Clear Sight


Popocatépetl, June 18th

Posted in volcanoes by BJ Deming on June 18, 2013
Tags: , , ,
CENAPRED

CENAPRED

That is the view a few minutes ago from CENAPRED’s Tochimilco cam. It was the clearest view – the summit was pretty much socked in, and now is totally obscured.

That’s a plume going straight up, and its gray tinge (more…)

Another explosion at Popocatépetl this afternoon

Posted in volcanoes by BJ Deming on June 17, 2013
Tags: , , ,
CENAPRED

CENAPRED

A busy day today!

At 1:23 p.m. local today, Don Goyo had an explosion that was the biggest I’ve seen since watching this volcano over the last year or two (note: I’m an amateur who just cruises volcano cams on the Net and loves geology).

The volcano then settled down to its baseline pattern and CENAPRED did not raise the alert level – it’s still Yellow, Phase 2.

I’m not going to start live-blogging again until the alert level is raised again, if and when it ever is. However, this explosivity seems new, though it’s certainly not anywhere close to what Popo has done in the past.

Will be sure to watch it more frequently and post about any major changes. You can do this, too, by clicking the CENAPRED link in the side bar. Their website is in Spanish but they do have an English bulletin there, as well as links to the webcams (“imagen”).

Here is CENAPRED’s special bulletin from today, translated with the help of Google Translate:

14:00 June 17 (June 17 1900 GMT)

Today at 13:23 h an explosion occurred at Popocatépetl volcano that generated an eruptive ash column over 4 km high and threw incandescent fragments at distances up to 2 km from the crater, which by its high temperature caused small fires in the grasslands (see figure 6), (see Figure 7). The ash has been carried to the northwest by the prevailing winds in the area, so it can be expected that in the coming hours ashfall will be recorded in populations of this sector, even in the southeastern portion of the City of Mexico. At the time of this report, the volcano has returned to its previous levels of activity. This type of event is among the scenarios considered in the current alert level, so the Volcanic Alert semaphore remains at Yellow Phase 2.

Edit: You can also view the event at Webcams de Mexico, even if you don’t speak Spanish. On their page, under “Archivo de videos (Timelapses)” select June 17 (it’s easy with the popup calendars) and “Todo el día” in the “Periodo” box. It goes pretty quickly. Try selecting 5 fps to slow it down.

Edit: Wait! This is better. Webcams de Mexico made a YouTube video and Erik Klemetti discusses it – check out the shock wave:

Popocatépetl restless today

Posted in volcanoes by BJ Deming on June 15, 2013
Tags: , , ,
CENAPRED

CENAPRED

The Colossus of Puebla was doing its thing today. Here is CENAPRED‘s 11 a.m. bulletin in English (more…)

Update on posts

Posted in American Civil War,volcanoes by BJ Deming on May 29, 2013

Yes, another one, just so you know what’s happening.

There is a lot happening in the Civil War in 1863, and I want to get a grip on the most important things, so posts are taking longer.

This late in the war, too, many different threads are starting to come together. Looking into the siege of Port Hudson, for example, brought to attention the Louisiana Native Guard and assorted things involving black US military troops, their use, misuse and abuse.

It takes time.

Also, Jefferson Davis’s birthday is coming up next week. I skipped him last year because I knew so little, but now I have more information and plan to write something in-depth. I was going to address slavery in that post, too, as he addresses it quite a bit in his history of the Confederacy, but that will have to wait for a separate post, as there will also be an anniversary post next week.

Fortunately, Popocatépetl volcano has not changed its recent pattern. Because of that, and with the monsoon clouds often blocking view of the volcano, I wrote my last live-blog post for a little while, unless something drastic happens, even though Don Goyo is still explosive and restless.

That will free up more time.

Thanks so much for your interest! Everything will eventually get posted. With luck, I might even get back on the Monday posting schedule for the Civil War anniversary!

