Thursday, May 24, 2012

Italian Government Approves Drilling Into Campi Flegrei

The Italian government has reversed a previous decision to disallow drilling into the Campi Flegrei supervolcanic region after concerns about the potential for increased seismicity and triggering of a super eruption were assuaged. The government had previously banned the project, which aims to drill some 4km below the earth's surface in the caldera to gain more knowledge about the composition of the massive magma chamber. Concerns were raised that drilling could cause an eruption, or dramatic rise in earthquakes.

Italy's relationship with geologists was recently damaged when Italian courts charged scientists with "failing to accurately predict a large earthquake" last year, in a move that was decried by the larger scientific community.

The new drilling plan is actually an investigatory operation that is going to look into the potential to develop geothermal energy in the area, as well as gauge the potential for future eruptions. The region has seen massive uplift since the 1960's, with former nautical ports that used to be below sea level now rising approximately 10 feet above it. This means inflation.

Inflation of magma chambers does not mean an eruption is imminent, but it is certainly motion towards a possible eruption in the future. However many so-called supervolcanoes regularly breathe in and out, from Yellowstone, to Long Valley, and of course Campi Flegrei. Campi Flegrei was last active in 1538, when the Monte Nuevo volcanic cone was formed. So the volcano does in fact have a record of recent historical eruptions, unlike the Yellowstone or Long Valley calderas. In fact, it is one of the only supervolcanoes on earth to have erupted in historical time, aside from the massive eruption of Tambora in 1815 (a VEI 7 event) which caused the famed "Year without a summer".

While it is highly unlikely that any drilling into Campi Flegrei would ever cause such a massive event, it is absolutely possible that minor quakes and tremblors will result from drilling into the magma chamber. Many volcanoes and volcanic areas around the world experience heightened seismicity, such as Clear Lake on the US West Coast, Hengill in Iceland, and Salton Buttes (Salton Sea). It would not surprise me in the least if drilling caused minor mag 1.0-3.5 quakes if the area is in fact developed into a geothermal farm.

In any case, the data produced by the investigative drilling will be of significant interest to the scientific community, and to the Italians, who live under constant threat of some very large, and very powerful volcanoes like Vesuvius. Better understanding of their volcanoes can only help the community and the world at large prepare for an eventual eruption.

Wednesday, May 16, 2012

Large Quake Swarm Under Herðubreið in Iceland

A large swarm of earthquakes is occurring just NE of the Askja caldera in Iceland. This began sometime yesterday and continues to the time of this writing (see below pic). It has recently been noted that Askja caldera was strangely ice free during the cold months, with the water still quite cold, yet unfrozen. Some theories about this pointed to possible underwater fumeroles, to chemical changes, and other theories, but as of yet nobody can fully explain why.


Picture graph from Iceland Meteorological Office


The current swarm of earthquakes is most likely related to magma dike intrusion. Currently I am unable to determine the depth of these quakes, but most quake swarms in Iceland are volcanic in nature, given that the entire land of Iceland is basically riding on top of a mantle plume, and is also smack-dab on the middle of a spreading ridge between the North American and European plates which are drifting away from each other.

The swarm's location is actually under a "tuya" named Herðubreið. A tuya is a volcano that most likely formed underneath a glacier, but never pierced the surface to produce an explosive eruption. There are many examples of tuyas in Iceland, Canada, Alaska, and other cold regions of the world where volcanism occurs. Most tuyas were formed during the ice age, as the ice back then was extremely thick and not even a volcanic eruption would have been able to break free of the ice. Herðubreið is theorized to have erupted in the last glacial ice period.

The nearby volcano, Askja, has also seen some recent possible activity (I covered the strange happenings at Askja in a previous post). The last time Askja erupted, according to the Smithsonian GVP, was in 1961 and produced lava flows from a fissure vent system near Öskjuvatn lake. The caldera forming event occurred in 1875, and was one of the largest eruptions seen in historical times by Iceland (with of course the exception of the famed Laki eruption that has been blamed for famine in Europe and the eventual catalyst for the French Revolution). An eruption from Askja today would likely consist of fissure fed lava flows with some minor explosions. The last report on activity at Askja included a satellite photo that seemed to show some very minor ash deposits near a crater on the rim of the lake, which may or may not be the result of an eruption (it could also be that it was ash was blown that direction from another deposit).

