A magnitude 3.1 earthquake near Oia, Kykládes, South Aegean, Greece, was reported only 15 minutes ago by the National Observatory of Athens (NOA), considered the main national agency that monitors seismic activity in Greece. The earthquake occurred at a very shallow depth of 7.30 km beneath the epicenter in the morning on Monday, July 21st, 2025, at 7:09 am local time. The exact magnitude, epicenter, and depth of the quake might be revised within the next few hours or minutes as seismologists review data and refine their calculations, or as other agencies issue their report.A second report was later issued by The Seismological Laboratory of the University of Athens (UOA), which listed it as a magnitude 2.9 earthquake. Other agencies reporting the same quake include the European-Mediterranean Seismological Centre (EMSC) at magnitude 3.3, The Aristotle University of Thessaloniki Geophysical Lab. (AUTH) at magnitude 2.8, and the citizen-seismograph network of RaspberryShake at magnitude 3.0.Based on the preliminary seismic data, the quake should not have caused any significant damage, but was probably felt by many people as light vibration in the area of the epicenter. Weak shaking might have been felt in Fira (pop. 2,400) located 2 km from the epicenter, Messaria (pop. 1,200) 5 km away, and Oia (pop. 3,400) 5 km away.Other towns or cities near the epicenter where the quake might have been felt as very weak shaking include Emporeio (pop. 1,900) located 9 km from the epicenter. In Ios (pop. 2,000, 34 km away), Naxos (pop. 7,100, 75 km away), and Paros (pop. 5,300, 76 km away), the quake was probably not felt.Earthquake data: Date & time: Jul 21, 2025 07:09 am (GMT +3) local time (21 Jul 2025 04:09 GMT)Magnitude: 3.1Depth: 7.30 kmEpicenter latitude / longitude: 36.43°N / 25.41°E (Nomos Kykladon, South Aegean, Greece)Primary data source: NOA