E-mail Story
Print Friendly
Send E-mail
Reprint story
Journal North: Home | Sports | Opinion | Obits | Entertainment
Sunday, June 21, 2009
In a Race To Record Bandelier
By Raam Wong
Journal Staff Writer
LOS ALAMOS — Archaeologists at Bandelier National Monument are in a race against time as they use laser scanners to document the park's crumbling cliff dwellings.
Jim Holmlund can envision a day when there are no cavates — hollowed out spaces in the rock — left at Bandelier. Instead, a visitor's experience might involve viewing three-dimensional models and an animated video of what once was.
While archaeologists are doing what they can to extend the life of the structures — anti-erosion efforts, stabilizing masonry walls — they also want to ensure that future generations of researchers have plenty of data to study.
“There's really no preservation technique that's going to allow us to preserve these cavates. They're going away,” said Holmlund, whose Tucson-based Western Mapping Co. is carrying out the scans. “Documentation is the preservation technique.”
Bandelier's cavates and rock art are continually hammered by weather, not to mention the monument's 300,000 annual visitors. Graffiti is a problem, too.
Off and on for the last four years, archaeologists have been scanning Bandelier's highest priority sites. The setup — a boxy laser atop a tripod — is reminiscent of a 19th century view camera.
Archaeologists have been studying and documenting the area at least since the 1880s, when Adolph Bandelier, a self-taught archaeologist from a wealthy banking family in Illinois, came to the New Mexico Territory. He lived among the Cochiti people, who first showed him Pajarito Plateau and Frijoles Canyon, site of the modern day monument. Bandelier made four archaeological excursions to the location between 1880 and 1904, recording more than 165 sites.
Film cameras were the primary tool for past documentary efforts. But photos can also leave a lot out, particularly when it comes to petroglyphs that are hard to reach or difficult to spot. Chalk was sometimes used to fill in the designs and make them easier to see. Researchers have also made renderings of the petroglyphs, a time-consuming process that's prone to human error.
The laser scans have allowed researchers to study petroglyphs that have long been invisible to the naked eye.
“There are huge differences between what the laser scan tells us and what we see,” said Bandelier architectural conservator Shannon Dennison.
In a lecture recently for the Sierra Club in Los Alamos, Dennison showed a hand-made drawing of a petroglyph done in the 1980s and compared it to a laser scan of the same area.
By manipulating color, light and other elements, the laser scan reveals many details missing from the drawing, including a face mask and a serpent's plume. No one way of manipulating the images brings out all the features, she said. But the work is expensive. The first round of scans a few years ago cost about $60,000, Dennison said.
The project is funded through the National Park Service's decade-old Vanishing Treasures program, which assesses and documents damage and makes repairs to sites at dozens of parks, mostly in the Southwest.
Previous efforts to document the approximately 1,110 cavates in Frijoles Canyon have occurred sporadically, Dennison said. But the work was never carried out systematically and failed to produce good maps.
Now, the archaeologists are in the midst of the first-ever extensive documentation of the cavates. Accessing the dwellings with tall ladders and even rappelling into a few, they're recording data about the cavates' integrity, niches, masonry walls, paintings and other features. All the data is entered into a computer database.
So far, Holmlund and his team have scanned about 20 cavates at Bandelier. A scan captures about 100 million points, and a single cavate might require 50 scans.
Each cavate is unique, and the scans can capture tiny features like finger and hand prints in the plaster, or tool marks in the ceiling, that might come in handy to future researchers.
The soft tuff was deposited on the Pajarito Plateau by volcanic eruptions more than a million years ago. Soft and fragile, the volcanic rock is similar to the popcorn ceilings popular in the 1970s.
The Anasazi people, who came to the area about 1,100 years ago, were hunters and farmers who grew corn, squash and beans, and harvested the wild native plants. They also took advantage of the soft rock to carve living and storage spaces.
As the population increased, the inhabitants built structures on the floor of the canyon, butting up against the canyon wall. Later, they built villages on the canyon floor and mesa tops.
At its peak, about 800 people lived in Frijoles Canyon. About A.D. 1550, the ancestral people of Pajarito Plateau, including Bandelier, left the area and relocated to other places along the Rio Grande.
Now, the elaborate art and cavates that they left behind are also disappearing. Masonry walls collapse overnight, and gusts of wind blast the tuff off the walls, creating an effect that resembles a snow storm at times.
“And this is happening every day,” Holmlund said.
You also can send comments via our comment form
|
|
