Scientific instruments discovered what appears to be a mass grave -- jumbled bones and other items scattered throughout the cemetery on the north side of the church -- as the search for nearly 2,000 bodies buried at Old Mission Santa Inés continued Wednesday.

The results are not unexpected for archaeologists familiar with burials at California missions.

“In a lot of other situations, we see individual graves,” said Davie Maki, an archaeological geophysicist who owns ArchaeoPhysics Geophysical Survey.

“Here, we’re more seeing like a cloud of small objects,” he said, as he slowly pulled the ground-penetrating radar unit across the uneven field pocked with the holes and mounds of gophers and ground squirrels.

In fact, the gophers and ground squirrels that have inhabited the fields around the mission for hundreds of years are part of the reason there are no clearly defined graves. They’re also the reason a lot of the objects are close to the surface.

“The burials are pretty shallow,” said Maki, noting the ground-penetrating radar was “seeing” as deep as 80 centimeters, or a little more than 31 inches. “We’re getting a lot of reflections between 30 and 60 centimeters (about 12 to 24 inches).

“The rodents have been mixing stuff up, bringing things to the surface,” he explained. “We’re seeing parts of burials and grave goods in the first 75 centimeters.”

Having completed a pull of the GPR unit along a 15-meter line in the grid survey, Maki walked to his laptop perched on a makeshift sled not far away and tapped a few keys to close the file and open a new file for the next pull.

Then he returned to the ground-penetrating radar unit, moved the 15-meter measuring tape 50 centimeters to the east, set the GPR unit next to it and began pulling the unit slowly along the tape.

“It’s not as clear as some situations,” he said of the results that appeared on the laptop -- a series of lines growing thicker and thinner, rising and falling, increasing and decreasing in intensity as they stretched across the screen. “But in the end, we’ll be able to tell the limits of the cemetery.”

“That’s probably good,” said an observer, who had just arrived at the site. “This is where the fiesta takes place. They might have to move it north a bit.”

The new arrival is Robert Hoover, professor emeritus of social sciences at Cal Poly. He and his son discovered the foundations of the soldiers’ barracks, which later became a store, that once stood along the west side of what is now the mission entry road from Highway 246.

They also helped locate the quarters for the Chumash Indians who lived and worked at the mission, and who make up about 1,700 of the 1,995 bodies buried on the mission grounds.

Hoover isn’t surprised that Maki’s preliminary results show what appears to be a mass grave.

“That’s what we would expect,” he said. “When someone died, they just made room. And there were no markers. There was probably just one large cross in the center.”

Bodies were buried shoulder to shoulder, head to toe, and in some cases, one atop another. Throw in the rodent action, and the result is bones, bone fragments and other items mixed and scattered over a wide area with no clear individual graves.

A history of searching

Based in Minneapolis, Minnesota, Maki was trained as an engineer, but he’s been doing archaeological surveys for some 20 years.

He’s also been keeping the GPR unit he uses alive since 1997, cannibalizing parts for it from other units and adding homemade touches of his own.

“There’s not much original on it anymore,” he said. “It’s sort of a steampunk version of a GPR.

“The manufacturer should use it for a commercial,” he added. “It’s been shot at in Yemen — well, they were shooting at me — and dragged through the desert in Syria and Kazakhstan.”

In those areas, Maki wasn’t looking for graves so much as for signs of civilization, villages and towns abandoned millennia ago and buried by the drifting soil of history.

“Before George Bush, we worked in the Middle East quite a lot,” Maki said. “Since George Bush, we’ve worked mostly in the U.S. — well, since all these wars started.”

Maki’s GPR unit beams radio waves at 450 MHz into the soil at 20 pulses per linear meter, creating a two-dimensional profile of what’s below it as the more solid objects reflect back a portion of the waves.

Pulling the unit along lines separated by 50 centimeters, Maki gets 40 pulses per square meter, and when all the lines are put together, he has a three-dimensional image of what’s underground that can be separated and dissected as needed.

“We can see the different depths, see what the pattern looks like,” he said. “The methods we’re using are all noninvasive. We work with Native Americans throughout the country, and they’re very enthusiastic about our methods.”

Because the vast majority of those buried at the mission are Chumash, some of the elders from the Santa Ynez Band of Chumash Indians visited the mission grounds Thursday morning to watch the survey and talk with Maki and his partner, Lewis Somers of Geoscan Research USA.

“The nice thing about what they’re doing is they’re getting a lot of information without disturbing anything,” Hoover said. “I like to have things left as they are. The longer they’re left undisturbed, the more valuable they are to future generations.”

Another data source

While Maki was dragging the GPR unit across the 40-by-15-meter search grid, Somers was several yards away conducting a separate survey of the grid using an electrical resistance meter.

Somers holds a doctorate in optical physics, but he described both the device he was using and the process he was following as “very simple.”

Essentially, he was sticking two probes into the ground at regular intervals and seeing how much electricity could pass though the soil between them — measuring the soil’s electrical resistance.

“The graves here are 99 percent decayed and gone away,” Somers said. “When you dig a grave shaft and put something in it, then put back the dirt, it’s different. The resistance is different.

“There are hundreds of burials in here, so clearly there aren’t going to be 1,700 grave shafts,” he said.

Because of that, the resistance meter won’t show where individual graves were located.

But it will be especially useful in determining where the original wall was located before the 1812 earthquake knocked it down and heavily damaged Santa Inés and other Central Coast missions.

“What’s exciting, I think, is pretty simple technology is useful in archaeology,” Somers said. “I think the real challenge is understanding archaeological features and formations in terms of physical properties instead of texture or color.”

Hoover said combining the various search techniques provides an improved understanding of history.

“I don’t pretend to be a geophysicist, and he doesn’t pretend to be an archaeologist,” Hoover said. “But we work well together.”

“I call that the cultural interpretation of geophysical data,” Somers said.

Final results

Maki said once this survey is complete, he’ll return to his lab and “crunch the numbers” to come up with final results.

“It seems to be corroborating what the dogs found,” Maki said of his preliminary results, referring to a search of the site a week ago by forensic canines. “At least that’s my initial thought. Once I get back, I’ll analyze the data properly.”

Then the images from the ground-penetrating radar, the electrical resistance measurements and the locations where the forensic canines got “hits” with their noses will all be combined.

“The end product will be a map looking down on the site made up of different images and different levels,” he said.

That map will be given to Sheila Benedict, the archivist for Old Mission Santa Inés who envisioned the project, obtained the grants to pay for it and brought in the dogs and handlers from the Institute for Canine Forensics and the team from ArchaeoPhysics.

Benedict said she isn’t really sure yet how the data will be used, other than to add it to the store of historical knowledge retained in the mission’s archives.

At the very least, it will show what areas are sacred ground, the final resting place of nearly 2,000 souls that should be left undisturbed.