Dreams of Summer: Living Under the Threat of Destruction at Wupatki

The San Francisco Peaks, a gigantic stratovolcano, rises beyond the ruins of the Citadel at Wupatki National Monument.

There is a huge difference between living close to the Earth without advanced technology and living in a highly technological society. Well, lots of differences actually, but today I'm thinking about living in ignorance of geological hazards. The thought arose because of our visit to the rather fantastic pueblos of Wupatki National Monument in the region east of Grand Canyon. There are lots of archaeological remains of the people who lived in the Colorado Plateau over the last 12,000 years, but few of them are as spectacular as the pueblos that were built between 1,100 and 1,285 AD. Many, maybe most, were fortresses. Some of these people seemed to be living in fear.

The Citadel ruin at Wupatki is built on the eroded remains of a basalt lava flow.

There has been a mountain of speculation about why the Ancestral Pueblo people and other cultures took such a defensive posture in their architecture. It is well known that most of the Colorado Plateau was abandoned in the late 13th century, and the hypotheses are numerous. There were a series of droughts, including a 25-year-long monster. These was evidence of warfare in a few places. Soils had washed away in many places. There could have been religious or cultural forces in place that caused migrations. It's an interesting issue that will keep archaeologists busy for a long time.

The view of the San Francisco Peaks from the top of the Citadel ruin.

Archaeology played a special part of our summer field studies journey across the Colorado Plateau. Half our students were majors in the subject (or possessed a lot of interest in the subject) who were learning geology. And our geologists were learning archaeology. I've been doing joint trips with our anthropology professors for a decade now, and we find a lot of common scientific ground as we travel through this fascinating landscape.

The hundred room pueblo at Wupatki

Wupatki National Monument preserves structures and sites of numerous ancient cultures, but the most visible were built by the Sinagua people, whose descendants still live in the region (the Hopi, Zuni,  Pima, Tohono O'odham, and Yavapai people). The region was a crossroads of sorts, and direct evidence suggests habitation as early as 500 AD. People lived at the site for 600 years, perhaps never suspecting that they were living on volcanic ground.

That changed in 1085 AD or so when Sunset Crater, a basaltic cinder cone, erupted, sending out lava flows, cinders and ash over a region totaling about 800 square miles (the longest lava flow was 6 miles long). Lava flows covered several villages.

It's possible that some cultural recognition of volcanism existed in the stories and traditions of the people who lived in the path of destruction, but maybe not. Can you imagine the impact of seeing a volcanic eruption in progress for the first time as a people? What kind of stories would be told explaining the phenomenon? Many of the old ruins are built on older volcanic deposits. Did the logical thinkers among the people recognize in a flash the origin of the ground and rock on which their homes were constructed?

In any case, the region was abandoned for a few decades, but settlers came back, finding that the ash had rejuvenated the soils. A gift of the gods? One wonders. They lived and built homes in the region for two more centuries before leaving the land for other places. Although the abandonment was part of a regional pattern, one can wonder if those two centuries included a healthy fear of the fires from down below in the crust?

Sunset Crater, the youngest volcano in the San Francisco Peaks Volcanic Field. It erupted about 1085 AD

The Sinagua people of Wupatki may or may not have known about volcanoes prior to 1085 AD, but in our highly technological society, we understand a great deal about volcanoes, and geology has provided us the tools to figure out the probabilities of future eruptions. Likewise, we are able to calculate to a reasonable degree the probabilities of earthquakes within given time frames (over a 30 year period, for instance). We can calculate flood probabilities before a particular storm arrives.  But that also means we live with a certain amount of fear. This is good in the sense of allowing the society to prepare. But fear can also be manipulated.

I can imagine a shaman or other kind of leader of the Sinagua threatening his or her people with the return of the legendary fire gods of the volcano to achieve some nefarious end. Can we imagine anyone who would be tempted to manipulate scientific knowledge into a fear of volcanoes (can you say "SUPERVOLCANO" nice and loud?) or earthquakes (can you say CASCADIA?) to achieve influence and power?

