This is an archived part of our Daily Volcano Activity report.
Click here to read the latest part of our report
This report was compiled out of many information sources by Armand Vervaeck, Jens Skapski, Georges Vitton and Rodger Wilson
Rodger Wilson volcano overview of July 31
Volcanic tremor (and eruptive activity?) at Veniaminof volcano (Alaska Peninsual) (station VNWF) has faded noticeably during the past 24 hours.
Earthquake rate of occurrence has fallen-off at Long Valley Caldera (CA) (station MCM), but earthquake magnitudes have been as strong as M2.5 overnight.
Rate of occurrence of small earthquakes and volcanic tremor is relatively high at Popocatepetl volcano (Mexico), but the volcano remains a picture of tranquility.
Pacaya volcano (Guatemala) (station PCG) has returned to its daily routine of strombolian "coughs" and sustained, low-level volcanic tremor following yesterday's large strombolian outburst.
Concepcion volcano (Nicaragua) (station CONN) continues to be affected by volcanic earthquakes and tremor, although there have been no reports of increased activity at the surface.
Turrialba volcano (Costa Rica) (station VTUC) has experienced an increasing number of pulses of volcanic tremor the past several days.
A moderate level of eruptive activity at Tungurahua volcano (Ecuador) (station RETU) shows no sign of abatement in the past day.
Rodger Wilson volcano overview of July 30
Sustained (co-eruptive) volcanic tremor continues to tremble within Veniaminof volcano (Alaska Peninsula) (station VNWF). Recent satellite thermal imagery detected a growing lava dome within the crater of Cleveland volcano (Aleutian arc) during the past few days. The volcano re-awakened last week with gas and ash emissions.
Seismicity (Magnitudes mainly < M1.0) continues in the "South Moat" of Long Valley Caldera (CA). Note the shallowing foci with time, indicating upward movement of hot fluid beneath the zone.
Numerous small volcano-tectonic earthquakes can be seen on seismograms from Popocatepetl volcano (Mexico), but the volcano paints a picture of tranquility this morning. I included a volcanocam view of a gas and emission which occurred at the volcano yesterday merely for aesthetic value.
Pacaya volcano (Guatemala) (station PCG) launched into strong strombolian-style eruption about four hours ago. Observers report an ash plume rose to between 1000 and 2000 meters above the volcano from the onset of the eruption. Seismic records indicate some decline in energy emanating from the volcano the past hour.
An episode of relatively strong volcanic tremor occurred at Turrialba volcano (Costa Rica) (station VTUC) early this morning. The cone remains blanketed by clouds, but again, there is no inidcation of eruptive activity associated with the seismicity.
Volcanic earthquakes and pulses of tremor continue at Concepcion volcano (Nicaragua) (station CONN).
Co-eruptive seismicity remains at a moderate level at Tungurahua volcano (Ecuador) (station RETU) today.
Rodger Wilson volcano overview of July 29
Volcanic tremor (and eruptive activity?) is slowly ebbing at Veniaminof volcano (Alaska Peninsula) (station VNWF). Earthquakes (to magnitude M3.0) continue in the vicinity of Mount Churchill volcano (Wrangell arc) (AK).
Earthquake activity remains relatively high beneath the South Moat of Long Valley Caldera (CA) (station MCM) today.
Volcanic tremor (and eruptive activity) continues to slowly decline at Pacaya volcano (Guatemala) (station PCG). Activity levels are also relatively low at the other two active Guatemalan peaks, Fuego and Santa Maria.
One of the few Central American volcanoes showing increased unrest is Concepcion (Nicaragua) (station CONN) which has exhibited elevated levels of harmonic tremor over the summer. Volcanic earthquakes have been slightly elevated in number and magnitude at San Cristobal volcano (station CRIN) during the past week.
Volcanic seismicity has increased slightly the past few days at San Miguel volcano (El Salvador) (station VSM)
Seismicity is lower again at Turrialba volcano (Costa Rica) (station VTUC).
Background tremor has fluctuated in amplitude the past week at Nevado Del Ruiz volcano (Colombia) (station OLLZ). More volcano-tectonic earthquakes struck Galeras volcano early today (station CUVZ).
Eruptive activity continues at Tungurahua volcano (Ecuador) (station RETU) but at diminishing levels.
Seismicity has dropped abruptly to a low level at White Island volcano (New Zealand), immediately after jumping to a very high level last week (with no significant eruptive activity transpiring!).
Rodger Wilson volcano overview of July 27
Volcanic tremor continues at Veniaminof volcano (Alaska Peninsula) (station VNWF) in-tandem with lava extrusion and strombolian explosions.
A relatively high level of small earthquakes continue along the southern boundary of Long Valley Caldera (CA) (station MCM) again today.
Continuous volcanic tremor (and likely strombolian activity) is slowly easing at Pacaya volcano (Guatemala) (station PCG).
Seismicity has rejuvenated at Turrialba volcano (Costa Rica) (station VTUC) through the day with bursts of earthquakes and relatively strong, sustained volcanic tremor at times. The Turrialba volcanocam remains cloaked in clouds, but there hasn't been any suggestion of increased surface activity (yet!).
Periods of elevated background volcanic tremor have affected Nevado Del Ruiz volcano (Colombia) (station OLLZ) during the past 24 hours.
Co-eruptive tremor and surface activity appear to be winding-down at Tungurahua volcano (Ecuador) (station RETU).
Eruptive(?) tremor at White Island volcano (New Zealand) also appears to be faltering in strength today.
