Monterey Canyon is a magnificent submarine geologic feature rivaling the Grand Canyon in both its size and beauty. But while anyone can visit the Grand Canyon—whether by flying over it in an airplane or descending into it on the back of a mule—exploring Monterey Canyon is far more challenging, requiring teams of scientists and engineers, a fully-staffed research vessel, and a variety of autonomous robots.
As a result, most people have never had a chance to see the majesty of Monterey Canyon. This year, we merged art with science to drain away the water and reveal the stunning topography of the geologic feature sitting right in our backyard.
Humans have only mapped a fraction of Earth’s intricate underwater landscape. Satellite imaging, which has allowed us to map the entirety of the Earth’s dry terrain and the distant surfaces of the Moon and Mars, cannot penetrate through the ocean to see the dramatic contours and features concealed below.
Charlie Paull, a marine geologist at MBARI, has been gathering bathymetric data on Monterey Canyon for 23 years. Sonar has long been used to map the seafloor, usually with equipment mounted on a ship’s hull. The ship travels back and forth, sending sound waves toward the ocean floor. When the sound waves hit the bottom, they bounce back to the surface, where the sonar receivers use the time it takes for the signals to return to the ship to indicate the depths of the seafloor. From a ship, the lateral resolution of the bathymetry decreases with increasing depth.
Modern multibeam sonars operated from a ship in 1,800-meter (roughly one mile) water depths can collect data with up to 25 meters (82 feet) in resolution; enough to paint the broad strokes of the canyon’s shape but limited in capturing the fine details. That’s where MBARI’s remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs)—and their ability to fly just above the seafloor—really shine as seafloor mapping tools.
The AUV uses the same sonar technology as those found on ships, but it adjusts its position to maintain a constant distance from the canyon floor and walls, revealing details as small as one meter (three feet) across. The ROVs can capture details as small as five centimeters (two inches) and one centimeter (0.4 inches) with sonar and lidar, respectively.
Monterey Canyon comes to life in Frame 48 animation
Despite its key role in the complex workings of Monterey Bay, the canyon is still largely unknown to the broader public. The seafloor mapping team realized that while MBARI’s strength is gathering detailed mapping data at various high resolutions, an external partner would be essential for integrating those datasets into an immersive visualization.
The team partnered with Frame 48, a post-production company based in Los Angeles that typically works in film and television. Paull oversaw the process along with colleagues Dave Caress, Eve Lundsten, and Jenny Paduan. They worked closely with the team at Frame 48 to layer the 25-meter (82-feet) resolution ship-based multibeam data and the one-meter mapping AUV data into a seamless landscape.
Frame 48 used a platform called Unreal Engine—used to build video games—so that the animators could add effects like lighting, texture, and camera movements in real time. Paull advised on details that would breathe new life into the canyon down to the color of the sediment and the striations in the canyon wall.
The animation flies viewers out over Monterey Bay and through the canyon’s main axis, providing educators, scientists, and science communicators with an invaluable tool to give Monterey Canyon the close-up it deserves.
This animation uses data collected over the past 22 years by MBARI’s mapping team to bring Monterey Canyon to life in an unprecedented level of detail. The highest-resolution animation of Monterey Canyon ever created, it uses a combination of ship-based multibeam data at 25 meters (82 feet) in resolution and autonomous underwater vehicle (AUV) multibeam mapping data at one meter (three feet) in resolution.
Uncovering an origin story
In addition to capturing the raw scale and grandeur of Monterey Canyon, the animation also sheds light on some of the battle scars carved into this feature over millions of years of geologic transformation.
Researchers originally did not know how active the canyon was. Many thought that the canyon was relatively static with underwater avalanches made up of a slurry of seawater and sand, or a turbidity current, probably only occurring once every half-century or so. When Paull and his colleagues deployed tools to measure turbidity currents and conditions of the canyon, they found a surprisingly active canyon axis. These currents occur multiple times a year and are strong enough to bury, displace, or destroy oceanographic instruments deployed on heavy frames.
Beyond the fundamental importance of mapping the deep sea, MBARI’s high-resolution mapping data will make it easier to track changes in Monterey Canyon over time. By mapping and comparing the bathymetry in the same areas, researchers will gain insight into the dynamic geologic processes that formed and continue to shape the canyon.
Carbon highway to the deep sea
The turbidity currents responsible for the evolution of Monterey Canyon’s geology are also closely linked to carbon transport to the deep sea. Very little food is available for animals living in the deep sea. Most organisms either feed on each other, or marine snowflakes made up of organic material like feces and dead animals—that drift from the well-lit, productive surface waters to the darker seafloor.
MBARI researchers measured the amount of carbon consumed by animals inhabiting the Monterey Deep Sea Fan and discovered that the vertical transport of nutrients could not account for the total amount of benthic activity observed. They determined that Monterey Canyon acts like a carbon highway, carrying nutrient-rich organic material like sunken kelp from the sea surface out to the abyssal plain. A single large turbidity flow could account for up to 85 percent of the annual organic carbon transport from the shore to the deep sea in a year.
Not only is the carbon conduit from the shore to the abyssal plain important for nourishing life in the deep sea, but it also plays an important role in our climate system. Plants and marine algae like kelp pull carbon dioxide—from both natural and human sources—out of the atmosphere to grow, and once they sink to the seafloor, they can trap carbon for thousands or even millions of years. Over long periods, the trapped organic carbon in the sediment can become deeply buried and pressed into solid rock and converted into oil and gas deposits.
Monterey Canyon as a proxy for other submarine canyons
Diverse life can be found in several different habitats throughout Monterey Canyon, including the sandy canyon floor, the mud-draped rocks on the canyon walls, and the dark midnight zone. Although most of these species aren’t only found in Monterey Canyon, their close proximity to shore enables MBARI researchers to more readily observe them in their natural habitat.
Understanding how Monterey Canyon changes over time can also provide insight into how other submarine canyons around the world might impact coastal communities. Catastrophic failures of the canyon walls could cause massive sediment deposits to slump into the canyon and set off a local tsunami. Destructive sediment flows could cut off critical telecommunications infrastructure installed on the seafloor.
MBARI’s continued work to map and visualize Monterey Canyon highlights this feature’s undeniable dynamism—a geologic treasure as vibrant and alive as the creatures who call it home.