Monday, January 19, 2015

Hunga Tonga-Hunga Ha'apai Erupts

Hunga Tonga-Hunga Ha'apai, one of many submarine calderas NE of New Zealand in an island arc, has begun causing some problems for flights in the area. What started as a minor steam and ash eruption has now turned into a semi-major eruption in the area. Steam and ash clouds are reaching extraordinary heights, and the ongoing eruption is rapidly building a new island.


Photo from Volcano-discovery.com


Residents have reported that the eruption plume was changing hourly from white steam, to black ash clouds, in what was probably the ebb and flow of the tides covering the vent and interacting with hot lava. The eruption has sustained itself for months now, with no signs of slowing, and has breached the surface in a Surtseyan eruption.

Other reports have come in about 'the sea turning blood red'. This is more than likely a red-algae bloom. Algae blooms are common when volcanic nutrients flood the ocean water. This recently occurred in Alaska, and Iceland.

Surtseyan eruptions start as under water eruptions, gradually breaching the surface, and creating an island. The term comes from the island of Surtsey in Iceland, which was created in an eruption during ht 1960's. This was the first such eruption of its kind clearly observed from start to finish. The Icelandic fire-god Surtr is the inspiration for the eruption type.

It is unknown if this island will remain as a permanent land body. Many volcanoes of this type create islands that are rapidly eroded by the sea in the years following the cessation of the eruption, however based on the pictures I've seen, the island looks every bit as solid as Surtsey, or Anak Krakatau. Anak Krakatau is probably a better comparison, as it was also a post-caldera cone, much like Hunga Tonga-Hunga Ha'apai is.




Monday, December 29, 2014

Super busy but will post again soon!

To my readers:

Thanks for staying tuned. I recently went through a large job change, and had some family emergencies to take care of, as well as the holidays. I will be resuming posts again shortly.

I have not updated blogs regarding Fogo, Bardarbunga, or the Nevada quake swarm because nothing really has changed, and things continue as they have been.

Fogo and Bardarbunga continue to erupt at this time with no signs of change. Fogo volcano has swallowed up more villages on the volcano floor, including some historic towns over 100 years old. Bardarbunga's lava field is now about 80+ sq km in area, and caldera subsidence slowly continues, although current data isn't available due to equipment loss and weather conditions for Iceland Met Office.

The Nevada quake swarm is still ongoing, and USGS is installing new equipment. Quakes of mag 1.0-4.7 have occurred.

If you're looking for some quick volcano updates for the week, the Smithsonian GVP is a great place for current info at their Weekly Report section.

I'll be back on 'the job' after New Years.

Have a great holiday season everyone!

-Matt

Sunday, November 23, 2014

Fogo Volcano Erupts

BREAKING:

Pico Do Fogo volcano, one of the Cape Verde islands, erupted about 4 hours ago, INVOLCAN's Facebook account reported.


No more information is available quite yet. A Google search turns up no news yet. The posted video showed a small ash plume a few thousand feet (estimated) high. The eruption does not appear to have occurred from the summit, so it could be a cinder cone building event. I will post more updates as they come in.

Fogo volcano last erupted in 1995, with a cone building event on its WSW flank. This event appears to be similar. 


Youtube video of the eruption of Fogo, 2014.

UPDATE: 11/25/2014

You can view footage of the eruption now on INVOLCAN's Facebook page. It appears to be a cone building event with a large lava flow at this time. People were evacuated out of the caldera area, and footage shows what appears to be a large amount of gas. Footage shows what appears to be large lava flows of 'clinker' (also called a'a' lava) destroying some brick buildings, so it does appear there has been some property damage. To my knowledge there have been no injuries or casualties.

Video news (in Portuguese) can be seen here




Youtube video of eruption plume (this is the small light blue area in the center screen)


Youtube video of lava destroying property and advancing.





Friday, November 14, 2014

Curious Quake Swarm in NW Nevada [UPDATED 1/19/15]

Nobody at all is reporting on this, although it's no secret either. There is an oddly shallow and very active quake swarm occurring in NW Nevada, about 65 KM ESE of Lakeview, Oregon (as USGS reports it) and it has been going on now for over a week and a half.

