Great Sitkin reported activity

Event Name : Great Sitkin 2002/5

Start:	May 27, 2002	Observed
Stop:	May 28, 2002	Observed

Seismicity with no confirmed eruption:

Description: This entry is not an eruption, but is a description of unusual earthquake activity at Great Sitkin that may be associated with volcanic events.



From 06/02 (BGVN 27:06) : "Abnormal tremor and earthquake swarms in May 2002

On 27 and 28 May the Alaska Volcano Observatory (AVO) detected anomalous seismicity at Great Sitkin, a volcano located 1,895 km SW of Anchorage, Alaska. On 27 May two periods of seismic tremor lasted for 20 and 55 minutes and on 28 May earthquake swarms began at 0306 and 1228. The earthquake swarms each began with a relatively large event (ML 2.2 and ML 4.3) followed by tens to hundreds of smaller aftershocks, most located 5-6 km SE of the crater at depths of 0-5 km. Both the tremor and earthquake swarms represent significant changes from background seismicity at Great Sitkin. However, aftershocks declined significantly overnight, and seismicity returned to background levels with a lack of recorded tremor since 27 May. Satellite imagery showed no signs of surface volcanic activity, and no reports of anomalous activity were received by AVO."