An earthquake of magnitude 6.6 struck off the northwest coast of Indonesia's Sumatra island on Friday, the GFZ German Research Center for Geosciences (GFZ) said. The quake was at a depth of 10 km (6.21 miles), GFZ said. Indonesia's weather and geophysics agency, BMKG, put the quake at 7.2 magnitude and at a depth of 19 km but said it had no potential to trigger a tsunami wave.