The area the quakes are occurring in does not seem to have any significant human population, and appears to be mostly mountainous desert, overlain by igneous rocks of what I'm guessing are older than pliestocene. There isn't a lot of info on the area, much less any geological information I'm able to find.

In any case it appears to be a long series of very shallow quakes ranging in size from <1.0 to greater than 3.5. The area does appear to be on a spreading rift, and probably has a past history of volcanism, but there are no records to confirm this.

As these quakes have ranged in depth from <2km to near surface, I'd say we are looking at a purely teconic event, and nothing related to volcanism. Again, there are no news articles or blogs I'm able to find. Below is a screenshot.


Google Earth Screenshot of location of quake swarm using USGS overlay.

I'm purely writing about this out of curiosity, and want to keep speculation to a bare minimum. I wonder if any USGS people would like to comment on what they suspect this is? It's happened before!

*****UPDATE 8/21/2014*****
Looks like the media and geologists are finally taking notice of this quake swarm. So far, indications are that it is purely tectonic, but they don't know yet. The area has a history of tectonic activity, however this swarm appears to be unprecedented for the region. Here are the few reports I could find on this:

http://www.oregonlive.com/pacific-northwest-news/index.ssf/2014/08/seismologists_are_tracking_swa.html
http://www.rgj.com/story/news/2014/08/19/earthquake-swarm-northwest-nevada-see-map/14301965/

*****UPDATE 8/29/2014*****

The quake swarm in NW Nevada continues, adding a magnitude 3.8, 3.2, and numerous smaller quakes. All are occurring at depths less than 2km, and some (probably not manually reviewed, and auto-detected quakes) are occurring near or at the surface according to the data feed (which is probably not accurate). So far there is no analysis from USGS aside from what has been briefly mentioned in articles. This 'swarm' is interesting at least to me. There are volcanic basalt cliffs in the area, and it does appear to be part of a rift zone. There is little to no human population in the area, and I am wondering if anyone has visited it to gain some visual observations, or install more instrumentation. At this time, it's being reported that this is purely tectonic, and there are no reports of anything to suggest otherwise, however volcanic activity or dike intrusion can't be ruled out given the composition of the surrounding rocks. Something odd is going on up there.

*****UPDATE 11/6/2014*****
Surprisingly, this swarm is still active. A 4.7 magnitude quake, and a 4.6 are so far the largest quakes of the resurgent swarm. There is no explanation from USGS other than 'this is probably tectonic'. I tend to agree, as the quakes are extremely shallow, in some cases appearing to be so shallow it reads as '0.0 km depth'. However, the 4.7M quake was at a depth of around 5km, which can indicate some sort of volcanic origin. It's still way to early to tell what's going on, and without comprehensive analysis by USGS or a geologist, I still have no new info to really put forth, other than the swarm has been active now for months, which is certainly unusual. I can find no analysis, GPS charts, or otherwise to give any more details, but I will follow up when any info comes out (I am keeping my eye on this). Stay tuned!

*****UPDATE 11/14/2014*****

The quake swarm continues, with USGS releasing a statement saying they are finally going to be out in the area installing new equipment, which should give us a much better picture about whether this even is simply tectonic 'exfoliation' events, rifting, or perhaps even volcanic (which is highly unlikely, but not impossible). The duration of the swarm is still quite interesting, as it has now been occurring for several months now.

***** UPDATE 11/24/2014*****

Seismologist have indeed installed new equipment, hence the better depth readings. They are working out whether or not this is volcanic or tectonic, as reported in the above link:

"Bill Hammond of the university’s Nevada Geodetic Laboratory said that while some residents wonder if the latest swarm is related to an extinct volcano in the Sheldon wildlife refuge, experts think it stems from the region’s faults. However, conclusively ruling out a volcanic source will require the additional seismic and geodetic measurements closer to the events,"

*****UPDATE 1/19/2015*****

Amazingly this swarm is STILL ongoing with little to no difference in behavior. USGS is still installing new instrumentation in the area, according to the latest info. So far they have not updated their previous statements that this is tectonic in nature. I have no cause to disagree.

