Wednesday, November 30, 2011

Three Of The World's Strangest Volcanoes (Dallol, Ol Doinyo Lengai, Indonesia Mud Volcano)

Most of us think of volcanoes as these conical peaks that shoot fire from their tops, or gigantic cauldrons of molten lava, but there are some extreme oddball volcanoes out there that I thought would be fun to take a look at given that there is no really new news out of El Hierro (Canary Islands), and the only really new eruption this week (Tungurahua) has been well-covered on the Internet.

While most volcanoes are content to erupt basalt, rhyolite, or tephra ash, there are some volcanoes that are not at all what you think of when thinking of a volcano. Today I'll cover three of these oddball volcanoes, and provide some cool pictures. I picked these as the top three I find to be most intriguing and out of character, and we'll start from the "least weird", although they are all unique in their own way.


#3) Dallol - African Rift Valley, Northern Ethiopia

Dallol is one of the strangest sites to see in the world. Formed north of the famed Erta Ale during an eruption in 1926, it is part of the African Rift Valley and has produced one of the world's oddest volcanoes. After its phreatic eruption in 1926, its depth (45m below sea level) has created a landscape not completely unlike the geysers and geothermal activity at Yellowstone. However, the landscape is so alien compared to Yellowstone, being that the geysers, pools, and solfataras spread continuously throughout the volcanic maar.

Dallol is currently being studied by scientists who search for "extremeophiles", or organisms that exist in extreme environments like volcanic vents, acid pools, and extreme temperature. In fact, Dallol is being used by not only biologists, but NASA scientists to determine the scope of how life can exist on other worlds. Scientists now theorize that life on this planet likely sprung up from volcanoes (or similar chemical/heat processes) like Dallol, especially under the ocean at great depths. This is the lowest known land volcano in the African Rift Valley.

Below photo of some geysers at Dallol (Wikipedia).


#2) The Mud Volcano in Indonesia

On the Island of East Java in Indonesia, to the SSE of Ketegan, sits humanity's only known man-made volcano. Referred to as Sidoarjo mud flow or the Lapindo mud. It was born on May 2006, when a natural gas company experienced a blow out on a piece of equipment that resulted in the release of extreme amounts of underground pressure (The gas company has tried to repeatedly claim that this was actually caused by a distant earthquake, but most scientists consider the case closed as to what caused this). 

The erupting mud has buried a local down, polluted water, and gives of a sulfuric smell for miles. The mud has become a huge nuisance to the local population, who have cordoned off the mud and directed it towards the Kali Porong river just to the South. The river mouth (which exits to the ocean) is a few miles from the outlet, which quickly gets rid of the muddy sediment and deposits it to the ocean.

You can read more about the Indonesia Mudflow at Wikipedia here.

#1) Ol Doinyo Lengai - African Rift Vally

Perhaps the strangest volcano is Ol Doinyo Lengai in the African Rift Valley. It erupts the most unique and rarest type of lava, carbonatite, and its eruptions are a bit bizarre to behold. Erupting small seeps of lava from flat plateaus at the summit, and producing bizarre spires of spattered carbonatite, this volcano behaves literally like none other. It is a stratovolcano and does produce pyroclastic flows, but rarely does it erupt with violent force. In fact, scientists routinely head to the summit to observe this oddball volcano seep its bizarre lavas onto the crater floors, and observe the creation of its famed spatter monoliths.

A good example of what I'm talking about can be seen below:

Note the grayish color of the lavas, and the small spires that are created when this volcano 'erupts'. This truly is a strange landscape!

Hope you enjoyed hearing about these three oddballs. 

Tuesday, November 29, 2011

Tungurahua (Ecuador) Volcano Has Major Explosion

Ecuador
11/29/2011

Tungurahua volcano, one of Ecuador's most active volcanoes, had a major explosion which began suddenly without warning. The ash column reached some 3 kilometers in the sky, with reports of incandescent lava being spewed out up to 300 meters from the summit, and 500 meters down the slopes. Tungurahua has, since 1999, displayed frequent explosive eruptions generating pyroclastic flows, lava bombs, and tephra. It has been active throughout historical time.

