Much has been said about the future of Yellowstone volcano in Wyoming, as movies, articles, tabloids, and more have come out in recent years. Movies like "2012", and various TV movies on Sci-fi channel, as well as numerous documentaries on Nat Geo and other channels have put into our field of vision the grim specter of a super eruption in the United States which would have global ramifications.
Yellowstone super volcano last erupted more than 600,000 years ago. It is part of a "mantle plume", a column of magma that reaches from the mantle of the Earth up through the crust, occasionally punching holes in the surface that end up as a super eruption. This particular mantle plume has been active for many millions of years. The plume actually travels Eastward over time, as is evidenced by the Snake River Plain. Looking at Google Earth or other topographical data, you can easily see the trail of destruction and creation it has left from Utah all the way East to Wyoming and Montana.
Numerous calderas, cinder cones, volcanoes, and finally the Yellowstone Caldera leave a trail of evidence of past catastrophe. The current Yellowstone Caldera was formed a couple million years ago, with eruptive activity ceasing around 600,000 years ago, the time of the last great eruption. A few smaller phreatic eruptions have occurred since then, but nothing on the scale of what we see in the movies.
The Yellowstone caldera typically erupts every 600,000 years and the last time it erupted was 680,000 years ago. Some scientists say it is overdue for an eruption, and indeed, uplift has occurred since quake swarms in the 70's marked new activity for the caldera. The uplift has actually moved the shores of Yellowstone Lake by several feet, and uplift continues at around 3cm a year. In 2010, there was a large quake swarm in the northern region of the caldera which had scientists extremely worried.
Even more worrisome were the results of low velocity zone imaging which showed that the mantle plume's magma chamber was far, far larger than originally thought, and a lot closer to the surface. The mantle plume actually extends under parts of Montana, and is thousands of cubic miles in volume. This, is a big volcano.
Whether or not the volcano will erupt within our lifetime is anyone's guess, but scientists are not losing any sleep over it. Yellowstone, if it were to erupt, would likely give plenty of warning before it does so. The way Yellowstone's mantle plume has behaved in the past is not actually a good indicator for how it will erupt in the future (and it WILL erupt), however scientists state that a super eruption would occur if several criteria are met:
First, the mantle plume must inflate the crust to the point of a magmatic eruption. This would be an obvious sign that the S is about to hit the fan. Second, the eruption would have to extrude so much lava onto the surface as to nearly empty our the magma chamber, leaving a void of gas underneath the caldera, that would theoretically need to collapse under the weight of the surface's new lava. This collapse would cause the crust to actually fall into the magma chamber, resulting finally in the much feared super eruption.
There are plenty of smaller scale examples to look at. Crater Lake in Oregon used to be a large Cascades mountain called Mount Mazama. When Mazama had a large scale eruption that emptied out its chamber, the mountain collapsed under its own weight creating a gigantic crater in the earth visible from space. It is now the United State's deepest, and purest blue lake.
Yellowstone's evil cousin, Toba volcano in Indonesia, has had a much larger effect on humanity than Yellowstone. Toba erupted a mere 70,000 years ago, and was responsible for not only changing the global climate and throwing the Earth into a mini Ice Age, but it nearly extinguished the human species. What was a thriving colony of over 500,000 individuals at that time was reduced to a genetic bottleneck of a mere 5,000 individuals worldwide!
An eruption of either Toba or Yellowstone today would be catastrophic, resulting in severe economic damage, environmental turmoil, not to mention a very pesky 6ft of volcanic tephra that would accumulate over most of the United States and the rest of the Northern Hemisphere. While people would not be killed by pyroclastic flows or falling lava bombs (as Yellowstone isn't exactly near any major population centers) the fallout from the eruption would kill most of the crops in the USA (which produces the most food exports of any country in the world) and would result in many health issues due to breathing in volcanic ash (imagine breathing in pulverized glass...).
In any case, no need yet to have any nightmares about Yellowstone, but as we can be hit in this world by literally ANY disaster, it's always important to be prepared. Earthquakes, tsunamis, floods, hurricanes, tornadoes, blizzards, asteroids/meteors, wildfires, cyclones.... just some of the things that go on in this world that we all should be prepared for. Make sure you have lots of canned food, batteries, flashlights, candles, blankets, and other essentials in an easy to access, but safe place. The life you end up saving could be your own.
