Friday, January 31, 2020

Quake Swarm And Rapid Surface Deformation Continues In Iceland

On Iceland's Reykjanes Peninsula, an ongoing swarm of concentrated temblor activity, coupled with rapid surface inflation is raising the possibility of the first volcanic eruption in nearly two centuries near the famed Blue Lagoon. The area has many geothermal features and is once of Iceland's largest producer of geothermal energy.

According to an article released on January 26th, 2020 on Iceland's Met Office website, "An inflation has been detected since January 21st and is centred just west of Mt. Thorbjorn on Reykjanes peninsula. The inflation is unusually rapid, around 3-4 mm per day and has accumulated to 2 cm to date. It has been detected both on continuous GPS stations and in InSAR images. The inflation is most likely a sign of magma accumulation at a depth of just a few km. If magma accumulation is causing the inflation, the accumulation is very small, with the first volume estimate is around 1 million cubic meters (0,001 km3)."

However, that was then, this is now...

Today's quake sequence now records larger quakes up to magnitude 4.4, with three others measuring 4.0, 3.4 and 3.2. Dozens of smaller magnitude temblors dare occurring at the moment.


Screenshot from Iceland Met Office


Today's activity marks a large increase from the initial activity. While magma accumulation has been confirmed, it is far too soon to say whether this will result in an eruption. The activity after the first rash of quakes subsided significantly in the past few days, but today it has surged with some of the strongest quakes in the sequence to date. 

The town of Grindavik lies near the swarm, as does the Blue Lagoon geothermal pools. If an eruption should occur, it would likely form along a SW-NE trend as a fissure eruption, as is the most common eruption type in this area. The lava would likely resemble a Hawaiian style effusive eruption. The area of activity is related to the Reykjanes volcanic system.

The last confirmed historical eruption in this system was a VEI 3 eruption in March of 1831, with two unconfirmed (VEI 0) eruptions in 1966 and 1970 - although the Smithsonian GVP may consider these to be doubtful. 

The Reykjanes system is part of the Mid-Atlantic rift, a spreading rift between the European and American tectonic plates, of which the entirety of Iceland is a result.

Sunday, January 12, 2020

Taal Volcano in Philippines Has Phreatic Eruption

**LIVE CAM NOW AVAILABLE**



Three hours later, a stronger explosion occurred.

The last major eruption of Taal occured in 1965, which sent pyroclastic flows and tsunami style waves through the lake which surrounds its currently active center. This was one of the Philippines most deadly eruptions.

The current statement from PHIVOLCS is below:




Several social media posts have shown first hand footage and imagery:



The last historical eruption of Taal was in 1977 with a VEI of 2. The largest historical eruption occurred in 1965 with a VEI of 4, killing many.

The new activity suggests there has been new magma injected into the system. This does not necessarily mean that a larger eruption is imminent, but it does typically mean that enough magma that has a heat flashpoint with water got close enough to flash water into steam, creating the latest explosion.

Phreatic eruptions are the result of a minor (or major) volume of water coming into close contact with molten rock. The rock could be older 'crystal mush', or cooler magma which did not have enough gas content to erupt until it came into contact with a water source, or in rare cases fresh magma from the injection source.

Taal volcano has been inflating, and the lake temperatures in the middle vents fluctuating, for years so this eruption is not entirely surprising. PHIVOLCS is monitoring the situation closely, and will be providing updates as soon as they can.

In the last several minutes, it appears an even larger eruption is now underway.



*****UPDATE 1/12/2020*****

Lava fountaining is now observed in the main crater of Taal:



Everyone on the central island has been evacuated. There is not currently an evacuation mandate for the residents around the larger lake (the central crater lake is now completely obliterated).

