Sierraville, CA
Sierraville CA has been experiencing some activity in an area not known for any recent previous volcanism. Over 100 small earthquakes shook the region last week, and this week a mag 4.7 with about 9 or so aftershocks rumbled the area on the 26th. Seismologists have been quoted as saying "What we think is happening is magma is being injected into the upper most mantle, right at the base of the crust and magma is starting to lift up the whole area."
This of course does not mean that a volcanic eruption will occur, but it does of course raise that chance.
The quakes have ranged from 20km - 12km in depth, still far from the surface. In many occasions (and you can really see this process in older more erosion-sculpted areas of the planet) dike intrustion stops there. What a dike intrusion is, is a fracture in the crust that is filled by magma. Sometimes this magma cools, and when eroded, creates a spectacular natural wall after the elements and uplift exposes the dike. In other cases, (this is more common in Iceland) dike intrusion leads to fissure eruptions.
The Sierraville quakes at this point are scientifically interesting, but probably pose little to no immediate threat. However, since these swarms have now been going on for a few weeks, it's definitely worth keeping an eye on, as this area is close to several other volcanic centers like Steamboat Springs, and Soda Lakes in Nevada. Anything is possible!
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
Monday, October 31, 2011
Uturuncu - The Bolivian waking giant
Uturuncu volcano in Bolivia is inflating at a (geologically) breakneck pace of 2cm a year, since measurements began at the volcano in 2000. This has been found to be one of the largest inflating volcanic regions on earth, with some concerned that this could lead to a supervolcano eruption in the future. Scientists however point out that it would take a combination of crustal structural weakness, large magma reservoir, and other factors that make this scenario extremely unlikely.
When large magma chambers inflate, it's really anyone's guess as to what can happen. Some times, small fractures in the crust can lead to a monogenetic volcanic field such as Michoacan-Guanajuato in central Mexico, large fissure type eruptions such as the famed Laki eruption in Iceland during the 1700's, large caldera forming events such as the catastrophic destruction of Mount Mazama in the Cascades which forms Crater Lake/Wizard Island, or of course the worst case scenario of a Toba or Yellowstone type eruption.
As humans living today have not even come remotely close to witnessing a super volcanic eruption (or any eruption with a higher than VEI 7), it remains highly unlikely that the inflation at Uturuncu would lead to a super volcano.
Uturuncu is thought to have last erupted during the Pleistocene, however fumeroles, and post glacial lava flows are present, suggesting later stage activity. These Andes range volcanoes are sneaky, and erupt without a moment's notice sometimes. Chaiten volcano in Chile was thought to be a long dormant dome, when it erupted quite suddenly in 2008, and the eruption is ongoing.
The Andes range along the Pacific Plate has seen major subduction earthquakes in quite recent history, ranging from mag 5.0-8.6, with a 5.7 quake having just occurred yesterday along the same latitude near Uturuncu. The constant seismicity in the area is a reminder of how easily our earth's crust can generate new magma by tectonic friction and subduction. Indeed the Pacific Ring of Fire is the most active region volcanically on the planet.
Chile and Peru have seen some of the most active seismicity in their history lately, and it would not surprise me in the very least if this leads to long dormant volcanoes such as Uturuncu erupting. As I had pointed out in an earlier post, Chile's Hudson volcano (which nobody even knew WAS a volcano until it erupted in the 1970's) has also sprung back to life, creating quite a buzz.
Uturuncu is NOT in imminent danger of eruption. This is a log-term trend that has been the center of ongoing debate amongst volcanologists and geologists for around a decade now. Indeed, there is no way to properly tell how long this has been going on as the region is very remote, and technology has only been sensitive enough to detect this within recent years.
New technology has enabled volcanologists to map magma chambers by recording seismic waves that pass through high and low velocity zones. Low velocity zones can be interpreted as magma chambers. Only recently were scientists able to actually map out the shape, depth, and size of the Yellowstone magma chamber (and much to their surprise, it is far larger, far deeper than they thought).
This technology should be used by scientists to map the underground chamber at Uturuncu. The more we understand how this magma is intruding, the better guesses can be made as to whether this volcano is a threat, and proper measures could be taken.
