Wednesday, December 4, 2013

Wednesday search challenge (12/4/13): When did the outflow reach the pyramid?

Last night a bunch of us had a meet-up in Silver Spring (Maryland) and got to chatting about SearchResearch.  If you’ve read this blog for a while now, you know that not everyone is local to Maryland, so it’s not a surprise that we started talking about other regular contributors.  Ramón is often among the first responders to the weekly search challenges, and last night I mentioned that he had recently sent me a beautiful photo of a mountain not far from where he lives.  

Naturally, this made me think of today’s search challenge.  Photo credit to Ramón for this pic (and for the inspiration to write this challenge).  

This isn’t just ANY old mountain, it’s a beautiful, and potentially deadly, volcano somewhere south of California.  (Juan will probably recognize it instantly as well.)  The rest of us will have to search it out and answer the following challenges: 

1. In what year did an outflow from this volcano cover some part of a nearby pyramid that was considered sacred to the rain goddess Chiconauhquiauhitl?  (And.. What's the name of the pyramid?)  
2. What are the volcanic domes in this caldera made of?  
3.  Will this volcano erupt again? 

As usual, please let us know the process you went through to find your sources.   Take note this time of what KINDS of information resources you’re considering.  Why do you believe the resources you’ve found are credible?  (We’ll talk more about credibility later this week or early next week.) 

Search on, volcanically! 


  1. Start: Google [Chiconauhquiauhitl]
    Fourth hit: Wikipedia [Great Pyramid of Cholula]
    No mention of volcanic activity.

    Google [Chiconauhquiauhitl volcano]
    Fourth hit:
    Travel in Mexico | Cholula y Puebla
    Mentions volcanic peak Popocatepetl active in recent history.
    Map shows it close to Cholula, but does not directly say outflow reached pyramid.

    Wikipedia [Popocatepetl]
    “On Wednesday May 8th, 2013 at 7:28 pm local time, Popocatépetl erupted again… plumes of ash… began to drift ESE covering areas of… the City of Puebla in smoke and ash.”
    Per the map in the Travel in Mexico article, Cholula is between Puebla and Popocatepetl, so this supports taking 2013 and Popocatepetl as the probably answers to question 1, if ash is considered outflow.

    Question 2:
    Wikipedia [Popocatepetl]:
    “Magma erupting from Popocatepetl has historically been predominantly andesitic, but it has also erupted large volumes of dacite. Magma produced in the current cycle of activity tends to be a mixture of the two”
    The probable answer to question two is “Basaltic andesite and dacite.”

    Question 3:
    Wikipedia [Popocatepetl]:
    “is a hyperactive volcano”
    The probable answer is “Yes”

    With Wikipedia, at least on non-controversial matters (religion, politics, and economics, the things you wouldn’t talk about in polite company), I take a trust-but-verify approach.

    To confirm the answer for Question 1:
    Wikipedia [Popocatepetl]
    Checked pictures against Ramón’s. Views from Mexico City seem consistent. The picture taken at sunrise shows peak angles that are roughly the same, the shoulders of the crater are in the same place, and a jutting rock on the right-hand slope of the Wikipedia picture corresponds to a jutting rock in Ramón’s picture.

    Wikipedia [List of Volcanoes in Mexico]
    (Assumption: Chiconauhquiauhitl being an Aztec goddess, her pyramid would be in Mexico, not Peru)
    Checked those with eruptions in human history to compare pictures to Ramón’s. None appear at all similar to Ramón’s photograph. Popocatepetl confirmed as answer to 1b.

    Google search [Popocatepetl Pyramid] (trying to confirm the answer for question 3) led to:
    “Potential for Large Eruptions at Popocatepetl”
    “We have found the 822AD lahars burying the lower 1m of the great pyramid of Cholula “

    This seems a more certain answer than the assumption and broad interpretation around taking the May 8th, 2013 ash plume as the answer, and the source (a volcanologist working for the JPL) can be considered an expert.

    Question 1: 822AD and Popocatepetl.

    To verify the answers to question two and three, followed the citations in the Wikipedia article on Popocatepetl.

