Monday, October 31, 2011

Sierraville CA Earthquake Swarm is Magma Dike Intrusion

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!

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!

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.


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!

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!

Monday, October 24, 2011

Special Report on Mauna Kea

Whoops! This almost slipped my mind!

Mauna Kea volcano on the big island of Hawaii has been jolted by some large and somewhat deep earthquakes just NW of the summit. The below snapshot from HVO (Hawaii Volcano Observatory to whom the picture is copyrighted , details the ongoing volcanic swarm below the tallest volcano on Hawaii.

Another image taken from Google Earth with the USGS KMZ layer installed shows a more detailed picture (below)

Mauna Kea does not have a record of ever having erupted during historical time and shows glacial moraines. The last known eruption occurred during the early holocene.

Many volcanologists including John Seach state that Mauna Kea is NOT a dead volcano, and assertively state that it WILL erupt in the future due to remnant magma chambers from when it was young and active. So the current swarm isn't entirely unusual, but it does appear a bit ominous.

The big island of Hawaii is one of the most volcanically active regions on the planet. Hualalai volcano last erupted in 1801 producing a voluminous lava flow that reached the sea and buried towns. Mauna Loa (the 2nd highest by a margin of only 35m) volcano last erupted in 1984 and was one of the largest eruptions in Hawaii's history, save for Kiluea which has been active since 1983 and in continuous eruption ever since, with no signs of slowing down.

If Mauna Kea should erupt, it will likely produce a flank cinder cone, and pahoehoe lava flows. Given the placement and distribution of the current quake swarm (which continues today), I would suspect this is the most likely possibility. Farmlands, and the nearby towns of Waimea and Kamuela would conceivably lie in the path of a pahoehoe flow if it ends up being a large one.

Hawaii is no stranger to volcanic destruction, which was the case recently with the town of Kalapana which was literally paved over by Kiluea. Mauna Loa caused widespread damage to towns and roads when it last erupted. Keep your eyes peeled on this one! An eruption is not considered imminent at this time, and the quakes at Mauna Kea are some 18KM deep at this time. If they get shallower, it might be time to get concerned... or get the cameras ready!

Mt. Hood Quakes

There are some ticking time bombs in the cascade range we truly wish would never awaken. From Shasta, to Hood, to Ranier, all of these could easily dwarf the eruption of Mt. St Helens given the right circumstances. Indeed in the past couple of weeks, some quakes have come mighty close, and even occurred under these sleeping giants.

Mt. Hood is one of the most historically active volcanoes in the Cascades, last having erupted in the 19th century. Hood is especially dangerous (and tricky to monitor) as are a lot of the cascades volcanoes due to its age and structural weakness. Being a very high volcano, ice and the placement/contraction of glaciers changes the chemical structure of the lavas over time, creating a sort of "lava rot". Oxidization of the adesite/dacite composition leads to occasional avalanches and collapses, similar to what was witnessed at St Helens in 1980, when structural weakness combined with doming of the NNW face combined to create a catastrophic failure of the volcanoes structure.

Hood has had several very minor eruptions as its most recent activity, but has otherwise been relatively quiet save for some recent earthquake activity. On Oct 20, two shallow 1.2-1.3 magnitude quakes occurred on its NNW face. The reason cascades volcanoes are tricky to monitor, is that sometimes these quakes are not tectonic or magmatic at all, rather they can be anything from avalanches, to snow/ice movement, to a simple release of deep steam. In this case, the quakes appear to be magmatic in nature, purely because of the location and depth... but I am NOT a seismologist so do not take my word for it.

Earlier last week, large quakes (mag 4.0 and less) occurred near Mount Rainier to the West of the summit. This does in fact appear to be magmatic, but again, a scientist should weigh in on this. Typically however, magma movement goes in cycles that generate many small harmonic tremors, which have not occurred at Rainier, so this could be purely tectonic too. Time will tell. Rainier is probably the most dangerous volcano in the Western USA, so it behooves us all to stay alert to its activities. Estimates of an eruption, pyroclastic flow, or lahar say that if this occurs at Rainier, people will not have enough time to get out of the way and hundreds of thousands (if not millions) of lives would be at risk. So scientists monitor its seismicity in order to even attempt to predict an eruption.

Some volcanoes give us warnings, as Nevado del Ruiz in Columbia (and unfortunately for the Columbians, these warnings are sometimes ignored... a mistake they won't be repeating soon!). In 1985, scientists detected volcanic tremor and a type of quake that had not been previously identified, called a "Long Period Event" or LPE. This directly preceded a catastrophic eruption that killed many, and displaced hundreds. Some scientists were on the mountain at the time of the eruption and ended up losing their lives.