Here are some links to the sources I referenced for this article! Enjoy reading about them as much as I did!
http://www.wired.com/wiredscience/tag/uturuncu/
http://adsabs.harvard.edu/abs/2001AGUFM.G31C0160P
http://en.wikipedia.org/wiki/Uturuncu
http://gamrconnect.vgchartz.com/thread.php?id=136114
When large magma chambers inflate, it's really anyone's guess as to what can happen. Some times, small fractures in the crust can lead to a monogenetic volcanic field such as Michoacan-Guanajuato in central Mexico, large fissure type eruptions such as the famed Laki eruption in Iceland during the 1700's, large caldera forming events such as the catastrophic destruction of Mount Mazama in the Cascades which forms Crater Lake/Wizard Island, or of course the worst case scenario of a Toba or Yellowstone type eruption.
As humans living today have not even come remotely close to witnessing a super volcanic eruption (or any eruption with a higher than VEI 7), it remains highly unlikely that the inflation at Uturuncu would lead to a super volcano.
Uturuncu is thought to have last erupted during the Pleistocene, however fumeroles, and post glacial lava flows are present, suggesting later stage activity. These Andes range volcanoes are sneaky, and erupt without a moment's notice sometimes. Chaiten volcano in Chile was thought to be a long dormant dome, when it erupted quite suddenly in 2008, and the eruption is ongoing.
The Andes range along the Pacific Plate has seen major subduction earthquakes in quite recent history, ranging from mag 5.0-8.6, with a 5.7 quake having just occurred yesterday along the same latitude near Uturuncu. The constant seismicity in the area is a reminder of how easily our earth's crust can generate new magma by tectonic friction and subduction. Indeed the Pacific Ring of Fire is the most active region volcanically on the planet.
Chile and Peru have seen some of the most active seismicity in their history lately, and it would not surprise me in the very least if this leads to long dormant volcanoes such as Uturuncu erupting. As I had pointed out in an earlier post, Chile's Hudson volcano (which nobody even knew WAS a volcano until it erupted in the 1970's) has also sprung back to life, creating quite a buzz.
Uturuncu is NOT in imminent danger of eruption. This is a log-term trend that has been the center of ongoing debate amongst volcanologists and geologists for around a decade now. Indeed, there is no way to properly tell how long this has been going on as the region is very remote, and technology has only been sensitive enough to detect this within recent years.
New technology has enabled volcanologists to map magma chambers by recording seismic waves that pass through high and low velocity zones. Low velocity zones can be interpreted as magma chambers. Only recently were scientists able to actually map out the shape, depth, and size of the Yellowstone magma chamber (and much to their surprise, it is far larger, far deeper than they thought).
This technology should be used by scientists to map the underground chamber at Uturuncu. The more we understand how this magma is intruding, the better guesses can be made as to whether this volcano is a threat, and proper measures could be taken.
Here are some links to the sources I referenced for this article! Enjoy reading about them as much as I did!
http://www.wired.com/wiredscience/tag/uturuncu/
http://adsabs.harvard.edu/abs/2001AGUFM.G31C0160P
http://en.wikipedia.org/wiki/Uturuncu
http://gamrconnect.vgchartz.com/thread.php?id=136114
Another Earthquake at Mauna Kea - Hawaii (updated 11/1/11)
A magnitude 2.2 quake struck the eastern flank of Mauna Kea Hawaii today at a depth of 27km. This quake follows on a swarm of quakes ranging from 20km-15km last week that had people wondering what was going on at this dormant volcano. HVO and USGS state that these quakes are more than likely simply crustal settling due to the weight of the mountain, however given that this quake is happening in a different location along some of the same latitudes that the shield volcano is constructed on, one has to wonder if there has been some minor dike intrusion... we will likely never know unless the volcano springs back to life.
Mauna Kea does not have this many earthquakes in a year typically, with over 20 tremors being detected within the month of October. This is very uncharacteristic of the volcano.
These types of swarms have happened in the past, and did not result in eruption, however many sources say the volcano WILL erupt again in the future.
At this point, I'll differ to the experts and say that this is unusual, but not unprecedented. It is still highly unlikely at this point that the volcano will erupt... but not out of the realm of possibility.
****************************************UPDATE**************************************************
Two more 2.2 quakes struck the base of Mauna kea at the same location as the large swarm. One was at a depth of 14km, indicating that whatever is going on, it is getting closer to the surface... Keep your eyes peeled!
Mauna Kea does not have this many earthquakes in a year typically, with over 20 tremors being detected within the month of October. This is very uncharacteristic of the volcano.
These types of swarms have happened in the past, and did not result in eruption, however many sources say the volcano WILL erupt again in the future.