If you would like to monitor the Yellowstone volcano on your own, you can do so at http://volcanoes.usgs.gov/yvo/ and see quakes as they happen as well as great scientific reporting from the USGS.
A blog dedicated to publishing new and interesting events regarding our active Earth. Topics include volcanoes, earthquakes, tsunamis, and other seismic events. RSS Feed now available: http://feeds.feedburner.com/VolcanoScienceAndNewsBlog
Thursday, November 3, 2011
Continuing Activity at El Hierro (Canary Islands, Spain)
The new eruption at El Hierro volcano in the Canary Islands has resumed heightened activity. The southern eruption which produced a submarine cinder cone and fissure system appears to have abated somewhat, with most of the seismic activity now migrating to the north shore of the island. The cone south of La Restinga is now in a degassing/minor eruption phase, with gas still being emitted and bubbling visible on the surface of the water.
The underwater eruption is the only other historical eruption since an eruption in the 1770's.
Seismic activity and harmonic tremor have increased, and some activity seems to be happening on the north side of the island. It is possible that an eruption could occur on the island itself, but it is not known nor expected at this time. There has been a lot of magma movement into the chamber, which is easy to see when looking at seismic maps. A low velocity zone lies under the island that indicates magma is again rising. Over 600 quakes were recorded yesterday alone, bringing the total tremors to over 10,000.
There have been (bad) rumors floating around the Internet on other blogs that say that these eruptions have formed a new island. This is untrue. No lava has breached the surface of the water and it remains about 100m below the surface, or farther. There has been no aerial ash emission, and there is no danger currently to those on land, unless an eruption of a fissure or cinder cone begins on the island itself.
There remains a maritime exclusion zone around the eruption center, and only scientific vessels from Spain's Oceanographic Institute have been allowed to send ROV's down to look at the eruption site (you can see some video of this in the link below).
http://www.youtube.com/watch?v=zGKHmAvQrNo
It is important not to hype up this eruption. Yes, it is a rare thing indeed for this island to experience any activity, however this is not a large eruption, and is merely scientifically fascinating at this point. To recap, NO ISLAND HAS BEEN CREATED. The eruption and seismicity is ongoing, and it is anyone's guess as to what will happen next. I will post some updates if anything more significant develops.
The underwater eruption is the only other historical eruption since an eruption in the 1770's.
Seismic activity and harmonic tremor have increased, and some activity seems to be happening on the north side of the island. It is possible that an eruption could occur on the island itself, but it is not known nor expected at this time. There has been a lot of magma movement into the chamber, which is easy to see when looking at seismic maps. A low velocity zone lies under the island that indicates magma is again rising. Over 600 quakes were recorded yesterday alone, bringing the total tremors to over 10,000.
There have been (bad) rumors floating around the Internet on other blogs that say that these eruptions have formed a new island. This is untrue. No lava has breached the surface of the water and it remains about 100m below the surface, or farther. There has been no aerial ash emission, and there is no danger currently to those on land, unless an eruption of a fissure or cinder cone begins on the island itself.
There remains a maritime exclusion zone around the eruption center, and only scientific vessels from Spain's Oceanographic Institute have been allowed to send ROV's down to look at the eruption site (you can see some video of this in the link below).
http://www.youtube.com/watch?v=zGKHmAvQrNo
It is important not to hype up this eruption. Yes, it is a rare thing indeed for this island to experience any activity, however this is not a large eruption, and is merely scientifically fascinating at this point. To recap, NO ISLAND HAS BEEN CREATED. The eruption and seismicity is ongoing, and it is anyone's guess as to what will happen next. I will post some updates if anything more significant develops.
Wednesday, November 2, 2011
Chile lowers alert level for Hudson Volcano (Cerro Hudson)
Chilean authorities today allowed the return of residents that were evacuated within 45km of Cerro Hudson which 'awoke' last week to put on a small show. While this volcano has, in the past, been subject to violent and highly destructive eruptions, it seems this new phase was characterized by super heated water making its way up to three vents within the caldera. Chilean scientists and USGS have determined that no magma movement was actually detected in this eruption.
When glacial melt water accumulates and seeps into a volcanoes hot center, it can pressurize and make its way back up to the surface. Sometimes this results in what is called a 'phreatic eruption', meaning an eruption of gas and steam. These eruptions are typically far less dangerous than a magma eruption, and typically don't last long. Think of it sort of like shaking a bottle of Coca Cola and then opening it. A big blast of gas and liquid comes out, but subsides quickly.
