Two earthquakes of Force 4 on the Richter scale rocked Kamchatka (Far East) on Thursday. According to the Kamchatka volcanology institute of the Far Eastern branch of the Russian Academy of Sciences, the first tremor of more than Force 4 was registered in the Northern part of the Avacha Bay, with its epicentre some 55 km from Petropavlovsk-Kamchatski. The second Force 4 bolt was registered at Shipunsky Cape on the eastern coast of the peninsula. According to scientists, seismic activity has stepped up in these regions. This is connected with the motion of the earth's crust at the junction of the oceanic and continental platforms.