Source: http://www.cosmostv.org/2014/08/yellowstone-super-volcanoresent-rumors.html (actually, this is good article)

Nah, I'm sure no one would fan the flames of fear in modern society...the internet and other mass media has brought knowledge and wisdom to us all.

The Abandoned Lands...A Journey Through the Colorado Plateau: Wupatki and Sunset Crater

When our field trip last month showed up anywhere, there was no longer any sense of abandonment...we were our own traveling traffic jam. The land that we were in felt abandoned, though. The northeast edge of the San Francisco Peaks Volcanic Field is exceedingly dry, and the volcanic rocks are so fissured and jointed that whatever water does fall from the sky seeps into the ground quickly and disappears. It's hard to imagine a civilization thriving here, but the pictures on today's blog reveal that people did indeed live here, for a century or so, but then they abandoned the region, perhaps for better agricultural prospects elsewhere.  It's certainly pretty barren today...

Welcome to Wupatki National Monument north of Flagstaff, and the adjacent Sunset Crater National Monument, site of one of the youngest volcanic features of the state of Arizona. There is a connection between the two parks...many of the dwellings were constructed in the decades following the eruptions at Sunset Crater around 1065-1085 AD. Some archaeologists attribute the population growth at the time to water retention capability of the volcanic cinders that blanketed much of the region. In some models, the new surfaces of cinders enriched the soils and caused a sort of "land rush" that brought different peoples together.

There was a mixing of four different cultures in the area, the Kayenta Ancestral Pueblans, the Sinagua, the Cohonina, and the Hohokim, and they left behind some impressive ruins. Our visit included an exploration of the Citadel (above), a 50 room complex, and Wupatki Village, a 100 room village. The Citadel Pueblo is glued to the top of a lava butte, and the walls merge almost seamlessly with the basalt flow.

The peaks of the San Francisco Peaks dominate the scenery. The mountain peaks are the ragged edges of a hollowed out stratovolcano which has not been active for several hundred thousand years. The summit may have been destroyed by a giant landslide similar to the one that precipitated the eruption of Mt. St. Helens in 1980.

The largest pueblo in the monument is Wupatki Village, which is unique both for its architecture and for its mixing of cultures. There is a "ball court" that reveals a cultural connection to the Hohokim to the south, an amphitheatre that is characteristic of the Sinagua people, and T-shaped doorways that are typical of the Ancestral Pueblans (formerly the Anasazi).

Like the Citadel, the buildings seem to grow out of the rock. The rock includes the shale and sandstone of the Triassic Moenkopi Formation which formed in mudflats and river floodplains. For building walls, they used red slabs of Moenkopi sandstone, yellowish slabs of Kaibab limestone, and chunks of basalt.

Why was the site abandoned in the late 1200's? I don't know, and neither do the archaeologists. The Native American cultures in the southwest today have their perspective, and their oral histories. The region is so marginal for agriculture that drought seems likely to have been involved, and one can imagine a series of cascading effects: food shortages, growing competition for the best growing sites, invasions from outside cultures, and so on. All one can really say is they were there, and within a few years they were somewhere else.

It isn't just an academic exercise to understand all the factors involved 800 years ago in the abandonment of the region; we are in the midst of a serious extended drought today, and there is a strong potential that the drought is related to climate change (in late June, Wupatki had only 15% of normal precipitation). The consequences of extended drought will occur whether politicians deny global warming or not. The Colorado River doesn't have enough water to meet demand in normal years. What happens when drought becomes the new normal? How will our society in the southwest cope?

Later on we stopped briefly at Sunset Crater, the possible cause of the "land rush". The cone in the background did not exist 1,000 years ago.

Here is the explanation of my "abandonment" theme for this series: http://geotripper.blogspot.com/2012/06/abandoned-landsa-journey-through.html