Rodger Wilson volcano overview of July 26
Cleveland volcano (Aleutian arc) (not seismically monitored) perked-up with a sustained emission of gas (and ash?) this week.
Veniaminof volcano (Alaska Peninsula) (station VNWF) continues to rumble with volcanic tremor, strombolian explosions and lava emission.
What appears to be low-level spasmodic tremor is apparent on seismograms along the southern margin of Long Valley Caldera (CA) (station MCM) this morning. Geothermal development also occurs in close proximity to these seismic stations so, this may be the source of the activity.
Volcanic tremor remains elevated at Pacaya volcano (Guatemala) (station PCG) and several gas and ash emissions have affected Santiaguito Dome Complex (Santa Maria volcano) (station STG3) during the past 24 hours.
Another (but short-lived) swarm of volcano-tectonic earthquakes occurred at Momotombo volcano (Nicaragua) (station MOMN) overnight.
Seismicity at Turrialba volcano (Costa Rica) (station VTUC) remains unstable with tremor-like bursts (volcanic earthquakes) currently being recorded there. The volcano is once again obscured by rain clouds this morning.
Sustained, relatively low-level gas and ash emission continues at Tungurahua volcano (Ecuador) (station RETU) today.
Eruptive activity (magmatic?) activity appears to be in progress at White Island volcano at this time. GNS raised the alert level at the volcano late yesterday due to a sharp increase in seismicity and following observations at the volcano by their personnel yesterday. Incandescence is visible on the "Rim" camera and seismicity is currently very high at the volcano.
White Island volcano (New Zealand) aviation color back to Yellow - (JS - July 26 - 08:24 UTC)
The prediction of Rodger Wilson in yesterdays report came true today with a confirmation of the New Zealand volcanologist of increased activity
A report from GNS Science / Geonet published at July 26 2013, 6:00pm states :
- White Island resumes pattern of minor activity
- Volcanic Alert remains at Level 1
- Aviation Colour Code raised from Green to Yellow.
GNS Science says that minor activity has become re-established at White Island over the last 24 hours. The Volcano Alert Level remains at Level 1 and Aviation Colour Code has been raised to Yellow.
Following an increase in volcanic tremor levels overnight and images of activity on the volcano cameras, a response visit was made this afternoon. Volcanologist Brad Scott reported they saw two styles of activity in the active vent. Audible jets of gas were being shot through the small lake and broader expanding ‘bubbles’ of dark lake sediments and debris were being ejected 20-30 m vertically. The activity is very similar to earlier this year.
The potential for larger, more explosive eruptions that might impact on visitors to the island is always present. Any larger eruptions may occur with no warning to any visitors to the island.
The ultimate outcome of the current activity at White Island remains unclear and GNS Science continues to closely monitor White Island through the GeoNet project. There is no reason to believe this change is related to the Cook Strait earthquakes.
Unrest at White Island began in July 2012, leading to explosive eruptions and ash emissions in August. A small lava extrusion occurred in November, followed by phreatic, steam driven activity in December which continued through January and February 2013. Very minor ash emissions have been interspersed throughout this eruption sequence as conditions within the craters have changed.
The Volcanic Alert Level ranges from 0 to 5 and defines the current status at a volcano. Level 1 indicates signs of volcanic unrest.
Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community.
Rodger Wilson volcano overview of July 25
Volcanic tremor at Veniaminof (accompanying lava emission there) (Alaska Peninsula) (station VNWF) is on the decline during the past 24 hours.
The interesting pattern of seismicity in the Southern Washington Cascades continues, now along the Western Rainier Seismic Zone located just south and west of Mount Rainier volcano. The northeast-trending zone through Mount Saint Helens volcano (previously discussed here) intersects the Mount Rainier zone, and likely accommodates compressional stress related to the incoming Juan De Fuca oceanic slab (subduction). The conjugate fault system forms a stress "transfer zone" between the volcanoes and further shows the intimate linkage between subduction zone tectonics, volcanic vent locations and activity. Mount Rainier and Mount Saint Helens volcanoes experienced "sympathetic" seismic unrest during the Fall of 2008 (and eruption at MSH!) and late Summer-Fall 2009 possibly related to stress transfer along these zones.
The rate of small earthquakes has declined along the southern margin of Long Valley Caldera (CA) (station MCM).
Volcanic tremor and small volcano-tectonic events are more frequent (as are gas and ash emissions) at Popocatepetl volcano (Mexico) today.
Volcanic tremor is sustained and elevated (as is strombolian activity) at Pacaya volcano (Guatemala) (station PCG).
Magnitudes (but not numbers) of earthquakes are reduced at Turrialba volcano (Costa Rica) (station VTUC).
Another "felt" volcano-tectonic earthquake occurred yesterday evening at Galeras volcano (Colombia) (station CUVZ) otherwise, the volcano has been relatively quiet.
Volcano-tectonic seismicity remains elevated at Sabancaya volcano (Peru) (station SAB).
Volcanic tremor (and likely eruptive activity) is on the rise again at Tungurahua volcano (Ecuador) (station RETU). The mountain is immersed in clouds again today.
Drumbeat earthquakes at White Island volcano (New Zealand) merged into volcanic tremor that has continued to increase (dramatically) in amplitude during the past 24 hours. Will this volcano finally erupt?
Strong activity from Tungurahua volcano, Ecuador (AV - July 24 - 19:14 UTC)
The IGEPN reported little before 15:00 UTC, the Tungurahua has started a phase of intense activity less than half an hour before. The observatory reported the presence of a high column of ash 5000 m above the crater (to be added to the height of the volcano = approx. 10,000 m) heading in the direction of Ambato.