The eruption at Cerro Hudson did create small amounts of ashfall near the volcano (as seen below)and blackened the snow topped mountains in the vicinity with a thin layer of ash. This ash was likely ash from a previous eruption, and not newly formed ash, as no magma was involved. The steam picked up the ash that was already on the caldera floor, and carried it with the steam.
However, as with most of these Andes range volcanoes, we can certainly expect more in the coming months from Chile, as activity has been at a high level for a lot of their volcanoes. The eruption at Puyehue-Cordón Caulle is ongoing, as with Chaiten. Eruptions from Llaima volcano, and Villarrica are frequent and typically cause lots of headaches for nearby residents and neighboring Argentina.
For now, it seems that Chileans can breathe a sigh of relief that this time, Cerro Hudson was kind enough to spare them the same misery caused by the recent Chaiten eruption, which caused severe damage to a nearby town of the same name, and blanketed Argentina with ash. The Chaiten eruption proved to be the biggest eruption this decade in Chile and one of it's all-timers. The area is still considered unfit for human habitation, and the instability of its growing obsidian dome remains a concern.
When glacial melt water accumulates and seeps into a volcanoes hot center, it can pressurize and make its way back up to the surface. Sometimes this results in what is called a 'phreatic eruption', meaning an eruption of gas and steam. These eruptions are typically far less dangerous than a magma eruption, and typically don't last long. Think of it sort of like shaking a bottle of Coca Cola and then opening it. A big blast of gas and liquid comes out, but subsides quickly.
The eruption at Cerro Hudson did create small amounts of ashfall near the volcano (as seen below)and blackened the snow topped mountains in the vicinity with a thin layer of ash. This ash was likely ash from a previous eruption, and not newly formed ash, as no magma was involved. The steam picked up the ash that was already on the caldera floor, and carried it with the steam.
However, as with most of these Andes range volcanoes, we can certainly expect more in the coming months from Chile, as activity has been at a high level for a lot of their volcanoes. The eruption at Puyehue-Cordón Caulle is ongoing, as with Chaiten. Eruptions from Llaima volcano, and Villarrica are frequent and typically cause lots of headaches for nearby residents and neighboring Argentina.
For now, it seems that Chileans can breathe a sigh of relief that this time, Cerro Hudson was kind enough to spare them the same misery caused by the recent Chaiten eruption, which caused severe damage to a nearby town of the same name, and blanketed Argentina with ash. The Chaiten eruption proved to be the biggest eruption this decade in Chile and one of it's all-timers. The area is still considered unfit for human habitation, and the instability of its growing obsidian dome remains a concern.
Tuesday, November 1, 2011
Clear Lake Seismic Swarms (ongoing)
It seems that since the late 1990's, Clear Lake (also called The Geysers Geothermal Field) in northern California, ongoing shallow quakes have plagued the region now for almost two decades. This first fascinated me as I was looking at the USGS real time quake maps on their website, and once I plugged in the real time KMZ file into Google Earth, it's been interesting to watch ever since.
Information on this ongoing quake swarm is a bit hard to come by. It seems that the longer this goes on, the less people are interested in this area of seismicity, so I thought I might "stoke the fire" a bit and get people to pay some attention to this.
The Clear Lake volcano has not had any historical eruptions, but the area is an active volcano. The landscape is dotted with cinder cones, maars (explosion craters), geothermal geysers, and lava domes. The area last erupted around 10,000 years ago, and has been anything but quiet ever since. Much like the geysers at Yellowstone, The Geysers Geothermal Field gets its heat source from a large silicic magma chamber that provides the heat source for one of the worlds largest geothermal power plants.
Locals state that these quakes are a direct result of water injection into the hot rock, which can lubricate fault lines, cause stress fractures in the rocks, and very rarely, lead to phreatic eruptions (gas and steam). This has not occurred at Clear Lake.
My fascination with this area is that it seems these quakes are a tad bit too large to be "merely" the result of geothermal drilling. Some quakes have ranged up to 5.0, while for the most part, you get 1.0-3.0 quakes daily in the region. This suggests to me that either human activities related to the power generators have destabilized some of the mountain regions around the lake, or seismic activity is related somehow to ongoing volcanic activity.
As this has been a consistent swarm for about two decades, there is no need to worry about any eruption in the near future, but my concern is that the area is not being studied by any publication-posting geologists. You would think that a swarm of this duration would be something of interest to geologists, but if you try to search for information, most of it is extremely old.