When you're having fun.  Photo:  Robert Couse-Baker

When you’re having fun. Photo: Robert Couse-Baker

Update

Posted in American Civil War,volcanoes by BJ Deming on May 26, 2013
Tags: ,

Well, with a busy work week and holiday, I’ve not been able to get back to the Civil War until today. They remembered it yesterday in Vicksburg, however:

It was 150 years ago today that Union Gen. Ulysses S. Grant decreed to a war-weary Vicksburg that wouldn’t give up: Let the siege begin.

It’s a challenging goal, but I will try to get the week’s Civil War post completed (it’s about halfway there) today and also next week’s, for automatic publishing tomorrow on Memorial Day, if possible.

Popocatépelt from CENAPRED's Tochimilo cam May 25, 2013

Popocatépelt from CENAPRED’s Tochimilo cam May 25, 2013

Popocatépetl

The Colossus of Puebla did not take a break over the last few days, either.

Fortunately the time-lapse program was on it except for some time yesterday when I had to go out. There is a week-long movie of it from the Tlamacas cam from last Saturday until yesterday, and a few more good images that I hope to get up in the live-blogging post today, as well.

CENAPRED is probably watching Popo closely. Per their bulletins yesterday and this morning, the volcano is having hours’ worth of spasmodic tremor and yesterday some harmonic tremor, too.

At the moment, it is having a big explosion.

Image from Webcams de Mexico.  I added labels for the steam (white) and ash (gray) columns.

Image from Webcams de Mexico. I added labels for the steam (white) and ash (gray) columns.

They are getting into the monsoon season in Mexico, and views of the volcano will be almost completely obscured by clouds soon, until around October.

Live-blogging Popocatépetl again (from May 12, 2013)

Posted in volcanoes by BJ Deming on May 12, 2013
Tags: , , ,
CENAPRED

CENAPRED

1:09 p.m. Eastern, June 10

It was a very busy week, and I missed the news (Spanish) that CENAPRED had lowered the alert at Popocatépetl back to 2.

Popo is still at yellow alert, and they are still monitoring it closely. According to the above news article, going back to phase 2 basically means that the 1500 marine, Army and Federal Police personnel that were deployed back in May can now return to regular duty.

10:34 a.m. Eastern, June 2

Don Goyo is behaving himself lately, but in yesterday’s bulletin CENAPRED shared three images of the crater taken during a May 28th overflight. They said about these:

On May 28 a reconnaissance flight of the volcano´s crater was carried out, in which the presence of a dome was corroborated. It is mostly covered by rock and ash fragments produced by the explosions of the few last weeks, with a small crater on its surface produced by the explosion of May 15th. Additionally, the scars left on the snow by the impact of ballistic incandescent fragments can be seen (see image), (see image), (see image).

Also, there was some activity on the PPIG webicorder on May 30th, so I started the time-lapse video capture program. Popo didn’t pop any more than usual, but lenticular clouds kept forming partially on the summit all afternoon, and around sunset, all but one big thunderstorm behind the volcano and to the left cleared, and spectacular lenticular clouds formed at the summit. My video process isn’t perfect, but I did get the basic images:

Those are stars moving across the night sky at the end, by the way. I’m not sure of the constellation, perhaps Cassiopea?

********************

How big is Popocatépetl?  That brightest "spark" is slightly under 1 mile (1.5 km) from the crater - only about halfway down the visible slope here.  CENAPRED Image 2

How big is Popocatépetl? That brightest “spark” is slightly under 1 mile (1.5 km) from the crater – only about halfway down the visible slope here. CENAPRED Image 2 under 10:00 h

3:45 p.m. Eastern, May 27

After this post, I will take a bit of a break, unless something drastic happens at Don Goyo – and it could at any time, although this morning’s CENAPRED bulletin shows the volcano is staying in its recent pattern, with less explosiveness perhaps in the last 24 hours (it’s still having harmonic tremor).

Lahars

An article today online in Ladobe (Spanish) reports that Director Aurelio Fernandez of CUPREDER (again, Spanish) reportedly said (per Google’s translation and mine) that the activity recorded by the Popocatepetl in recent years is negligible compared to the potential of the colossus, which, he said, ranks as one of the most explosive in the Americas. In comparing eruptions over the last 1000-2000 years, this volcano’s activity in the last 20 years hasn’t even left a layer in the subsurface; in 100 years, it hasn’t marked the surface.

