Servicio Nacional de Geología y Minería (SERNAGEOMIN) raised the alert status for the Cerro Hudson volcano in southern Chile recently. The Chilean government reported that before this morning nearly 900 volcanic earthquakes were noticed, most of which were not felt by residents living in the area. 119 people are currently evacuated from the Lake Caro area, and authorities are trying to evacuate another 13 individuals.
There are now three steam vents on the volcano, one of which is also emitting ash. Some photos taken from a recent flyby of the volcano can be seen here.
The ice-filled caldera (10-km-wide, or ~ 6.2 miles) of the Cerro Hudson volcano was not recognized until its first 20th-century eruption in 1971. Cerro Hudson is the southernmost volcano in the Chilean Andes related to subduction of the Nazca plate beneath the South American plate, and is 280 km (~ 174 miles) east of the Nazca-Antarctic-South American triple junction. An eruption about 6700 years ago was one of the largest known in the southern Andes during the Holocene, and a 1991 eruption was Chile’s second largest of the 20th century.
News report: Hudson Volcano forces evacuations in Southern Chile
Eruptions blogpost: Alert Status Raised to Red at Chile’s Hudson
There have been many reports online about an eruption currently happening off the coast of El Hierro (Spanish for "the iron"), which is one of the Canary Islands off the west coast of Africa. El Hierro is the smallest island in the archipelago, and the SW-most and least studied of the Canary Islands.
Earthquakes began in July, leading to speculation whether an eruption might occur. The eruption likely started before October 11, 2011, followed by a combination of gas bubbles and green & brown discoloration of the ocean surface, confirming people's suspicions that an undersea eruption was occuring.
Courtesy Dèsirée Martín
Volcanic gases mixing with seawater caused the water to become more acidic, resulting in a number of fish seen floating on the surface.
Currently, it appears that the activity is dying down, making it unlikely that a new island may appear. However, it is important to note that activity can change.
The Spanish newspaper El Mundo has an informative animation on the eruption, provding information on the geography of El Hierro, location and size of craters and cinder cones, and the ocean sea floor surrounding the island.
YouTube videos of the eruption are also available:
The Icelandic Meteorological Office announced Saturday May 21 at 2:00 pm CDT the eruption of the volcano Grímsvötn in Iceland (N64,24, W0172) following a short period of tremor. This is Iceland’s largest volcano. The eruption started under ice but spewed a plume up to 65,000 feet. Grímsvötn is a well monitored volcano. It last erupted in October 2004 and lasted about a week.
This eruption was larger than last year’s Eyjafjallajokull eruption, but will likely have less impact on air traffic. While Keflavik, the Iceland’s larges airport, was shut down, the ash plume from Grímsvötn is currently drifting east and north away from Europe.
Volcanic Ash Advisory Centers are set up across the globe to monitor volcanic ash and issue warnings as appropriate. These centers make use of satellite observations to monitor the eruptions and the movement of the ash cloud. Below is a link to a satellite animation of the eruption. This is a European satellite and the time between images is about 15 minutes.
Courtesy USGS/Cascades Volcano ObservatoryThe gigantic volcano seething under Yellowstone National Park could be ready to erupt with the force of a thousand Mt. St. Helenses! Large parts of the U.S. could be buried under ash and toxic gas!
Or, y'know, not.
This story has popped up in a couple of places recently, including National Geographic's website and, more sensationally, the UK's Daily Mail. Shifts in the floor of Yellowstone's caldera indicate that magma may be pooling below the surface, a phenomenon that might be the very earliest stages of an eruption. Then again, it's difficult to predict volcanic eruptions with much accuracy because there's no good way to take measurements of phenomena happening so far below the earth's surface.
Incidentally, the contrast in tone between the two stories makes them an interesting case study in science reporting: The Daily Mail plays up the possible risk and horrific consequences of an eruption, while National Geographic is much more matter-of-fact about the remoteness of that possibility. Which do you think makes better reading?
Eyjafjallajökull isn't the only volcano to rock our modern world. Thirty years ago today Mount St. Helens erupted in Washington State, making it one of the most spectacular and devastating volcanoes in the history of the United States. For those of us who were not alive or old enough to remember the event, here is a haunting description of the explosion from Boston.com:
"On May 18th, 1980, thirty years ago today, at 8:32 a.m., the ground shook beneath Mount St. Helens in Washington state as a magnitude 5.1 earthquake struck, setting off one of the largest landslides in recorded history - the entire north slope of the volcano slid away. As the land moved, it exposed the superheated core of the volcano setting off gigantic explosions and eruptions of steam, ash and rock debris. The blast was heard hundreds of miles away, the pressure wave flattened entire forests, the heat melted glaciers and set off destructive mudflows, and 57 people lost their lives. The erupting ash column shot up 80,000 feet into the atmosphere for over 10 hours, depositing ash across Eastern Washington and 10 other states."
And for everyone, here are some fabulous Boston.com photos to commemorate the event.
Ash fall from volcanic eruptions is a major problem for folks who live in the areas impacted by these eruptions. I used to think of ash fall like snow. But its not snow - volcanic ash is tiny jagged pieces of rock and glass. Its hard (you can't use a snowblower to get rid of it, it'll wreck your blower), abrasive, mildly corrosive, conducts electricity when wet, and does not dissolve in water. Think about that - when it rains you don't get the ash washed away - you just get icky mud. Its a major problem.
Also be sure to check out the Alaska Volcano Observatory's page on Mt. Redoubt's activity.
The volcano has moved to a more steady, but less explosive, eruption pattern.
Courtesy USGSAlso be sure to check out the Alaska Volcano Observatory's page on Mt. Redoubt's activity.
The alert status for Mount Soputan in Indonesia has been raised to the third highest level on their four-level system after beginning a minor eruption on Monday.
The region around the volcano is relatively uninhabited, with the closest villages at least 5 miles away. Still, residents were warned to stay a safe distance from the volcano.
The Soputan stratovolcano is one of Indonesia's most active volcanoes.
Courtesy Juan Carlos Diago, 1995 (Bernardo Pulgarín, INGEOMINAS, Colombia).Nevado del Huila, a volcano in Columbia, erupted shortly before midnight on Monday forcing about 3,500 people to evacuate. The eruption was preceded by seismic activity that started on April 8.
Before this recent activity, Nevado del Huila had been quiet since the 16th century.
In 1985 25,000 people were killed when another Columbian volcano, Nevado del Ruiz, erupted initiating a series of deadly lahars.
Jabal at-Tair, a small island formed entirely by a volcano was thought to be dormant until yesterday. But following several days of small earthquakes it erupted last night, September 30th at 7pm spewing lava and ash into the air at great heights.
Sadly it appears that several soldiers based on the island have died in the eruption although the number of people hurt is not immediately clear.
The volcanism that created the island is the result of two continental plates, Africa and Arabia, rifting apart from each other with the Arabian Plate (Saudi Arabia, Yemen, and more) moving away to the northeast. While this rifting is pretty old, beginning about 540 million years ago, the Red Sea only started to form about 55 million years ago. The Red Sea is widening at a rate of about .6 inches a year which accounts for the volcanic activity that we see there now.
More on the Red Sea's geologic history.