Meanwhile, in Puebla . . .

See update at bottom of post, or click the Popocatepetl link at the top of this page.

This is a 2011 view of nearby Popocatepetl volcano from downtown Puebla.

Today, people in this Mexican city are watching Popocatepetl with concern (you can follow updates on its activity through the link in the top menu–it has been a bit more restless lately).

Reportedly (Spanish), Puebla State’s Civil Protection director has made a public statement. Per Google Translate of this linked news story:

Although in the last hours and days the Popocatépetl volcano has presented constant explosive activity, with incandescent fragments expelled by the crater, the Civil Protection director of the state of Puebla, Rubén Darío Herrera Cabrera, assures that it is a normal cyclic activity and that there is nothing to worry about.

The incandescent fragments, explained the head of Civil Protection, are pieces of the dome . . .

Even though spectacular fumaroles have been seen in recent days, the largest of which is 2,400 meters above the crater, there is nothing to worry about; “Another point that is constantly monitored is the seismicity and that is totally low, we have very few reports of seismicity, which gives us peace of mind,” said Herrera Cabrera, adding that the volcanic warning light continues in Yellow Phase 2.

This is an image from last night’s explosion as seen from one of CENAPRED’s webcams:


This is a night-time image, but the camera is a very good one and the Moon is quite bright. That’s chunks of incandescent material blown out of the crater, not flowing lava. Popo’s lava is very sticky and forms a dome in its crater that eventually pressurizes and blows up–apparently this is the demise of Dome #78. (CENAPRED)

Again, just click on the link at the top of the page for links to more information about Popocatepetl and updates from me.

Update, September 25, 2018: Popo got into a dramatic mood yesterday; updates are at the Popocatepetl link at the top of this page. Meanwhile, here is an eruption the volcanologists monitoring this volcano captured–it’s just one of several yesterday:

Featured image: Luisalvaz, via Wikimedia. CC BY-SA 4.0


Popocatepétl: A Dangerous Volcano

August 12, 2018: I’ve just read this scientific paper (open-access, freely downloadable from Springer), written by volcanologists in easy-to-understand English, that describes just how difficult it is to manage a potentially violent volcano like Popocatepétl over a long-term “semi-crisis” like the one unfolding there today. Check it out! It really gives you good background on both the volcano and its human setting.

People in central Mexico have always felt a strong personal link with Popocatepétl, which they often call Don Goyo.

As we saw last time, when this volcano broke its five-decade silence with a VEI-2 bang in 1994, local people responded with traditional ceremonies; artists were drawn to the event; government officials took emergency measures; and scientists expanded their monitoring networks.

For almost a quarter of a century now, Don Goyo has been on center stage. People have adjusted to it and are moving on with their lives, as people always do after a natural disaster.

But scientists just updated the official hazard map (Spanish) for Popocatépetl, which we’re going to take a look at in this post.

The volcanologists did reassure everybody that there is no sign of any increased or upcoming increase in activity; the volcano is still at a “Yellow, Phase 2” alert level.

Also, to counter popular rumors, they stated in no uncertain terms that Don Goyo is not connected to Guatemala’s Fuego, which recently had a deadly eruption, or to Kilauea, out in Hawaii, with its spectacular lava flows. Each of these three volcanoes has its own plumbing system and exists for different geological reasons.

The problem with Popocatépetl is that, not only in 1994 but also at any point in modern times, this volcano has never shown the levels of violence that the geologic record proves that it is capable of.

And now Don Goyo has 25 million human neighbors, unfamiliar with its historic power and living less than 65 miles (100 km) away from its summit.

Ashfall risk from Popocatépetl

Ashfall risk for Popo

See CENAPRED’s hazard map (Spanish) for details. “Ciudad de México” is Mexico City.

  • The dotted line shows the area that would get at least 4 inches (10 cm) of ash if Don Goyo had another eruption as powerful as one about 14,000 years ago.
  • Red: In a big eruption, this unfortunate area could get lots of volcanic ash (up to yards/meters in depth) as well as a bombardment of rocks up to a foot (30 cm) in size.
  • Orange: Just a little ash would fall here in a small eruption, but up to 3 feet (1 meter) or more in a big one.
  • Yellow: This region isn’t at much risk of ashfall in small eruptions at Popocatepétl, but it could get several inches (dozens of centimeters) in a large eruption.

Seismic sensors, deformation monitoring, and gas/hydrothermal studies can pick up signs of such approaching events, especially the big ones.
Continue reading

Mount Merapi

Indonesia is an exciting place for geoscientists, but the rest of us get a little confused by all the headlines about erupting volcanoes there: Tambora, Bromo, Sinabung, Agung, Merapi . . .

Let’s focus on that last one, because it has recently begun to stir again.