    Citation for the answer to question two led to an abstract presented at the American Geophysical Union ( authored by Sosa, G., Gardner, J.E., and Lassiter, J.C. (all from University of Texas, according to their e-mail addresses)
    “In the last 23 ky Popocatepetl, a dominately andesitic volcano, has erupted at least 5 large volumes of dacitic magma”

    Google [Lassiter] confirms Dr. John C. Lassiter is a professor in the School of Geosciences there. Link mining shows Dr. James E. Gardner to also be a professor there. No G. Sosa is identified in the list of faculty.
    Still, credentials enough to consider it a credible source.

    Question 2: Basaltic andesite and dacite

    The citation for the introductory sentence to the article on Popocatepetl led to the Smithsonian’s Global Volcanism Program page on Popocatepetl, which reports ongoing volcanism of Popocatepetl, reinforcing the answer to question three (Also, the 3D rendering shows the same projection a third of the way down from the crater that Ramón’s photo shows).

    Question 3: Yes

  2. 1. In what year did an outflow from this volcano cover some part of a nearby pyramid that was considered sacred to the rain goddess Chiconauhquiauhitl? (And.. What's the name of the pyramid?) 822 AD, Great Pyramid of Cholula

    2. What are the volcanic domes in this caldera made of? Lava

    3. Will this volcano erupt again? It seems to be in a continuous state of eruption.

    Search took about 30 minutes.

    Web search - Chiconauhquiauhitl pyramid

    Great Pyramid of Cholula - Wikipedia, the free encyclopedia

    Web search Cholula, Puebla, Mexico volcanoes – led me to El Popocatepetl and Iztaccihuatl

    Image searches on each name - it had to be El Popocatepetl

    Web search - El Popocatepetl - wikipedia

    Web search - El Popocatepetl eruptions – lots of Wikipedia articles but nothing substantial. However there was a cool video of a recent eruption.

    Web search - Popocatepetl pyramid - good overview - 822 AD lahars partially covered the bottom of the pyramid.

    Picture of the pyramid with the mountain in the background.

    Web Search - El Popocatepetl volcanic domes

    Site that monitors current activity –

    Popocatépetl volcano eruptions:
    1345-47, 1354, 1363(?), 1488, 1504, 1509(?), 1512, 1518, 1519-23(?), 1528, 1530, 1539-40, 1542, 1548, 1571, 1580, 1590, 1592-94, 1642, 1663-65, 1666-67, 1697, 1720, 1802-04, 1827(?), 1834(?), 1852(?), 1919-22, 1923-24, 1925-27(?), 1933, 1942-43, 1947, 1994-95, 1996-2003, 2004-ongoing

    This site also mentions lava domes and says they are made up of lava a magma. Other sites confirmed this but no additional detail on composition.

  3. I did recognize the volcano :) On a clear day, I was able to see the Popocatépetl from Mexico City.

    1. I found that the volcano erupted between 700-850 AD, reaching the Great Pyramid of Chulula.
    2. A mixture of a mixture of dacite and basaltic andesite.
    3. Hopefully not too bad, but yes, it will. It's still active.

    I tried the search using only content in Spanish, which is something unusual for me. Ironically, I found a report from FAMSI ( that was written in English and translated to Spanish: . So pretty credible I'd say.

  4. Good day, Dr. Russell, fellow


    First, it is a great honor and privilege to be in your SearchResearch Challenge . Thank you!

    Searched (trying like probably others will make it):

    Trimmed image and [volcano near pyramid ] Found: Image of volcano "Popocatépetl"

    Found: Great Pyramid of Cholula
    "artificial mountain"

    Tlachihualtepetl legend and Great Pyramid the he largest pyramid in the world, in terms of volume (over 4.45 million cubic meters)

    [¨Popocatepetl domes made of *]
    Infrared satellite monitoring at Popocatepetl Ctrl F "Dome"

    [Define Dacitic]
    [Popocatepetl eruption History]

    Popocatépetl volcano that lead to

    Eurption History. First in 7150 BCE

    [Popocatepetl eruption AROUND(3) pyramid]

    Appeasing the Volcano Gods Article talks about Volcano, Hernán Cortés and shrines. Also talks about eruption.

    [popocatepetl eruptions] Google Scholar
    Repeated volcanic disasters in Prehispanic time at Popocatépetl, central Mexico: Past key to the future?

