Fresh tremor of magnitude 5.1 struck far-east in Petropavlovsk-Kamchatsky, Russia today, reported the US Geological Survey (USGS). The tremor was recorded at 07:17:36 (UTC+05:30), with its epicentre located 144 km southeast of the Kamchatsky region at a depth of 25 km.Tremor follows a powerful 8.8-magnitude earthquake that struck near Russia’s Kamchatka Peninsula earlier in the week. According to experts, the quake was caused by intense tectonic activity along a major subduction zone where the Pacific Plate slides beneath the Okhotsk Plate. This zone lies within the Pacific “Ring of Fire,” a seismically active belt notorious for frequent earthquakes and volcanic eruptions. The vertical displacement of the seafloor during the 8.7-magnitude quake triggered a tsunami, leading to wave alerts in multiple Pacific nations, including Russia, Japan, and the United States. Adding to the region’s turmoil, the Krasheninnikov volcano in Kamchatka erupted overnight for the first time in over 600 years on August 3, 2025. The rare volcanic activity closely followed the July 29 magnitude 8.8 earthquake off the coast of Petropavlovsk, intensifying concerns over tectonic instability in the area.