April 05 , 2016. EN. Villarica , Bromo , Popocatepetl , California Volcanoes .

Home / blog georges Vitton / April 05 , 2016. EN. Villarica , Bromo , Popocatepetl , California Volcanoes .

April 05 , 2016. EN. Villarica , Bromo , Popocatepetl , California Volcanoes .

April 05 , 2016.

 

Villarica , Chile :

Special volcanic activity report (REAV)
REGIONS Araucania -Los Rios.

April 3, 2016, 50 10 am
The National Service of Geology and Mining (SERNAGEOMIN) through the Volcanological Observatory of Southern Andes (OVDAS) announces that Sunday, April 3, 2016, at 07h 50 (10: 50GMT), the monitoring stations near the Villarrica volcano, recorded an increase of the energy of the seismic signal of volcanic tremor (signal related to the circulation of fluids in volcanic conduits).

 

villarica

In the case of Villarrica, they are closely related to the dynamics of the lava lake, and reached maximum values of reduced displacement of 20 cm2 and seismic amplitudes of 28 microns / sec,  values considered as moderate for this volcano. In addition, through the  web cameras installed around the volcano, it was observed an increase in the surface activity, represented by the observation of an incandescent and strombolian activity at the crater.
In addition, RSAM values exceeded for more than an hour, the threshold for yellow alert.
Because of this situation and the characteristics of a volcano with a conduit open and characteristics of lava lakes active, it may be an unwanted activity related to the current dynamic, involving the expulsion of ballistic fragments projected in areas near the crater.

 

villarica


Monitoring parameters indicate that the basic thresholds have been exceeded, the level of technical volcanic alert is changed in Amarillo.
Therefore, it is considered that the high risk area in the current scenario corresponds to a radius of 1 km from the center of the crater, it is recommended to apply access restrictions in this area.
SERNAGEOMIN -OVDAS continuous online monitoring and report timely to the changes in volcanic activity in the region

Source : SERNAGEOMIN -OVDAS

Photos : Sernageomin

 

Bromo , Indonésia :

During the period from February 18 to 25, 2016, it was recorded 6 eruptions earthquake  and episodes of constant tremor with maximum amplitude ranges from 1 to 24 mm. From the date of February 22, 2016, the seismic tremor was recorded continuously with a maximum magnitude of 0.5 to 2 mm, eruptions earthquake were not recorded.

Deformation.
The deformation monitoring of Bromo uses the method of EDM (electronic distance measurement) and inclinometer. The EDM method consists of three monitoring points and on 8 February 2016, it was created permanent checkpoints: G. Kursi, Bromo and Mount Batok, allowing measurement despite the frequent fog around Mount Bromo.
The deformation measurements, tilt and EDM shows fluctuations and a stable trend.

 

bromo

EVALUATION
The visual activity not could be clearly determined, the Bromo being enveloped in fog. The issuance of thick white gray smoke with a high column of 50 to 900 meters high with a change in direction between the North-East and WestSouthwest was noted. No rumblings over the last five days have been recorded.
The recording of the seismicity is dominated by a constant tremor with a maximum amplitude which fluctuated in the range of 1 to 30 mm and dated on February 22, 2016, the dominant maximum amplitude of the tremor was 0.5 to 2 mm . No earthquake eruption was recorded.
Measurements of deformation with tilt and EDM shows fluctuations but a stable trend.

 

bromo

CONCLUSIONS:

Seismic activity is dominated by constants Tremor vibration  with an amplitude in decrease and lack of eruption earthquakes. The threat of an eruption in the form of emission of ash and emission of material that could happen to a radius of 1 km remains. Based on observational data and analysis of seismic data, visual, and the potential danger of eruption, the activity level of Bromo is reduced from level III (SIAGA) to level II (waspada) on February 26 2016.
The activity level of Bromo will be raised / lowered if an increase / decrease in activity was found  by volcanic experts of Center for     Volcanology and Geological mitigation .