    [Cholula Great Pyramid] in Google Scholar
    Reinterpreting the Great Pyramid of Cholula, Mexico and
    Mountain of heaven, mountain of earth: The Great Pyramid of Cholula as sacred

    [tlachihualtepetl] in web and books. Found: The Great Pyramid Tlachihualtepetl and the Sanctuary of The
    Remedies with photos about the the History of the construction of Sanctuary of The Remedies


    1. In what year did an outflow from this volcano cover some part of a nearby pyramid that was considered sacred to the rain goddess Chiconauhquiauhitl? (And.. What's the name of the pyramid?)
    A. 80 AD and the last major took place according to Smithsonian about 800 AD. The name of the pyramid is "Tlachihualtepetl" Nahuatl for "Artificial mountain"

    2. What are the volcanic domes in this caldera made of?
    A. Dacitic Lava

    3. Will this volcano erupt again?
    A. Yes. The volcano name means smoking mountain. And it is the most watched volcano in the world, just in case a major eruption can come. Since 1994 is in activity and in eruption warning.

    I searched for site and information from reliable sources like books, articles and specialized websites. Also, check the data to verify it.

  5. “The Smoking Mountain” Popocatepetl “Popo”

    Having had the benefit of asking Ramón about his photos posted I did some research back in the autumn
    Volcano Discovery so I knew it was the ‘Popo’ located 50 miles southwest of Mexico City in the state of Puebla in the Trans Mexican Volcanic Belt. (Ramón tu más reciente foto de los dos montañas es muy bonita. Tienes nuestro sobre el terreno experto para esta búsqueda. Yo espero que siga fijando fotos.)

    Query Wikipedia for preliminary search. See Reference #1--

    The Smithsonian Institute Global Volcanism Program has an impressive website for volcanoes worldwide. It indicates that Popo, a stratovolcano, last major eruption occurred in 823 A.D. as evidenced by “ice core” and it lasted 90 days more or less. You will find a map and the coordinates for this volcano

    Oregon State website indicates as well that the last great eruption was 822 A.D. The outflow “lava &/or pyroclastic materials [tephra-ash, pumice, rock & hot gases] was 822 A.D. “Lahars [destructive mudflow] burying the lower 1 meter of the Great Pyramid of Cholula and the Puebla Valley.”

    Query [Popocatepetl pyramid]

    Cholula as mentioned at Atlas Obscura website “An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top” is situated 45 kms east of Popo.

    Nuestra Señora de los Remedios sits on top of the great pyramid as mentioned at the

    Archaeological Institute. It suggests the location may have been chosen to appease the gods.

    Wikipedia tells us Popo is the most hyperactive volcano in Mexico.“Magma erupting from Popocatepetl has historically been predominantly andesitic (grey volcanic rock), but it has also erupted large volumes of dacite (contains free quartz).Magma produced in the current cycle of activity tends to be a mixture of the two.”

    This website on Lava Domes Lava Domes is not specific to Popo but interesting nonetheless.

    The dangers lie in the type of eruption. A plume of ash into the air through a gravitational collapse can affect large communities like Mexico City and Puebla. Or air traffic can be interrupted which did occur in summer 2013. As well the collapse of the rim or side flow can direct pyroclastic flow in any direction which is why it has to be monitored closely.

    New lava dome forming July 2013 written by Erik Klemetti an assistant professor of Geosciences at Denison University states “Popocatepetl needs to be taken seriously”.

    National Geographic providing updates on activity in 2013 indicating activity and concerns.

    As well AccuweatherApril 2012 indicates 3 out of scale of 7 for potential threats.

    Will it erupt again - the potential threat is documented.

  6. In regards to credibility I had hoped to include a well-documented video in my results but finding UFO's over Popo was not my idea of credible reporting.

    As well I went back to see if there were any "sensationalized" stories regarding the recent activities at Popo. My SERP with Query [popocatepetl sensational] leads me to Query [Popocatepetl Volcano Nightmare: 19 Million Prepare to Evacuate in Mexico] and see the websites that ran with this headline. I think the more sensational a headline the more likelihood the article gets regurgitated lacking in foundation.