At this point, I'll differ to the experts and say that this is unusual, but not unprecedented. It is still highly unlikely at this point that the volcano will erupt... but not out of the realm of possibility.
****************************************UPDATE**************************************************
Two more 2.2 quakes struck the base of Mauna kea at the same location as the large swarm. One was at a depth of 14km, indicating that whatever is going on, it is getting closer to the surface... Keep your eyes peeled!
Thursday, October 27, 2011
Hudson Volcano (Cerro Hudson) Eruption in Chile
As if Chile hadn't experienced enough disaster within recent years from Chaiten to Puyehue-Cordón Caulle, another massive volcano was sent into red alert yesterday on Oct 26th, 2011. Cerro Hudson in southern Chile erupted with a bang, causing avalanches and prompting evacuations as this relatively newly discovered volcano popped its top again.
The below is information from the Smithsonian Global Volcanism Program (GVP):
"The ice-filled, 10-km-wide caldera of the remote 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. The massive, 1905-m-high Cerro Hudson covers an area of 300 sq km. The compound caldera is drained through a breach on its NW rim, which has been the source of mudflows down the Río de Los Huemeles. Two cinder cones occur north of the volcano and others occupy the SW and SE flanks. Hudson has been the source of several major Holocene explosive eruptions. An eruption about 6700 years ago was one of the largest known in the southern Andes during the Holocene; another eruption about 3600 years ago also produced more than 10 cu km of tephra. An eruption in 1991 was Chile's second largest of the 20th century and formed a new 800-m-wide crater in the SW part of the caldera."
Add Oct 26th's eruption to the list now!
Looking at the volcano on Google Earth (Seen Below) shows that this is a massive caldera containing stratovolcano. This is a dangerous volcano, like most of the Andes range volcanoes, so authorities in the area are taking exactly zero chances.
The Below picture is from USGS, and was taken yesterday I believe.
Mount Hudson. Aerial photo by Norm Banks,U.S. Geological Survey
When Chaiten volcano blew up after more than 8,000 or so years of dormancy, it took Chile by surprise. The volcano had shown little or no warning signs prior to the eruption. Years later, Puyehue-Cordón Caulle began an eruptive phase that spread tephra and ash to the east covering neighboring Argentina with a gray ash cloud that forced airports closed, and caused lots of damage to livestock, crops and the economy.
Time will tell what Cerro Hudson has in store for Chile, but if the eruptions of its neighbors are any indication, we could be seeing activity from this volcano for months, maybe years. The Andes range volcanoes tend to be quiet for a very long time, and erupt suddenly. The eruption at Chaiten and Puyehue-Cordón Caulle are still ongoing. Chaiten erupted in 2008 and has not ceased its eruptive phase as of this writing. So Hudson could be active for a long time to come.
More information on this eruption can be found here at one of Chile's English language news sites.
I'll post some updates as they become available!
************UPDATE***************
As of right now, the volcano has erupted up to three separate columns of steam and ash in the main caldera. The ash/steam emissions have reached 3 miles high, although a major eruption is not expected to be imminent, as per a statement by ONEMI (Ministerio del Interior y Seguridad Pública). People have been evacuated, and given the volcanoes past two eruptions since 1971, they are taking no chances.
Previous eruptions devastated livestock and piled ash as much as 18 inches high. Since this volcano is covered by glaciers, if a full blown eruption does in fact take place, lahars and pyroclastic flow are a serious possibility. Lahars would most likely be first on the menu, and when the volcanoes top is clear of ice, the ash and gas could pose a very real hazard.
Air traffic is very likely to be affected in Chile and Argentina as a result of this eruption if it increases in scale. For now it is mostly fine ash, steam, and gas.
The below is information from the Smithsonian Global Volcanism Program (GVP):
"The ice-filled, 10-km-wide caldera of the remote 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. The massive, 1905-m-high Cerro Hudson covers an area of 300 sq km. The compound caldera is drained through a breach on its NW rim, which has been the source of mudflows down the Río de Los Huemeles. Two cinder cones occur north of the volcano and others occupy the SW and SE flanks. Hudson has been the source of several major Holocene explosive eruptions. An eruption about 6700 years ago was one of the largest known in the southern Andes during the Holocene; another eruption about 3600 years ago also produced more than 10 cu km of tephra. An eruption in 1991 was Chile's second largest of the 20th century and formed a new 800-m-wide crater in the SW part of the caldera."
Add Oct 26th's eruption to the list now!
