This 24-hour period was probably the most active during the last 5 days. Twenty locatable earthquakes occurred during this period, but due to a computer failure only three were located. These three occurred in the St George's Hill area at depths in the range of 4-6 km. Most of the other earthquakes probably occurred in the St. George's Hill area as well. The largest earthquake, at 05:08 was of magnitude 3.0 and was followed by a sequence of 8 earthquakes in a two hour period. There have been several small long-period earthquakes recorded at the Gages seismometer, and some periods of low-amplitude broadband tremor. This tremor has increased in amplitude after 14:00 today, and has been continuous. Four larger long-period events also occurred. The computer system has been repaired and is now functioning satisfactorily.
Measurement of the Long Ground to Castle Peak EDM line was made today, but persistent low cloud cover prevented measurement of the other lines. The line showed a slight shortening of about 2 mm, suggesting that the recent line-lengthening trend has reversed. The GPS sites at St George's Hill, Radio Antilles, Harris' Lookout and Chances Peak were occupied today, but the data are still being processed.
Visual observations were attempted both from Chances Peak and the helicopter, but low cloud cover prevented any sighting of the crater area.