It is completely unknown at this time whether Herðubreið is an active volcano, however given the quake swarm, I would suspect that it is not completely dead. As Chaiten volcano, and Nabro volcano both recently proved, volcanoes long thought to be dead can spring back to life without warning. This is more than true in Iceland, so Herðubreið is a volcano that should be monitored in my opinion (and I am quite sure that it is now). There is no way to tell what type of eruption might occur at Herðubreið, but I would suspect that if any eruption occurs, it will be explosive. There are no towns or villages near Herðubreið as it is in one of the more remote and inhospitable locations in Iceland, so the danger level from pyroclastic flow or otherwise is quite low, however its location could pose a nuisance from ash to Europe.


*****UPDATE 5/18/2012*****

The quake swarm under Herðubreið is still ongoing at this time. Approximately 15+ quakes have occurred under the volcano within the last 48 hours.

Monday, May 14, 2012

Katla Reported To Be Melting Ice

A report from the Iceland Volcano and Earthquake Blog by Jon Frimann seems to suggest that Katla volcano in Iceland has been experiencing some ice melt and creating some jökulhlaups (glacier outburst floods). Jon suggests that a geologist who is close to the monitoring efforts on the volcano is recording harmonic tremor since April 28th, which suggests magma is on the move, and possibly making contact with the base of the glacier.

The months of April and May have so far been pretty quiet for the volcano when it comes to seismicity. While there have been many small earthquakes, they are few and far between. Tremor is not necessarily registered as an earthquake by seismometers, but is picked up by waveform monitors designed to listen to this type of tremor. Harmonic tremor typically denotes the movement of magma within a system, and is typically seen as a precursor to a potential eruption...

But then again, oftentimes (a recent figure from the USGS states something more like 90% of the time) harmonic tremor and magma intrusion doesn't lead to an eruption. Personally I would not go ringing the alarm bells yet on Katla volcano. If it was actually gearing up for an eruption, it is highly likely you would see many more rock fracturing earthquakes, followed by land swell indicated by GPS measurements. This would most likely take at least 1-2 weeks given the history of many Icelandic volcanoes, and would give us plenty of warning ahead of time.

Indeed, there has not been a recent eruption in Iceland that did not give off some fairly obvious warnings before the main event. The eruption of Eyjafjallajökull was preceded by GPS measurements that indicated the mountain was swelling outwardly, then harmonic tremor/volcanic quakes, ultimately resulting in the fissure eruption at Fimmvörduhals, and finally the main caldera eruption at the summit. Katla, despite its ongoing geothermal action, has not yet displayed the sequence of events that suggest an eruption is imminent.

Katla volcano will erupt in the future. Maybe even the very near future. But right now, I wouldn't hedge any bets on this being really soon. As the summer months warm Iceland, ice will most certainly melt, and it will be easier for geothermal heat to assist in this process. There will undoubtedly be adjustments to the earth's crust when the level of ice falls, and seismicity will probably pick up a little bit. For now, I (and I'm sure Jon Frimann) will be watching Katla a bit more closely. 

Friday, May 11, 2012

Alaska's Mt Iliamna Flexes But Doesn't Blow

Alaska's Mount Iliamna, which I earlier reported to be experiencing dike intrusion, has begun to subside in terms of its heightened seismicity. According to AVO, "Seismic activity at Iliamna Volcano remains slightly above background, and the rate of seismic activity has declined over recent weeks. Nothing unusual was observed in web camera and cloudy satellite images over the past 24 hours.The current activity at Iliamna does not indicate an imminent or certain eruption. A similar seismic swarm at Iliamna in 1996-1997 was not followed by eruptive activity. Prior to an eruption, AVO would expect to see a further increase in earthquake activity."