Tungurahua viewed from Juive Grande, Ecuador (AFP, Pablo Cozzaglio)

(From the Smithsonian GVP:)
Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major volcanic edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II itself collapsed about 3000 years ago and produced a large debris-avalanche deposit and a horseshoe-shaped caldera open to the west, inside which the modern glacier-capped stratovolcano (Tungurahua III) was constructed. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1999 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925.

Monday, November 28, 2011

El Hierro Erupts With New Vents

El Hierro, Canary Islands, Spain
11/28/2011

El Hierro volcano put on a show this weekend as new submarine vents have opened erupting several "Jacuzzis" into view. Pieces of steaming lavas were seen on the surface of the water, and samples were collected by IGN (the Spanish Geological Authority). The samples revealed that several types of magmas are being mixed in this eruption, including low silica basanite, trachyte, and rhyolite. This conforms with the assertion that at least two separate magma columns are coalescing beneath the island to fuel the ongoing eruption.

An image of the multiple "jacuzzis" off the southern coast of La Restinga.


Early morning webcam views showed intermittent jacuzzis, with some floating pumice visible on the water surface, although the most vigorous activity seems to have occurred over the weekend.

There have been several short pauses in the eruption since it began more than two months ago, however seismicity remains constantly active. Tens of thousands of tremors have hit the island in the phase that led to the eruption, and they continue to be recorded at more than 500 events a day, although most cannot be felt by residents.

I will post more updates as they come available, but the reporting out of the island has been lacking to say the least. National Geographic is now on the scene, so at least we can expect a documentary similar to the one about the Iceland volcano that erupted last year to air on TV soon. For now, I am relying on reports from IGN, Wired News, and other sources to cobble together this report. Every article I read points out a different aspect of the eruption, but I'd like to put the whole picture together, hence this blog.

Saturday, November 26, 2011

Columbia's Galeras Volcano Alert Level Raised to Orange

BOGOTA, Columbia
11/26/2011

INGEOMINAS, the Columbian volcano monitoring institute, has raised the alert level at Galeras volcano to Orange, after a spate of "tornillos", or rapidly increasing, slowly decreasing harmonic tremor was recorded over the past couple of weeks. These harmonic signals are characteristic of Galeras, which, in 1992 were detected by seismologists and identified as magma intrusion. Unfortunately for the seismologists who were curious about these tremors, they decided to hike to the summit, and were caught in an eruption.

The signals have been said to successfully predict eruptions within a few days at Galeras, and have been used as models for other active volcanoes. Harmonic tremor signals are generally thought to indicate magma intrusion for most volcano types, especially stratovolcanoes, and this research mostly comes from Galeras.

From Wikipedia:
"Galeras is considered the most active volcano in Colombia, followed by Nevado del Ruiz. Its earliest activity during the Holocene has been dated at 7050 BC ± 1000 years through radiocarbon dating. Other eruptions similar to this event include those in 3150 BC ± 200 years, 2580 BC ± 500 years, 1160 BC ± 300 years, 490 BC ± 100 years, and in 890 AD ± 200 years. Typically these eruptions consist of a central vent explosion, conducive to an explosive eruption causing pyroclastic flows and/or lahars. Eruptions in more recent times, which have been recorded consist of those in 1535, December 1580, July 1616, 1641, 1670, 1754, November 1796, June 1823, October 1828, 1834, October 1865, July 1889, 1891, December 1923, October 1924, October 1932, February 1936, July 1947, January 1950, 1974, February 1989, January 1990, January 1993, March 2000, June 2002, July 2004, November 2005, and October 2007. Reported incidents with no official proof occurred in 1836, 1930, 1933, and 1973."