The latest (Translated to English) update from PHIVOLCS:

"DOST-PHIVOLCS indicates an increase in Alert Level 4 (hazardous eruption imminent) from Alert Level 3 (magmatic unrest) to the current status of the Long Range. Starting at 5:30 pm (PST), volcanic activity is intensified which includes continuous eruption of steam-laden tephra columns with a height of 10 to 15 kilometers with occasional lightning and rainfall. ash extends north of the volcano to Quezon City. Volcanic tremor was also recorded starting at 11:00 am, with two earthquakes of magnitude 2.5 (6:15 pm) and 3.9 (6:22 pm) in Tagaytay City and Alitagtag, Batangas in force Intensity III.

In the event, DOST-PHIVOLCS raises Alert Level 4 to the state of the High Volcano where dangerous eruption is possible within hours to days. DOST-PHIVOLCS strongly recommends total evacuation from Taal Volcano Island and further evasion of hazardous or high-risk areas within a 14-kilometer radius from Taal Main Crater due to possible threat of having a pyroclastic density current (fast waves of very hot smoke and ash) and volcanic tsunami. Areas north of the Taal Volcano are advised to guard and beware of the effects of continuous and long-term rainfall. Civil aviation authorities should advise aircraft to avoid flying around the volcano because of the danger of ash and ballistic fragments from the eruption column. DOST-PHIVOLCS will continue to monitor the Taal Volcano's activity and release an update to the public."

Next update:

"Taal Volcano entered a period of intense unrest beginning with phreatic or steam-driven activity in several points inside the Main Crater at 1:00 PM of 12 January 2020 that progressed into magmatic eruption at 02:49 AM to 04:28 AM of 13 January 2020. This magmatic eruption is characterized by weak lava fountaining accompanied by thunder and flashes of lightning. At 2:00 PM yesterday, booming sounds were heard at Talisay, Batangas.

The Philippine Seismic Network has recorded a total of seventy-five (75) volcanic earthquakes in Taal region as of 5:00 AM, January 13, 2020. Thirty-two (32) of these earthquakes were felt with intensities ranging from Intensity II – V in Tagaytay City, Cabuyao, Laguna, Talisay, Alitagtag, Lemery and Bauan, Batangas. Such intense seismic activity probably signifies continuous magmatic intrusion beneath the Taal edifice, which may lead to further eruptive activity.

Alert Level 4 still remains in effect over Taal Volcano. This means that hazardous explosive eruption is possible within hours to days. DOST-PHIVOLCS strongly reiterates total evacuation of Taal Volcano Island and areas at high risk to pyroclastic density currents and volcanic tsunami within a 14-kilometer radius from Taal Main Crater. Areas in the general north of Taal Volcano are advised to guard against the effects of heavy and prolonged ashfall. Civil aviation authorities must advise aircraft to avoid the airspace around Taal Volcano as airborne ash and ballistic fragments from the eruption column pose hazards to aircraft. DOST-PHIVOLCS is continually monitoring the eruption and will update all stakeholders of further developments."

The following live feed is now available:



*****UPDATE 1/12/2020*****

The interest in Taal volcano has apparently brought he Smithsonian Global Volcano Program (GVP) offline, this is likely due to too much Internet traffic.

*****UPDATE 1/12/2020*****

There is now a live camera provided by rt.com https://www.rt.com/on-air/478090-taal-volcano-eruption-philippines/

*****UPDATE 1/13/2020*****

Taal volcano is still erupting. PHIVOLCS has recommended a 17-km (10.5 mi) exclusion zone around the eruptive center, which covers the towns and villages around the larger Lake Tall. Despite the urgent warnings from PHIVOLCS, some people are sneaking back to their homes in desperation, attempting to grab belongings or livestock.

Heavy ash mixing with rainfall has created a black sludge rain made of ash and mud which is making life miserable for many. The fine ash mixed with water is extremely heavy, so building collapses are now a serious risk. Ash suspended in air is hazardous to breathing, as volcanic ash is made of small volcanic glass shards. Inhaling these seriously damages lungs, so masks are essential.