CUPREDER, by the way, is a regional disaster prevention center based at the University of Puebla, while CENAPRED works at the national level. CENAPRED does the monitoring at the Colossus of Puebla, along with two institutes at Mexico’s National University and with collaboration from the USGS.

A boulder carried by one of Popocatepetl's past lahars.  University of Castilla-La Mancha

A boulder carried by one of Popocatepetl’s past lahars. University of Castilla-La Mancha

Other CUPREDER academics, including Vincent Nolasco, are quoted in the Ladobe article as saying that Santiago Xalitzintla and San Nicolas de los Ranchos are at risk of lahars. Xalitzintla, he noted, experienced one in June 1997, and there was another one in the same zone on January 22, 2001.

I don’t envy CENAPRED volcanologists and emergency professionals their job. Popocatépetl is going to be socked in with clouds and lahar detection will be difficult without good visibility.

Other hazards

Fortunately, the alert level at Don Goyo is still yellow, albeit at the highest sublevel of 3. The volcano is restless, though, and as noted in Part 1 of Operative Plan Popocatépetl, it can be quite dangerous if things escalate.

Risk Map from Operative Plan Popocatepetl

Risk Map from Operative Plan Popocatépetl. Circled areas are zones 1, 2 and 3, described below. Click to enlarge.

According to Google’s translation with some cleanup by me, the Plan’s background section notes:

From the beginning of our era [after the conquest, I think...BJD], its eruption of lava has stopped as its main vent is completely blocked. In the course of centuries it has only had strong eruptions through internal cracks, which have cast moderate-sized stones, ash and large gaseous fumes huge distances. It did have three side vents south and southeast, but after the eruptions in 1919 there have been only two.

The main map shows three different areas: 1, 2 and 3, according to their danger. Colors of these areas are intended to show that the greatest risk is to the top of the volcano. Each zone includes all hazards associated respectively volcanic eruptions large, medium and small.

Area 1, being the closest to the top of the volcano, is what poses a greater danger because it is the eruptions most commonly affected, regardless of their magnitude. This area encloses hazards such as volcanic material flows at high temperatures that descend the volcano at extremely high speeds (100-400 km/hr) [those hot puffy death clouds known as pyroclastic flows...BJD] and lahars that move following existing channels at lower speeds.

Area 2 has less risk than area 1 in that it is affected by eruptions less frequently. However, eruptions that have reached this area produce a degree of danger similar to Area 1. The frequency of occurrence of volcanic events affecting this area is 10 times every 15,000 years on average.

Area 3 covers an area that has been affected in the past by extraordinarily big eruptions. Eruptions of such magnitude are relatively rare, so that the risk within these areas is lower in relation to that areas 1 and 2, closer to the volcano. The hazards in area 3, however, are essentially the same as those of the other areas.  In the past 40,000 years there have been 10 eruptions of this type.

Zone 1. This could be affected by the fall of significant amounts of volcanic sand [they didn't say "ceniza" so I'm not translating it as "ash" ... BJD] and pumice, whose accumulations reach several centimeters in the case of small eruptions or several meters, with blocks of up to 30 cm [about 1 foot ... BJD], in very large eruptions.

Zone 2. This could be affected by moderate fall of volcanic sand and pumice, whose thickness can vary from a minimum of 1 mm (light covering of fine powder) in small eruptions to up to a meter in large eruptions.

Zone 3. This would be less affected by falling volcanic sand or pumice. There would not be fall during small eruptions but it could accumulate tens of centimeters during very large eruptions.

There is a remote possibility that a part of Popocatepetl could collapse, causing a giant landslide.

This would move at high speed (about 100 km/hour) [a little over 60 mph - yes, this has happened there...BJD] up to a maximum distance of approximately 80 miles, destroying everything in its path.

Over the past 40,000 years, 2 large landslides occurred south of the volcano, covering large areas; if another event of this kind happened, it probably also would head south. Generally large deformations that can be observed precede these collapses.