Wednesday, November 23, 2011

Hawaii's Mauna Loa Making Some Noise

Hawaii (Big Island), USA 11/23/2011

Mauna Loa, Earth's largest active volcano, is showing signs of heightened seismicity in the last few weeks. A mag. 3.0 quake struck on 11/20 followed by a 3.9, at a depth of around 5km. Smaller quakes and aftershocks also occurred. Today, mag 1.9 and 1.7 tremblors struck under the summit and NW flank of the volcano at a depth of 20.80 km (12.92 mi). These could just be purely structural or tectonic, as no heightened gas emission of fumerole temperature changes have been noted aside from the usual night/day fluctuations.

This follows on the heels of the earthquake activity at it's slightly taller neighbor, Mauna Kea, which experienced a large earthquake swarm about a month ago, with small aftershocks continuing. HVO stated in regards to this event "On the afternoon of October 19, a magnitude-4.5 earthquake occurred beneath the northwest flank of Mauna Kea at the start of a swarm more than 50 smaller quakes over the next several hours. The earthquakes were the result of crustal adjustments beneath the volcano and not to volcanic activity. Other than the swarm, typical seismicity was recorded - 6 events shallower than 20 km deep and 5 events deeper than 20 km." Although Mauna Kea did not experience volcanic tremor, as the scientists state, the same cannot be assumed for Mauna Loa without further analysis, given that, like Kiluea, it is one of the worlds most active volcanoes.

HVO's description of Mauna Loa (below):

"Re-inflation of Mauna Loa's shallow magma storage reservoirs started immediately following the most recent eruption in 1984, then turned to deflation for almost a decade. In mid-2002, inflation started again, just after a brief swarm of deep long-period (LP) earthquakes. A more intense swarm of (more than? about?) 2,000 deep LP earthquakes occurred in late 2004, immediately preceding a dramatic increase in inflation rate. Inflation slowed again in 2006, ceased altogether in late 2009, and resumed slowly in late 2010.

Rising gradually to more than 4 km above sea level, Mauna Loa is the largest volcano on our planet. Its long submarine flanks descend to the sea floor an additional 5 km, and the sea floor in turn is depressed by Mauna Loa's great mass another 8 km. This makes the volcano's summit about 17 km (56,000 ft) above its base! The enormous volcano covers half of the Island of Hawai`i and by itself amounts to about 85 percent of all the other Hawaiian Islands combined.

Mauna Loa is among Earth's most active volcanoes, having erupted 33 times since its first well-documented historical eruption in 1843. Its most recent eruption was in 1984."

It's important to note that these earthquakes could easily be crustal adjustments, and not related to any magma intrusion. However given Mauna Loa's history of destructive eruptions, it absolutely pays to keep an eye peeled on this gigantic volcano, that has caused much destruction to the environment, and property on the Big Island. Unlike Kiluea, which is sort of 'aimed away' from most populated centers on the Big Island, Mauna Loa looms over much of the Island, coincidentally making property very cheap, and insurance very expensive. Ahh, the price of paradise.

El Hierro Volcano Resumes Activity

El Hierro, Canary Islands, Spain 11/23/2011

El Hierro volcano resumed its vent activity this week with multiple vents opening up underwater near the ongoing eruption site. Videos from the webcams placed on the island show multiple "stains" in the water, and there was video posted of a large gas bubble bursting to the surface barely East of the original vent. Earthquakes on the island have been ongoing, and have not ceased even when the vent was not active.

This indicates that magma is still very much on the move under El Hierro. Earthquake activity continues to the north of El Golfo, where scientists are trying to determine whether another vent has opened there as well. Many local bloggers on El Hierro are complaining that the local authorities and company Telefonica, and Movistar have been absent on daily reporting, and this is creating some local controversy. Calls have been made for local authorities to step up coverage in an effort to bring in tourists, citing what they see as an opportunity for promoting their island that is being missed.