Looking at the volcano on Google Earth (Seen Below) shows that this is a massive caldera containing stratovolcano. This is a dangerous volcano, like most of the Andes range volcanoes, so authorities in the area are taking exactly zero chances.
The Below picture is from USGS, and was taken yesterday I believe.
When Chaiten volcano blew up after more than 8,000 or so years of dormancy, it took Chile by surprise. The volcano had shown little or no warning signs prior to the eruption. Years later, Puyehue-Cordón Caulle began an eruptive phase that spread tephra and ash to the east covering neighboring Argentina with a gray ash cloud that forced airports closed, and caused lots of damage to livestock, crops and the economy.
Time will tell what Cerro Hudson has in store for Chile, but if the eruptions of its neighbors are any indication, we could be seeing activity from this volcano for months, maybe years. The Andes range volcanoes tend to be quiet for a very long time, and erupt suddenly. The eruption at Chaiten and Puyehue-Cordón Caulle are still ongoing. Chaiten erupted in 2008 and has not ceased its eruptive phase as of this writing. So Hudson could be active for a long time to come.
More information on this eruption can be found here at one of Chile's English language news sites.
I'll post some updates as they become available!
************UPDATE***************
As of right now, the volcano has erupted up to three separate columns of steam and ash in the main caldera. The ash/steam emissions have reached 3 miles high, although a major eruption is not expected to be imminent, as per a statement by ONEMI (Ministerio del Interior y Seguridad Pública). People have been evacuated, and given the volcanoes past two eruptions since 1971, they are taking no chances.
Previous eruptions devastated livestock and piled ash as much as 18 inches high. Since this volcano is covered by glaciers, if a full blown eruption does in fact take place, lahars and pyroclastic flow are a serious possibility. Lahars would most likely be first on the menu, and when the volcanoes top is clear of ice, the ash and gas could pose a very real hazard.
Air traffic is very likely to be affected in Chile and Argentina as a result of this eruption if it increases in scale. For now it is mostly fine ash, steam, and gas.
Wednesday, October 26, 2011
Update on Mauna Kea - Hawaii
The USGS and HVO issued a statement on the earthquake swarm at Mauna Kea that started on Oct 19th, and ended (seemingly) on the 20th. Their statement seems to indicate that these quake swarms, as far as their scientists are considered, is a result of crustal settling due to Mauna Kea's large size (one of the largest shield volcanoes in the world). They state that Mauna Kea probably will not erupt, and that this could be a purely tectonic swarm.
Mauna Kea has had no eruptions in human history, although it is not a dead volcano by any means. The "bio" for Mauna Kea on HVO states that it will erupt in the future, although nothing on the same scale of its neighbors, Mauna Loa and Kiluea.
I do not know at this time whether or not they have done any monitoring to identify any magma beneath Mauna Kea (with some censors, you can identify and plot in 3D what is referred to as a "low velocity zone", where signals travel through hardened rock faster than liquid magma) to come to the conclusion that this is crustal settling. I would suspect that given the fact that no previous eruptions are known, that this could be mere speculation on the part of the scientists, but who am I to say?
The placement, depth, and numbers of the quakes to me seem to indicate at least a 'burp' in the magma that lies below Mauna Kea. This may or may not lead to an eruption, as 18km below the mountain is still pretty far. If it gets within 5km I might start to worry, but for now it seems, Mauna Kea is back to its restive state, and people in Hawaii should probably not lose any sleep over the dormant volcano. They have plenty of others to worry about!
Mauna Kea has had no eruptions in human history, although it is not a dead volcano by any means. The "bio" for Mauna Kea on HVO states that it will erupt in the future, although nothing on the same scale of its neighbors, Mauna Loa and Kiluea.
I do not know at this time whether or not they have done any monitoring to identify any magma beneath Mauna Kea (with some censors, you can identify and plot in 3D what is referred to as a "low velocity zone", where signals travel through hardened rock faster than liquid magma) to come to the conclusion that this is crustal settling. I would suspect that given the fact that no previous eruptions are known, that this could be mere speculation on the part of the scientists, but who am I to say?
The placement, depth, and numbers of the quakes to me seem to indicate at least a 'burp' in the magma that lies below Mauna Kea. This may or may not lead to an eruption, as 18km below the mountain is still pretty far. If it gets within 5km I might start to worry, but for now it seems, Mauna Kea is back to its restive state, and people in Hawaii should probably not lose any sleep over the dormant volcano. They have plenty of others to worry about!
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