Perhaps you’ve seen this video from May 11, 2018:

Indonesian volcanologists later determined that was a steam-driven (“phreatic”) explosion that happened when magma came in contact with ground water circulating in the volcano’s walls.

Wonder why ordinary people would be relaxing and eating in such a desolate place?

Continue reading

Guest Videos: The Hidden Secrets of Minerals

Bubbles happen. And sometimes they are awesome.

Here is a bubble that formed inside of sea salt in a solution that a student at Finland’s Tampere University of Technology was making.

Gas pockets also form naturally in halite (rock salt). These are even more awesome because this air is the atmosphere as it was back in the day, not what we have today. Such air bubbles allow Earth scientists to directly study conditions in the distant past.

This recently made the news when researchers analyzed 800-million-year-old air found in Australian halite and found more oxygen than they expected. The discovery could change our understanding of how early animals evolved.

Inclusions have been found in volcanic rocks, too.

Molten rock degasses–this is why volcanologists measure CO2, sulfur, and other gases on a sleeping volcano. As magma rises toward the surface, those gas levels increase. It’s a way to see inside the volcano before it erupts.

Some gas remains in lava after it has erupted. There isn’t much and it’s not as easy to measure as a gas bubble, since what was once molten rock is now frozen. This is why melt inclusions are solid and glassy. (Oppenheimer)

Nevertheless, there is sometimes enough gas left for scientists to get an idea of how much climate-changing gases an ancient eruption released. (Self and Rampino)

For instance, one reason the Deccan Traps flood basalt in India is sometimes associated with the dinosaur-killing K-Pg mass extinction (in addition to the asteroid impact) is because its eruption may have released at least 200 times as much sulfur as the 1991 eruption of Mount Pinatubo (Oppenheimer), whose sulfur cloud cooled the world 1 degree Fahrenheit between 1991 and 1993.

Melt inclusions also convey a lot of information about the physical conditions at the source of the magma they formed in, many miles below our feet.

And then there are Hadean zircons. These small crystals found in igneous rock contain information that is changing how we picture the very early Earth.

Mineral inclusions in antarctic zircons also provide clues about what was going on back in the Hadean.

Perhaps the biggest inclusion-related surprise for geoscientists is the discovery of tistarite–a very rare titanium-based mineral–in melt inclusions found in rock that was erupted during the Cretaceous in what is now northern Israel.

How rare is it? Tistarite formed along with the Solar System and only one grain of it has been found in a meteorite. No one suspected there was any on Earth.

Now it looks like geologists may have to rewrite their textbooks on the deep Earth’s geochemistry!

Featured image: Eurico Zimbres. CC BY-SA 2.5.

Oppenheimer, C. 2011. Eruptions That Shook the World. Cambridge: Cambridge University Press. Retrieved from

Self, S., and Rampino, M. 2012. Flood basalts, mantle plumes and mass extinctions. The Geological Society. Last accessed March 23, 2018.

La Palma Eruption Unlikely Any Time Soon

Just saw in the online news that there is concern about increased seismicity at La Palma volcano in the Canary Islands.

According to experts who reportedly met Friday, magma did move inside the volcano, but it was a relatively small amount and very deep–almost 20 miles below the surface.

Of course they are monitoring this closely, but no warnings have been issued yet.

Featured image: NASA

Guest Video: Hawaii’s Vog

Vog is volcanic smog, and thanks to Kilauea’s longstanding eruption, there’s a lot of it in Hawaii right now. But this video from the University of Hawaii also shows somebody climbing a snow-covered volcano, and someone else snowboarding. In Hawaii. Cool!

Featured image: Vent at Kilauea’s Halemaumau crater, by Scot Nelson (Flickr). CC BY 2.0.

Guest video: Iceland’s Laki Volcano 1783

Today, volcanic eruptions are spectator sports…whee!

The volume of lava poured out by Bardarbunga volcano’s ongoing eruption just surpassed that of all other effusive eruptions in Iceland since the eruption of Laki Volcano in 1783-1784. Bardarbunga is tiny in comparison to Laki, though.

It’s difficult for us to understand just how huge and how devastating that eruption was for Iceland and the rest of the world.

Fortunately, we aren’t facing the same risk today from Bardarbunga.

Here are two short videos the BBC posted from its Timewatch episode on Laki. Check out this source for more details on that eruption, too.


Guest video: USGS, “Volcano Hazards”

Time is a bit short this week, so today I am just sharing some USGS videos about volcanic hazards and Yellowstone volcano. (Be sure to check out the USGS website listing alert status of all US volcanoes.)

What’s that? Yellowstone?

Yes! Here is a three-part series of informative videos about the supervolcano by Jacob Lowenstern, scientist in charge at the Yellowstone Volcano Observatory.