The IGEPN website is unfortunately down and as Rodger said earlier no access to seismograms and/or webcam images.
We were lucky that the MODIS satellite has passed at the right time over the volcano (at 15:35 UTC), which still allows to have an idea of the extent of the plume about 1 hour after it started. The cloud was already 25 km to the north-west of the crater.
Currently no local newspapers have reported information about ash fall, but IGEPN reported that ash fall may be possible in the villages located in the windward direction.
Translated from the original French article at CultureVolcan earlier today (http://laculturevolcan.blogspot.fr/)
Rodger Wilson volcano overview of July 24
Volcanic tremor again accompanies low-level strombolian activity within Veniaminof caldera (Alaska Peninsula) (station VNWF) today.
While not directly associated with volcanic activity, a scientifically interesting earthquake occurred immediately west of the central Oregon Cascades overnight. The earthquake's depth (42 km) is what makes it interesting since earthquakes along the subducted (Juan De Fuca) oceanic plate are noteably rare in this area.
Small earthquakes remain frequent along the southern boundary of Long Valley Caldera (CA) (station MCM).
Periods of stronger harmonic tremor have reappeared at Concepcion volcano (Nicaragua) (station CONN) during the past 24 hours.
Elevated seismicity continues at Turrialba volcano (Costa Rica) (station VTUC), but may be now flagging in strength. No volcanic tremor is apparent in overnight records.
A magnitude M3.2 earthquake rattled Galeras volcano (Colombia) (station CUVZ) early today. The event was felt in at least one nearby community.
More robust seismicity has returned at Sabancaya volcano (Peru) today with several M2-M3 events visible on records (station SAB) from the volcano.
Seismograms from the Ecuadoran volcano were not accessible at the time of this writing.
Hydrothermally-generated earthquakes appear on the wane at White Island volcano (New Zealand) after peaking in numbers per hour late yesterday.
Rodger Wilson volcano overview of July 23
Volcanic tremor continues to accompany strombolian explosions and lava extrusion at Veniaminof volcano (Alaska Peninsula) (station VNWF).
What appear to be small seismic events continue to be detected by a single seismometer (station HUO) located over the inflating area west of Three Sisters Volcanic Center (OR). Similar tiny events have occasionally been observed on nearby seismometer MOON during the past week. A local earthquake is observed on station MOON today. The tiny events may be electronic impulses generated internally by the monitoring system (equipment malfunction).
Periodic volcanic tremor accompanies generally quiet degassing at Popocatepetl volcano (Mexico) today.
Volcanic earthquakes and a period of volcanic tremor occurred at restive San Cristobal volcano (Nicaragua) (station CRIN) overnight.
What may be explosion/phreatic eruption signals (including volcanic tremor) are apparent on the seismogram from Turrialba volcano (Costa Rica) (station VTUC) this morning. The volcano is cloaked in mist at this time. OVSICORI released a statement yesterday describing the dramatic increase in seismicity at the volcano this past week (including over 1000 events per day on 18 July along with the appearance of periods low-frequency volcanic tremor).
Continuous gas and ash emission characterizes activity at Tungurahua volcano (Ecuador) (station RETU) again today. The Reventador volcano seismometer is malfunctioning, but brief glimpses of the volcano also indicate that eruptive activity continues there.
Seismicity at White Island volcano (New Zealand) is building to a crescendo. Will this lead to stronger eruptive activity?
Rodger Wilson volcano overview of July 22
Volcanic tremor (though diminished) continues to accompany lava extrusion and strombolian activity at Veniaminof volcano (Alaska Peninsula) (station VNWF). Deep low-frequency earthquakes are visible on seismograms from Mount Spurr volcano (Alaska Range) (station CKT) today.
Another pulse of small earthquakes is occurring at Mount Hood volcano (OR) today. Seismic activity continues on regional faults near Mount Saint Helens volcano (WA). Note activity along the NE-trending zone now predominates with a cluster of events NE of the volcano beginning last week. The NE-trending fault zone, extending through the volcano supplies silicic magma (Dacite) to the surface, while the currently inactive NW-trending (Mount Saint Helens Fault Zone) supplies basaltic magma to the lower and middle crust beneath the cone. Numerous tiny events also continue over the inflating area west of the Three Sisters Volcanic Center (OR) (station HUO).
Small earthquakes remain frequent near Mammoth Mountain volcano (CA) (station MRD).
Volcanic tremor has been sustained at Popocatepetl volcano (Mexico) overnight, while the volcano currently quietly degases.
Volcanic tremor at San Cristobal volcano (Nicaragua) (station CRIN) remains pulsatory producing numerous low-frequency earthquakes there. Explosion signals were recorded at the volcano late yesterday.
The tempo of earthquakes (mixed with a few short pulses of volcanic tremor) at Turrialba volcano (Costa Rica) (station VTUC) increased overnight.
Periodic increases in background tremor (and a few small local earthquakes) affected Nevado Del Ruiz volcano (Colombia) (station OLLZ) during the past 24 hours.
Strong tremor continues at Tungurahua volcano (Ecuador) (station RETU), but external activity (as visible in the Tungurhua volcanocam) appears to amount to strong "chugging" (degassing) possibly mixed with minor amounts of volcanic ash.
The tempo of "clone" earthquakes increased overnight at White Island volcano (New Zealand).