PHIVOLCS is expecting a larger eruption 'within hours or days', which could end up being as large, or larger, than the eruption of Mt. Pinatubo in 1991.

Their latest update is below:






The main airport is reportedly reopened after the winds shifted to the SW, so there is an opportunity for some to flee the volcano while there is still time.

*****UPDATE FROM PHIVOLCS 1/14/2020  (Philippines Local Time)*****

"For the past 24 hours, Taal Volcano’s activity has been characterized by continuous eruption of the Main Crater due to magmatic and hydrovolcanic activity. This ongoing eruption generated 500-meter tall lava fountains topped by dark gray steam-laden plumes reaching approximately 2 kilometers tall that dispersed ash to the southwest and west of the Main Crater. Flashes of volcanic lightning were observed at the base of the degassing plumes this morning. New vents opened up on the northern flank where short 500-meter lava fountains, and within the main crater where steam plumes, have emanated.

Since the last update, heavy ashfall from the ongoing continuous activity of Taal Volcano has reportedly fallen on the municipalities of Lemery, Talisay, Taal, and Cuenca, Batangas.

The Philippine Seismic Network has recorded a total of two hundred twelve (212) volcanic earthquakes in Taal region as of 2:00 AM, January 14, 2020. Eighty-one (81) of these earthquakes were felt with intensities ranging from Intensity I – V in Tagaytay City, Cavite. Such intense seismic activity probably signifies continuous magmatic intrusion beneath the Taal edifice, which may lead to further eruptive activity.

Sulfur dioxide (SO2) emission was measured at an average of 5299 tonnes/day on 13 January 2020.

Alert Level 4 still remains in effect over Taal Volcano. This means that hazardous explosive eruption is possible within hours to days. DOST-PHIVOLCS strongly reiterates total evacuation of Taal Volcano Island and areas at high risk to pyroclastic density currents and volcanic tsunami within a 14-kilometer radius from Taal Main Crater. Areas in the general north of Taal Volcano are advised to guard against the effects of heavy and prolonged ashfall. Civil aviation authorities must advise aircraft to avoid the airspace around Taal Volcano as airborne ash and ballistic fragments from the eruption column pose hazards to aircraft. DOST-PHIVOLCS is continually monitoring the eruption and will update all stakeholders of further developments."

*****UPDATE 11/14/2020*****

A live video stream is now available at the top of the blog.

PHIVOLCS is now reporting that 'fissures and cracks' have appeared SW of Taal Volcano Island, near the coastal cities. This could mean that the magma intrusion under Tall extends beyond the boundaries of the larger caldera Lake Taal. This of course could mean that a much larger eruption is possible.

I did look up the names of the mentioned towns on Google Earth, and all but one were closely clustered to the SW, which may suggest that these reports are accurate, and that new cracks and fissures are opening up a long distance from the central eruptive vent. Time will tell. If this is true, the magma chamber has made multiple paths to the surface, and effusion of lava will be likely.





Monday, November 11, 2019

Large Quake Swarm At Iceland's Askja Volcano

ASKJA VOLCANO - ICELAND

A large quake sequence totalling hundreds of tremors is ongoing at Askja volcano since 11/9/2019. The largest quake so far has been a magnitude 3.2 quake. The swarm appears to be on the NE margin of the main caldera in an area that has in the past issued lava flows through fissures. There is no clear answer from the Iceland Meteorological Office or other sources as to whether or not this is magmatic or tectonic in nature.

Blogger Jon Frimann seems to indicate the swarm is tectonic, while VolcanoDiscovery.com seems to suggest this is related to magma dike intrusion. Again, no official source has confirmed any of this.


Screen grab from Iceland Meteorological Office showing current state of swarm at Askja caldera.

Askja caldera has seen dramatically increased seismicity since the eruption of Bardarbunga (Holuhraun fissure) commenced and ended and has had minor seismicity daily since. The last eruption of Askja was a VEI 2 occurring in Oct 1961, however it has proven capable of much, much larger eruptions, with a VEI 5 on New Years of 1875. Any current eruptive cycle would likely be a VEI 2 or 3, depending on the interactions with water/ice and magma supply.