A large eruption or collapse would be accompanied by giant mudflows and powerful floods. These would travel distances of tens of kilometers through the canyons down Popocatépetl.

Gosh.

Well, that last is the absolutely worst-case scenario and it’s not unlike that posed, for example, by Mount Rainier in Washington State. Extremely unlikely but not impossible, in other words.

They do have a graph in the plan showing the likelihood of various scenarios. From what I’ve read – and keep in mind that I’m not particularly well read, nor an expert – my understanding is that flank collapse can happen without warning, because it’s just basically ground failure. There don’t have to be magma movements or earthquakes to set it off (though such things possibly could if the wall was weak enough), so movement sensors might not pick up any precursors.

Perhaps that as well as the extreme unlikeliness of such an event in our lifetimes is why they didn’t include that possibility in their graph. They’ve got most of the others covered:

Operative Plan Popocatépetl

Operative Plan Popocatépetl (click to enlarge)

All you need to know, if Spanish is not your thing, is that they estimate that chances are 70% to 90% that Popo will continue having small eruptions; 10% to 25% that it will increase to a moderate intensity; and 2% to 5% that it could go plinian (like Mount St. Helens in May 1980, if not necessarily at the same intensity).

So, yeah, I’m glad I don’t have CENAPRED’s job now that the volcano will often be shrouded in clouds this summer. However, last year it just kept cooking along and finally settled down a bit in the fall. Hopefully, something similar will happen this year.

I’ll post again if and when something changes, up the scale or, preferably, back down to a lower alert level when live-blogging really won’t matter much.

********************

3:15 p.m. Eastern, May 26

As mentioned in the update today (which has a couple of good images of Popo), I had to skip a few days but Popocatépetl didn’t – CENAPRED has noted sizable amounts of spasmodic and harmonic tremor, and the volcano continues to have intermittent small to moderate explosions.

Here is one of the smaller explosions, seen from two different cams (Tlamacas on the left and Alztomoni on the right):

CENAPRED (click to enlarge)

CENAPRED (click to enlarge)

Here is a video of the activity from May 18 through May 25, as seen from the Tlamacas cam, sequential in roughly 2-minute captures except for 81 bad segments, some duplicates and a few out-of-sequence images that I apologize for and will try to avoid on future videos:

Popocatépetl had a blast overnight

Posted in volcanoes by BJ Deming on May 8, 2013
Tags: , ,

Last night, the Colossus of Puebla reminded everybody that it’s not just another pretty face, simmering away prettily in the background.

Per the 11 a.m. CENAPRED bulletin:

CENAPRED

CENAPRED

May 08 11:00h (May 08, 16:00 GMT)

Yesterday the monitoring system of Popocatepetl recorded an episode of high amplitude spasmodic tremor that began yesterday between 19:28 h and 01:59 h today, from this time began to decrease in amplitude until 03:48 h. This episode was accompanied by a column of ash that came to reach an approximate height of 3000 meters above the crater southeast direction … . There were reports of ash fall in the towns of San Pedro Benito Juarez, San Juan Tianguismanalco, Atlixco and in some areas of the city of Puebla. Most of the episode of tremor was accompanied by the emission of incandescent fragments at an average distance of 500 meters from the crater, mainly on the northeastern slope.

Prior and subsequent to this episode were 40 low-intensity exhalations. Also, today at 07:23 h there was another of moderate intensity that issued small amount of ash that moved towards the southeast of the volcano … . Also today was recorded at 08:37 h a volcanotectonic earthquake of magnitude 1.9. At the time of this report shows the continuous emission of steam and gas, eastbound … .

Ashfall in Puebla last night.  Source

Ashfall in Puebla last night. Source

Yesterday was a very long work day, both in the “day job” of medical transcription and in writing, and I missed it. Erik Klemetti posted about it. There are some more good pictures at that link.

I think the high-amplitude tremor shows that this was an actual eruption, not just a dome blowing. The question is . . . what next? Popo could settle back into its earlier pattern for the foreseeable future, or not. Anyway, CENAPRED hasn’t raised the alert level above Yellow and Don Goyo is, for the moment, sitting quietly on its dignity as if to say, “What? What’s all the fuss about?”