Eruption at San Cristobal volcano, Nicaragua ? - (Rodger Wilson - early July 22 UTC)
Seismic signals suggestive of explosive activity were recorded late this afternoon at San Cristobal volcano (Nicaragua) (station CRIN). INETER has not released a notice confirming the activity though.
Rodger Wilson volcano overview of July 21
Data for the Alaskan volcanoes were not available at the time of this writing but, I may not have to go that far away to find an active volcano! Observe the Husband seismogram (station HUO) located directly astride the inflating area west of Three Sisters Volcanic Center (OR). I have been watching these small, likely non-locatable events (since they're not being located by PNSN) at this location since May when a pulse of four locatable events occurred at the volcano. This station has experienced telemetry problems through the period, which made viewing difficult and confusing. In the past few days, the telemetry issue seems to have auto-corrected or was fixed and now I am more confident that these are in fact true (albeit very small) earthquakes. Similar sized events became apparent on Three Sisters seismic records in the days leading-up to the May 2004 earthquake swarm there (but not in these numbers!).
Volcanic tremor has become more established at Popocatpetl volcano (Mexico) this morning, as the volcano continues to vigorously (at times) degass.
All three Guatemalan volcanoes have shown more vigor during the past few days. While Fuego volcano is staid this morning, both Pacaya (station PCG) and Santiaguito (station STG3) volcanoes show stronger (co-eruptive) seismicity.
Both Nicaraguan volcanoes Telica (station TELN) and Concepcion (station CONN) have slipped back into (relative) slumber following nearly a month-long bout of unrest at each cone.
Amplitude and numbers of seismic events continues to increase at Turrialba volcano (Costa Rica) (station VTUC). Watch this one!
Although reduced from last week, seismicity continues to run "hot" (pardon the pun!) at Sabancaya volcano (Peru) (station SAB).
Another eruption appears underway at Tungurahua volcano (Ecuador) (station RETU) this morning. A brief glimpse of the volcano through rain clouds shows a light-colored plume emanating from the cone.
White Island volcano (New Zealand) still trembles with frequent hydrothermally-generated seismicity.
Turrialba, Costa Rica - (AV - July 20)
2 days of 30 second time lapse webcam activity of the volcano. The seismogram shows still some periods of higher activity. If the weather permits, these can also be seen on the video. Flashes of intense light in the steam clouds to the left of the incandescent vent spot.
Rodger Wilson report July 19
Even away from home and only sporadic linked to the internet, Rodger keep sending us updates
Sabancaya update July 18 :
The dVT earthquakes have increased to 1500 events/day. A swarm who started on July 16 culminated in a strong Ml 5.9 earthquake which we reported in our in-depth article (strange that IGP has kept the 5.1 vs 5.9 reported by other agencies for a long time). On the other hand, the earthquakes associated with fluid passage (LP) and the Hybrid type remain low in number. The evolution of the volcanic activity is continuously being evaluated within a Scientific Committee (permanent session).
For the full IGP report, which in part repeats what we said before in our in-depth article, click here. The image and parts of the report are a bit late. The graphic below ends on July 16 (strong earthquake).
More news on the volcano in the Peruvian National Press who states that scientists are saying that the earthquakes are being generated due to the volcano. Those among you reading our reports know this already for months. The moderate to strong earthquakes have been reported since quite some time and IGP Peru has reported on a regular basis about them.
Sources : IGP Peru and partly CultureVolcan earlier today (http://laculturevolcan.blogspot.fr/)
Turrialba, Costa Rica
This volcano has periodic peaks in tremor and if the weather permits (only now and then) the flashes of activity can well be seen, especially at night.
Rodger Wilson away for a few days
I will be away from the computer for several days so, reports will be spotty at best. Do want to pass-on some apparent stronger (phreatic eruptive?) tremor occurred at Turrialba volcano (Costa Rica) (station VTUC) overnight. Have your team keep an eye on this one and Tungurahua which hasn't quite simmered yet either!
Nyamuragira volcano, Democratic Republic of the Congo - (Georges Vitton - July 17)
A thick plume rose from the summit of Nyamuragira volcano in June 2013. Located near the eastern boundary of the Democratic Republic of the Congo, Nyamuragira is one of Africa’s most active volcanoes. Its plume is rich in water vapor—which condenses rapidly in the humid tropical air—and sulfur dioxide, which lends a blue tint in natural-color satellite imagery (top). Carbon dioxide, fluorine, and chlorine gas are also found in Nyamuragira lavas and likely present in the gas plume.
The source of the plume appears to be a pit nestled within the caldera that tops Nyamuragira. If outgassing magma was near the surface, then the intense heat would cause a bright red glow in shortwave infrared light (included in the lower, false-color image). No such glow is visible atop Nyamuragira, but it is present on neighboring Nyiragongo Volcano, which has featured a lava lake for more than a decade.
These images were collected on June 11, 2013, by the Operational Land Imager on Landsat 8. In natural color (top), the rainforest is dark green, clouds are white, and the sulfur-rich volcanic plume is very light blue. Barren land at Nyamuragira’s summit and lava flows are brown or black. In false-color, clouds are mostly white and volcanic plumes are cyan. Forest and other vegetation is bright green. Fresh lava flows from the 2011–12 eruption of Nyamuragira are black, and older lava flows appear as brown tendrils running down the mountain’s flanks. Agricultural fields in the southeast (lower right) corner of the image also appear brown.
Rodger Wilson volcano overview of July 17
Strong tremor accompanies continued emission of lava and small strombolian explosions at Veniaminof volcano (Alaska Peninsula) (station VNWF). A recent photo shows the current activity at the volcano.