Thursday, November 13, 2014

Mauna Loa Priming For Eruption [UPDATED 11/13/2014]

Mauna Loa Priming For Eruption
Hawaii’s largest volcano, Mauna Loa, is priming for eruption according to the Hawaiian Volcano Observatory (HVO). A statement from HVO says the following:

“MAUNA LOA VOLCANO (VNUM #332020)
19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Seismicity continued to be slightly elevated; deformation patterns may suggest renewed inflation.

Monitoring data through the month of September 2014:

Seismicity: Seismicity at Mauna Loa remains elevated in several parts of the volcano. In late September, a swarm occurred to the west of Moku`āweoweo Crater. The swarm had a maximum magnitude of 2.4 and several events that were large enough to be located. In total, there were up to 150 separate earthquakes that were part of this swarm, most too small to be recorded on enough stations to be accurately located, however we infer that their location is similar to the formal locations of the larger events. The same area had a swarm in September and October of 2013. Several long period earthquakes were present at depths from 50 km to the shallow edifice, with most LP earthquakes between 9 and 15 km depth. Earthquake rates on the Upper Southwest Rift Zone (Sulfur Cone) remain elevated, though similar to the past couple of months. Seismicity rates in the Moku`āweoweo Crater increased over previous months with approximately 50 very small events in the past month at shallow (<5 km) depths. All earthquakes in the past month have been small relative to earthquake sequences observed before eruptions in 1975 and 1984.

Deformation: On Mauna Loa, GPS data continue to show a broad pattern of displacements suggesting inflation. Preliminary modeling shows the data to be consistent with inflation of one or more magma reservoirs, with the majority of the volume accumulating in a dike-like body beneath the caldera and upper rift zones. Reinflation may have started very slowly in April or May of this year. Displacement rates have been variable, with higher rates in July and August and slowing again in September.”

While this does not mean Mauna Loa is at risk for imminent eruption, it does mean that it is more likely than before. Historically, Mauna Loa is Hawaii’s most active volcano, although it has not had an eruption since its last event in 1984. It had erupted about 33 times since its first documented eruption in 1843. Its eruption in 1984 produced some fast moving lava flows which did cause property damage, and it is likely future eruptions will be similar in style.

At this time, it would be a good idea for islanders to begin seriously preparing for a future eruption. There is no way to tell where an eruption might begin on Mauna Loa, all surrounding areas are at risk. It is interesting that Kilauea still shows no signs of stopping its eruption, as the constant outflow of lava tends to prevent rapid inflation at Mauna Loa, so this could mean Hawaii’s mantle  plume may be getting a bit more active, but that’s just speculation. If it were true, we might expect to see more activity from Loih’i, and possibly Hualai or Mauna Kea (although activity at Mauna Kea is highly unlikely).

*****UPDATE 11/13/2014*****

Mauna Loa continues to inflate. GPS readings show a broad pattern of displacement, and fumerole temperatures are rising at the summit. It is likely the volcano will erupt within the next year or so. The new report from HVO is below:

"MAUNA LOA VOLCANO (VNUM #332020) 

19°28'30" N 155°36'29" W, Summit Elevation 13681 ft (4170 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

Seismicity continued to be slightly elevated; deformation patterns may suggest renewed inflation.

Monitoring data through the month of October 2014:

Seismicity: Earthquake rates on the Upper Southwest Rift Zone (Sulfur Cone) remain elevated, though similar to the past couple of months. Seismicity rates in the Mokuʻāweoweo Caldera remains elevated with approximately 40 very small events in the past month at shallow (<5 km) depths. All earthquakes in the past month have been small relative to earthquake sequences observed before eruptions in 1975 and 1984.

Deformation: GPS data continue to show a broad pattern of displacements suggesting inflation. Preliminary modeling shows the data to be consistent with inflation of one or more magma reservoirs, with the majority of the volume accumulating in a dike-like body beneath the caldera and upper rift zones. Reinflation may have started very slowly in April or May of this year. Displacement rates have been variable, with higher rates in July and August, slowing in September and possibly slightly picking up again near the end of October.