CENAPRED

CENAPRED

Edit: 9:25 p.m. Eastern

Now this is just showing off:

Unretouched image (except for drop shadow) from CENAPRED's Tianguismanalco webcam for Popocatépetl

Unretouched image (except for drop shadow) from CENAPRED’s Tianguismanalco webcam for Popocatépetl – click to enlarge

That’s one of those webcam captures that leave a smile on your face for the rest of the day. Just happened to hit it right. It’s nice, too, that the Tianguismanalco cam is usually the one that is all ashed over when Don Goyo is fussing.

Edit: May 11, 2013

Just wanted to insert this webicorder capture from May 9-10. PPIG is the online webicorder SSN has for Popocatépetl.

I don’t understand this, specifically, the point where it ends.

National Seismology Service, Geophysics Institute, National University of Mexico

National Seismology Service (SSN), Geophysics Institute, National University of Mexico

CENAPRED put out an extra bulletin about this yesterday (May 10):

May 10 15:20 h (May 10, 20:20 GMT)

At 11:42 h (local time) started a train of exhalations followed by segments of harmonic tremor of medium to high amplitude, which lasted until 14:43 h. This internal activity represents possible magma ascent. Nevertheless, except for low intensity exhalations of ash at the beginning of this episode, it hasn##t been reflected with any important external eruptive activity. At the time of this report, the cloud cover does not allow observations of the volcano, so it cannot be ruled out that other ash exhalations might have ocurred.

The Volcanic Alert Level remains at Yellow Phase 2.

Unfortunately, I didn’t didn’t have the webcam capture going. Here is an image CENAPRED included in their bulletin, showing Don Goyo at 1004. I believe you can see the seismographic impact on the webicorder (above):

CENAPRED

CENAPRED

After that oomph! moment, PPIG shows activity picking up some in the midmorning, and then especially around 1320 and going on consistently until around 1435 with a bit more just before 1445.

Popocatépetl update, and why it’s my favorite volcano

Posted in volcanoes by BJ Deming on April 28, 2013
Tags: , , , ,

The Colossus of Puebla had some explosions later in the week after my last post, but I held off on posting as CENAPRED didn’t raise the alert level, and I also wanted to explain why this volcano interests me so. There just wasn’t time to do all that during the work week.

Activity

Clouds obscured the webcam views much of this week, probably because (more…)

Popocatépetl update for April 23

Posted in volcanoes by BJ Deming on April 23, 2013
Tags: , , ,

There’s a treat (at least for volcanophiles) at the end of this brief post.

First, in yesterday’s post I linked to Erik Klemetti’s recent post on Popocatépetl in which he noted that the uptick in explosiveness might be due to either a lot of water reaching hot rock or the volcano clearing out its throat some.

Yesterday, it seemed like “throat clearing” might explain it, but on the few times I could check the webcams today (had a busy work day), Don Goyo was sending up plumes of what CENAPRED says is water vapor and gas, with only small amounts of ash.

Like this: (more…)

Update: A bit more on Popocatépetl and the Civil War post this week

Posted in volcanoes by BJ Deming on April 22, 2013
Tags: , , ,

First, the Civil War anniversary post this week – got a late start, but it will be out some time tonight/early tomorrow morning.

As for Popocatépetl, it’s keeping this amateur guessing! A look at Don Goyo via the Tochimilco webcam just now is very ashy:

Cough!  Cough! Hack!  (CENAPRED)

Cough! Cough! Hack! (CENAPRED)

And the Tlamacas webcam shows ongoing light ash emission, too, at times perhaps a little explosive:

CENAPRED

CENAPRED

This falls within the activity described for Yellow Phase II by CENAPRED, but the volcano has been more explosive lately (hence, the recent overflight, presumably). On the 16th, Erik Klemetti at Eruptions noted that Popo’s explosions “might have been caused by the clear[ing] of any dome/plug material in the vent area or water getting deeper into the hot rocks at the summit.”

What are you doing, Colossus of Puebla?

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