There have been lawsuits brought by locals who wish the plant to be shut down, so it could be they hired some lobbyists to quiet the USGS, or any freelance scientists. There's simply no way to tell without some deep investigations.
In any case, the below picture was taken today showing the location of these quake swarms. As you can see, there are a lot, and a daily scan of the area just reveals more and more. I'd personally love it if the area was surveyed by an agency not tied to the geothermal power plant for an objective view.
Information on this ongoing quake swarm is a bit hard to come by. It seems that the longer this goes on, the less people are interested in this area of seismicity, so I thought I might "stoke the fire" a bit and get people to pay some attention to this.
The Clear Lake volcano has not had any historical eruptions, but the area is an active volcano. The landscape is dotted with cinder cones, maars (explosion craters), geothermal geysers, and lava domes. The area last erupted around 10,000 years ago, and has been anything but quiet ever since. Much like the geysers at Yellowstone, The Geysers Geothermal Field gets its heat source from a large silicic magma chamber that provides the heat source for one of the worlds largest geothermal power plants.
Locals state that these quakes are a direct result of water injection into the hot rock, which can lubricate fault lines, cause stress fractures in the rocks, and very rarely, lead to phreatic eruptions (gas and steam). This has not occurred at Clear Lake.
My fascination with this area is that it seems these quakes are a tad bit too large to be "merely" the result of geothermal drilling. Some quakes have ranged up to 5.0, while for the most part, you get 1.0-3.0 quakes daily in the region. This suggests to me that either human activities related to the power generators have destabilized some of the mountain regions around the lake, or seismic activity is related somehow to ongoing volcanic activity.
As this has been a consistent swarm for about two decades, there is no need to worry about any eruption in the near future, but my concern is that the area is not being studied by any publication-posting geologists. You would think that a swarm of this duration would be something of interest to geologists, but if you try to search for information, most of it is extremely old.
There have been lawsuits brought by locals who wish the plant to be shut down, so it could be they hired some lobbyists to quiet the USGS, or any freelance scientists. There's simply no way to tell without some deep investigations.
In any case, the below picture was taken today showing the location of these quake swarms. As you can see, there are a lot, and a daily scan of the area just reveals more and more. I'd personally love it if the area was surveyed by an agency not tied to the geothermal power plant for an objective view.
Mexico earthquake near island volcanoes
A Magnitude 6.3 earthquake struck off the Western coast of Southern Mexico this morning near two volcanically active islands. The quake struck on a strike-slip type fault, about 115 miles from the volcanic islands of Bárcena (which last erupted spectacularly in 1952), and Socorro whos last eruption was in 1993 and was submarine.
This eruption is not expected to result in any eruptions as it was purely tectonic in nature. An aftershock of 4.2 occurred shortly afterward.
Mexico has experienced many large to major quakes within the past couple of years. A 7.4 magnitude quake struck near the Cerro Prieto volcanic cone on Easter of 2010, causing widespread damage on the Mexican side of the border, where only a few buildings reported damage in nearby San Diego and Imperial Valley. The quake was felt as far away as the upper United States.
While this recent quake will not likely result in any volcanic unrest, it could conceivably aggravate the fault that caused the Easter quake, and will likely cause some unrest on the San Andreas fault if that does occur. The fault that the current quake lies on is a spreading-slip type fault, wheras the Pacific plate is moving away from the North American plate, and will likely "jiggle" the Rio Grande rift plate.
If anything further develops, I will post an update!
This eruption is not expected to result in any eruptions as it was purely tectonic in nature. An aftershock of 4.2 occurred shortly afterward.
Mexico has experienced many large to major quakes within the past couple of years. A 7.4 magnitude quake struck near the Cerro Prieto volcanic cone on Easter of 2010, causing widespread damage on the Mexican side of the border, where only a few buildings reported damage in nearby San Diego and Imperial Valley. The quake was felt as far away as the upper United States.
While this recent quake will not likely result in any volcanic unrest, it could conceivably aggravate the fault that caused the Easter quake, and will likely cause some unrest on the San Andreas fault if that does occur. The fault that the current quake lies on is a spreading-slip type fault, wheras the Pacific plate is moving away from the North American plate, and will likely "jiggle" the Rio Grande rift plate.
If anything further develops, I will post an update!
Subscribe to:
Posts (Atom)