The earthquake swarm near Mount Churchill (Wrangell arc) (AK) rumbles-on with event magnitudes as high as M3.5 during the past 24 hours. Additional events closer to the volcano have occurred during that period.
I have included a diagram showing the continued crossing pattern of recent seismicity along fault zones at Mount Saint Helens volcano (Cascade arc)(WA). A beautiful example of the interplay between regional tectonics and volcanism. Also visible are recent seismic events recorded at nearby Mount Rainier (WA) and Hood (OR).
Numerous small earthquakes continue along the southern margin of Long Valley Caldera (CA) (station MCM) and near Mammoth Mountain volcano to the west.
Pulses of tremor and small volcano-tectonic events continue at Popocatepetl volcano (Mexico) today.
Amplitude of episodic harmonic tremor at Concepcion volcano (Nicaragua) (station CONN) has diminished during the past day,...but continues. Elevated seismicity at nearby Telica volcano (station TELN) continues as well.
Seismicity at Turrialba volcano (Costa Rica) (station VTUC) is increasing with the return of higher magnitude events overnight and more importantly,...the appearance of bursts of volcanic tremor.
Pulses of tremor and low-frequency events (indicative of fluid movement) affected Nevado Del Ruiz volcano (Colombia) (statin OLLZ) overnight.
Seismicity remains elevated at Sabancaya volcano (Peru) (station SAB). See also our in-depth report of the strong earthquake in this area.
Co-eruptive seismicity affects both Ecuadoran volcanoes Tungurahua (station RETU) and Reventador (station CONE) again today. A brief part in the clouds reveled a small gray plume issuing from Reventador volcano this morning,...no such luck for viewing activity at Tungurahua.
Hydrothermally-generated "clone" earthquakes ebb and flow in numbers at White Island volcano (New Zealand).
OMI satellite data indicate SO2-enriched plumes drifting from Popocatepetl, Tungurahua, and Sakurajima (Japan) volcanoes during the past 24 hours. A photo taken from the Kyoto University volcanocam shows a strong explosive eruption at Sakurajima at around 4 UTC today.
Update Sabancaya volcano, Peru July 16
Larger magnitude earthquakes are now occurring within the current earthquake swarm at Sabancaya volcano (Peru) (station SAB).
Update Arenal volcano, Costa Rica July 16
A lot of rockfall (with explosions?) activity at Arenal volcano (Costa Rica) (station VACR) today.
Rodger Wilson volcano overview of July 16
Strong volcanic tremor (and presumably lava emission) continues today at Veniaminof volcano (Alaska Peninsula) (station VNWF).
An energetic earthquake swarm continues at/near Mount Churchill (Wrangell arc) (AK) today. Nearly 100 earthquakes have been detected during the past 24 hours with a maximum magnitude of M3.5 during that period. Some events have recently occurred closer to the volcano.
Small volcano tectonic earthquakes rattle Popocatepetl volcano (Mexico) this morning, but the rate of emission events is low and recent OMI satellite imagery reveals a slackened output of SO2 from the volcano. CENAPRED overflew the cone yesterday and observed a pit where the most recent lava dome once stood.
A relatively small gas and ash emission was recorded (by both seismic and photographic methods) early today at the Santiaguito dome complex (Santa Maria volcano) (Guatemala) (station STG3).
Seismicity continues to slowly wane at Telica volcano (Nicaragua) (station TELN). Episodes of harmonic tremor continue to plague Concepcion volcano (station CONN).
The tempo of seismicity has increased at Turrialba volcano (Costa Rica) (station VTUC) but magnitudes of individual events are smaller since an earthquake swarm began at the volcano earlier this week. The volcano's seismic behavior is somewhat reminiscent of the activity we just witnessed at Telica.
Periods of increased background tremor, a swarm of low-frequency (volcanic) earthquakes, and now the appearance of larger magnitude volcano-tectonic earthquakes overnight all imply that magma is on the move again within Nevado Del Ruiz volcano (Colombia) (station OLLZ).
An energetic earthquake swarm is also underway at Sabancaya volcano (Peru) (station SAB) today.
An apparently (from seismic data) strong eruption is underway at Tungurahua volcano (Ecuador) (station RETU) at this time (the volcano remains cloaked in clouds). Strong seismicity accompanies lava emission at Reventador volcano (station CONE).
Small "clone" earthquakes (with intermittent pulse of volcanic tremor) continue at White Island volcano (New Zealand).
OMI satellite data show an SO2 plumes drifting from Tungurahua and Popocatepetl volcanoes.
Rodger Wilson volcano overview of July 15
Low-level eruptive activity continue at Tungurahua volcano (Ecuador) (station RETU) today. The mountain remains cloaked in clouds. Reventador volcano (station CONE) continues to grumble as well (mostly internally).
Significant earthquake swarms continue at/near Mount Churchill volcano (Wrangell arc) (AK) (a magnitude M4.2 event just occurred there) and at Turrialba volcano (Costa Rica) (station VTUC). We should keep a close eye on the activity at Turrialba as the volcano has been building toward an eruption for over the past decade.
Elsewhere in Central America, an explosion occurred late yesterday at Fuego volcano (Guatemala) (station FG3), volcanic seismicity continues its slow decline at Telica volcano (Nicaragua) (station TELN), and episodic harmonic tremor continues to affect Concepcion volcano (Nicaragua) (station CONN).
OMI satellite data depicts SO2-enriched plumes drifting from Popocatepetl volcano (Mexico), Turrialba, and Sakurajima volcano (Japan).
