Between 8 January and 24 October 2001, 27 events with magnitudes between 1.1 and 3.6 were recorded in the vicinity of Martigny. Ten of these occurred between 23 and 28 February, including two quakes with magnitudes of 3.6 and 3.5. Oriented south-west to north-east (SW-NE), the vertical fracture surface activated by this series lies at a depth of around 6 km and extends for a length of almost 2 km.