By 19:00 on 25 August there had been about 1200 earthquakes at depths of 5-12 km, mostly around the northern tip of the intrusion northeast of Bárðarbunga which had migrated further to 6-7 km north of Dyngjujökull. More than twenty tremors were of intensity M3-M4, and one was a M5.1 which occurred within the caldera at 16:19. There was no sign of volcanic harmonic tremor.