), the magnitude reached 4.1, but the Czech seismic network’s automatic localisation registered it as 4.4.

Jana Doubravova, from the Institute of Geophysics of the Czech Academy of Sciences, told CTK that experts’ calculations subsequently put the magnitude at 3.8.

“It felt stronger, because the epicentre was not that deep, about 6.7 km underground, compared with the previous tremors that occurred nine kilometres underground,” Doubravova said.

The Cheb area is known as the one with most frequent earthquakes in the country, which, however, have always been relatively mild, never having a devastating character.

The earthquake swarm reappeared in the Cheb area on May 10 after a certain pause. Later in May, the tremors got weaker but never stopped, with a stronger tremor appearing last night again.

The tremors are probably caused by the weakening of the crust under this part of west Bohemia. Earthquake swarms that include up to thousands of small tremors within a period of several days or months are typical in such cases.

The Cheb area saw its ever strongest tremors at the end of 1985 and beginning of 1986, when they reached 4.6 magnitude, Tomas Fischer, from the Institute of Hydrogeology, told CTK.