Eruption prediction is probably never going to be even as close as predicting the weather, especially in our lifetimes. But every volcano is different, and some are more obvious than others. Some however, give very little warning before eruption, as was the case in Chile with Chaiten volcano, which had not erupted for over 8,000 years. Nabro volcano in Eritrea erupted a couple months ago, never having shown any historical activity whatsoever. These eruptions were preceded by large quakes (mag 5.0 and greater), and erupted only hours later.

Keeping track of earthquakes as they relate to volcanoes is a fun hobby, and who knows? It might be the hobby that ends up saving lives. Stay tuned!

Wednesday, October 19, 2011

The Thrill of Eco Tourism

I visited my first volcano when I was 16. My family had taken a trip to Maui, where I got my first glimpse of Haleakala volcano (which has not had an eruption since the 18th century), and was immediately captivated by the sheer beauty of a barren moonscape dotted with craters. It turned me into a major volcano geek.

Years later I returned to Hawaii to go on an ultimate volcano adventure. My girlfriend and I had basically blown every cent on this adventure but it was well worth it. We saw Diamond Head crater in Honolulu, and then took a small plane over to the big island where we toured Kiluea. We first stopped at the area between Kiluea and Mauna Loa, where we saw the steam vents and fumeroles that were dotted amongst the forest. It was a bizarre landscape. You could really feel the volcano underneath your feet, smell it, and feel the heat from the steam vents.

We made our way to the summit of Kiluea at Halema'uma'u crater, and witnessed the most spectacular active caldera we'd ever seen. We went to the rim of Kiluea'iki (little Kiluea crater) and saw the seemingly fresh floor covered in still degassing/steaming lavas from a 1960's eruption that produced a spectacular hillside cinder cone.

We then made our way down to the town of Kalipana, which was absolutely paved over by a flow during the 1980's-90's. The black sand beach was particularly nice. To the northwest of the black sands beach, we witnessed new land being born. A process as old as the planet itself, and we got so close we could feel the heat of the lavas hitting the ocean, and the sound of the steam hissing off the molten river of rock. Occasional explosions at night put fireworks to shame. The power!

Topping it off, we took our first skydiving lesson over Honolulu. As I breathed deeply in the clouds, I was awestruck by the eroding volcanic landscape I could see so clearly from the sky. This planet is old, and new at the same time. The land is always changing in Hawaii, and no two visits will show you the same place, especially on the Big Island. This was the beginning of a major obsession.

Following Hawaii, I went on a road trip north to Oregon through California, stopping at Lassen, The Geysers, Shasta (did not know they had caverns there, that was a treat), Belknap crater, and finally, Crater Lake. Below is a nice panorama of Crater Lake taken on what had to be the most beautiful clear day I have ever seen. The photo, while nice, does NOT do the place justice. The majesty of Crater Lake renewed in me a sense of awe, and the addiction to volcano eco tourism swelled. Now I can't even think of visiting a vacation destination without making a detour towards a volcano. There is simply no substitute for being there. Smelling the air, the lavas, feeling the low rumble of magma beneath your feet, knowing that what lurks below is powerful, ancient, and constant.

If you've never visited one of these beasts, let me tell you, even as an Atheist, it is a spiritual moment. You can really feel the connection with the past and understand ancient man and his reverence for the powerful forces of nature. Sun and Volcano worship was the beginning of deities, and it is never so apparent than when you're staring something in the face that is more powerful than anything on the planet. It baffles me as to why we make up stories, when its plain to see... Volcanoes and the Sun are responsible for our existence. And for that, you can call me a volcano worshiper!

Tuesday, October 18, 2011

Earthquake "swarm" near Lavic Lake, California

Within the last few days, there have been several large (2.0-4.0) and very shallow (2km-1km) quakes hitting the Lavic Lake/Amboy Crater region in Southern California. While the area does lie on a tectonic fault position near the San Andreas faultline, the placement and depth of the quakes could very well mean that magma is on the move, and quite near the surface. The quakes are clustered in a very concentrated area, and are very near to past volcanic activity such as Lavic Lake, Amboy Crater, and more in the region. The mountains near the quake center are very old volcanoes, so it would not be entirely surprising if indeed there was dike intrusion or magma movement near the surface... definitely something to keep an eye on!

Below is an image from Google Earth, with the real time USGS Quake overlay.