    Wikipedia I still thinks is a good place to start and often as in my results for this search they will link to well-known respected websites, institutions and have references and external links. Can the sources be cross-referenced? It's like not clicking on a link on an email to prevent phishing. Use your own sources when questionable and see if similar results come to the surface.

  7. I started by heading over to Ramón's Google+ posts. Having him in my circles I knew he posts many beautiful pictures of the volcanos near him. That gave me the name of the volcano - Popocatepetl.
    [ Popocatepetl ] to Global Volcanism Program | Popocatépetl and Cenapred On the Smithsonian site it has eruption history and a tab with references. The Cenapred site appears to be the emergency preparedness site for the volcanoes in Mexico.
    Next [ Popocatepetl pyramid ] to Potential for Large Eruptions at Popocatepetl and Appeasing the Volcano Gods - Archaeology Magazine Archive . The Oregon State page gave me "We have found the 822AD lahars burying the lower 1m of the great pyramid of Cholula..." I didn't think the article from Archeology. org was useful except to confirm the name - The Great Pyramid of Cholula (until later.)
    I switched back to trying to find when lava first went far enough to get to the pyramid. [ Popocatepetl pyramid lava ] to this powerpoint presentation. Scanned the slides and stopped at slide 16. "lahars" that is the second time I saw that word.
    [ define lahars ] to 1. a destructive mudflow on the slopes of a volcano. Check the question again and it doesn't ask about lava but overflow.
    [ Chiconauhquiauhitl ] to Wikipedia - Great Pyramid of Cholula and got "Just before the arrival of the Spanish, the pyramid was considered sacred to a rain goddess called Chiconauhquiauhitl (Goddess of the Nine Rains)."
    For the next question I figure a good place to start on what makes up the caldera would be Google Scholar and search [ Popocatepetl caldera ] to A caldera-forming eruption ~ 14,100 14C yr BP at Popocatépetl volcano, México: Insights from eruption dynamics and magma mixing They had me at Tutti Frutti! Since you were looking for credible sources I went to the U.S. Geological Survey site and searched [ Popocatepetl ] and [ Popocatepetl caldera ] and didn't really get anything.

  8. Google Search [ Popocatepetl caldera formed ] and find a book "Geology of México: Celebrating the Centenary of the Geological Society of México" pp 199-201 Page 201 has a great timeline/stratigraphic image of past eruptions.
    I go back and try to find another source for flow reaching the pyramid [ pyramid cholula 850..700 lahar ] but the range search but the range search doesn't appear to work in reverse, so [ pyramid cholula 700..850 lahar ] to COMMENTS - Mesoamerican Research Foundation The Google Quick Scroll extension leads me to "NOTE: Beginning in 1993, scientific studies find that volcanic activity has produced several eruptions, two of which were the most violent. The first was, ''at the beginning of the present era'' or first century A.D. The second was, ''between A.D. 700 and 850.'' (Plunket & Urunuela 1998)." [ Plunket & Urunuela 1998 ] to the PDF "Mountain of sustenance, mountain of destruction: The prehispanic experience with Popocatépetl Volcano" Page 4 talks about the artifacts and the time period based on radiocarbon dating suggesting they were covered sometime between 700-900AD. Page 7 becomes interesting because it states ...a zone that should show the presence of these deposits if indeed they reached the Pyramid – to date have failed to find stratigraphic evidence of these lahars (López et al., 2002a,b; Plunket and Uruñuela, 2002b, 2005a,b). Excavations on the campus of the Universidad de las Américas to the east of the Great Pyramid have demonstrated that, in areas where stratigraphy is intact, lahar deposits are also absent although a sterile layer of sandy volcanic ash consistently seals the black clay deposits of the Classic period; cultural materials overlying this layer belong to the Early Postclassic (Plunket and Uruñuela, 2005b, p.103)."

    1. In what year did an outflow from this volcano cover some part of a nearby pyramid that was considered sacred to the rain goddess
    Chiconauhquiauhitl? (And.. What's the name of the pyramid?)
    I don't know. The last article appears to say that suggestions that the flow reached the The Great Pyramid of Cholula are in dispute.

