Shiveluch Volcano (Kamchatka, Russia): Continuing Activity, Frequent Small Glowing Avalanches

The activity at the volcano has been a bit lower during the past days, although overall similar to the past weeks. The lava dome continues to grow steadily.

During the past nights, we observed frequent, but mostly small glowing avalanches from the active dome as well as small ash emissions and intense steaming. The upper third of the dome, now over 800 m high, seems to be active with many incandescent spots visible.

No larger events (pyroclastic flows traveling beyond the base of the cone or explosions with significant ash emissions) have been observed since our arrival on 16 Mar. According to the volcano observatory, internal activity remains elevated, and the risk of a major dome collapse continues to increase.

Satellite Images Reveal Interconnected Plumbing System That Caused Bali Volcano To Erupt

A team of scientists, led by the University of Bristol, has used satellite technology provided by the European Space Agency (ESA) to uncover why the Agung volcano in Bali erupted in November 2017 after 50 years of dormancy.

Their findings, published today in the journal Nature Communications, could have important implications for forecasting future eruptions in the area.

Two months prior to the eruption, there was a sudden increase in the number of small earthquakes occurring around the volcano, triggering the evacuation of 100,000 people.

The previous eruption of Agung in 1963 killed nearly 2,000 people and was followed by a small eruption at its neighboring volcano, Batur.

Because this past event was among the deadliest volcanic eruptions of the 20th Century, a great effort was deployed by the scientific community to monitor and understand the re-awakening of Agung.

During this time, a team of scientists from the University of Bristol’s School of Earth Sciences, led by Dr Juliet Biggs used Sentinel-1 satellite imagery provided by the ESA to monitor the ground deformation at Agung.

Dr Biggs said: “From remote sensing, we are able to map out any ground motion, which may be an indicator that fresh magma is moving beneath the volcano.”

In the new study, carried out in collaboration with the Center for Volcanology and Geological Hazard Mitigation in Indonesia (CVGHM), the team detected uplift of about 8-10 cm on the northern flank of the volcano during the period of intense earthquake activity.

Dr Fabien Albino, also from Bristol’s School of Earth Sciences, added: “Surprisingly, we noticed that both the earthquake activity and the ground deformation signal were located five kilometres away from the summit, which means that magma must be moving sideways as well as vertically upwards.

“Our study provides the first geophysical evidence that Agung and Batur volcanoes may have a connected plumbing system.

“This has important implications for eruption forecasting and could explain the occurrence of simultaneous eruptions such as in 1963.”

Extratropical Volcanoes Influence Climate More Than Assumed

The eruption of Mount Pinatubo in 1991 had a significant impact on climate, decreasing global mean temperature by about 0.5°C. Like the famous eruptions of Krakatau (1883) and Tambora (1815), Pinatubo is located in the tropics, which has been considered an important factor underlying its strong climate forcing. However, an international research group led by the GEOMAR has now published a study in the journal Nature Geoscience that shows that explosive extratropical eruptions can have a strong impact on the climate, too.

In recent decades, extratropical eruptions including Kasatochi (Alaska, U.S., 2008) and Sarychev Peak (Russia, 2009) have injected sulfur into the lower stratosphere. The climatic forcing of these eruptions has, however, been weak and short-lived. So far, scientists have largely assumed this to be a reflection of a general rule—that extratropical eruptions lead to weaker forcing than their tropical counterparts. Researchers from the GEOMAR Helmholtz Centre for Ocean Research Kiel, the University of Oslo, the Max Planck Institute for Meteorology in Hamburg together with colleagues from Switzerland, the U.K. and the U.S. now contradict this assumption in the international journal Nature Geoscience.

“Our investigations show that many extratropical volcanic eruptions in the past 1,250 years have caused pronounced surface cooling over the Northern Hemisphere, and in fact, extratropical eruptions are actually more efficient than tropical eruptions in terms of the amount of hemispheric cooling in relation to the amount of sulfur emitted by the eruptions,” says Dr. Matthew Toohey from GEOMAR, first author of the current study.

Large-scale cooling after volcanic eruptions occurs when volcanoes inject large quantities of sulfur gases into the stratosphere, a layer of the atmosphere that starts at about 10 to 15 kilometers height. There, the sulfur gases produce a sulfuric aerosol haze that persists for months or years. The aerosols reflect a portion of incoming solar radiation, which can no longer reach the lower layers of the atmosphere and the Earth’s surface.

Until now, the assumption was that aerosols from volcanic eruptions in the tropics have a longer stratospheric lifetime because they have to migrate to mid or high latitudes before they can be removed. As a result, they would have a greater effect on the climate. Aerosols from eruptions at higher latitudes would be removed from the atmosphere more quickly.

The recent extratropical eruptions, which had minimal but measurable effects on the climate, fit this picture. However, these eruptions were much weaker than that of Pinatubo. To quantify the climate impact of extratropical vs. tropical eruptions, Dr. Toohey and his team compared new, long-term reconstructions of volcanic stratospheric sulfur injection from ice cores with three reconstructions of Northern Hemisphere summer temperature from tree rings dating back to 750 CE. Surprisingly, the authors found that extratropical explosive eruptions produced much stronger hemispheric cooling in proportion to their estimated sulfur release than tropical eruptions.

To understand these results, Dr. Toohey and his team performed simulations of volcanic eruptions in the mid to high latitudes with sulfur amounts and injection heights equal to that of Pinatubo. They found that the lifetime of the aerosol from these extratropical explosive eruptions was only marginally smaller than for tropical eruptions. Furthermore, the aerosol was mostly contained within the hemisphere of eruption rather than globally, which enhanced the climate impact within the hemisphere of eruption.