You can see pretty clearly here that these are shallow, strong quakes. While this could easily be purely tectonic in nature, it is worrisome that these quakes are so very near to past volcanism in the region, and the quakes certainly line up between Amboy and Lavic Lake.

I'll update this post should anything new develop. In the meantime, this area is not populated, save for some military operations, and is probably not a danger to any major city. So there is no real reason for panic or concern. If an eruption does occur in this area, it will likely be nothing more than scientifically and historically interesting. Nothing like the movie "Volcano" where one erupted in the middle of Los Angeles!

Other interesting seismicity in California that piques my interest is the ongoing earthquake swarms in the Geysers Geothermal Field in Northern California on the edge of the Clear Lake volcanic field. Research indicates these quakes are most likely a result of geothermal development in the area (this being one of the largest geothermal plants in the world), and more than likely has nothing to do with magma movement. Scientists theorize that Clear Lake contains an old silicic magma chamber, detached from the mantle, that is slowly cooling, but provides plenty of renewable thermal energy to power the plants. Locals have complained that it makes the region highly unstable, and new drilling has ceased.

Also in California, the Ubehebe Craters area has shown in the last week that it is also seismically active, with many small quakes occurring just under one of the eastern cones in the field. This area last erupted around 6000 years ago, with layers of tephra covering some ancient native American artifacts. But as Chaiten volcano in Chile demonstrated in 2008, and Nabro volcano in Eritrea (which is an ongoing eruption last I checked!), long dormant volcanoes can easily wake up given the right circumstances. Indeed, this was witnessed recently, and in the 1940's when a volcano in Mexico grew out of a farmer's cornfield to become the Paricutin volcano in the Michoacan-Guanajuato volcanic field.

If indeed the activity near Lavic Lake does result in a volcanic eruption, the event will likely be quite similar to the Paricutin eruption, producing a monogenetic volcanic cinder cone not unlike Amboy or the vents at Lavic Lake. This means that an eruption, if it does occur, will produce one or two cones, and probably never erupt again in the same spot, as monogenetic cinder cones do not repeat their eruptive cycles due to the nature of the magma pocket that briefly feeds them.

Stay tuned, and stay alert!

Wednesday, October 5, 2011

Ongoing noteworthy eruptions - October

Nabro Volcano - Eritrea

This from the Smithsonian Global Volcanism Program:

"According to NASA's Earth Observatory, satellite images of Nabro acquired on 28 September showed heat from the vent in the central crater, and from an area 1.3 km S of the vent that indicated an active lava flow. A small and diffuse plume rose from the vent. A region of seemingly thicker black ash (that completely covered the sparse vegetation) was noted S of the crater and thinner layers of ash (with some areas of visible vegetation) flanked either side of the region." - GVP

Nabro volcano is a prominent stratovolcano in Eritrea, which has not previously erupted in historical time until recently when it had a massive explosion, and lava effusion which resulted in a kilometers long lava flow. Nabro had been previously thought to have ended its eruptive phase, but this now turns out not to be true. Could we be seeing more from this long-dormant volcano in the near future? Satellite images shown on Irish Weather Online seem to suggest the old volcano isn't quite done waking up just yet.

El Hierro Volcano - Canary Islands

The El Hierro unrest is ongoing. This volcano has not erupted since 1793. Over 1,100 volcanic tremors have been detected within the last few days, the largest quake being a 3.8. Ground deformation has continued up to 35mm. Local officials have placed residents on alert, and asked them to stockpile emergency supplies. At this point, the activity seems to be off of the coast, but this can change rapidly if magma races to the surface.

Katla Volcano - Iceland

Amateur volcanologist Jón Frímann has been using his own seismic equipment in conjunction with Icelandic Meteorological websites to report on the volcanoes of Iceland. Recently there has been some speculation on his part about whether an eruption is imminent, as there have been swarms of quakes within Katla's caldera. I personally do not believe an eruption is imminent at this time, as Katla has had minor burps since the eruption of Eyjafjallajökull last year. This volcano IS expected to be the next eruption in Iceland, however they took their eye off of Grimsvötn volcano, and it erupted before Katla. It could indeed be that dike intrusion and ice melt are occurring however. Time will tell here.

Cleveland Volcano (Chuginadak Island) - Alaska

NASA detected thermal anomalies over the growing lava dome, The Alaska Volcano Observatory (AVO) reported. A slowly growing lava dome (there is an awesome time laspe picture on their page right now) increases the risk of an explosive eruption, but does not necessarily mean one will happen. This has been going on for over a month now.