The second vent that has opened is on the east flank of the first vent, and is erupting simultaneously at this time. The eruption has weakened a bit, and we are not seeing any Surtseyan activity (ie: lava/gas/ash breaking the water's surface) at this time, although if the eruption gains some strength, this could resume at any time.

A maritime exclusion zone remains in place, and the webcam at Telefonica remains up and running. Observations I made this morning clearly show the two stains in the water. A small one to the left (East) of the screen, and a long slick going to the right (West) of the screen. Enjoy the below video which shows the second stain appearing!

Monday, November 21, 2011

Popocatepetl Blows Its Top

Mexico City, Mexico

One of Mexico's largest and most active volcanoes had a large eruption yesterday, 11/20/2011, as its lava dome failed allowing ash, gas, and magma to blow out of its top, resulting in an ash plume approximately 3 miles high. The volcano is typically not a danger to anyone, and rare ash fall in populated places is typically not a nuisance. Nonetheless, authorities have places a 12km exclusion zone around the volcano as a precaution.

The below photo from the AP shows the towering ash column over Mexico City.


Popocatepetl (or Popo) has been erupting intermittently since December 1994, and is a good tourist attraction for Mexico, although unlike Hawaii's volcanoes, it's a bit more dangerous to get to the summit of this stratovolcano due to its sometimes explosive nature. However, as you can see, it makes for a beautiful backdrop in the distance to Mexico City.

Popo has had several major plinian eruptions, the most recent of which occurred at about 800 A.D. This resulted in pyroclastic flows, lahars, and ash fall. It is probable that Popo will have a similar episode in the very distant future. For now, it's one of those volcanoes that is simply fun to watch.

Thursday, November 17, 2011

Katla - The Icelandic Ticking Time Bomb

It was almost two years ago when the Icelandic volcano of Eyjafjallajökull erupted with a surprise display of fissure driven lava effusion, and an explosive eruption from the summit caldera. The volcano which had not erupted for over 120 years burst to life with a spectacular display, but also wreaked havoc on air travel for most of Europe and some parts of the Americas. Indeed this volcano eruption was probably one of the most costly in recent history not to life, but to the economies around the Northern Hemisphere.

As most people know by now, Eyjafjallajökull is dwarfed by its larger, and more violent, neighbor, Katla Volcano under the Mýrdalsjökull glacier. Katla, when it does have a large eruption, is up to 10 times more powerful than Eyjafjallajökull at its peak strength. And as history says, when Eyjafjallajökull blows up, Katla will not be far behind. Typically, an eruption from Eyjafjallajökull is followed rather closely by one from Katla, however this time it has been more than a year until Katla finally started showing signs of dike intrusion and ice melt.


During July, 2011, Katla produced what is widely thought to be a minor subglacial eruption, which caused a series of "Jökulhlaups" or glacier outburst floods that ended up taking out a bridge down river and causing other minor damage to infrastructure. This was a minor burp compared to what Katla can truly do, and lately it seems that Katla may be again gearing up for a larger show.




Blogger Jon Frimann who runs the "Iceland Volcano and Earthquake blog" has been monitoring the situation under Katla with his geophones, and states that dike intrusion is probably occurring under Katla (other volcanologists such as John Seach have also suggested that this is occurring), which will eventually lead to an eruption.

It looks like Katla will erupt sooner, rather than later, but as is the case with most volcanoes, attempting to predict when an eruption will happen is a waste of time, as is proven time and again. Unless volcanoes give very clear and consistent signals, such as the ongoing activity at El Hierro volcano in the Spanish Canary Islands did, it's really anyone's guess as to how and when they'll blow their tops.

And it's certainly not as if scientists don't have enough active volcanoes in the world to study, there are hundreds if not thousands of active volcanoes on our planet. The challenge is that each volcano is different, erupts differently, are made of different stuff, and sit on different types of geological settings. Each volcano has to be carefully analyzed and its own unique behavior mapped, so there can never truly be a "one size fits all" standard for volcanic eruption prediction. Only being prepared, and staying observant.