Quake swarms and dike intrusions often amount to no activity on the surface of a volcano, so until the Iceland Met Office chimes in with an official prognosis, anything should be considered speculative at this point, however this is indeed a dramatic rise in activity even from the rise in activity post-Bardarbunga. The Bardarbunga dike intrusion has been theorized by some to have affected or influenced the Askja system, so it's anyone's guess at this point.

An eruption of Askja will not likely threaten any population in Iceland, but as seen with Grimsvotn and Eyjafjallajökull, it could conceivably pose a threat to air travel around Europe.

*****UPDATE 11/12/2019*****

The swarm is still ongoing at this time. Volcano Discovery has updated their news feed to include the following report (although take it with a grain of salt as there is still no official word out of Iceland regarding the quake sequence):

"An swarm of earthquakes is occurring near the Askja caldera, in an area approx. 10 km ENE from the rim and at depths around 5 km. More than 550 small quakes have been recorded during the past 5 days, but so far, most quakes have been tiny. The largest events were two shocks with magnitudes 3.2 and 3.4, felt by local residents. The swarm is likely caused by an intrusion of magma into an underground fissure (dike), which could but not necessarily must (and most often does not) lead to an eruption."

Today's largest tremors have been around the 2.5 range, with most quakes much smaller.


*****UPDATE 2 - 11/12/2019*****
The Iceland Meteorological Office has issued the following statement, which more closely suggests that this is tectonic - not volcanic - in nature:

"Specialist remark

An earthquake swarm started the 7th of November just east of Askja volcano and is still ongoing. Around 700 earthquakes have been recorded in the area since the swarm started. The largest earthquake was about M3.4 and occurred on the 9th of November. In addition to that earthquake, one earthquake > M3.0 has been detected during the swarm until now. No volcanic tremor has been detected in the area. This is more like brittle type tectonic earthquakes related to continental drift. Earthquake swarms occur regularly around Herðubreið and Askja. The IMO is monitoring the activity 24/7.

Written by a specialist at 12 Nov 17:11 GMT"



Tuesday, July 9, 2019

Small Quake Swarm SW Of Mount Hood

MOUNT HOOD, OREGON, US

A small seismic sequence of quakes is occurring on the SW flank of Mount Hood, Oregon today, with the largest quakes registering at magnitude 2.1. Around 60 quakes (at the time of this writing) have been registered so far. USGS CVO reports that this is likely purely tectonic in nature and is not the result of magma movement.


"On the afternoon of July 8, 2019 a swarm of small earthquakes started near Mount Hood, Oregon. As of 11:00 AM PDT on July 9, the Pacific Northwest Seismic Network has located more than 30 earthquakes, all occurring about 1 mile ENE of Government Camp and about 5 miles south of the Mount Hood summit. The earthquakes are relatively shallow (2-3 miles) and are likely too small (maximum magnitude 2.1) to be felt. Swarms in this area have occurred multiple times over the past two decades, most recently in 2014, with the largest event being a M 2.9 on September 14, 2001.

The largest event ever recorded near Mount Hood was a M 4.5 on June 29, 2002, at a location 3 miles south of the summit. Based on similarity to past seismic sequences near Mount Hood and on past studies of seismicity in the Mount Hood area, we infer that these earthquakes are occurring on tectonic faults and are not directly related to volcanic processes occurring beneath Mount Hood. http://ow.ly/PqBZ50uWRtz Mount Hood earthquake map: http://ow.ly/GY6u50uWRtI PNSN TDH webicorder http://ow.ly/n1xk50uWRtA"


Mount Hood, along the Cascades arc of volcanoes, was last confirmed to have erupted in 1865 with an unconfirmed eruption in 1869, according to the Smithsonian GVP.