The Secret of Screaming Volcanoes Explained - (AV - July 15)
Not far from Anchorage, Alaska, there is a volcano that screams. Then falls silent. Then erupts and throws volcanic ash 10 kilometers into the sky. Then starts all over and does it again, and again.
This strange and repeating seismic behavior was discovered in the 2009 eruptions of Redoubt Volcano by Alicia Hotovec-Ellis of the University of Washington. But now she and her colleagues have a model to explain what might cause all the screaming and then the silence before the volcanic storm.
To get an idea what the screaming sounds like – converted from seismic waves, sped up 60 times into audible sound waves – listen to this file which is a real recording of Redoubt Volcano. What you hear is a drum beat of quakes that get faster and faster until they blur together in a rising sound and then go quiet. It's the blurred rising sound that has been called the scream.
Read the full article here
Powerful explosion at Tungurahua, Eacuador
On top of Rodger's overview and description, we also want to inform you about the comments of CulturVolcan (French volcano observer)
The activity of Tungurahua, which showed signs of a gradual increase in the past two days, produced a powerful explosion around 11:50 UTC. The seismic signal associated with this event is clearly visible on the seismograms IGEPN (like it can also be seen on Rodger's images below).
Locally significant cloud cover prevents a clear view of events, but the webcam installed at the observatory has given us a glimpse of the co-pyroclastic ash cloud mainly in the gullies and Aschupashal Vazcun.
Translated from the original French article at CultureVolcan earlier today (http://laculturevolcan.blogspot.fr/)
Rodger Wilson volcano overview of July 14
Seismicity indicates an eruption just occurred or is very near to occurrence at Tungurahua volcano (Ecuador) (station RETU). Earthquake activity had been increasing at the volcano the past three days. Nearby volcano Reventador (station CONE) appears to simmer in deference to the activity at Tungurahua. Webcams TUNGURAHUA – IGEPN1 – IGEPN2 – IGEPN3 – IGEPN4 – IGEPN5 – IGEPN6
Volcano-tectonic earthquake activity also continues at Popocatepetl volcano (Mexico) today, indicating that magma intrusion continues beneath the volcano. The Popocam shows a large SO2-rich plume emanating from the cone.
Seismicity remains elevated along the southern margin of Long Valley Caldera (CA) (station MCV) today. A magnitude M2.7 (felt) event just occurred at the volcano.
An interesting swarm of earthquakes is also underway at/near Mount Churchill volcano in the Wrangell volcanic arc (AK). A similar swarm occurred there in the 1990's and was deemed by AVO as tectonic in nature. The linear pattern of today's seismicity there also suggests fault movement, but given the sparse seismometer coverage in the region, earthquake locations must be further scrutinized to make sure they are not occurring closer to the volcano. Mount Churchill experienced the two largest Holocene eruptions in North America between 1900 and 1250 years ago. A small caldera that likely resulted from the eruption is visible in the accompanying satellite photo.
Rodger Wilson volcano overview of July 13
important seismicity has just begun in the past few hours at Turrialba (Costa Rica) (station VTUC)!
Volcano-tectonic seismicity has also re-appeared at Popocatepetl volcano (Mexico) during the same period.
Both Fuego (station FG3) and Santa Maria (station STG3) volcanoes (Guatemala) have exhibited pre-eruptive (at Fuego) and co-eruptive(at Santiaguito) seismicity today.
Concepcion volcano (Nicaragua) (station CONN) continues to experience periods of harmonic tremor and current OMI satellite data show an SO2 anomaly over the volcano as well. Nearby volcano Telica (station TELN) continues to tremble with volcanic seismicity, but at a slowly decreasing tempo over the past week.
Seismograms from Galeras volcano (Colombia) (station CUVZ) show small gas and ash outburst continued there today.
Volcanic seismicity increased during the past 48 hours at Tungurahua volcano (Ecuador) (station RETU) but now appears to be on the decrease without culminating with eruptive activity. Periods of strong volcanic (eruption?) tremor have affected Reventador volcano (station CONE) during the past 36 hours.
OMI satellite data depicts SO2 plumes at or near Concepcion (Nicaragua), Nyiragongo volcano (DRC), and Sakurajima volcano (Japan) today.
I also included a diagram of recent seismicity near Mount Saint Helens volcano (Cascade arc WA) which shows a nice crossing pattern of regional faults affecting the location of the volcano. The northwest-trending zone is the Mount Saint Helens Fault Zone which accomodates deep intrusion (12-35 km depth) of basaltic magma beneath the cone (as denoted by deep low frequency earthquakes which occur along the trend SE of the volcano. The northeast-trending zone has no formal name but appears to accomodate shallow (pre-eruptive) intrusion at the volcano. Given it NE trend, the zone ultimately results from the interaction between the incoming Juan De Fuca oceanic plate and the North American plate.
Daniel Garcia-Castellanos descent in an Icelandic volcano crater - (July 13)
Daniel Garcia Castellanos is a geoscientist working for CSIC in Barcelona. He is on a holiday in Iceland and could not resist using the facilities of "inside the volcano", a unique project who allows people to go down in the emptied crater pipe of the Thrihnukagigur volcano. Daniel made a very good video showing the colorful minerals at the crater walls. Something even more special is to see is a once crater magma chamber. Amazing !
Read the additional comment from Daniel here.
Whenever you visit Iceland, do not hesitate and include this descent in your itinerary.
A very good slide presentation (in pdf format) of the project can be read by clicking here.
