A swarm of 1600 earthquakes with an average magnitude of 1.5 up to 3 began at 03:00 on August 16, 2014. There were very strong indications of ongoing magma movement, in connection with dyke intrusion according to the Icelandic Meteorological Office. The activity was in fact two swarms; one located east of Bárðarbunga caldera; and one at the edge of Dyngjujökull glacier just east of Kistufell. The Aviation Color Code was raised to Yellow. By 18 August about 2600 earthquakes were detected, with some larger than magnitude 3, the largest of which being of magnitude 4.5. The Aviation Color Code was raised to Orange. The majority of events were recorded at a depth of 5-10 km.