Updated summary of the principal activity observed from 25 to 28 August
This is a special report, following the intense seismic activity that occurred in the area near the Sabancaya in the last 24 hours. Earthquakes that are reported in this report are located 6 km north and north – east of the crater. This is the first time since 2013, that the epicenters are so near the crater in large numbers.
– The number of earthquakes VTPS or « proximal volcano-tectonic« have significantly increased, reaching an average of 92 VT / day, much higher than the value of the previous period (23 VT / day) .There has been a peak of 281 VTP on August 28th .The energy also rose sharply, mainly due to the occurrence of an earthquake magnitude 4.8 ML registered on August 28 at 4:11 UTC. The location of these earthquakes is very near the crater in distances .
– The number of LP type events (associated with the passage of fluids) fell for this report, to an average of 57 LP / day less than the previous period (71 LP / day). In addition, energy remain low.
– The number of hybrid events (associated with magmatic material rising) remained at a low average, scoring five HIB / day. However, it is observed that increased energy on August 28, reaching 225 MJ.
-The Type of seismicity VT or volcano tectonic, rose sharply in this report, to achieve a rate of 173 VT / day, while in the previous period, it was recorded only 48 VT / day.
-The Tremor type events for this report, saw their rates decrease to 05 Tremor / day. The energy of these events is low.
During the early hours of August 28, 53 earthquakes LP type and 06 hybrid earthquakes are recorded. Later, at 4:11 p.m. UTC, the most important type of event VT, with a magnitude of M 4.8, was recorded. Then occurred many type of VT earthquakes, reaching the peak of 540 in less than 11 hours.
During this period, the type of VT seismicity is mainly distributed very close to the volcano area, which is called VTP (less than 6 km from the volcano). 3 events were recorded on August 28, of significant magnitude, the first , M 4.8 at 4:11 UTC, the second , M 3.5 at 4:18 UTC and the third, M 3.4 at 4:17 UTC. Depths are low and vary between 6 and 9 km. On August 28, were recorded 84 VTS events with magnitudes between 1.0 and 4.8 ML and shallow depths, between 4 and 10 km.
August 29, 2015. Sabancaya, Peru :
Source : IGP /OVS
Photos : Andina .com .