Is Europe really ready for round two of the volcanic dust cloud? They were extremely cocky last time, when they got desperate to begin flying airplanes through the ash, there are many reports that the British paid scientists to downplay publicly the danger of volcanic dust on airplane jet engines. There should be no need for proof of the dangers of ash-laden air going through hot jets that the danger is very real. There have already been plenty of examples of near fatal encounters with ash clouds, and ones that were fatal. I don't care how bad you want to fly, its not worth the risk!

If Katla erupted lets say, next week, (which it probably won't), the damage to the Eurozone would likely be immense, as the region is struggling with its own bubble-burst and recession, which has threatened the European Union and its monetary system. Throw in the inability to fly planes throughout the region, and it's like throwing gas on the fire. Given Europe's less-than-scientific analysis of volcanic ash and airplane engines, I'd say that this increases greatly the chances of some airplane getting slammed by ash, and crashing. I truly hope that doesn't occur and that wiser people prevail and choose life over money, but money is a powerful motivator these days.

In any case, keep your eyes peeled on Katla. If it has a large eruption, it will probably end up being the eruption of the decade for the Northern Hemisphere and for Westernized Civilization. It's highly doubtful an eruption would result in any deaths, save from tourists who get a bit too close or freeze if they get lost, and would likely simply be an economic killer. It will be an historic event, nonetheless. Stay tuned!

Monday, November 14, 2011

Nyamuragira Eruption Biggest In Last Century

Democratic Republic of Congo, Nyamuragira - Virunga National Park
10/14/2011

Nyamuragira's new eruption has been called by scientists the "biggest eruption of the volcano within the last century" after a 1km long fissure erupted last week. The eruption was preceded by many tectonic quakes, and has also shaken nearby Nyiragongo volcano, which is far more destructive than its neighbor. Scientists state that the Nyamuragira eruption poses little to no threat to the dwindling population of lowland mountain gorillas in Virunga National Park, or nearby Goma, but worry that tectonic activity may stir an eruption at Nyiragongo, which would turn out to be quite worrisome.

The below video shows the now cone-like eruptive center (this is very similar to the fissure that opened up at Icelands Eyjafjallajokull volcano in 2010), and has a great interview with a local volcanologist describing the current eruption, and concerns about Nyiragongo volcano.



This is one of those eruptions that is truly a spectacular site to behold, with persistent lava fountaining, and slow moving lava flows. Enjoy the video!

Friday, November 11, 2011

Sierraville CA Earthquake Swarm/Dike Intrusion Continues

Sierraville, CA resumed its magma dike intrusion tremors this week, with several quakes recorded today alone. The largest quake, a mag 2.3 tremor, was recorded at a depth of 18mi underground, much shallower than the earlier swarm which suggest magma is in fact on the rise as scientists have said. The dike intrusion started about two months ago, and has so far caused no major damage. The picture below shows the locations of the quakes.


The area of the activity is the same area as the previous activity that I pointed out in an earlier post. This is consistent with dike intrusion and slow uplift of magma toward the surface. The quakes started at a depth of about 30M, and now are at around 18M, so this is significant in that magma dike quakes are getting shallower. It is anyone's guess as to what will happen if the quakes get yet more shallow.

Signs of an impending eruption could include tree kill (as was the case in the 1990's at Mammoth Mountain) which is a result of CO2 being rapidly released along with sulfuric gasses, hot springs showing an elevation in temperature/phreatic eruption, or even a full blown fissure eruption. Given the speed that these quakes are moving upward, and the duration of the dike intrusion, I would assume that there are very powerful pressures working the magma up and would not rule out the possibility of a new volcanic feature in the area.

Keep your eyes peeled on Sierraville, and if you live there, stay vigilant.

