November 01 , 2017. EN. Nevado Del Huila , Turrialba , Poas , Rincon de la Vieja , Piton de la Fournaise , White Island .
November 01 , 2017.
Nevado Del Huila , Colombia :
Subject: Weekly activity bulletin of the Nevado del Huila volcano
The level of activity of the volcano continues at the level:
Amarillo level, changes in the behavior of volcanic activity.
On the analysis and evaluation of the information obtained through the surveillance network of the Nevado del Huila volcano, during the week between 24 and 30 October 2017, the Colombian Geological Service, Observatorio Vulcanológico y Sismológico de Popayán informs than :
During the evaluated period, 274 seismic events were recorded, of which 180 were related to rock fracturing processes (type VT) and 94 with fluid dynamics in volcanic canals. Of these, 93 were classified as long-period type events (LP type) and one (1) as low-energy volcanic tremor pulse (TR type).
From the seismicity recorded during the week, stands out the VT event that occurred on October 29 at 18:57 (local time), which had a calculated magnitude of 3.1 degrees on the Richter scale, and was located under the central peak.
Among the images obtained during the week through the web cameras of Tafxnú, Maravillas and La Palma, we observed the degassing of the volcanic system, characterized by white columns emitted from the top of the volcano.
The sensors for monitoring soil deformation, magnetic fields and infrasonic waves have not recorded any variations to highlight.
Therefore, it is concluded that during the evaluated period, the volcano continued to exhibit stable behavior.
The Colombian Geological Survey continues to monitor the evolution of the volcanic phenomenon and will inform in a timely manner about any changes that may occur.
Source : Ingeominas
Turrialba , Poas , Rincon de la Vieja , Costa Rica :
Daily report of the state of the volcanoes of Poás, Turrialba and Rincón de la Vieja: 31 October 2017
Updated at 11:00 am
Turrialba Volcano: activity over the last 24 hours:
The seismic activity during the last 24 hours has been characterized by the recording of discontinuous volcanic tremor signals, and volcanic earthquakes of low amplitude, variable duration and low frequency (LP) but low amplitude. When it is possible to observe the volcano through the web camera, we can see that a persistent degassing of a plume of water vapor, magmatic gas and fine aerosols in the environment, similar to the days precedents. Sometimes the plume contains small amounts of ash. Emissions are maintained less than 500 meters above the crater.
Several eruptions have been recorded in the last 24 hours. The eruptions at 10:30 and 11:05 (local time, October 30) emitted ashes 500 meters above the active crater. An eruption at 14:45 emitted ashes 200m above the crater. Ash falls have been reported at Pacayas, and the smell of sulfur at Tierra Blanca and Cot.
At the time of this report, the winds at the top of the volcano are variable, but they are mainly directed to the southwest, with speeds of up to 35km / h.
Volcano Poás: activity over the last 24 hours:
The level of seismic activity is low. Several small low frequency and low amplitude seismic events have been recorded sporadically. When it is possible to see through the camera, continuous degassing is observed up to 200 m above the active crater.
Yesterday, an eruption was reported at 3:50 pm, with ash reaching 300 m above the active crater.
At the time of this report, the winds at the top of the volcano are variable, but they are mainly directed to the south, with speeds of up to 28 km / h.
Rincón de la Vieja Volcano: activity over the last 24 hours:
During the last 24 hours, it is possible that yesterday around 01:25 a phreatic eruption was generated, observed by some inhabitants of Buenos Aires of Upala.
OVSICORI-UNA remains vigilant on seismic and volcanic activity.
Source : Ovsicori
Piton de la Fournaise , La Réunion :
21°14’38 » S
55°42’29 » E
Alert level: Vigilance
– Number of landslides from 30-10-2017: 6
Area affected by landslides:
– Number of volcanic-tectonic earthquakes (VT) from 30-10-2017: 2
Area concerned by the VTs:
– Volcano-tectonic earthquake of greater magnitude of 30-10-2017:
Duration: 4.91 s
Magnitude of duration: 0.51
Location of earthquakes over 2 months. Only localizable earthquakes have been represented on the map.
The observatory records seismic events not shown on this map because they are not localizable due to their low magnitude.
To see the number of earthquakes detected by the observatory’s networks, you can refer to its last Activity Bulletin.
– The GPS of the zone summit record an inflation, witnessing the putting in pressure of a superficial source.
– GPS in the far field record inflation, witnessing the setting in pressure of a deep source.
Illustration of the summit deformation over 2 months. Here is shown a baseline (variation of distance between two GPS receivers) crossing the crater Dolomieu (see location). A rise is synonymous with elongation and therefore swelling of the volcano; conversely, a decrease is synonymous with contraction and therefore deflation of the volcano. Any periods colored in light pink correspond to eruptions.
Low concentrations of SO2 (coupled with CO2) and H2S (coupled with H2O vapor) in the summit emissions of Piton de la Fournaise.
Source : Ovpf
White Island , New Zealand :
Earthquake swarm develops in outer Bay of Plenty , Published: Wed Nov 1 2017 3:00 PM
A moderate earthquake swarm is now under way off shore Bay of Plenty
On Sunday 29 Oct, what appeared as a small earthquake sequence, consisting of some small foreshocks and a moderate mainshock started. On Sunday evening the largest event was a M4.1 event at 11.24 pm and 9 km depth. This was followed by what appeared as normal aftershocks on Monday. This has now developed into a typical Bay of Plenty earthquake swarm. Swarms come in a variety of forms and it is not possible to easily judge the future of them. Some have the stronger phase near the start, others in the middle, while some swarms have the stronger activity at the end. We anticipate this one will continue in the short term.
On Tuesday evening at 8.36 pm a M4.7 event occurred at 6 km depth. This was followed by many smaller aftershocks. Then this morning at 11.58 am there was a M4.8 event at 7 km depth. This is the largest event so far in the swarm. These events are being felt by coastal Bay of Plenty residents. The swarm is located about 12-15 km east of White Island. White Island is the nearest geographic location so our automated location software naturally reports them as being nearby. White Island is a large volcano with a significant footprint under the sea, being about 6 x 10 km at 300 m depth. However, these earthquakes are well beyond the footprint of the volcano, hence we consider them to be caused by regional faulting, rather than related to the volcano.
So far, we have located 137 earthquakes in the swarm that range in magnitude from M1.7 to 4.8. The depths range from 2-13 km. Many active faults are mapped in the offshore Bay of Plenty area, hence it is seismically active and we record numerous earthquakes every year in the area. In the last 12 months, we have located 114 earthquakes in the same area as the current earthquake swarm. These have ranged in magnitude from M1.6 to 4.1, while the depths have ranged from around 2-10 km. In the last 5 years there have been 3 earthquakes over M4.0 in the same area. There have 3 over M4.0 so far in this swarm.
Source : Géonet