CotoPaxi Volcano - Ecuador seismic status

[Bob]

Activity continues, with brief respites

[Bob]

Yesterday evening there were some strong eruptive events, reminding me of Reventador's seismic pattern. The larger scale events were about 2200 (10pm) local time.

Today's seismic pattern remains ACTIVE.

Listen to a sample of the tremor:

Source: https://youtube.com/watch?v=ZVTg1H7U1-I

[Bob]

Eruption pattern activity continues. An increase in activity was noticed starting at about 0030 local time, (with a large bump)..

A slight (very slight) decrease in activity was noticed today a little after noon, and remained lower until about 1pm local time, where stronger activity progressed.

The volcanic institute, reported this:

August 22, 2015

Today the volcano dawned clear and it was easy to see that the column of steam and ash leaving the crater was more sustained and high compared to previous days.

They provided this image:

and this image

Also report with this increase in ASH emission was an increase on toxic gases. (exact amounts were not available for posting at this time)

[Bob]

A larger event about 1717 local time preceded a major decrease in activity. That can happen if the magma chamber has a large chunk of rock fall in, then it "bursts" out, creating a pulse. Never-the-less, 'things' shifted, and with this shift the seismic pattern switched to a "puffing pattern", reminiscent of an old style steam locomotive..

Between midnite and shortly after 2am local there was hardly any activity - then seismic activity resumed, and was pulsing once again. The spacing between the pulses was decreasing to a lower periodicity, (slower cycle between the radical changes).

Strong seismic emission started again, indicating internal activity within the volcano about 0530 local time, and is continuing with a cyclic periodicity of about 1 hour between large high amplitude activity and activity reduced by about 1/4 amplitude.

(Note - if the graphics are not appearing to show full graphics, with traces over most of the page, do a right click on the image and then select, Open image in a New Tab, and then see if the graphic looks more complete. One can't get data past the current local time in Ecuador.)

[Bob]

Cotopaxi last nite continued to be very active - this morning a slight drop back to the "steam locomotive-like" puffing, the resumption of strong continual seismic tremor (and ash cloud).

By 1500 local time the seismic tremor reduced a bit with some abrupt spiking activity - which is indicative of "things breaking" and/or falling. If there is continual activity, this pattern would appear - a pulse/explosion, followed by strong seismic activity, and then a 1 hour oscillation period of strong and weaker cycles of seismic tremor - we shall see what happens in the next hours.

[Bob]

Cotopaxi continues to emit, non-stop today:

[Bob]

Strong activity today for Cotopaxi

Last night, about 6PM (1800 local time), output diminished a bit, and went back to the old steam locomotive 'puffing style' of emission.

Later however about 9:00 am local time very strong activity resumed and is continuing. Again, very reminiscent of the volcano Reventador (also in Ecuador, one of the most almost continually active volcanoes).

[Bob]

A little more calm today with the Volcano CotoPaxi

The one hour slow cyclic eruption period has resumed once again.

[Bob]

Output from the volcano reduced substantially last nite, with a pattern which resembled "rocks" falling into the hot zone, then subsequently, tremor started to appear. Within the pattern is a slow wave of building, receding building and receding, and so forth.. The quietest period was near the 2300 hour window.

This morning about 0900 local, the puffing pattern has resumed.

Above, a night photo, showing the ash cloud of the eruption.

[Bob]

Lower (reduced) emission from CotoPaxi Volcano

Recent emission map (26th)

[Bob]

Output continues to diminish, when eruption happens, a 2-3 hour outburst is being noticed - slow waves..

[Bob]

Moderate cyclic eruption pulsation, matching the 'slow wave" cycle persisted till about midnight, then dropped off until the morning, at which time the slow eruption wave resumed. Activity has seemed to be diminishing regularly. When the low clouds clear, the optical image of the volcano has been providing interesting views (live camera).

[Bob]

Activity was watched over the last few days, and it continued to decrease ever-more. Currently these are the last 24 hours activity monitoring reports (the subsequent 12 hours report is assembling):

[Bob]

Sept 4th and 5th marked the last larger ash output streams from the CotoPaxi Volcano.. however, the Volcanic Institute recommends NOT taking a complacent viewpoint at this time.

Deep seismic activity continues under the cone:

Thermal IR photographic of the Volcano (brighter is stronger/higher temperatures)

Visually, ashfall has been diminishing:

The glacier at the top of the Volcano has been showing numerous cracks and fissures. Lahars are still possible should activity resume, and the Volcanic Institute says such activity could resume in the next upcoming weeks.

Seismic activity. Pulses are noted as spikes followed by or preceded by tremor events. The Volcanic Institute did point out a large seismic event in the past week was note for continued observation that volcanic activity has not subsided, just diminished to deeper activity.

[Bob]

Small seismic pulses continue to emit around the CotoPaxi volcano -

Decreased seismic energy and the size of the ash emissions. Possibility of new pulses of activity.

Summary:
Since the September 5 (report N.- 14) there has been a decrease in the levels of seismic energy and the size and ash content of the columns emission of Cotopaxi volcano.

