April 28 , 2019.

Kamchatka , Sheveluch :

VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA).

Issued: April 27 , 2019 
Volcano:Sheveluch (CAVW #300270)
Current aviation colour code:ORANGE
Previous aviation colour code:orange
Source:KVERT
Notice Number:2019-85
Volcano Location:N 56 deg 38 min E 161 deg 18 min
Area:Kamchatka, Russia
Summit Elevation:10768.24 ft (3283 m), the dome elevation ~8200 ft (2500 m)

Volcanic Activity Summary:
A growth of the lava dome continues (a viscous lava blocks extrude out on the northern part of it), a strong fumarolic activity and an incandescence of the dome blocks and hot avalanches accompanies this process. According to satellite data, gas-steam plume containing ash on the height about 4.0 km a.s.l. continies to drift to southeast of the volcano.
Explosive-extrusive eruption of the volcano continues. Ash explosions up to 32,800-49,200 ft (10-15 km) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft.

Volcanic cloud height:
14432 ft (4400 m) AMSL Time and method of ash plume/cloud height determination: 20190427/2224Z – Video data

Other volcanic cloud information:
Distance of ash plume/cloud of the volcano: 62 mi (100 km)
Direction of drift of ash plume/cloud of the volcano: ESE / azimuth 122 deg
Time and method of ash plume/cloud determination: 20190427/2240Z – Himawari-8

Source : Kvert.

Photo :  Yu. Demyanchuk. IVS FEB RAS, KVERT.

Montserrat , Soufrière Hills :

MVO Weekly Report for the Period 20th to 26th April 2019

Activity at the Soufrière Hills Volcano remains low.
The seismic network recorded 2 VT events this week.
Five traverses were done using the boat traverse method to measure SO2 flux values on 25th April. The average flux measured was 477 t/d.

Pyroclastic flows can occur at any time without warning on any side of the volcano, including Gages from where they can travel rapidly into Plymouth. Tracks across the Belham Valley can be destroyed or heavily modified by flash flooding or lahars, and caution should be exercised crossing the valley during and after rainfall.

The Hazard Level is 1. There is no public access to Zone V, including Plymouth. Maritime Zones E and W are daytime transit only between sunrise and sunset (boats may sail through the zone but must not stop). Anyone who ignores these restrictions is liable to be prosecuted.

Source : MVO

Photo : Wikipédia.

Mexico , Popocatepetl :

April 27, 11:00 am (April 27, 16:00 GMT)

During the last 24 hours, thanks to the monitoring systems of the Popocatépetl volcano, 23 exhalations have been identified accompanied by water vapor and gas that the winds have dispersed mainly towards the east. In addition, 50 minutes of low amplitude tremor and two volcano-tectonic earthquakes of magnitudes M2 and M1,7 were recorded at 13:51 and 22:52 yesterday respectively.

Throughout the night, a slight incandescence was observed on the crater.
During the morning, a constant emission of water vapor and gas was observed.

Yesterday, with the support of the Federal Police (FP) and the participation of experts from the National Center for Disaster Reduction (CENAPRED) and the Institute of Geophysics of the National Autonomous University of Mexico (UNAM), a recognition of conditions of the crater of Popocatépetl was carried out.

During the overflight, it was found that no new lava dome had been formed.
The surveillance of Popocatépetl volcano is carried out continuously 24 hours a day. Any change of activity will be reported quickly.

CENAPRED urges NOT to APPROACH the volcano and especially the crater, because of the risk of falling ballistic fragments, and in case of heavy rains, to move away from the bottom of the ravines because of the risk of mudslide and debris.

The volcanic alert semaphore of Popocatepetl is located in PHASE 3 YELLOW.

Source et photo : Cenapred.

Indonesia , Merapi :

Mount Merapi Activity Report from 19 to 25 April 2019

I. RESULTS OF OBSERVATION
Visual
The weather around Mount Merapi is generally sunny in the morning, in the evening and in the cloudy and foggy afternoon. White degassing smoke is noted, thin to thick with low pressure. The maximum height of smoke is 700 m, leaning to the west, observed from the Selo observation post on April 25, 2019 at 5:40 pm WIB.
The morphological analysis of the crater area based on photographs of the Southeast sector revealed no significant morphological changes. The volume of the lava dome based on the analysis of aerial photographs with a drone of April 9, 2019 was 466,000 m3. Since January 2019, the volume of the lava dome has been relatively constant due to the fact that most magma extrusions collapse directly into the upper parts of Kali Gendol as avalanches and hot clouds.
Within a week, there were 5 avalanche clouds with a maximum slip distance of 1200 meters upstream of Kali Gendol.

Seismicity
This week, Mount Merapi seismicity recorded five avalanche earthquakes (APs), 27 earthquakes (DG), 5 superficial volcanic earthquakes (VTB), 17 multiple phase earthquakes (MPs) , 171 avalanche earthquakes (RF), 8 low frequency earthquakes (LF) and 15 tectonic earthquakes (TT). DG, VTB and LF events this week have increased compared to last week.

Deformation
The deformation of Mount Merapi, monitored by EDM and GPS this week, showed no significant change.

Rain and lahars.
This week, rain fell around Mount Merapi with a rainfall intensity of 28 mm / hour for 120 minutes, measured at the observation post of Mount Merapi in Selo on April 19, 2019. No cases of descent from lahars or increased flow in the rivers descending from Merapi have been recorded.

II. CONCLUSION AND ADVICE
Conclusion
Based on the results of the visual and instrumental observations, it was concluded that:
1. The lava dome is currently in a stable state with a relatively low growth rate.
2. The volcanic activity of Mount Merapi is still quite high and is at the activity level « WASPADA ».

Source : BPPTKG

Photo : Antara/Hendra Nurdiyansyah