Friday, July 5, 2019

Large Quake Sequence Hits Southern California

A large sequence of temblors is striking Southern California at the moment. This sequence so far is tectonic, not volcanic in origin, however it is striking very close to two dormant volcanic fields: The Coso Volcanic Field, and the Lava Mountains Volcanic Field.

The first major temblor, a magnitude 6.4 quake, spawned many aftershocks along the adjascent fault lines on 7/4/2019, and the second, larger shock struck at very shallow depth to the NW, at a magnitude of 7.1. Multiple aftershocks have since occurred, closer to the epicenters of the Coso Volcanic field, with the largest so fat at magnitude 5.5.

What this means for the area is not known. If this is purely a tectonic sequence, not much damage should occur outside of the immediate area. The Coso Volcanic Field has active geothermal power plants, and a few military installations.

The last identified eruptive period in this area was some 33,000 years ago, although suspected Holocene centers are inferred through morphology. It is tough to gauge the age of these volcanoes due to the desert climate, which can make older volcanism look younger than it actually is.


Google Earth screenshot with USGS quake overlay, and my volcano database.

More, larger quakes are possible. As has been theorized in the past, large quakes at the Southern end of the San Andreas fault line can propagate to the NW, creating a chain of events, although it is far too soon to see if this is the case.

Earthquakes, fault lines, and volcanic systems can and have interacted with each other in the past, however, given the age of the last eruption at the Coso Volcanic Field, an eruption still remains highly unlikely to occur. 

Residents in the vicinity should check their preparedness plans, and have an evacuation kit ready, if necessary, in the event of a larger quake.

Scientists in CA have long stated that CA is locked and loaded for 'The Big One" a quake of 8.0-9.0 in magnitude - and have advised that people have a plan in case of this event. California on average has had a large quake of 8.0 or more every 100 years or so, and for this, they are overdue.

It is important to note that USGS requires ample time to study each significant event, review the waveforms, and study factors like depth, whether these are purely fault slips, and whether subsequent events are purely tectonic in nature. No conclusions can be reached until all the data is in. Again, it is unlikely that this sequence would result in an eruption of nearby volcanic systems, but this is not unprecedented.

******UPDATE 7/8/2019*****

USGS CALVO Released the following statement regarding the Coso Volcanic Field:

"July 06, 2019 An earthquake swarm started on the evening of July 5 at the southern margin of Coso Volcanic Field in Inyo County, California. The swarm activity was triggered by a magnitude M5.4 earthquake at 9:19 PM PDT located 20 km (~20 miles) ESE of Little Lake, which itself was likely an aftershock of the M7.1 earthquake that occurred about an hour earlier 17 km NNE of Ridgecrest, and south of the Coso area. An average of about 30 earthquakes per hour have been detected since, most within the range of magnitude M1 to M3. No ground deformation indicative of volcanic activity has been detected, and there is no imminent threat of an eruption. The California Volcano Observatory will continue to monitor the situation for any sign of volcanic activity and provide updates as warranted.

The Coso Volcanic Field is located on the eastern side of the Sierra Nevada mountains at the northern end of the Mojave Desert, about 64 km (~40 miles) north of Ridgecrest. The field covers about 150 square miles primarily within the Naval Air Weapons Station at China Lake, and is comprised of lava domes, lava flows, and cinder cones erupted over the past 250,000 years. The most recent eruption was about 40,000 years ago."

Many large earthquakes have hit California in it's very long history. While this can and does create a lot of quake activity near the field, the 'crystal mush' in the magma chamber would still need fresh injection of magma into its chamber to trigger an eruption.

While Coso is not a good candidate for eruption, other volcanoes around the world remain 'primed', or close to an eruption, and a large earthquake sequence could indeed initiate an eruptive event. One such volcano is Mt. Fuji in Japan, which, according to Japanese authorities, is pressurized, and a large earthquake along its intersecting fault line could weaken the pressure on the chamber, thus causing an eruption.