Thursday, November 10, 2011

El Hierro Eruption Nears Water Surface (Video)

Stunning video from MSNBC shows the volcano eruption on El Hierro in the Canary Islands erupting huge bubbles, and nearly breaking the surface of the water. (Shown Below)

Visit msnbc.com for breaking news, world news, and news about the economy


The volcano has entered the Surtseyan phase, meaning it is about to break the ocean surface and begin to form solid land. As the eruption is ongoing and shows no signs of slowing down as of this writing, the volcano may very well produce a brand new island right before our eyes! Volcanic tremor and harmonic tremor are ongoing and it is still unconfirmed whether or not another eruptive vent has opened up to the north of El Golfo on El Hierro. This needs some follow up to determine.

Wednesday, November 9, 2011

Nyamuragira (Democratic Republic of Congo) Erupts in a Spectacular Fissure Eruption

Africa's most active volcano is putting on a spectacular light show once again, as a 1km long fissure has opened up spewing rivers of molten lava. Nyamuragira erupts nearly every two years, occasionally causing destruction to the Virunga National Forest (home of up to 200 mountain lowland gorillas and other rare wildlife), and the city of Goma, which so far has escaped any damage (and they do not expect the current eruption to reach the city).

Nyamuragira used to contain one of the worlds largest lava lakes until it drained catastrophically in 1938. Since then it has erupted every couple of years or so, usually with flank or fissure eruptions outside the summit caldera. Its nearby cousin, Nyiragongo, is also one of the most active volcanoes in Africa, These volcanoes are part of a spreading rift, which causes them to be extremely active.

You can check out a great video of the fissure eruption here.

These eruptions typically last anywhere from a couple days, to weeks or months, and usually result in excellent footage of Hawaiian style fissure eruptions. Although this is an active and dangerous volcano, fatalities are usually a non-issue as the lava is slow moving (with the exception of the 1938 incident).

Tuesday, November 8, 2011

El Hierro Eruption Enters Surtseyan Phase

It could be just a matter of hours or days before the volcano at El Hierro breaks the ocean surface in what is referred to as a "Surtseyan Eruption" phase. The volcano had a period where it looked like it was calming down a few weeks ago, but as some astute volcanologists pointed out, the ongoing quake swarm meant anything but calming down. A couple weeks ago, quakes were detected that indicated not one, but two magma chambers coalescing into one, which would increase the volatility of the eruption when the two magma types mix.

The eruptive phase currently underway seems to indicate that another eruption has already (or will soon have) started to the north of the El Golfo region of the island (the site of a massive landslide over 50,000 years ago). The activity to the south of La Restinga has continued unabated, and the locals are marveling at what they call the "Jaccuzzis" in the water off the coast. The Jacuzzis they refer to are the underwater plumes of superheated water and ash that resemble the surface water of a jacuzzi spa.

In the past few days there have been reports of ejecta actually breaking the water's surface, and pyroclastic rocks that formed underwater are beginning to wash up on shore. Thus scientists can predict that the eruption will soon overpower the pressure of the surface water, and begin to erupt ash and gas above the ocean, eventually leading to either 'ephemeral islands', or, as they have been speculating, a "Surtseyan" eruption.

The term Surtseyan is a reference to the Icelandic island of Surtsey, whos birth in the 1960's was the first historically witnessed account of a volcano breaking the surface of the ocean to rapidly form a volcanic island. This island was quickly 'built' by the eruption, and as a result has undergone extensive erosion since its birth, and unless it erupts again (which is unlikely for Surtsey) will likely erode and be swallowed by the sea within decades. This could be true of the El Hierro eruption, but the lava types and eruption types above water have yet to be determined.

If the El Hierro/La Restinga volcano does break the surface, it will likely start with large ash emissions, due to the water hitting the molten lava, and quickly build an ephemeral island. If the eruption continues and the ocean is cut off from the eruption crater, more solid and viscous lavas could be erupted onto the surface, creating a much more stable island.