Iliamna has not erupted since monitoring began, but is suspected to have erupted in the Holocene. Due to active glaciation in the region, some volcanoes and mountains in the area display morphologies that make them look far older than they actually are. Iliamna has active fumeroles on the SE face near the summit that have been shown to be much more active after the previous swarm of earthquakes a few months back.

The diminishing seismicity can mean several things, but in this case it most likely means that the dike intrusion has slowed or ceased, and most likely has begun the slow process of cooling.

It seems, much like the 1996-1997 dike intrusion, this will most likely not result in an eruption. Due to the depth of the magma intrusion (from under a kilometer, to over 7km in depth) and the massive amounts of ice on the volcano, the magma will most likely degas and cool. This does not mean activity can't resume at any time however, as the area could easily experience another injection of magma at any time.

It is my guess that the above statement from AVO means they will probably lower the alert level for the volcano in the next couple of weeks, but continue to keep an eye on the simmering mountain. If new magma intrusion occurs now, it could trigger uplift and possible slope failure, compounded by a possible eruption. There are no GPS monitoring devices on Iliamna, however there is a network of seismic sensors all around it. Uplift is only measured by the occasional satellite job.

Tuesday, May 8, 2012

The Desert And A Tragic Occurrence

While I was out in Anza-Borrego State Park this weekend, I was able to view an incredible landscape that is as harsh as it is beautiful. We hiked around the park and visited the desert palms in a canyon, as well as taking an opportunity to look at the various rocks and minerals in the area. I was highly surprised to find evidence of past volcanism pretty much everywhere, from small red cinder rocks from a nearby dead volcano known as Table Mountain, to blocks of andesite in areas that were eroded so that previous dike intrusions were exposed. We also saw plenty of quartz (a favorite sign for gold miners that there is gold somewhere in the area!).

All that, and we had a great time stargazing and had a brilliant view of the "Super-Moon" that was out on the weekend.

Unfortunately, I was only able to snap a few photos of the trip, as our technology tends to fail int he high-heat of the desert. Even more unfortunately, we were witness to a search and rescue team that was called out to a tragic scene. A man exploring the mud caves with his family fell down a crevasse with no shirt, no shoes, no water, and eventually died.

This is a warning to people who want to explore these mud caves. While they are a nice break from the desert heat, and are fantastic to see, they are HIGHLY unstable, and are prone to flash flooding, collapses due to the seismicity in the area, and are extremely brittle, unlike most limestone caves. This fate could easily have befallen me on the day of the Easter Quake in 2010, when I was actually exploring the caves myself. I left about one hour before the 7.4 quake hit the area, and a subsequent visit to the same cave revealed it did collapse.

So with these pictures, remember this... the desert is a very beautiful place, but it can easily become a nightmare, especially for those who take risks in a wilderness that has a very hard time forgiving mistakes. My thoughts go out to the family of this man, and I hope that this serves as a warning for people to stay out of the mud caves and not to take any unnecessary risks.





Friday, May 4, 2012

Making a Trip To A Fault Line

This weekend, my girlfriend and I will be going out to the Ocotillo Desert, a place that has active seismicity following the Easter 2010 7.4 earthquake, and the site of a recently discovered parallel fault line to the famed San Andres fault. While my trip will not be very scientific (mostly Cinco de Mayo fun) I will be posting a gallery of pictures from the area, and hopefully I get to experience one of the hundreds of small (1.0-3.0) tremors that occur on the fault daily (with of course no danger to myself or others!).

My last trip to the desert occurred on Easter of 2010. The day of the 7.4 tremblor. My cousin, my girlfriend, and myself were on a journey in the desert to explore the famed Ocotillo mud caves, but due to some large cave collapses that occurred before we arrived, we had turned around to go home, disappointed, but nonetheless relieved to be leaving the 90+ degree heat, and of course, take a nice shower (you get a bit nasty staying out in the desert for a few days!).

Literally the second I arrived back at my place (which at the time was in an area of San Diego known as Bay Park/Clairemont), I sat on the couch to relax, when all of a sudden, we all heard a rumbling noise, and then felt violent shaking. We immediately recognized this as an earthquake and promptly exited the building and went to stand on the lawn.  The next thing I knew, the ground was heaving violently back and forth, and we could literally see ripples, like waves travelling through the grass, as the land lifted up and dropped down rapidly.