    2. What are the volcanic domes in this caldera made of?
    I'm confused if you're really asking about the cone or the caldera. Either way - too many things to list. Please refer to pages 199-201 of Geology of México: Celebrating the Centenary of the Geological Society of México

    3. Will this volcano erupt again? Cenapred suggest yes and everyone should be prepared. Ramón be safe!

  9. Extra this is what my tabs looked like at the end.

    1. Fred your tabs and mine looks almost the same. I know the volcano and it was great to search and find information that I didn´t know before and also read the answers in the SearchResearch. Thanks again for doing the Challenge Dr. Russell

  10. I worked the questions as I could find the answers on the SI site so they are backward.
    3. Yes is will erupt again. The first recorded eruption being 7150 BCE. The most recent period of activity was 10/30-11/5/13 according to - their source being Centro Nacional de Prevencion de Desastres (CENAPRED).
    2. As I am not very science oriented I had to look up the definition of caldera - which I found on : (again choosing the website for the geology department from San Diego State University eliminated the issue of credibility)
    According to the SI website this is a Stratovolcano and according to How Volcanoes Work (the SDSU site) a volcano of this type produces a crater-lake type caldera when the volcanos collapse into the void of the magnum chamber. Therefore the dome is made of lava - the most recent dome, according to SI was observed on 7/10/13 and seen to have been destroyed when the volcano was observed by air again on 7/15/13.
    1. When I searched for the name of the volcano I learned it was near the Great Pyramid of Cholula so that would be the pyramid in question. I came across an article "Mountain of sustenance, mountain of destruction: The prehispanic experience with Popocatépetl Volcano" written by Patricia Plunket published in July 2006 in Journal of Volcanology and Geothermal Research 170 (2008) 111–120 which states, if I am reading it correctly, that while the volcano did erupt sometime between 700AD-900AD (late Classic Period) it did not cover the Pyramid for the following reason:
    "Finally, it is important to consider that, during the latter half of the Classic, the Great Pyramid fronted on a large plaza bounded by a low platform on the south and another substantial mound to the west (Cerro Cocoyo [Fig. 6], now severely mutilated). These structures would not only have protected the Great Pyramid from the lahars, but they also would have contributed erosion materials to the deposits excavated in the plaza. We conclude that the evidence for the destruction of Cholula by massive lahars from Popocatépetl during the Late Classic is problematic and needs to be reevaluated, by both geologists and archaeologists."
    Plunket's premise is that the volcanic flow (lahars) from this period may not have actually reached the Great Pyramid, based on geologic observations, and needs to be re-examined.
    This search took about 45 minutes. While I had the answers quickly I had to do a lot of side research as I didn't truly understand all the terminology in connection with the volcano and volcanic activity. I also took the time to find credible sources of information and avoided Wikipedia entirely. I used the USGS website for the definition of lahars.

    1. Edie -- That's an interesting bit of observation (the Plunket article from 2006). The question of "did the lahars reach the pyramid" turns out to be more complicated than first observed. I think the issue here isn't whether the lahars reached the pyramid, but whether or not they destroyed parts of the pyramid. I suspect that both could be true--the lahars reached the pyramid (or came darn close) AND they didn't destroy the pyramid. We'll have to let the vulcanologists fight this one out.

  11. This is interesting because normally Anne and I work on these search quests together. This time we started off separately. I first uploaded the picture into google images and got nothing. Then added the search term Chiconauhquiauhitl to my query and got this result which led me to the travel site triposa. That site gave me the information that the pyramid was called The Great Pyramid of Cholula. Anne took a different track. She assumed south of California was Mexico so she searched for volcanoes Mexico. She got about 10 different names of volcanoes. She narrowed down to 3 and searched all 3. She added Chiconauhquiauhitl to her search and found the name of the mountain. All the results showed the name of the volcano was Popocatepetl. These results also showed a number of news reports for fairly recent activity so yes, this volcano could erupt again. The pyramid was covered by volcanic mudflows in the year 800. We searched in google books using the query . The answer was found in the book: Dangerous Neighbors: Volcanoes and Cities on page 53. To find out what the crater was made from we switched to google scholar to make sure we were getting more authoritative results. Got the answer in the abstract of an article in the Journal of Vulcanology. Did a simple search for crater Popocatepetl.