13/03/2015. Turrialba, Vesuve, Ruang.
Turrialba, Costa Rica :
The National Seismological Network (RSN) reports that today 12 March at 10:53 local time, there has been an explosive event of the Turrialba volcano on a larger scale compared to episodes of Sunday, 8 and Tuesday, March 11, 2015 .
This episode has been accompanied by a seismic signal with volcanic tremor broad spectrum of frequencies with dominant peaks at 2.2 Hz and 8.7 Hz and a duration of about 25 minutes.
The volcanic tremor is a continuous signal caused by the vibrations of the walls of the ducts associated with the flow of water vapor mixture of gas and ash, leaving a lot of pressure.Within minutes after the explosion, a series of volcano-tectonic and volcanic events were recorded. The ash covered about 40 km, according to the volcanologist at the University of Costa Rica (UCR), Gino Gonzalez, reports came from several points of San Jose.”We report ash falls in much of San Jose, including Plaza de la Cultura, San Pedro, Desamparados, we are talking about a distance of about 40 kilometers from the volcano, the ash that fell is whitish, almost grayish, explained González.He said seismic activity continues, “the volcano underground tremor signs that, once again, these events may now or in the coming days to reproduce,” said volcanologist.
10:53 After the event, a second eruptive episode took place at 1:38 p.m. h, on a larger scale and a duration of about 48 minutes. The seismic signal that accompanies the process is on a wide spectrum of frequency tremor with dominant peaks at 2.2 Hz and 8.7 Hz. Based on information from the field of Geol Raúl Mora, said that loud explosions were heard. The RSN is awaiting the development of this activity.
Authorities say they are on alert to report any new event.
Source : RSN / Avcan.
Photos : Sherine France / Twitter.
Vesuve, Italie :
Seismic swarm of Vesuvius 10/03/2015.
Between 4:01 p.m. 3:22 p.m. was recorded on Mount Vesuvius an swarm of earthquake of about 30 small-scale events. The maximum magnitude of 1.6 is observed (Event 15:30). Events are located in shallow (less than 1 km) below the crater.
The characteristics of this swarm are no different from others, observed in recent years on Vesuvius and do not indicate significant changes in the state of the volcano.
Source : Osservatorio Vesuviano
Photo : ac-lille.fr
Ruang, Sulawesi du Nord, Indonesie :
The results of the seismic monitoring showed a significant increase, particularly in volcanic earthquakes (VA), since March 6, 2015. An earthquake of this type may indicate a process of fracturing volcanic rocks in the body of volcano due to the pressure of the magma to the surface. Other recorded seismicity are the tectonic earthquake ground (TJ) and local tectonic earthquakes (TL). Since 15 November 2014, tectonic seismicity of Punggungan Mayu / Lempeng Laut Maluku has increased. This can help to increase the pressure on the magma reservoir.
Visually no significant changes have been noticed. No smoke in the crater was found
From 6 to 12 March 2015 the seismic activity of G. Ruang tends to show a significant increase.
Based on the results of the seismic monitoring and visual analysis, since March 12, 2015 at 16:00 pm the level of activity of G. Ruang went from “Normal” (Level I) to “Alert” (Waspada, level II). Intensive surveillance is conducted to assess the activities of G. Ruang and the dissemination of the danger of eruption .If there is a change, a significant increase / decrease in volcanic activity of G. Ruang, level activity can be lowered / raised to the level of activity and the threat.
Source : vsi.esdm.go.id
Photo : Wikipedia