The Chilean volcano Copahue erupted an ash cloud yesterday, which rose to an altitude of 3700 m and drifted in a southeasterly direction. Already last week there was a comparable ash emission
Copahue is located in the Bio Bio region and on the border with Argentina. The complex stratovolcano consists mainly of andesite. El Agrio is currently active from about a dozen craters. An acidic crater lake is bubbling in this crater. The Copahue is covered by a glacier. Larger volcanic eruptions threaten lahars. The alarm status is “yellow”.
An earthquake of magnitude 6.6 occurred in the central region of the Mid-Atlantic Ridge, the epicenter of which was located between South America and Africa, more precisely 1218 km north of Acaraú in Brazil. The hypocenter was located at 10 km depth. Only last week there had been a strong earthquake in this region.
The border of several continental plates runs along the Mid-Atlantic Ridge. The submarine ridge is the birthplace of the Atlantic Ocean. Because of the divergence of the continental plates, they move apart and do not collide, as is the case in subduction zones. This causes less tension in the rock than at subduction zones and earthquakes occur less frequently.
In the past weeks the volcano in Tanzania appeared again and again in the news, so also today. The reason for this is a larger thermal anomaly in the crater. It can be seen on sentinel satellite photos and is generated by the coldest lava in the world. It flows over the crater floor. The anomaly is located on the northwestern rim of the crater and a new hornito may have formed there. This year there was mostly a large hornito active in the center of the crater. There you can still see solidified lava.
Yesterday, lahars went off at the Ecuadorian volcano Sangay. Around 10.30 am (local time) corresponding seismic signals with a low frequency were registered. The seismologists of the Geophysical Institute in Ecuador issued a warning. Since the start of the activity in May 2019, heavy rainfall has been regularly triggering lahars. The mudslides not only pose a serious danger to people living in the immediate vicinity of the volcano, but also change the hydrology of the area: water is dammed up and river water is contaminated.
The lahars are formed when water mobilizes deposited volcanic ash on the volcanic slope. The material comes not only from explosive eruptions, but also from pyroclastic flows. Currently there is a VONA warning of volcanic ash at an altitude of 6400 m.
The volcano Rincon de la Viejá (Costa Rica) started on Sunday with a series of eruptions. Within 15 hours 3 phreatic eruptions were generated. The last of these eruptions manifested on Monday morning and was the strongest of the series. It not only produced water vapor but also tephra, which rose up to 500 m above crater level. Already in the previous week there were several eruptions.
The volcano is located in the province of Guanacaste. On its slopes a wonderful dry forest spreads out. I climbed the volcano in 1994 and can well remember the species richness of the forest: howler monkeys, sloths, armadillos and coatis met me at every turn. The coati are extremely voracious and at that time they plundered my food supply, which I had attached to a rope between 2 trees. Nevertheless the coati reached the food and I experienced 3 rather hungry days. Unfortunately I did not see the crater, because the summit was covered in clouds during my 3-day stay at the volcano.
In the Chilean region of Atacama, it shook with a magnitude of 6.8. A second earthquake brought it to 6.5. The earthquake centers were located at 30 km and 10 km depth. The epicenters manifested themselves on the coast, 69 km north of Vallenar. Almost 45,000 people live in the city. There have been several moderate aftershocks with magnitudes in the range of 5. The stronger earthquake occurred at 4:09 UCT. In Chile it was midnight at that time. So people were torn from their beds at night. It is not yet known if there was any major damage. Strong earthquakes are particularly dangerous at night, because most people are in buildings and could be killed by falling parts. Fortunately, the direct surroundings around the epicenters are quite sparsely populated.
Update 15:00: Apparently there was an episode of increased activity tonight that also involved the Northeast Crater. A livecam image shows a double lava fountain from New South East Crater and Northeast Crater.
Original message: In the last hours the Etna tremor has increased significantly and is now moving in the red zone. At the same time the LGS upgraded the automatically generated pre-warning level to “orange”. Since yesterday noon, more and more signals in the infrasonic range have been detected. They occasionally have a relatively high acoustic pressure of 3-4 bar and come from the direction of the New South East Crater. On the livecam this morning you can only see steam rising. But it is only moderately windy, so I do not assume that the measured values are falsified by the wind. In fact, yesterday hikers walking on the rim of Bocca Nuova observed the sudden onset of an ash eruption from the saddle vent of New South East Crater. Satellite images show ash emissions from the New South East Crater and a thermal anomaly in the Northeast Crater. I wouldn’t be surprised if we would see some activity here in the next weeks.
Etna on Sicily continues to eject ash clouds in phases. So it is also active this morning. The volcanic ash rises several hundred meters high and is transported by the moderate wind in southeastern direction. The scene of the event is the saddle vent, which had formed on the ridge between the Old and New Southeast crater cones. Interestingly, the activity of the last months seems to be more and more limited to this crater. This indicates a migration of the conveyor system to the west of this cone group. The actual main crater of the New South East Crater Cone rarely gets involved in the eruption process. A VONA message was not generated. The VAAC Toulouse last reported an ash cloud on August 25. Although no heat radiation was recorded, images of nighttime eruptions show that red glowing tephra was erupted.
The earthquake activity is moderate. Most of the earthquakes have magnitudes between 1 and 2 and are scattered over the volcano, sometimes not concentrated under the Valle del Bove. The tremor amplitude varies greatly and is mostly in the yellow range. It looks like the eruptive behavior of the volcano is relatively stable. Although Etna is always good for a surprise, I don’t see any sign of major changes in the short term.
In the crater area of Irazu Volcano, a large part of the slope has collapsed and slipped down. According to OVSICORI expert Cyril Muller, there were at least 100 small landslides on August 25th. A crack in the slope had widened by 40 centimeters. Yesterday morning the big landslide occurred, in which several million cubic meters of material slid down. Due to the bad weather conditions, there are only pictures of the edge of the landslide so far. It manifested itself at the border of an antenna park. 2 containers with transmission equipment were torn into the depths. The rest of the antenna equipment is now directly at the edge of the slide and could still slide down. The antenna park is located southwest of the crater, on a ridge that ends directly at the crater rim.
The event was not unexpected. Already in May 2019 a major landslide occurred. At that time, the main crater to the north was affected and a 10 m high tidal wave was triggered in its crater lake. In the meantime the crater lake had practically disappeared. Scientists observed the increasing crack formation in the crater walls for a long time.
The Irazu is located a few kilometers east of the capital San José and is with a height of 3.432 m the highest volcano in Costa Rica. The last eruption was in 1994 and due to the current development the alarm status is set to “red”. Sudden changes in the load of the volcano could lead to pressure changes inside the volcano and trigger eruptions. In addition, deeply descending crevasses could open. However, there is no evidence that there is an active magma body under the volcano. Therefore an immediate eruption is unlikely.
Stromboli increased its activity again. Yesterday the live cam observers of our FB group managed to capture some nice screenshots. Currently the activity is considered moderate by the LGS, and there may be phases of increased activity. The acoustic explosion pressure yesterday reached 2.02 bar and 65 eruptions were detected. At the moment comparatively much glowing tephra is landing on Sciara del Fuoco. This is not only due to the explosion strength, but also to the crater morphology.
Stromboli is one of the word’s most active volcano. The lighthouse of the meditarrane is in almoust continously eruption for 2000 years.
The Chilean volcano Copahue erupted an ash cloud yesterday, which rose to an altitude of 3700 m and drifted in a southeasterly direction. Already last week there was a comparable ash emission