There are many similarities to Icelandic and Hawaiian volcanoes in this eruption, but more so with Hawaiian style island building. Off the southern coast of the big Island of Hawaii, a small volcano is quietly erupting named Loihi. However due to the depth it is erupting at, it is not expected to break the oceans surface for over 10,000 years! The Canary Islands, much like Hawaii, are part of a slowly moving 'hotspot' or mantle plume, the same as Hawaii. It is quite likely that activity over time will migrate to the SW, the same as Hawaii, building small-medium sized volcanic islands as the eons pass.

Keep your eyes peeled on the webcams, as you might be lucky enough to witness the birth of new land!

Monday, November 7, 2011

Oklahoma Earthquake is Biggest Ever in Areas History

Oklahoma suffered a 5.6 magnitude quake on 11/5/2011 which is the biggest ever to hit the region (the previous record was a 5.5). After many weeks/months of small tremblors, the area was jolted by the 5.6 mag quake which caused damage to highways, and damage to houses. Luckily there were few, if any, serious injuries to residents.

Geologists have yet to figure out what the cause of the quakes are. These quakes, including the 5.6, are at a depth of ~5km or less, which is geologically quite shallow. Some residents suspect "fracking" and other oil/gas industry activities may have something to do with the tremblors, but this theory would fail to explain why large quakes up to mag 5.5 have happened in the same area in the past.

It could be a combination of the two. The area does lie on what is referred to as the "New Madrid Fault Line" and has produced large quakes in other areas of the country along the fault. It could be that tension in conjunction with fracking or drilling is setting a few things in motion, however I don't want to jump to any conclusions, rather I'd like to see what USGS can come up with now that they have seismographs and other equipment installed in the area.

Most people do not think of the middle-USA as a seismically active region, but it surely is! Earlier this year, a quake in Virginia rattled the East Coast "Like a bell" and sent shockwaves as far as Canada and DC, causing damage to the Washington National Monument that have yet to be fully repaired. Occasional aftershocks do still hit the area from time to time, although those should diminish over time.

The Oklahoma quakes have been ongoing for some time, and it is a wonder that the USGS has not really given much interest to the area. You'd think they'd be pouring over data to determine what's going on. As the area is not known for any recent volcanism, you can probably rule out a volcano, and assume this is purely tectonic... but we just don't know until an adequate study is done.

In the meantime, as I have said before, it's always good to have an emergency preparedness kit handy in your house for just such unforseen disasters. It is very good that nobody was hurt on the highway when it collapsed, and even better still that damage to private property was at a minimum. Stay safe!

Friday, November 4, 2011

AVO Downgrades Cleveland Volcano Alert Status to Yellow

Alaska Volcano Observatory (AVO) downgraded Cleveland Volcano to Yellow (alert)status today, as the eruption has ground to a halt. The latest activity consisted of slow lava dome extrusion at the summit. No explosive eruptions occurred during this period.

AVO states that activity could resume at any time, and that a collapse of the lava dome could produce avalanches or ash.

Cleveland Volcano is one of the most active in the Aleutian Islands and has erupted plenty of times in recent history. This volcano, due to its remoteness and other factors such as weather and the vastness of the Alaskan islands, does not have a seismic monitoring station, and reports from the area are hard to come by. AVO relies on satellite monitoring and anecdotal evidence to monitor the volcano.

The Aleutian Islands are one of the most volcanically active areas in the United States, aside from the big island of Hawaii, and the Cascades, which have not seen any real eruptive activity since the explosion of Mt. St. Helens in 1980.

You can always check the status of volcanoes in Alaska and the Russian Kamchatka Peninsula at http://avo.alaska.edu.

Thursday, November 3, 2011

Uplift at Yellowstone Super Volcano (ongoing)

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.

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.

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.

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.

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!