From my location, the USGS said the quake would have felt more like a 6.0 than a 7.4. This particular quake was felt all the way up to Montana!

Anyway, look forward to enjoying some nice hi-resolution pictures of the Ocotillo landscape this Monday. I will be excommunicado until then!

Japan's Iwo Jima (Ioto) Volcano Showing Signs of Activity

A report from Japan's Meteorological Agency indicates new activity at the famed WWII island of Iwo-Jima (Ioto). The report details that a new fumerole has opened, and there was water discoloration in the water near the island. Famed for its role in WWII when US forces were striking at Japan, most people don't realize it is actually an active volcano! While Iwo-Jima didn't have explosions during the war (without the aid of bombs and artillery), the island constantly fumes with acidic pools, fumeroles, and is prone to frequent, and small, phreatic eruptions.

The Smithsonian GVP characterizes Iwo-Jima here:

"Ioto (also known as Iwo-jima) in the central Volcano Islands portion of the Izu-Marianas arc lies within a 9-km-wide submarine caldera. Ioto, Iwo-jima, and Io-jima are among many transliterations of the name, which means "Sulfur Island;" the volcano is also known as Ogasawara Io-jima to distinguish it from several other "Sulfur Island" volcanoes in Japan. The triangular, low-elevation, 8-km-long island narrows toward its SW tip and has produced trachyandesitic and trachytic rocks that are more alkalic than those of other Izu-Marianas arc volcanoes. The island has undergone dramatic uplift for at least the past 700 years accompanying resurgent doming of the caldera. A shoreline landed upon by Captain Cook's surveying crew in 1779 is now 40 m above sea level. The Moto-yama plateau on the NE half of the island consists of submarine tuffs overlain by coral deposits and forms the island's high point. Many fumaroles are oriented along a NE-SW zone cutting through Moto-yama. Numerous historical phreatic eruptions, many from vents on the west and NW sides of the island, have accompanied the remarkable uplift."

The island rises from the seafloor to the surface due to the Pacific and Asian plate subduction zone, very close to the Marianas Trench, the deepest chasm on earth, where famed film director James Cameron just set a new depth record for an upcoming documentary on the trench. The Marianas Trench is a result of severe collision and subduction of the two plates and is prone to frequent submarine, and island volcanism, as well as very powerful earhquakes ranging up to 8.6 in magnitude (as far as we know). This is South of the fault that caused the devastating 9.0 earthquake in Japan last year which resulted in a large tsunami, and damaged the nuclear power plant at Fukushima.

Other volcanoes currently erupting in Japan include Sakura-jima, Kirishimayama (Shinmoedake), Miyake-jima, Suwanose-jima, Satsuma-Iojima, and Fukutoku-Oka-no-ba.

Japan, much like Indonesia, Russian Kamchatka, The West Coast of the USA, and the entire coast of South America, is part of the so-called Pacific Ring of Fire, and is quite prone to earthquakes and frequent volcanic eruptions. Most eruptions are fairly benign, and Japan has a large appetite for geothermal energy, and volcanic hot springs which the locals consider great medicine for skin ailments, and skin health. Locals love to use the hot water, and fine ash for exfoliation, and relaxation, and the volcanic resort towns are world renowned for their innovative use of what most people consider to be a dangerous and destructive force... but when your culture is as old as some of the volcanoes themselves... well, you either adapt or you don't!

A follow up also on the purported activity at Japan's Mt Fuji, which I touched on a while back. NO new info, video, photos, or anything of the sort has confirmed the news report from Japan about a "row of new craters" on the eastern flank, and recent satellite photography did not reveal these features on the mountain. I suspect that someone was rather mistaken, and wished to hype up the possibility of the eruption. In my previous blog post on Mt. Fuji, I pointed out that I was highly skeptical of the possibility of eruption, due to Fuji's worldwide fame, and the swiftness at which social media can cover such an event. Fuji is not an inconspicuous volcano, and I assume if there was ANY activity, it would be huge news quite fast.