The study goes on to show the importance of injection height within the stratosphere on the climate impact of extratropical eruptions. “Injections into the lowermost extratropical stratosphere lead to short-lived aerosol, while those with stratospheric heights similar to Pinatubo and the other large tropical eruptions can lead to aerosol lifetimes roughly similar to the tropical eruptions,” says co-author Prof. Dr. Kirstin Krüger from the University of Oslo.

The results of this study will help researchers to better quantify the degree to which volcanic eruptions have impacted past climate variability. It also suggests that future climate will be affected by explosive extratropical eruptions. “There have been relatively few large explosive eruptions recorded in the extratropics compared to the tropics in recent centuries, but they definitely do happen,” says Dr. Toohey. The strongest Northern Hemisphere cooling episode of the past 2500 years was initiated by an extratropical eruption in 536 CE. This new study explains how the 536 CE eruption could have produced such strong cooling.

Popocatepetl Volcano Erupts In Mexico

MEXICO, (CNN) — The Popocatepetl volcano registered a strong explosion Tuesday evening in the states of Puebla and Morelos, in central Mexico, according to Mexico’s civil protection authority.

The explosion caused lava and ashes to spew, with a smoke plume almost two miles high emanating from the volcano’s dome.

Authorities have asked locals to remain in their homes.

No initial reports of damages or injuries have been reported.

Stromboli Volcano (Italy): Frequent And Strong Explosions From 6 Vents, Observation Report From Close

The activity of the volcano remains elevated – magma is still standing high inside its conduits.

When observed from close earlier today, there were 6 active vents producing intermittent strombolian explosions of small to large size (see annotated image of the crater terrace with the vents indicated as on a map):
The new cinder cone that has been built recently around the NE vent displayed mild and continuous lava spattering with intense lava glow at night, as well as strombolian explosions of small to moderate size (ejection heights racing from few tens of meters to approx. 150 m) at intervals of 10-20 minutes.

The strongest explosions, however occurred from both the easternmost vent (below the more active NE cone, far right in the picture) as well as (and more frequently) from the westernmost vent, both ejecting incandescent material to certainly more than 200 m height and bombs reaching much of the crater terrace and its surroundings. Intervals of explosions were about one every 10-15 minutes vor the western vent and more rarely from the easternmost one (once per 30-40 minutes). As has been typical for the past decades, the westernmost vent usually generated significant amounts of ashes, while all other vents had almost no ash during their explosions.

Some of the most notable eruptions, however, occurred from a vent in the NW area of the crater area: it forms a steep-sided, symmetric, conical shaped small cone and frequently erupted dense, candle-like lava fountains, as well as sometimes only mostly gas jets. Its eruptions were often accompanied by very loud detonation sounds. Occasionally, this vent also produced beautiful “smoke rings” (ring vortexes), apparently caused by pulsating gas emissions from its circular vent.

A small vent just east of the mentioned westernmost vent also erupted in similar, but weaker style (narrow jets of lava) occasionally. Last, the formerly called “central crater”, in the southern central part of the crate terrace also had infrequent, typically small to moderately-sized classic strombolian eruptions. In the past this vent (located in the lower center of the image) often displayed constant glow and spattering, but did not do so today.

All in all, explosions occurred at intervals of about 2-3 minutes from all 6 vents combined.

Santorini Volcano (Greece): Earthquake Swarm Southwest Off The Island

An earthquake swarm has been occurring near the island since this morning. So far, 16 quakes of magnitudes between 2 and 3.9 and at depths ranging between about 30-6 km have been detected.

The quakes are clustered about half way between Santorini’s SW end and the Christiana Island group.

The strongest shock with magnitude 3.9 occurred at 10:27 local time and might have been felt weakly by residents of the southern part of Santorini.

Although the quakes are near the Kameni line, a tectonic lineament in SW-NE direction which has been the preferred location for magma ascent (i.e. formation of volcanic vents) in the volcano’s past few 100,000 years of history, there is currently no indication that the earthquakes are volcanic in origin. It is much more likely that they represent a normal tectonic event.

However, Santorini being both a popular tourist destination and an active volcano, the situation merits close monitoring.

Bali Volcano Shoots New Burst Of Ash; Flights Unaffected

A volcano on Indonesia’s tourist island of Bali shot a new burst of hot ash into the air early Sunday in the latest of the country’s several eruptions within a week.

Mount Agung erupted for about three minutes, spewing white clouds of smoke and ash more than 700 meters (2,300 feet) into the air, the Volcanology and Geological Mitigation Agency said in a statement.

The eruption of the 3,031-meter (9,940-foot) volcano didn’t prompt evacuations, and its alert status remains at the second-highest level. The agency warned tourists to stay away from the danger zone in a 4-kilometer (2.5-mile) radius around the crater.

Agency spokesman Sutopo Purwo Nugroho said that white dust from the eruption blanketed several villages close to the mountain slope in Karangasem district.

Ngurah Rai International Airport spokesman Arie Ahsanurrohim said that flights were operating normally. Authorities said the air around Denpasar, the Bali provincial capital, is clear from ash.

More than 140,000 people had fled the area around the mountain in late September after its alert status was raised to the highest level, indicating an eruption may be imminent. The alert status was lowered two weeks later, allowing for the return of those displaced from government shelters.

An eruption in 1963 killed about 1,100 people. Agung lies about 70 kilometers (45 miles) northeast of Bali’s tourist hotspot of Kuta.

It is among more than 120 active volcanoes in Indonesia, which is prone to volcanic eruptions and earthquakes because of its location on the so-called “Ring of Fire” — a series of fault lines stretching from the Western Hemisphere through Japan and Southeast Asia.

Last week, Anak Krakatau in Indonesia’s Sunda Straits erupted and collapsed into the sea, causing a tsunami that killed 431 people on Java and Sumatra. More than 46,600 were displaced.