Alcatraz being preserved in 3D
SAN FRANCISCO — In May 1946, chaos erupted when six prisoners who were determined to escape from Alcatraz Island overpowered guards and grabbed weapons and keys.
They seized a cell block at the federal penitentiary for two days, prompting the Marines to respond and throw grenades into the building from the roof. By the end of the “Battle of Alcatraz” in the middle of San Francisco Bay, three inmates and two guards were dead.
Seventy-eight years later, tourists at the prison turned park can still see a spray of pock marks in the cement floor that were left by those hurled explosives.
The divots, shallow in size but deep in history, will now be preserved forever, along with every other nook on Alcatraz. Scientists and technology experts spent three weeks in December using cameras, drones and a robot dog to gather 4 trillion bytes of data to build the first 3D map of the island in color.
Every building inside and out was frozen in time. Every tunnel, every piece of cellblock graffiti, every rusted prison bar, every wildflower, every gull dropping. Every corner of “the Rock” was captured with precision within a centimeter.
The unusual project was born from worries over climate change and the sea level rise that will inevitably encroach on Alcatraz, where chunks of the perimeter wall are already eroding and falling into the bay. Scientists have warned California could experience several feet of sea-level rise by the end of the century, along with ever more dangerous storm surges.
The 3D map could help local leaders track the effects of climate change on the San Francisco Bay Area. It could also allow National Park Service officials to visualize potential flooding at Alcatraz and protect the island against future damage, said Pete Kelsey, a technologist who spearheaded the mapping endeavor.
For example, he noted, the dock would be at serious risk if waters rise, and the boats that land there not only bring tourists but also deliver fresh water and remove sewage. Without a dock, the island would quickly become unusable, he said.
Because Alcatraz is so well known, the map might be “a vehicle to wake people up, to snap people into a different sort of consciousness about climate change,” Kelsey said.
Alcatraz, which sits just over a mile north of San Francisco, has had many chapters. It was originally a fort and a military prison. During its most famous stretch, from 1934 to 1963, it operated as a high-security federal penitentiary and housed such notorious convicts as Al Capone, Machine Gun Kelly and Robert Stroud, known as the Birdman of Alcatraz.
In 1969, Native Americans occupied the site for 19 months to protest the government’s treatment of their people. After opening to the public in 1973,
Alcatraz has become a popular tourist attraction and bird sanctuary that is part of the Golden Gate National Recreation Area.
Like many National Park Service properties, Alcatraz is at risk on numerous fronts. It faces a possible earthquake. It is vulnerable to fires or floods. It could be the target of a terrorist attack. It also suffers from plain old wear and tear from its 1.5 million annual visitors, with some of its buildings and equipment badly deteriorating.
Traipsing around the island on a recent day, Kelsey said it was important to have a 3D baseline in order to track changes and damage to Alcatraz. Kelsey owns Seattle-based VCTO Labs, which has captured everything from military ships to football stadiums for the purposes of preservation, education and moviemaking.
“The data we capture can answer questions,” he said. “It can lead to discovery. It makes the invisible visible.”
The National Park Service
will maintain the rights to the 3D map, and no money changed hands in the making of the map, Kelsey said.
He believes the 3D map provides the National Park Service with endless opportunities. It could be used by movie studios, which wouldn’t need to film on Alcatraz but could instead use the 3D data with a green screen. It could be turned into a video game or a virtual reality experience using Apple Vision Pro or Meta headsets. It could be replicated with a 3D printer.
“My selfish dream is that it’s the world’s first virtual national park,” Kelsey said.
Pete Gavette, a park archaeologist, said smaller efforts to map the island had taken place before but this was the first time that “every nook and cranny” had been mapped in 3D. Gavette said it would be useful for the staff to see all corners of the island since staff members aren’t allowed to enter spaces considered too hazardous because of asbestos, lead paint or structural damage.