 

Source : VSI

Photos :  PVMBG

 

Popocatepetl , Mexico :

April 04, 11:15 h (April 05, 16:15 GMT)

During the last 24 hours, 96 long period events were registered and five explosions yesterday at 16:44 h and 20:31 h the latter generated a ash column of 2 km height above the crater, which moved towards the northeast. Likewise, the fall of incandescent fragments were observed, mainly on the east and southeast slopes of the volcano at a distance of 3.5 km, because of this some fires were generated in the upper part of the forest . This explosion caused ashfall in the towns of Juan C. Bonilla and Coronango, both in the state of Puebla. The remaining three explosions were recorded today at 06:54, 7:14 and 07:49 h.

.

popo

At moment of this report the volcano have a continuous emission of steam and gas towards east

The semaphore of volcanic alert of volcano Popocatepetl remains located in Amarillo Fase 2.

 

Source : Cenapred.

Photo : AP/ Arturo Andrade

 

 

 California Volcanoes ,  United – States :

Current Volcano Alert Level: all NORMAL
Current Aviation Color Code: all GREEN

Activity Update: All volcanoes monitored by CalVO using telemetered, real-time sensor networks exhibit normal levels of background seismicity and deformation. Volcanoes monitored include Mount Shasta, Medicine Lake Volcano, Clear Lake Volcanic Field, Lassen Volcanic Center, Long Valley Volcanic Region, Coso Volcanic Field, Ubehebe Craters, and Salton Buttes.

Observations for March 1, 2016 through March 31, 2016 :

Mt Shasta: One earthquake at or above M1.0 was detected (M1.06).
Medicine Lake: No earthquakes at or above M1.0 were detected.
Lassen Volcanic Center: Five M1.0 or greater earthquakes were detected, with the largest registering M1.42. Many of these events occurred during two minor seismic swarms on March 23, 2016 near the Shasta-Tehama-Plumas County lines about 14 km north of the town of Mill Creek and March 26, 2016 near the Shasta-Tehama-Plumas County lines about 8 km north of the town of Mineral.
Clear Lake Volcanic Field: Two M1.0 or greater earthquakes were detected, with the largest registering M2.63. [Note: The typical high level of seismicity was observed under the Geysers steam field located at the western margin of CLVF. The largest event was M2.90].

Mount Shasta

Mount Shasta


Long Valley Volcanic Region: In Long Valley Caldera, 16 earthquakes of M1.0 or greater were detected. The largest event registered M2.15. No earthquakes at or above M1.0 were detected in the Mono Craters region. No earthquakes at or above M1.0 were detected under Mammoth Mountain. [Note: The typical high level of seismicity was observed south of the caldera in the Sierra Nevada range. The largest event registered M2.58].
Ubehebe Craters: No earthquakes at or above M1.0 were detected.
Salton Buttes: Sixteen earthquakes of M1.0 or greater were detected. The largest registered M2.14.
Coso Volcanic Field: The typical high level of seismicity was observed, with 24 earthquakes M1.0 or greater. The largest registered M2.47.

 

The Short Story of Ubehebe Crater in Death Valley National Park
March 31, 2016

New research by scientists at CalVO indicates that Ubehebe Craters formed about 2100 years ago during a single eruptive event. Ubehebe Craters are a lone cluster of volcanic craters in the northern half of California’s Death Valley National Park. CalVO geologists Judy Fierstein, Wes Hildreth, and Duane Champion investigated the sequence of rocks to determine whether the 15 craters formed as several independent eruptions over hundreds of years from a long-lasting, deep magma source, or whether they formed at one time.

 Ubehebe Craters

The scientists are confident that the craters are monogenetic—created during one explosive episode when magma interacted with groundwater, over several days, weeks or months (but certainly not over hundreds of years). Their evidence: first, dozens of layers of rocks ejected during successive eruptive pulses are « conformable »—no time is represented by erosion or anything else between them, so all layers must have fallen during a short-lived eruption sequence. Second, they note that the composition of basaltic cinder samples does not vary—meaning that a single batch of magma fed the multi-crater phreatomagmatic episode. Third, measured paleomagnetic directions are almost exactly the same; again, not much time could have passed between crater-forming pulses.

Short-lived eruptive sequences like the ones that formed Ubehebe Craters are common in volcanically active areas (for example, throughout the Cascade Range). This is the only young volcano in Death Valley National Park, which was otherwise a volcanically quiet area for the last million years.

Source : Calvo

 

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