August 01 , 2016. EN. Reventador , Fuego , Chikurachki , Katla .
August 01 , 2016.
Reventador , Ecuador :
Incandescent rocks fall from Volcan Reventador .
31 JULY 2016. The Geophysical Institute (IG) of the National Polytechnic School reported that on Sunday July 31 2016, during the morning, incandescent rocks were observed falling about 1,000 meters below the Reventador volcano crater.
The Geophysics Institute said the volcano remains « high eruptive activity » and that by lowering cameras, incandescent rocks was observed.
On the seismicity, the IG said yesterday from 11:00 until that hour today, there were « 59 explosions (EXP), 6 episodes of harmonic tremor (TRA), 4 episodes of tremor emission (TRE), 45 events long period (LP) and 5 events volcano tectonic (VT) « .
Reventador volcano of 3,560 meters high, is about 90 kilometers east of Quito and has been active since 2002, when it issued a huge column of ash, carried by wind, to the capital.
Although the area where the Reventador volcano is situated, is not very populated, it crosses a road linking the Andean region with the northern Amazon region, as well as two pipelines that carry crude from the fields of Amazonian extraction to ports boarding in the Pacific.
Source : EL COMERCIO
Fuego , Guatemala :
After about 44 hours, the twelfth paroxysm of the Fuego volcano ends.
As shown in the graph of RSAM activity, from 21:00 (local time) on July 29, the latter has remained constant, showing minor explosions generating ash plumes that do not exceed 4,500 meters (14.763 feet).
As a relic of this eruption, two lava flows were observed towards the canyons Las Lajas and Santa Teresa with an approximate length of 1,500 meters, which should completely disappear in the next hours.
The ash falls that during the evolution of the eruption, were scattered on the west flank of the volcano, greatly affecting communities in this direction, persist in the environment, but should disappear entirely in the next hours.
Source : Insivumeh
Photo : Eduardo Pérez Montepeque
Chikurachki , Kouriles Islands , Russia :
An explosive eruption of the volcano Chikurachki took place on 27 July, ash plumes have risen to 4/5 km and spread to about 176 km northeast of the volcano. Low ash falls were recorded in Severo-Kurilsk (Paramushir island). No anomaly or ash plume was observed since July 27. The volcano Chikurachki is not monitored with seismic instruments. The KVERT monitors satellite and receives occasional visual observations. The KVERT continues to monitor the volcano Chikurachki .
Chikurachki, the highest volcano on Paramushir Island in the northern Kuriles, is actually a relatively small cone constructed on a high Pleistocene volcanic edifice. Oxidized basaltic-to-andesitic scoria deposits covering the upper part of the young cone give it a distinctive red color. Frequent basaltic plinian eruptions have occurred during the Holocene. Lava flows from 1781-m-high Chikurachki reached the sea and form capes on the NW coast; several young lava flows also emerge from beneath the scoria blanket on the eastern flank.
The Tatarinov group of six volcanic centers is located immediately to the south of Chikurachki, and the Lomonosov cinder cone group, the source of an early Holocene lava flow that reached the saddle between it and Fuss Peak to the west, lies at the southern end of the N-S-trending Chikurachki-Tatarinov complex. In contrast to the frequently active Chikurachki, the Tatarinov volcanoes are extensively modified by erosion and have a more complex structure. Tephrochronology gives evidence of only one eruption in historical time from Tatarinov, although its southern cone contains a sulfur-encrusted crater with fumaroles that were active along the margin of a crater lake until 1959.
Source : Kvert , Gvp.
Photo : L. Kotenko, IVS FEB RAS , Yaka Skorjanc .
Katla , Iceland :
On the micro-earthquake activity at Mýrdalsjökull.
29 JULY 2016. The following summary by the Icelandic Meteorological Office is about a recent increase in earthquake activity at the ice-covered Katla volcano, Iceland. Media interest in Iceland’s volcanoes has remained high since the Eyjafjallajökull eruption of 2010, hence the summary is intended as an official monitoring statement, in case of diverging media reports.
Since mid-June, earthquake activity within the caldera of the ice-covered Katla volcano has increased above background levels. More than 100 shallow-seated earthquakes have been detected in Katla caldera since 1 June 2016, which is almost four times the monthly average compared to previous years. Earthquakes occurred mainly in bursts ranging from minutes to hours, often with 20 events or more. The two largest earthquakes since the unrest began occurred on 26 July at 03:42 and 03:50 UTC, respectively, both with a magnitude of Mw3.2.
Such summertime increases in seismicity are common at Katla and the ongoing activity within the caldera is similar to summertime unrest observed in 2012 and 2014. Often this increased seismicity occurred in association with drainage of meltwater from several known ice-cauldrons, formed due to hydrothermal activity, as observed almost annually. Since late June 2016 there have been three small floods in Múlakvísl river, an outlet from Mýrdalsjökull, in addition to a flood from the Entujökull glacier. Presently, water-level and electrical conductivity measurements at the bridge over Múlakvísl show increased drainage of geothermal meltwater from Mýrdalsjökull – the ice-cap overlying Katla. We have received several reports throughout the summer of a hydrogen sulphide stench from glacial rivers around Myrdalsjökull.
One of many ice-cauldrons in Mýrdalsjökull, which are geothermally formed. Some are aligned above the eastern rim of the Katla caldera, which lurks underneath the ice-cap. In the center of the caldera, the ice is over 500 m thick. Melt water from the surface of the glacier has collected in the bowl, giving the blue colour, but that is irrelevant to the activity discussed in this article.
Around Katla we are not detecting signs of increased ground deformation or bursts of seismic tremor, which are both signals that might indicate movement of magma. We continue to monitor Katla closely and will issue updates on IMO‘s web-site if the situation intensifies. Our assessment is that the volcano is in a period of summertime unrest and it does not show signs of impending eruption, although we cannot rule-out a sudden escalation in seismicity in connection with a hazardous flood.
Source : Verdurstofa, OMI.
Photo : modernsurvivalblog , © Reynir Ragnarsson.