The occurrence of an earthquake of magnitude 3.4 to 4.5 km under the crater of the volcano and the progressive increase in small particle sized material in volcanic ash, which has as its source the fragmentation of magma in the magma chambers. This decrease in activity may be temporary and could be followed by new pulses eruptive activity.

Activity start and peak and diminishment cycle:

The last 10 days on the right side of the peak have shown continual diminishment of activity in seismic output, as well as ash and gas outflow.

The occurrence of an earthquake of magnitude 3.4 on the crater and observed changes in the proportion of small particle sized material in the ash suggests that magma continues moving slowly inside the volcano. As observed, it is considered that the decline in activity in recent days may be temporary and one can not rule out the occurrence of new pulses of eruptive activity.

[Bob]

The Chilean Event is at the bottom of the top graphic; this seismic monitor at CotoPaxi (Ecuador) is showing the large 8.3 Chilean earthquake. It can be observed the primary event, and the slow waves afterwards, the "rocking" and the secondary quake event as well. Within this are the events from the CotoPaxi volcano itself (the brief spikes)..

[Bob]

After shocks (the long duration patterns such as at 23:36 pm for 4 minutes) from the Chilean Event continue to be recorded up in Ecuador, at CotoPaxi's volcano. The CotoPaxi volcano continues to output "pulses" (as projected by the Volcano Institute) such as at 03:37 am. Pulses result from pressure build-up and "releases" explosively occurring. This volcano is not asleep (and nor is the region on the Ring of Fire). The double pulse pattern is a representative signature of the Ecuadorian eruptions.

[Bob]

After shocks continue from Chile's Event (two this afternoon local time, about 3 minutes per).

CotoPaxi volcano itself continues to experience spikey "events" and an occasional explosion in the magma chamber.

[Bob]

The continual spikes are creating concern for those in the volcanic Institute - they have published this scenario projection:

3 Scenarios:
The following scenarios for the next days to weeks arise as possible; these contemplate the occurrence of increases of volume of magma from the magma chamber into the reservoir:

a) slowly come back with several major pulses of magma into the reservoir, spaced apart by a time of several weeks or months. In this case, several pulses of eruptive activity materialize several times, so this eruption process continues for months (type Tungurahua March 2013). The thickness of accumulated ash are important in the prevailing wind directions. This eruptive phase can produce bursts of moderate size with ballistic drops bombs that reach up to 5 km from the crater with small pyroclastic flows (type Tungurahua July 2013). Additionally they can form lahars (volcanic mudflows and debris) generated by secondary volcanic material mixing with rainwater or snowmelt in the upper area of the volcanic cone. In this scenario lahars could be moderately small and mainly affect the area of ​​the Cotopaxi National Park. The eruption ends up in that case being a VEI 2-3. At the time of publication of this report this is the most likely scenario;

b) the ascending magma pulses have higher volumes and greater speed of ascent. This makes the high pressures produced the volcanic vent violently (explosively) open and paroxysmal eruptions VEI 3-4 (type Cotopaxi June 1877, November 2002 Reventador, Tungurahua August 2006) occur. Such happens with the generation of pyroclastic flows on all sides as the central character crater, predominantly towards the wind direction. Pyroclastic flows can reach the foot of the volcano. Contact between pyroclastic flows and the glacial ice produces a melting glacier. This liquid formation part of the lahars that descend by one or some of the drains that are born in the volcano are monitored. These lahars would become moderate to large size and could travel tens to hundreds of kilometers by river valleys leaving deposits which are meters to tens of meters thick. Additionally production of sharp falls of ash and lapilli (gravel) associated with this activity is possible. The shell thickness drop could reach more than 2.5 cm to more than 50 km of the volcano on the main wind direction. In general, to paroxysmal eruptions, there could be other smaller eruption sources which would be declining in intensity then activity would cease for several months or years. Depending on what the size of eruptive episodes are or not more diverse lahares are possible and they could be much smaller in volume than the main event flow. The final size of the eruption is a VEI 4. At the time of publication of this report, this scenario is less likely than a);

c) this scenario does not completely rule out a possibility of decrease of the eruptive activity in case the new intrusion of magma does not rise to surface areas. However, based on monitoring parameters and volcanic history of Cotopaxi, this scenario is the least likely.

These scenarios can be changed according to the evolution of the volcano's internal events..

Micrograph of ASH particles that are in the air:

Ash-cloud dispersion region:

The volcano is TILTING, moving in shape due to internal magma shifts - numerous volcanic tremor events and pulses have been noted:

Trace data on the radial and tangential axes inclinometers vs the number of earthquakes recorded until September 15, 2015. It is noted that there during the last 10 days it clearly deviated from the previous observations. Stay alert.

[Bob]

Stirring the pot... so to speak.. or "Volcanic Connected-ness"

The repeated after-shocks coming from the Chilean 8.3 quake have been helping apparently to increase the spiky volcanic pulses, the rock fault "breaking activity" within the magma chambers and pipes that make up the CotoPaxi underground geological system.

Note prior and after the 6 minute aftershot event (about 12:47 PM local) in the graphic below - low spike events prior (take a look above at post 118 also, similar spike increase proceed after the long duration aftershock event) and then increase of number/intensity/duration of the spike events afterwards..