Rodger Wilson volcano overview of July 12
Most volcanoes we watch continue to "tease" with small episodes of seismicity, but no eruptive activity to speak of. Included in that group are: Akutan volcano (Aleutian arc) (station AKV), Long Valley Caldera (CA) (station MCS), Popocatepetl (Mexico), Momotombo (station MOMN), Cerro Negro (station CNGN), Telica (station TELN) and Concepcion (station CONN) in Nicaragua and Tungurahua (station RETU) and Reventador (station CONE) volcanoes in Ecuador. Small volcanic earthquakes ebb and flow at White Island volcano (New Zealand) also.
Update : Since the above report, an ash emission event has begun at Popocatepetl volcano (Mexico). The current Popo seismogram suggests this is only a minor/moderate event unless there is a lag between the most current data and what is posted on the UNAM website (likely!).
Mild eruptive activity occurred yesterday at Popocatepetl, and Nevado Del Ruiz (Colombia, sorry no updated seismic data!). Gas and ash emissions have occurred today at Galeras volcano (Colombia) (station CUVZ), and low level lava emission continues at Veniaminof volcano (Alaska Peninsula) (station VNWF).
As mentioned above, volcano-tectonic earthquake swarm (magma intrusion) is underway at Popocatepetl today, suggesting the volcano is not ready to simmer just yet.
SO2 plumes were detected at or near Popocatepetl, Nevado Del Ruiz, Nyiragongo (DRC), and Langila (New Guinea) volcanoes.
Erta Ale, Dallol, Ethiopia - (Georges Vitton - July 12)
Evelyne Pradal reports in the "LAVE" journal about her his trip to Ethiopia at February.
"The lava lake of Erta Ale is currently very high in the pit crater, about thirty meters from the edge. Very active on the south and north side, against the wall of the pit crater, with bubbles that jump regularly a few meters. Lots of tears and Pele's hair lining the edge of the crater since the overflow burst a few months ago.
Hydrothermal activity near the site of the 1926 eruption. Geysers 2 to 4 m high. A soda lake at 72 °C.
Hamed Ela has now a couple of hours electricity per day. Mobile phone do have connectivity at Dallol, and the road connects from Mekele to Hamed Ela.
Source: Evelyne Pradal, LAVE magazine.
Veniaminof volcano, Alaska - (Georges Vitton - July 12)
AVO reports on July 11 : Nearly continuous low-level volcanic tremor has been ongoing, and satellite images have detected thermal anomalies at Veniaminof over the past 24 hours. FAA web camera images of the volcano from Perryville showed incandescence from the intracaldera cone overnight. These data indicate an ongoing low-level eruption characterized by effusion of lava and emission of minor amounts of ash and steam.
Video of a "small" explosion at Sakura-jima volcano, Japan - (Georges Vitton - July 11)
One of the great (older) video's from Richard Roscoe (photovolcanica)
Sakurajima volcano lies close to the city of Kagoshima in southern Japan. Since 1955, several prolonged phases of explosive activity from the Showa crater have been observed. The video shows a typical explosive eruption associated with a small pyroclastic flow. First, a detailed video is shown where the ejection of a dense jet of material triggering the flow can be seen. The wider angle view shows the same eruption filmed with a second camera to give a better overview. The video is copyrighted material!.
Rodger Wilson volcano overview of July 11
Not alot of eruptive activity to report today,...save for continued outgassing at Popocatepetl volcano (Mexico) and possibly (according to OMI satellite data) Sheveluch volcano (Kamchatka Peninsula).
Flurries of small earthquakes struck both Momotombo (station MOMN) and Concepcion (station CONN), the latter experienced harmonic tremor as well, overnight (both in Nicaragua) and nearby volcanoes San Cristobal and Telica (station TELN) continue to exhibit elevated seismicity.
OMI satellite sensors detected SO2-enriched plumes of varying sizes drifting from Popocatepetl, Nevado Del Ruiz (Colombia), Nyiragongo (DRC), Ambrym (Vanuatu), Mayon (Philippines), and Langila (New Guinea) volcanoes.
Alos forgot to mention the continued high seismicity (with little external activity) at Reventador volcano (Ecuador) (station CONE) and SO2 plume at Sakurajima volcano (Japan) as well!
Gamkonora volcano, Indonesia - (Georges Vitton - July 11)
CVGHM reported that observers at the Gamkonora observation post in Gamsungi (6 km NW), West Halmahera, reported that during 27 May-30 June diffuse white plumes rose up to 300 m above the crater rim. Seismicity declined overall, but a seismic crisis characterized by continuous tremor was detected on 10 June; tremor was not detected during 13-30 June. The Alert Level was lowered to 2 (on a scale of 1-4) on 1 July. Residents and tourists were asked not to venture near the crater within a radius of 1.5 km.
The shifting of eruption centers on Gamkonora, at 1635 m the highest peak of Halmahera, has produced an elongated series of summit craters along a N-S trending rift. Youthful-looking lava flows originate near the cones of Gunung Alon and Popolojo, south of Gamkonora. Since its first recorded eruption in the 16th century, Gamkonora has typically produced small-to-moderate explosive eruptions. Its largest historical eruption, in 1673, was accompanied by tsunamis that inundated villages.
Rodger Wilson volcano overview of July 10 (Update)
I forgot to mention an earthquake swarm began yesterday at Mount Hood volcano (Oregon) (station TDH). A magnitude M1.4 event just occurred and, thus far, has been the largest event in the sequence of small earthquakes.