Gas: No significant changes in SO2, CO2 were recorded by the Mokuʻāweoweo gas monitor; however, a minor deviation in fumarole temperature was recorded over the past two months. The correlation between fumarole temperature increase, elevated seismic tremor levels, and tilt values reported in September was coincidental. This month, we've continued to record a fairly sharp anomalous 2-3 degree C temperature increase.

Background: 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 several thousand deep Long Period (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 active 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 the largest active volcano on Earth and 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. For more information on Mauna Loa, see the USGS Fact sheet available at http://pubs.usgs.gov/fs/2012/3104/fs2012-3104.pdf. 

CONTACT INFORMATION:
askHVO@usgs.gov"

Wednesday, November 12, 2014

Italian Geologists Convicted Of Manslaughter Acquitted

In a trial that shocked the scientific world, several Italian geologists were convicted by the Italian court of 'downplaying the potential for damage of an earthquake in the L'Aquila region' in 2009. This conviction was the first precedent set to actually convict scientists for failing to do something that nobody in the world can do - predict when, where, and how strong an earthquake will be. It all started in 2009 when the L'Aquila Italy quake, a magnitude 6.3 quake, damaged historical buildings, and modern infrastructure. The damage was widespread, and during a time of economic turmoil, this exacerbated public outrage and people demanded 'someone be held responsible'.

Many in the world and media considered their convictions as precedent for forcing scientists to 'predict earthquakes'. They have now been acquitted of manslaughter charges, and released from prison after five years.

The convictions of these scientists prompted a mass-exodus of geological professionals from Italy to other countries. The fact that this ever happened damaged Italy's scientific community, seemingly irreparably. It is unclear whether the scientists acquittal will reverse the damage to the trust the scientific community had with the Italian government.


Tuesday, November 11, 2014

Quake Swarm South Of Lassen Volcanic Center

A nice quake swarm is occurring just South of Lassen Volcanic Center in California, US. The largest quake so far in the series has been a 3.9, and at this time the swarm is ongoing. So far around 35 quakes have occurred in the area over magnitude 1. It is unclear at this time whether the quakes are tectonic or volcanic in nature, however the fact that most are quite shallow could indicate this is merely a tectonic or hydrothermal event. Time will tell.


Quake swarm south of Lassen. Screenshot from Google Earth with USGS realtime quake overlay.

In all probability, as with many California quake swarms, this is related to fluid/hydrothermal movement within the crust, and probably isn't any big deal. The quakes to the East of the swarm seem to be at depths of up to 8km deep, and the ones to the West get progressively shallower. While this could indicate magma dike intrusion, that would be surprising, as some quakes are occurring on the surface, and so far there are no reports of activity in this very popular mountain hiking spot. It is likely, as most swarms in CA, that this will not result in an eruption, but it is still too early to know. 

Lassen last erupted in 1914-1917, California's only stratovolcano eruption in the last century. The eruption started with a phreatic explosion, and ended up building, and subsequently destroying, a summit lava dome which flung large boulders many miles from the summit. The famous 'Hot Rock' monument is a large boulder from this eruption. 

Lassen will likely erupt again in the future, although the current events are unlikely to make this happen. As with most West Coast volcanoes, their eruptions are infrequent, but very powerful. Should an eruption at Lassen occur in modern times, it would be more damaging than its previous eruption as the land around it has been developed.

So far, the news is slow to report, and they have less info than I do on my blog.

*****UPDATE 11/12/2014*****

The quake swarm continues. So far no quakes bigger than the 3.9. Most have been fairly near the 'middle' of the swarm area today, around depths of 4km. There has been no really detailed statement from USGS so far, other than 'swarms in this area are common' and 'this does not appear to be related to volcanic activity'. As I do not know where I could possibly view tremor plots in this area like you can with Alaskan, or Icelandic volcanoes, I can't really offer any more analysis than anyone else outside the USGS. If anything further actually develops, I'll update this post, but my guess is this is just another little swarm in the area, and not a whole lot will happen.