Seismicity in the period under review was similar to the very low level of seismicity observed before and after the swarm of volcano-tectonic earthquakes reported yesterday. The only notable seismic activity was two small volcano-tectonic earthquakes on 11 February at 19:25 and 12 February at 04:52; these occurred in the same area as yesterday's swarm. Very small hybrid earthquakes (dominant frequencies 3-5 Hz) with magnitudes less than 1 have occurred about every hour on the two nearest stations to the volcano (Gages and Chances Peak). Other seismic signals observed throughout the period that are associated with small rockfalls. A magnitude 2.7 earthquake about 60 km from the island was recorded by the seismic network at 15:41 on 12 February.
EDM measurements were made on the eastern triangle to Castle Peak and on the Windy Hill-Farrells-St George's Hill triangle today. There was no change in slant distances at these two triangles.
Visual observation of the volcano was made from the helicopter twice today. Growth continues to be focused at the top central and western parts of the dome. During a late morning flight a small pyroclastic flow was observed as debris from the central parts of the dome avalanched to the south. Steam emission at the top of the dome continue to be quite vigorous.