Rodger Wilson volcano overview of July 10
Eruptive activity (mostly strong degassing today) continues at Popocatepetl volcano (Mexico).
Volcano-tectonic events have "popped-up" on seismograms at San Cristobal volcano (Nicaragua) (station CRIN) during the past 24 hours. Following a swarm of small volcano-tectonic events, pulses of harmonic tremor have recurred at Concepcion volcano (station CONN). Numerous volcanic earthquakes continue at Telica volcano (station TELN), and a few small, local events continue in the vicinity of Momotombo volcano (station MOMN).
Pulses of volcanic tremor are evident on seismograms at Nevado Del Ruiz volcano (Colombia) (station OLLZ) this morning.
Elevated volcanic tremor appears to have eased at Tungurahua volcano (Ecuador) (station RETU) after increasing yesterday. Seismicity (and degassing?) remains high at Reventador volcano (station CONE).
SO2-enriched plumes were observed by OMI satellite sensors to be drifting from Ruiz, Tungurahua and Sakurajima (Japan) volcanoes during the past 24 hours.
Rodger Wilson volcano overview of July 9
A short-lived episode of shallow (event depths < 10 km) seismicity occurred overnight at Iliamna volcano (AK) (station INE), while deep seismicity (event depths 12 - 20 km) continues along a NE-striking line through Mount Saint Helens volcano (WA).
Seismicity also continues beneath the "South Moat" of Long Valley caldera (CA) (station MRD). today.
Eruptive activity (including ashfall on surrounding communities) continues at Popocateptl volcano (Mexico).
Small earthquakes appear to be on the decline at Momotombo volcano (Nicaragua) (station MOMN), while earthquake amplitudes have increased (but event numbers have decreased) at nearby Telica volcano (station TELN). This appears to be "normal" cyclic behavior as we observed similar activity at the volcano last spring. Volcanic tremor has diminished at Concepcion volcano (station CONN) following a volcanic earthquake there late yesterday.
Another explosion(?), rockfall(?) is visible on the Arenal volcano (Costa Rica) (station VACR) seismogram this morning.
Volcanic tremor briefly increased overnight at Nevado Del Ruiz volcano (Colombia) (station OLLZ). Two ash emission events are visible on seismograms this morning at Galeras volcano (station CUVZ).
Volcanic tremor also appears to have increased within Tungurahua volcano (Ecuador) (station RETU) since yesterday. Internal activity remains high at Reventador volcano (station CONE).
Hydrothermally-derived "clone" earthquakes continue to rattle White Island volcano (New Zealand).
Popocatepetl activity Time Lapse - (AV - Georges Vitton - Rodger Wilson - July 9 - 15:45 UTC)
Continuing activity at Popocatepetl, Mexico.
We recorded 6 hours of Cenapred webcam images (1 image every 30 seconds). During the nightly hours explosions can clearly be seen, some lava bombs ejected on the slopes.
The volcanic alert level remains at yellow stage 3.
El Hierro volcano Island, Canary Islands, Spain - (AV - July 8 - 14:01 UTC)
Something worth to tell the readers of this page is that this afternoon, a Magntude 3.1 earthquake at a depth of 22 km struck the El Golfo bay (Frontera side of the island)
Click here to be linked to our (still ongoing) El Hierro report.
Heard Island volcano, Indian Ocean - (Georges Vitton - July 8 - 13:17)
Modvolc has spotted yesterday a thermal anomaly at the top of Heard Island, a volcanic island south of Kerguelen in the Indian Ocean. This is the first signal detected on the volcano since May. Eruptive activity was marked at the time by the presence of a lava flow on the southwest side of the volcano and was identified during March through satellite data. The island is uninhabited.
The presence of these thermal signals is very irregular, partly because of the almost continuous presence of large masses of clouds that block the signal and make it invisible to satellites and probably also because the eruptive activity is irregular at this volcano.
The current phase is, in any event, of little importance as the the MODIS images from which MODVOLC is getting his data, show no trace of ash (no explosive or very low activity) or not even a degassing plume. Taking into account findings of the recent past, it is possible that a small low lava lake is responsible for the thermal signal. But only sharper observations (direct observation or high-resolution satellite imagery (weather)) will be able to tell us more about the current state of activity.
Translated from the original French article at CultureVolcan earlier today (http://laculturevolcan.blogspot.fr/)
Rodger Wilson volcano overview of July 8
Another pulse of seismicity occurred overnight beneath the "South Moat" of Long Valley Caldera (CA) (station MCB), perhaps in response to passage of earthquake waves associated with the magnitude M7.2 New Guinea earthquake (also visible on seismogram).
Popocatepetl volcano (Mexico) has continued to erupt almost continuously overnight. OMI satellite data shows sustained profuse emission of SO2 from the volcano (indicative of arrival of a large volume of "new" magma near the surface).
Small local earthquakes continue at Momotombo volcano (Nicaragua) (station MOMN), and volcanic tremor continues to affect nearby volcanoes Telica (station TELN) and Concepcion (station CONN).
The level of "background" tremor at Nevado Del Ruiz volcano (Colombia) (station OLLZ) increased overnight.
Volcano seismicity (presumably reflecting mostly internal activity) remains high at Reventador volcano (Ecuador) (station CONE).
Numerous volcanic "clone" earthquakes have affected White island volcano (New Zealand) since early this month. GNS interprets the activity to result from hydrothermal processes not renewed magmatic intrusion.
I included volcanocam photos of Fuego and Santa Maria volcanoes (Guatemala) only to show their tranquil state (as also indicated by seismograms from each volcano) today.